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llvm-project/llvm/lib/Support/Unix/PathV2.inc

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//===- llvm/Support/Unix/PathV2.cpp - Unix Path Implementation --*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the Unix specific implementation of the PathV2 API.
//
//===----------------------------------------------------------------------===//
//===----------------------------------------------------------------------===//
//=== WARNING: Implementation here must contain only generic UNIX code that
//=== is guaranteed to work on *all* UNIX variants.
//===----------------------------------------------------------------------===//
#include "Unix.h"
#include "llvm/Support/Process.h"
#if HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#if HAVE_FCNTL_H
#include <fcntl.h>
#endif
#ifdef HAVE_SYS_MMAN_H
#include <sys/mman.h>
#endif
#if HAVE_DIRENT_H
# include <dirent.h>
# define NAMLEN(dirent) strlen((dirent)->d_name)
#else
# define dirent direct
# define NAMLEN(dirent) (dirent)->d_namlen
# if HAVE_SYS_NDIR_H
# include <sys/ndir.h>
# endif
# if HAVE_SYS_DIR_H
# include <sys/dir.h>
# endif
# if HAVE_NDIR_H
# include <ndir.h>
# endif
#endif
#if HAVE_STDIO_H
#include <stdio.h>
#endif
#if HAVE_LIMITS_H
#include <limits.h>
#endif
// Both stdio.h and cstdio are included via different pathes and
// stdcxx's cstdio doesn't include stdio.h, so it doesn't #undef the macros
// either.
#undef ferror
#undef feof
// For GNU Hurd
#if defined(__GNU__) && !defined(PATH_MAX)
# define PATH_MAX 4096
#endif
using namespace llvm;
namespace {
/// This class automatically closes the given file descriptor when it goes out
/// of scope. You can take back explicit ownership of the file descriptor by
/// calling take(). The destructor does not verify that close was successful.
/// Therefore, never allow this class to call close on a file descriptor that
/// has been read from or written to.
struct AutoFD {
int FileDescriptor;
AutoFD(int fd) : FileDescriptor(fd) {}
~AutoFD() {
if (FileDescriptor >= 0)
::close(FileDescriptor);
}
int take() {
int ret = FileDescriptor;
FileDescriptor = -1;
return ret;
}
operator int() const {return FileDescriptor;}
};
error_code TempDir(SmallVectorImpl<char> &result) {
// FIXME: Don't use TMPDIR if program is SUID or SGID enabled.
const char *dir = 0;
(dir = std::getenv("TMPDIR" )) ||
(dir = std::getenv("TMP" )) ||
(dir = std::getenv("TEMP" )) ||
(dir = std::getenv("TEMPDIR")) ||
#ifdef P_tmpdir
(dir = P_tmpdir) ||
#endif
(dir = "/tmp");
result.clear();
StringRef d(dir);
result.append(d.begin(), d.end());
return error_code::success();
}
}
namespace llvm {
namespace sys {
namespace fs {
TimeValue file_status::getLastModificationTime() const {
TimeValue Ret;
Ret.fromEpochTime(fs_st_mtime);
return Ret;
}
error_code current_path(SmallVectorImpl<char> &result) {
#ifdef MAXPATHLEN
result.reserve(MAXPATHLEN);
#else
// For GNU Hurd
result.reserve(1024);
#endif
while (true) {
if (::getcwd(result.data(), result.capacity()) == 0) {
// See if there was a real error.
if (errno != errc::not_enough_memory)
return error_code(errno, system_category());
// Otherwise there just wasn't enough space.
result.reserve(result.capacity() * 2);
} else
break;
}
result.set_size(strlen(result.data()));
return error_code::success();
}
error_code copy_file(const Twine &from, const Twine &to, copy_option copt) {
// Get arguments.
SmallString<128> from_storage;
SmallString<128> to_storage;
StringRef f = from.toNullTerminatedStringRef(from_storage);
StringRef t = to.toNullTerminatedStringRef(to_storage);
const size_t buf_sz = 32768;
char buffer[buf_sz];
int from_file = -1, to_file = -1;
// Open from.
if ((from_file = ::open(f.begin(), O_RDONLY)) < 0)
return error_code(errno, system_category());
AutoFD from_fd(from_file);
// Stat from.
struct stat from_stat;
if (::stat(f.begin(), &from_stat) != 0)
return error_code(errno, system_category());
// Setup to flags.
int to_flags = O_CREAT | O_WRONLY;
if (copt == copy_option::fail_if_exists)
to_flags |= O_EXCL;
// Open to.
if ((to_file = ::open(t.begin(), to_flags, from_stat.st_mode)) < 0)
return error_code(errno, system_category());
AutoFD to_fd(to_file);
// Copy!
ssize_t sz, sz_read = 1, sz_write;
while (sz_read > 0 &&
(sz_read = ::read(from_fd, buffer, buf_sz)) > 0) {
// Allow for partial writes - see Advanced Unix Programming (2nd Ed.),
// Marc Rochkind, Addison-Wesley, 2004, page 94
sz_write = 0;
do {
if ((sz = ::write(to_fd, buffer + sz_write, sz_read - sz_write)) < 0) {
sz_read = sz; // cause read loop termination.
break; // error.
}
sz_write += sz;
} while (sz_write < sz_read);
}
// After all the file operations above the return value of close actually
// matters.
if (::close(from_fd.take()) < 0) sz_read = -1;
if (::close(to_fd.take()) < 0) sz_read = -1;
// Check for errors.
if (sz_read < 0)
return error_code(errno, system_category());
return error_code::success();
}
error_code create_directory(const Twine &path, bool &existed) {
SmallString<128> path_storage;
StringRef p = path.toNullTerminatedStringRef(path_storage);
if (::mkdir(p.begin(), S_IRWXU | S_IRWXG) == -1) {
if (errno != errc::file_exists)
return error_code(errno, system_category());
existed = true;
} else
existed = false;
return error_code::success();
}
error_code create_hard_link(const Twine &to, const Twine &from) {
// Get arguments.
SmallString<128> from_storage;
SmallString<128> to_storage;
StringRef f = from.toNullTerminatedStringRef(from_storage);
StringRef t = to.toNullTerminatedStringRef(to_storage);
if (::link(t.begin(), f.begin()) == -1)
return error_code(errno, system_category());
return error_code::success();
}
error_code create_symlink(const Twine &to, const Twine &from) {
// Get arguments.
SmallString<128> from_storage;
SmallString<128> to_storage;
StringRef f = from.toNullTerminatedStringRef(from_storage);
StringRef t = to.toNullTerminatedStringRef(to_storage);
if (::symlink(t.begin(), f.begin()) == -1)
return error_code(errno, system_category());
return error_code::success();
}
error_code remove(const Twine &path, bool &existed) {
SmallString<128> path_storage;
StringRef p = path.toNullTerminatedStringRef(path_storage);
struct stat buf;
if (stat(p.begin(), &buf) != 0) {
if (errno != errc::no_such_file_or_directory)
return error_code(errno, system_category());
existed = false;
return error_code::success();
}
// Note: this check catches strange situations. In all cases, LLVM should
// only be involved in the creation and deletion of regular files. This
// check ensures that what we're trying to erase is a regular file. It
// effectively prevents LLVM from erasing things like /dev/null, any block
// special file, or other things that aren't "regular" files.
if (!S_ISREG(buf.st_mode) && !S_ISDIR(buf.st_mode))
return make_error_code(errc::operation_not_permitted);
if (::remove(p.begin()) == -1) {
if (errno != errc::no_such_file_or_directory)
return error_code(errno, system_category());
existed = false;
} else
existed = true;
return error_code::success();
}
error_code rename(const Twine &from, const Twine &to) {
// Get arguments.
SmallString<128> from_storage;
SmallString<128> to_storage;
StringRef f = from.toNullTerminatedStringRef(from_storage);
StringRef t = to.toNullTerminatedStringRef(to_storage);
if (::rename(f.begin(), t.begin()) == -1) {
// If it's a cross device link, copy then delete, otherwise return the error
if (errno == EXDEV) {
if (error_code ec = copy_file(from, to, copy_option::overwrite_if_exists))
return ec;
bool Existed;
if (error_code ec = remove(from, Existed))
return ec;
} else
return error_code(errno, system_category());
}
return error_code::success();
}
error_code resize_file(const Twine &path, uint64_t size) {
SmallString<128> path_storage;
StringRef p = path.toNullTerminatedStringRef(path_storage);
if (::truncate(p.begin(), size) == -1)
return error_code(errno, system_category());
return error_code::success();
}
error_code exists(const Twine &path, bool &result) {
SmallString<128> path_storage;
StringRef p = path.toNullTerminatedStringRef(path_storage);
if (::access(p.begin(), F_OK) == -1) {
if (errno != errc::no_such_file_or_directory)
return error_code(errno, system_category());
result = false;
} else
result = true;
return error_code::success();
}
bool can_write(const Twine &Path) {
SmallString<128> PathStorage;
StringRef P = Path.toNullTerminatedStringRef(PathStorage);
return 0 == access(P.begin(), W_OK);
}
bool can_execute(const Twine &Path) {
SmallString<128> PathStorage;
StringRef P = Path.toNullTerminatedStringRef(PathStorage);
if (0 != access(P.begin(), R_OK | X_OK))
return false;
struct stat buf;
if (0 != stat(P.begin(), &buf))
return false;
if (!S_ISREG(buf.st_mode))
return false;
return true;
}
bool equivalent(file_status A, file_status B) {
assert(status_known(A) && status_known(B));
return A.fs_st_dev == B.fs_st_dev &&
A.fs_st_ino == B.fs_st_ino;
}
error_code equivalent(const Twine &A, const Twine &B, bool &result) {
file_status fsA, fsB;
if (error_code ec = status(A, fsA)) return ec;
if (error_code ec = status(B, fsB)) return ec;
result = equivalent(fsA, fsB);
return error_code::success();
}
error_code file_size(const Twine &path, uint64_t &result) {
SmallString<128> path_storage;
StringRef p = path.toNullTerminatedStringRef(path_storage);
struct stat status;
if (::stat(p.begin(), &status) == -1)
return error_code(errno, system_category());
if (!S_ISREG(status.st_mode))
return make_error_code(errc::operation_not_permitted);
result = status.st_size;
return error_code::success();
}
error_code getUniqueID(const Twine Path, uint64_t &Result) {
SmallString<128> Storage;
StringRef P = Path.toNullTerminatedStringRef(Storage);
struct stat Status;
if (::stat(P.begin(), &Status) != 0)
return error_code(errno, system_category());
Result = Status.st_ino;
return error_code::success();
}
error_code status(const Twine &path, file_status &result) {
SmallString<128> path_storage;
StringRef p = path.toNullTerminatedStringRef(path_storage);
struct stat status;
if (::stat(p.begin(), &status) != 0) {
error_code ec(errno, system_category());
if (ec == errc::no_such_file_or_directory)
result = file_status(file_type::file_not_found);
else
result = file_status(file_type::status_error);
return ec;
}
perms prms = static_cast<perms>(status.st_mode & perms_mask);
if (S_ISDIR(status.st_mode))
result = file_status(file_type::directory_file, prms);
else if (S_ISREG(status.st_mode))
result = file_status(file_type::regular_file, prms);
else if (S_ISBLK(status.st_mode))
result = file_status(file_type::block_file, prms);
else if (S_ISCHR(status.st_mode))
result = file_status(file_type::character_file, prms);
else if (S_ISFIFO(status.st_mode))
result = file_status(file_type::fifo_file, prms);
else if (S_ISSOCK(status.st_mode))
result = file_status(file_type::socket_file, prms);
else
result = file_status(file_type::type_unknown, prms);
result.fs_st_dev = status.st_dev;
result.fs_st_ino = status.st_ino;
result.fs_st_mtime = status.st_mtime;
result.fs_st_uid = status.st_uid;
result.fs_st_gid = status.st_gid;
return error_code::success();
}
// Modifies permissions on a file.
error_code permissions(const Twine &path, perms prms) {
if ((prms & add_perms) && (prms & remove_perms))
llvm_unreachable("add_perms and remove_perms are mutually exclusive");
// Get current permissions
// FIXME: We only need this stat for add_perms and remove_perms.
file_status info;
if (error_code ec = status(path, info)) {
return ec;
}
// Set updated permissions.
SmallString<128> path_storage;
StringRef p = path.toNullTerminatedStringRef(path_storage);
perms permsToSet;
if (prms & add_perms) {
permsToSet = (info.permissions() | prms) & perms_mask;
} else if (prms & remove_perms) {
permsToSet = (info.permissions() & ~prms) & perms_mask;
} else {
permsToSet = prms & perms_mask;
}
if (::chmod(p.begin(), static_cast<mode_t>(permsToSet))) {
return error_code(errno, system_category());
}
return error_code::success();
}
error_code setLastModificationAndAccessTime(int FD, TimeValue Time) {
timeval Times[2];
Times[0].tv_sec = Time.toPosixTime();
Times[0].tv_usec = 0;
Times[1] = Times[0];
if (::futimes(FD, Times))
return error_code(errno, system_category());
return error_code::success();
}
// Since this is most often used for temporary files, mode defaults to 0600.
error_code unique_file(const Twine &model, int &result_fd,
SmallVectorImpl<char> &result_path,
bool makeAbsolute, unsigned mode) {
SmallString<128> Model;
model.toVector(Model);
// Null terminate.
Model.c_str();
if (makeAbsolute) {
// Make model absolute by prepending a temp directory if it's not already.
bool absolute = path::is_absolute(Twine(Model));
if (!absolute) {
SmallString<128> TDir;
if (error_code ec = TempDir(TDir)) return ec;
path::append(TDir, Twine(Model));
Model.swap(TDir);
}
}
// From here on, DO NOT modify model. It may be needed if the randomly chosen
// path already exists.
SmallString<128> RandomPath = Model;
retry_random_path:
// Replace '%' with random chars.
for (unsigned i = 0, e = Model.size(); i != e; ++i) {
if (Model[i] == '%')
RandomPath[i] = "0123456789abcdef"[sys::Process::GetRandomNumber() & 15];
}
// Make sure we don't fall into an infinite loop by constantly trying
// to create the parent path.
bool TriedToCreateParent = false;
// Try to open + create the file.
rety_open_create:
int RandomFD = ::open(RandomPath.c_str(), O_RDWR | O_CREAT | O_EXCL, mode);
if (RandomFD == -1) {
int SavedErrno = errno;
// If the file existed, try again, otherwise, error.
if (SavedErrno == errc::file_exists)
goto retry_random_path;
// If path prefix doesn't exist, try to create it.
if (SavedErrno == errc::no_such_file_or_directory && !TriedToCreateParent) {
TriedToCreateParent = true;
StringRef p(RandomPath);
SmallString<64> dir_to_create;
for (path::const_iterator i = path::begin(p),
e = --path::end(p); i != e; ++i) {
path::append(dir_to_create, *i);
bool Exists;
if (error_code ec = exists(Twine(dir_to_create), Exists)) return ec;
if (!Exists) {
// Don't try to create network paths.
if (i->size() > 2 && (*i)[0] == '/' &&
(*i)[1] == '/' &&
(*i)[2] != '/')
return make_error_code(errc::no_such_file_or_directory);
if (::mkdir(dir_to_create.c_str(), 0700) == -1 &&
errno != errc::file_exists)
return error_code(errno, system_category());
}
}
goto rety_open_create;
}
return error_code(SavedErrno, system_category());
}
// Make the path absolute.
char real_path_buff[PATH_MAX + 1];
if (realpath(RandomPath.c_str(), real_path_buff) == NULL) {
int error = errno;
::close(RandomFD);
::unlink(RandomPath.c_str());
return error_code(error, system_category());
}
result_path.clear();
StringRef d(real_path_buff);
result_path.append(d.begin(), d.end());
result_fd = RandomFD;
return error_code::success();
}
error_code mapped_file_region::init(int FD, bool CloseFD, uint64_t Offset) {
AutoFD ScopedFD(FD);
if (!CloseFD)
ScopedFD.take();
// Figure out how large the file is.
struct stat FileInfo;
if (fstat(FD, &FileInfo) == -1)
return error_code(errno, system_category());
uint64_t FileSize = FileInfo.st_size;
if (Size == 0)
Size = FileSize;
else if (FileSize < Size) {
// We need to grow the file.
if (ftruncate(FD, Size) == -1)
return error_code(errno, system_category());
}
int flags = (Mode == readwrite) ? MAP_SHARED : MAP_PRIVATE;
int prot = (Mode == readonly) ? PROT_READ : (PROT_READ | PROT_WRITE);
#ifdef MAP_FILE
flags |= MAP_FILE;
#endif
Mapping = ::mmap(0, Size, prot, flags, FD, Offset);
if (Mapping == MAP_FAILED)
return error_code(errno, system_category());
return error_code::success();
}
mapped_file_region::mapped_file_region(const Twine &path,
mapmode mode,
uint64_t length,
uint64_t offset,
error_code &ec)
: Mode(mode)
, Size(length)
, Mapping() {
// Make sure that the requested size fits within SIZE_T.
if (length > std::numeric_limits<size_t>::max()) {
ec = make_error_code(errc::invalid_argument);
return;
}
SmallString<128> path_storage;
StringRef name = path.toNullTerminatedStringRef(path_storage);
int oflags = (mode == readonly) ? O_RDONLY : O_RDWR;
int ofd = ::open(name.begin(), oflags);
if (ofd == -1) {
ec = error_code(errno, system_category());
return;
}
ec = init(ofd, true, offset);
if (ec)
Mapping = 0;
}
mapped_file_region::mapped_file_region(int fd,
bool closefd,
mapmode mode,
uint64_t length,
uint64_t offset,
error_code &ec)
: Mode(mode)
, Size(length)
, Mapping() {
// Make sure that the requested size fits within SIZE_T.
if (length > std::numeric_limits<size_t>::max()) {
ec = make_error_code(errc::invalid_argument);
return;
}
ec = init(fd, closefd, offset);
if (ec)
Mapping = 0;
}
mapped_file_region::~mapped_file_region() {
if (Mapping)
::munmap(Mapping, Size);
}
#if LLVM_HAS_RVALUE_REFERENCES
mapped_file_region::mapped_file_region(mapped_file_region &&other)
: Mode(other.Mode), Size(other.Size), Mapping(other.Mapping) {
other.Mapping = 0;
}
#endif
mapped_file_region::mapmode mapped_file_region::flags() const {
assert(Mapping && "Mapping failed but used anyway!");
return Mode;
}
uint64_t mapped_file_region::size() const {
assert(Mapping && "Mapping failed but used anyway!");
return Size;
}
char *mapped_file_region::data() const {
assert(Mapping && "Mapping failed but used anyway!");
assert(Mode != readonly && "Cannot get non const data for readonly mapping!");
return reinterpret_cast<char*>(Mapping);
}
const char *mapped_file_region::const_data() const {
assert(Mapping && "Mapping failed but used anyway!");
return reinterpret_cast<const char*>(Mapping);
}
int mapped_file_region::alignment() {
return process::get_self()->page_size();
}
error_code detail::directory_iterator_construct(detail::DirIterState &it,
StringRef path){
SmallString<128> path_null(path);
DIR *directory = ::opendir(path_null.c_str());
if (directory == 0)
return error_code(errno, system_category());
it.IterationHandle = reinterpret_cast<intptr_t>(directory);
// Add something for replace_filename to replace.
path::append(path_null, ".");
it.CurrentEntry = directory_entry(path_null.str());
return directory_iterator_increment(it);
}
error_code detail::directory_iterator_destruct(detail::DirIterState &it) {
if (it.IterationHandle)
::closedir(reinterpret_cast<DIR *>(it.IterationHandle));
it.IterationHandle = 0;
it.CurrentEntry = directory_entry();
return error_code::success();
}
error_code detail::directory_iterator_increment(detail::DirIterState &it) {
errno = 0;
dirent *cur_dir = ::readdir(reinterpret_cast<DIR *>(it.IterationHandle));
if (cur_dir == 0 && errno != 0) {
return error_code(errno, system_category());
} else if (cur_dir != 0) {
StringRef name(cur_dir->d_name, NAMLEN(cur_dir));
if ((name.size() == 1 && name[0] == '.') ||
(name.size() == 2 && name[0] == '.' && name[1] == '.'))
return directory_iterator_increment(it);
it.CurrentEntry.replace_filename(name);
} else
return directory_iterator_destruct(it);
return error_code::success();
}
error_code get_magic(const Twine &path, uint32_t len,
SmallVectorImpl<char> &result) {
SmallString<128> PathStorage;
StringRef Path = path.toNullTerminatedStringRef(PathStorage);
result.set_size(0);
// Open path.
std::FILE *file = std::fopen(Path.data(), "rb");
if (file == 0)
return error_code(errno, system_category());
// Reserve storage.
result.reserve(len);
// Read magic!
size_t size = std::fread(result.data(), 1, len, file);
if (std::ferror(file) != 0) {
std::fclose(file);
return error_code(errno, system_category());
} else if (size != len) {
if (std::feof(file) != 0) {
std::fclose(file);
result.set_size(size);
return make_error_code(errc::value_too_large);
}
}
std::fclose(file);
result.set_size(size);
return error_code::success();
}
error_code map_file_pages(const Twine &path, off_t file_offset, size_t size,
bool map_writable, void *&result) {
SmallString<128> path_storage;
StringRef name = path.toNullTerminatedStringRef(path_storage);
int oflags = map_writable ? O_RDWR : O_RDONLY;
int ofd = ::open(name.begin(), oflags);
if ( ofd == -1 )
return error_code(errno, system_category());
AutoFD fd(ofd);
int flags = map_writable ? MAP_SHARED : MAP_PRIVATE;
int prot = map_writable ? (PROT_READ|PROT_WRITE) : PROT_READ;
#ifdef MAP_FILE
flags |= MAP_FILE;
#endif
result = ::mmap(0, size, prot, flags, fd, file_offset);
if (result == MAP_FAILED) {
return error_code(errno, system_category());
}
return error_code::success();
}
error_code unmap_file_pages(void *base, size_t size) {
if ( ::munmap(base, size) == -1 )
return error_code(errno, system_category());
return error_code::success();
}
} // end namespace fs
} // end namespace sys
} // end namespace llvm
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