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

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//===- llvm/Support/Unix/Path.inc - Unix Path Implementation ----*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements the Unix specific implementation of the Path API.
//
//===----------------------------------------------------------------------===//
//===----------------------------------------------------------------------===//
//=== WARNING: Implementation here must contain only generic UNIX code that
//=== is guaranteed to work on *all* UNIX variants.
//===----------------------------------------------------------------------===//
#include "Unix.h"
#include <limits.h>
#include <stdio.h>
#if HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#if HAVE_FCNTL_H
#include <fcntl.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_SYS_MMAN_H
#include <sys/mman.h>
#endif
#include <dirent.h>
#include <pwd.h>
#ifdef __APPLE__
#include <mach-o/dyld.h>
#include <sys/attr.h>
#include <copyfile.h>
#elif defined(__DragonFly__)
#include <sys/mount.h>
#endif
// Both stdio.h and cstdio are included via different paths 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
# define MAXPATHLEN 4096
#endif
#include <sys/types.h>
#if !defined(__APPLE__) && !defined(__OpenBSD__) && !defined(__FreeBSD__) && \
!defined(__linux__) && !defined(__FreeBSD_kernel__) && !defined(_AIX)
#include <sys/statvfs.h>
#define STATVFS statvfs
#define FSTATVFS fstatvfs
#define STATVFS_F_FRSIZE(vfs) vfs.f_frsize
#else
#if defined(__OpenBSD__) || defined(__FreeBSD__)
#include <sys/mount.h>
#include <sys/param.h>
#elif defined(__linux__)
#if defined(HAVE_LINUX_MAGIC_H)
#include <linux/magic.h>
#else
#if defined(HAVE_LINUX_NFS_FS_H)
#include <linux/nfs_fs.h>
#endif
#if defined(HAVE_LINUX_SMB_H)
#include <linux/smb.h>
#endif
#endif
#include <sys/vfs.h>
#elif defined(_AIX)
#include <sys/statfs.h>
// <sys/vmount.h> depends on `uint` to be a typedef from <sys/types.h> to
// `uint_t`; however, <sys/types.h> does not always declare `uint`. We provide
// the typedef prior to including <sys/vmount.h> to work around this issue.
typedef uint_t uint;
#include <sys/vmount.h>
#else
#include <sys/mount.h>
#endif
#define STATVFS statfs
#define FSTATVFS fstatfs
#define STATVFS_F_FRSIZE(vfs) static_cast<uint64_t>(vfs.f_bsize)
#endif
#if defined(__NetBSD__) || defined(__DragonFly__) || defined(__GNU__)
#define STATVFS_F_FLAG(vfs) (vfs).f_flag
#else
#define STATVFS_F_FLAG(vfs) (vfs).f_flags
#endif
using namespace llvm;
namespace llvm {
namespace sys {
namespace fs {
const file_t kInvalidFile = -1;
#if defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || \
defined(__minix) || defined(__FreeBSD_kernel__) || defined(__linux__) || \
defined(__CYGWIN__) || defined(__DragonFly__) || defined(_AIX) || defined(__GNU__)
static int
test_dir(char ret[PATH_MAX], const char *dir, const char *bin)
{
struct stat sb;
char fullpath[PATH_MAX];
int chars = snprintf(fullpath, PATH_MAX, "%s/%s", dir, bin);
// We cannot write PATH_MAX characters because the string will be terminated
// with a null character. Fail if truncation happened.
if (chars >= PATH_MAX)
return 1;
if (!realpath(fullpath, ret))
return 1;
if (stat(fullpath, &sb) != 0)
return 1;
return 0;
}
static char *
getprogpath(char ret[PATH_MAX], const char *bin)
{
/* First approach: absolute path. */
if (bin[0] == '/') {
if (test_dir(ret, "/", bin) == 0)
return ret;
return nullptr;
}
/* Second approach: relative path. */
if (strchr(bin, '/')) {
char cwd[PATH_MAX];
if (!getcwd(cwd, PATH_MAX))
return nullptr;
if (test_dir(ret, cwd, bin) == 0)
return ret;
return nullptr;
}
/* Third approach: $PATH */
char *pv;
if ((pv = getenv("PATH")) == nullptr)
return nullptr;
char *s = strdup(pv);
if (!s)
return nullptr;
char *state;
for (char *t = strtok_r(s, ":", &state); t != nullptr;
t = strtok_r(nullptr, ":", &state)) {
if (test_dir(ret, t, bin) == 0) {
free(s);
return ret;
}
}
free(s);
return nullptr;
}
#endif // __FreeBSD__ || __NetBSD__ || __FreeBSD_kernel__
/// GetMainExecutable - Return the path to the main executable, given the
/// value of argv[0] from program startup.
std::string getMainExecutable(const char *argv0, void *MainAddr) {
#if defined(__APPLE__)
// On OS X the executable path is saved to the stack by dyld. Reading it
// from there is much faster than calling dladdr, especially for large
// binaries with symbols.
char exe_path[MAXPATHLEN];
uint32_t size = sizeof(exe_path);
if (_NSGetExecutablePath(exe_path, &size) == 0) {
char link_path[MAXPATHLEN];
if (realpath(exe_path, link_path))
return link_path;
}
#elif defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || \
defined(__minix) || defined(__DragonFly__) || \
defined(__FreeBSD_kernel__) || defined(_AIX)
StringRef curproc("/proc/curproc/file");
char exe_path[PATH_MAX];
// /proc is not mounted by default under FreeBSD, but gives more accurate
// information than argv[0] when it is.
if (sys::fs::exists(curproc)) {
ssize_t len = readlink(curproc.str().c_str(), exe_path, sizeof(exe_path));
if (len > 0) {
// Null terminate the string for realpath. readlink never null
// terminates its output.
len = std::min(len, ssize_t(sizeof(exe_path) - 1));
exe_path[len] = '\0';
return exe_path;
}
}
// If we don't have procfs mounted, fall back to argv[0]
if (getprogpath(exe_path, argv0) != NULL)
return exe_path;
#elif defined(__linux__) || defined(__CYGWIN__)
char exe_path[MAXPATHLEN];
StringRef aPath("/proc/self/exe");
if (sys::fs::exists(aPath)) {
// /proc is not always mounted under Linux (chroot for example).
ssize_t len = readlink(aPath.str().c_str(), exe_path, sizeof(exe_path));
if (len < 0)
return "";
// Null terminate the string for realpath. readlink never null
// terminates its output.
len = std::min(len, ssize_t(sizeof(exe_path) - 1));
exe_path[len] = '\0';
// On Linux, /proc/self/exe always looks through symlinks. However, on
// GNU/Hurd, /proc/self/exe is a symlink to the path that was used to start
// the program, and not the eventual binary file. Therefore, call realpath
// so this behaves the same on all platforms.
#if _POSIX_VERSION >= 200112 || defined(__GLIBC__)
if (char *real_path = realpath(exe_path, NULL)) {
std::string ret = std::string(real_path);
free(real_path);
return ret;
}
#else
char real_path[MAXPATHLEN];
if (realpath(exe_path, real_path))
return std::string(real_path);
#endif
}
// Fall back to the classical detection.
if (getprogpath(exe_path, argv0))
return exe_path;
#elif defined(HAVE_DLFCN_H) && defined(HAVE_DLADDR)
// Use dladdr to get executable path if available.
Dl_info DLInfo;
int err = dladdr(MainAddr, &DLInfo);
if (err == 0)
return "";
// If the filename is a symlink, we need to resolve and return the location of
// the actual executable.
char link_path[MAXPATHLEN];
if (realpath(DLInfo.dli_fname, link_path))
return link_path;
#else
#error GetMainExecutable is not implemented on this host yet.
#endif
return "";
}
TimePoint<> basic_file_status::getLastAccessedTime() const {
return toTimePoint(fs_st_atime, fs_st_atime_nsec);
}
TimePoint<> basic_file_status::getLastModificationTime() const {
return toTimePoint(fs_st_mtime, fs_st_mtime_nsec);
}
UniqueID file_status::getUniqueID() const {
return UniqueID(fs_st_dev, fs_st_ino);
}
uint32_t file_status::getLinkCount() const {
return fs_st_nlinks;
}
ErrorOr<space_info> disk_space(const Twine &Path) {
struct STATVFS Vfs;
if (::STATVFS(const_cast<char *>(Path.str().c_str()), &Vfs))
return std::error_code(errno, std::generic_category());
auto FrSize = STATVFS_F_FRSIZE(Vfs);
space_info SpaceInfo;
SpaceInfo.capacity = static_cast<uint64_t>(Vfs.f_blocks) * FrSize;
SpaceInfo.free = static_cast<uint64_t>(Vfs.f_bfree) * FrSize;
SpaceInfo.available = static_cast<uint64_t>(Vfs.f_bavail) * FrSize;
return SpaceInfo;
}
std::error_code current_path(SmallVectorImpl<char> &result) {
result.clear();
const char *pwd = ::getenv("PWD");
llvm::sys::fs::file_status PWDStatus, DotStatus;
if (pwd && llvm::sys::path::is_absolute(pwd) &&
!llvm::sys::fs::status(pwd, PWDStatus) &&
!llvm::sys::fs::status(".", DotStatus) &&
PWDStatus.getUniqueID() == DotStatus.getUniqueID()) {
result.append(pwd, pwd + strlen(pwd));
return std::error_code();
}
#ifdef MAXPATHLEN
result.reserve(MAXPATHLEN);
#else
// For GNU Hurd
result.reserve(1024);
#endif
while (true) {
if (::getcwd(result.data(), result.capacity()) == nullptr) {
// See if there was a real error.
if (errno != ENOMEM)
return std::error_code(errno, std::generic_category());
// Otherwise there just wasn't enough space.
result.reserve(result.capacity() * 2);
} else
break;
}
result.set_size(strlen(result.data()));
return std::error_code();
}
std::error_code set_current_path(const Twine &path) {
SmallString<128> path_storage;
StringRef p = path.toNullTerminatedStringRef(path_storage);
if (::chdir(p.begin()) == -1)
return std::error_code(errno, std::generic_category());
return std::error_code();
}
std::error_code create_directory(const Twine &path, bool IgnoreExisting,
perms Perms) {
SmallString<128> path_storage;
StringRef p = path.toNullTerminatedStringRef(path_storage);
if (::mkdir(p.begin(), Perms) == -1) {
if (errno != EEXIST || !IgnoreExisting)
return std::error_code(errno, std::generic_category());
}
return std::error_code();
}
// Note that we are using symbolic link because hard links are not supported by
// all filesystems (SMB doesn't).
std::error_code create_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 (::symlink(t.begin(), f.begin()) == -1)
return std::error_code(errno, std::generic_category());
return std::error_code();
}
std::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 std::error_code(errno, std::generic_category());
return std::error_code();
}
std::error_code remove(const Twine &path, bool IgnoreNonExisting) {
SmallString<128> path_storage;
StringRef p = path.toNullTerminatedStringRef(path_storage);
struct stat buf;
if (lstat(p.begin(), &buf) != 0) {
if (errno != ENOENT || !IgnoreNonExisting)
return std::error_code(errno, std::generic_category());
return std::error_code();
}
// 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) && !S_ISLNK(buf.st_mode))
return make_error_code(errc::operation_not_permitted);
if (::remove(p.begin()) == -1) {
if (errno != ENOENT || !IgnoreNonExisting)
return std::error_code(errno, std::generic_category());
}
return std::error_code();
}
static bool is_local_impl(struct STATVFS &Vfs) {
#if defined(__linux__) || defined(__GNU__)
#ifndef NFS_SUPER_MAGIC
#define NFS_SUPER_MAGIC 0x6969
#endif
#ifndef SMB_SUPER_MAGIC
#define SMB_SUPER_MAGIC 0x517B
#endif
#ifndef CIFS_MAGIC_NUMBER
#define CIFS_MAGIC_NUMBER 0xFF534D42
#endif
#ifdef __GNU__
switch ((uint32_t)Vfs.__f_type) {
#else
switch ((uint32_t)Vfs.f_type) {
#endif
case NFS_SUPER_MAGIC:
case SMB_SUPER_MAGIC:
case CIFS_MAGIC_NUMBER:
return false;
default:
return true;
}
#elif defined(__CYGWIN__)
// Cygwin doesn't expose this information; would need to use Win32 API.
return false;
#elif defined(__Fuchsia__)
// Fuchsia doesn't yet support remote filesystem mounts.
return true;
#elif defined(__EMSCRIPTEN__)
// Emscripten doesn't currently support remote filesystem mounts.
return true;
#elif defined(__HAIKU__)
// Haiku doesn't expose this information.
return false;
#elif defined(__sun)
// statvfs::f_basetype contains a null-terminated FSType name of the mounted target
StringRef fstype(Vfs.f_basetype);
// NFS is the only non-local fstype??
return !fstype.equals("nfs");
#elif defined(_AIX)
// Call mntctl; try more than twice in case of timing issues with a concurrent
// mount.
int Ret;
size_t BufSize = 2048u;
std::unique_ptr<char[]> Buf;
int Tries = 3;
while (Tries--) {
Buf = llvm::make_unique<char[]>(BufSize);
Ret = mntctl(MCTL_QUERY, BufSize, Buf.get());
if (Ret != 0)
break;
BufSize = *reinterpret_cast<unsigned int *>(Buf.get());
Buf.reset();
}
if (Ret == -1)
// There was an error; "remote" is the conservative answer.
return false;
// Look for the correct vmount entry.
char *CurObjPtr = Buf.get();
while (Ret--) {
struct vmount *Vp = reinterpret_cast<struct vmount *>(CurObjPtr);
static_assert(sizeof(Vfs.f_fsid) == sizeof(Vp->vmt_fsid),
"fsid length mismatch");
if (memcmp(&Vfs.f_fsid, &Vp->vmt_fsid, sizeof Vfs.f_fsid) == 0)
return (Vp->vmt_flags & MNT_REMOTE) == 0;
CurObjPtr += Vp->vmt_length;
}
// vmount entry not found; "remote" is the conservative answer.
return false;
#else
return !!(STATVFS_F_FLAG(Vfs) & MNT_LOCAL);
#endif
}
std::error_code is_local(const Twine &Path, bool &Result) {
struct STATVFS Vfs;
if (::STATVFS(const_cast<char *>(Path.str().c_str()), &Vfs))
return std::error_code(errno, std::generic_category());
Result = is_local_impl(Vfs);
return std::error_code();
}
std::error_code is_local(int FD, bool &Result) {
struct STATVFS Vfs;
if (::FSTATVFS(FD, &Vfs))
return std::error_code(errno, std::generic_category());
Result = is_local_impl(Vfs);
return std::error_code();
}
std::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)
return std::error_code(errno, std::generic_category());
return std::error_code();
}
std::error_code resize_file(int FD, uint64_t Size) {
#if defined(HAVE_POSIX_FALLOCATE)
// If we have posix_fallocate use it. Unlike ftruncate it always allocates
// space, so we get an error if the disk is full.
if (int Err = ::posix_fallocate(FD, 0, Size)) {
#ifdef _AIX
constexpr int NotSupportedError = ENOTSUP;
#else
constexpr int NotSupportedError = EOPNOTSUPP;
#endif
if (Err != EINVAL && Err != NotSupportedError)
return std::error_code(Err, std::generic_category());
}
#endif
// Use ftruncate as a fallback. It may or may not allocate space. At least on
// OS X with HFS+ it does.
if (::ftruncate(FD, Size) == -1)
return std::error_code(errno, std::generic_category());
return std::error_code();
}
static int convertAccessMode(AccessMode Mode) {
switch (Mode) {
case AccessMode::Exist:
return F_OK;
case AccessMode::Write:
return W_OK;
case AccessMode::Execute:
return R_OK | X_OK; // scripts also need R_OK.
}
llvm_unreachable("invalid enum");
}
std::error_code access(const Twine &Path, AccessMode Mode) {
SmallString<128> PathStorage;
StringRef P = Path.toNullTerminatedStringRef(PathStorage);
if (::access(P.begin(), convertAccessMode(Mode)) == -1)
return std::error_code(errno, std::generic_category());
if (Mode == AccessMode::Execute) {
// Don't say that directories are executable.
struct stat buf;
if (0 != stat(P.begin(), &buf))
return errc::permission_denied;
if (!S_ISREG(buf.st_mode))
return errc::permission_denied;
}
return std::error_code();
}
bool can_execute(const Twine &Path) {
return !access(Path, AccessMode::Execute);
}
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;
}
std::error_code equivalent(const Twine &A, const Twine &B, bool &result) {
file_status fsA, fsB;
if (std::error_code ec = status(A, fsA))
return ec;
if (std::error_code ec = status(B, fsB))
return ec;
result = equivalent(fsA, fsB);
return std::error_code();
}
static void expandTildeExpr(SmallVectorImpl<char> &Path) {
StringRef PathStr(Path.begin(), Path.size());
if (PathStr.empty() || !PathStr.startswith("~"))
return;
PathStr = PathStr.drop_front();
StringRef Expr =
PathStr.take_until([](char c) { return path::is_separator(c); });
StringRef Remainder = PathStr.substr(Expr.size() + 1);
SmallString<128> Storage;
if (Expr.empty()) {
// This is just ~/..., resolve it to the current user's home dir.
if (!path::home_directory(Storage)) {
// For some reason we couldn't get the home directory. Just exit.
return;
}
// Overwrite the first character and insert the rest.
Path[0] = Storage[0];
Path.insert(Path.begin() + 1, Storage.begin() + 1, Storage.end());
return;
}
// This is a string of the form ~username/, look up this user's entry in the
// password database.
struct passwd *Entry = nullptr;
std::string User = Expr.str();
Entry = ::getpwnam(User.c_str());
if (!Entry) {
// Unable to look up the entry, just return back the original path.
return;
}
Storage = Remainder;
Path.clear();
Path.append(Entry->pw_dir, Entry->pw_dir + strlen(Entry->pw_dir));
llvm::sys::path::append(Path, Storage);
}
void expand_tilde(const Twine &path, SmallVectorImpl<char> &dest) {
dest.clear();
if (path.isTriviallyEmpty())
return;
path.toVector(dest);
expandTildeExpr(dest);
return;
}
static file_type typeForMode(mode_t Mode) {
if (S_ISDIR(Mode))
return file_type::directory_file;
else if (S_ISREG(Mode))
return file_type::regular_file;
else if (S_ISBLK(Mode))
return file_type::block_file;
else if (S_ISCHR(Mode))
return file_type::character_file;
else if (S_ISFIFO(Mode))
return file_type::fifo_file;
else if (S_ISSOCK(Mode))
return file_type::socket_file;
else if (S_ISLNK(Mode))
return file_type::symlink_file;
return file_type::type_unknown;
}
static std::error_code fillStatus(int StatRet, const struct stat &Status,
file_status &Result) {
if (StatRet != 0) {
std::error_code EC(errno, std::generic_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;
}
uint32_t atime_nsec, mtime_nsec;
#if defined(HAVE_STRUCT_STAT_ST_MTIMESPEC_TV_NSEC)
atime_nsec = Status.st_atimespec.tv_nsec;
mtime_nsec = Status.st_mtimespec.tv_nsec;
#elif defined(HAVE_STRUCT_STAT_ST_MTIM_TV_NSEC)
atime_nsec = Status.st_atim.tv_nsec;
mtime_nsec = Status.st_mtim.tv_nsec;
#else
atime_nsec = mtime_nsec = 0;
#endif
perms Perms = static_cast<perms>(Status.st_mode) & all_perms;
Result = file_status(typeForMode(Status.st_mode), Perms, Status.st_dev,
Status.st_nlink, Status.st_ino,
Status.st_atime, atime_nsec, Status.st_mtime, mtime_nsec,
Status.st_uid, Status.st_gid, Status.st_size);
return std::error_code();
}
std::error_code status(const Twine &Path, file_status &Result, bool Follow) {
SmallString<128> PathStorage;
StringRef P = Path.toNullTerminatedStringRef(PathStorage);
struct stat Status;
int StatRet = (Follow ? ::stat : ::lstat)(P.begin(), &Status);
return fillStatus(StatRet, Status, Result);
}
std::error_code status(int FD, file_status &Result) {
struct stat Status;
int StatRet = ::fstat(FD, &Status);
return fillStatus(StatRet, Status, Result);
}
unsigned getUmask() {
// Chose arbitary new mask and reset the umask to the old mask.
// umask(2) never fails so ignore the return of the second call.
unsigned Mask = ::umask(0);
(void) ::umask(Mask);
return Mask;
}
std::error_code setPermissions(const Twine &Path, perms Permissions,
bool RespectUmask) {
SmallString<128> PathStorage;
StringRef P = Path.toNullTerminatedStringRef(PathStorage);
if (RespectUmask)
Permissions = static_cast<perms>(Permissions & ~getUmask());
if (::chmod(P.begin(), Permissions))
return std::error_code(errno, std::generic_category());
return std::error_code();
}
std::error_code setLastAccessAndModificationTime(int FD, TimePoint<> AccessTime,
TimePoint<> ModificationTime) {
#if defined(HAVE_FUTIMENS)
timespec Times[2];
Times[0] = sys::toTimeSpec(AccessTime);
Times[1] = sys::toTimeSpec(ModificationTime);
if (::futimens(FD, Times))
return std::error_code(errno, std::generic_category());
return std::error_code();
#elif defined(HAVE_FUTIMES)
timeval Times[2];
Times[0] = sys::toTimeVal(
std::chrono::time_point_cast<std::chrono::microseconds>(AccessTime));
Times[1] =
sys::toTimeVal(std::chrono::time_point_cast<std::chrono::microseconds>(
ModificationTime));
if (::futimes(FD, Times))
return std::error_code(errno, std::generic_category());
return std::error_code();
#else
#warning Missing futimes() and futimens()
return make_error_code(errc::function_not_supported);
#endif
}
std::error_code mapped_file_region::init(int FD, uint64_t Offset,
mapmode Mode) {
assert(Size != 0);
int flags = (Mode == readwrite) ? MAP_SHARED : MAP_PRIVATE;
int prot = (Mode == readonly) ? PROT_READ : (PROT_READ | PROT_WRITE);
#if defined(__APPLE__)
//----------------------------------------------------------------------
// Newer versions of MacOSX have a flag that will allow us to read from
// binaries whose code signature is invalid without crashing by using
// the MAP_RESILIENT_CODESIGN flag. Also if a file from removable media
// is mapped we can avoid crashing and return zeroes to any pages we try
// to read if the media becomes unavailable by using the
// MAP_RESILIENT_MEDIA flag. These flags are only usable when mapping
// with PROT_READ, so take care not to specify them otherwise.
//----------------------------------------------------------------------
if (Mode == readonly) {
#if defined(MAP_RESILIENT_CODESIGN)
flags |= MAP_RESILIENT_CODESIGN;
#endif
#if defined(MAP_RESILIENT_MEDIA)
flags |= MAP_RESILIENT_MEDIA;
#endif
}
#endif // #if defined (__APPLE__)
Mapping = ::mmap(nullptr, Size, prot, flags, FD, Offset);
if (Mapping == MAP_FAILED)
return std::error_code(errno, std::generic_category());
return std::error_code();
}
mapped_file_region::mapped_file_region(int fd, mapmode mode, size_t length,
uint64_t offset, std::error_code &ec)
: Size(length), Mapping(), Mode(mode) {
(void)Mode;
ec = init(fd, offset, mode);
if (ec)
Mapping = nullptr;
}
mapped_file_region::~mapped_file_region() {
if (Mapping)
::munmap(Mapping, Size);
}
size_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!");
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::getPageSizeEstimate();
}
std::error_code detail::directory_iterator_construct(detail::DirIterState &it,
StringRef path,
bool follow_symlinks) {
SmallString<128> path_null(path);
DIR *directory = ::opendir(path_null.c_str());
if (!directory)
return std::error_code(errno, std::generic_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(), follow_symlinks);
return directory_iterator_increment(it);
}
std::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 std::error_code();
}
static file_type direntType(dirent* Entry) {
// Most platforms provide the file type in the dirent: Linux/BSD/Mac.
// The DTTOIF macro lets us reuse our status -> type conversion.
#if defined(_DIRENT_HAVE_D_TYPE) && defined(DTTOIF)
return typeForMode(DTTOIF(Entry->d_type));
#else
// Other platforms such as Solaris require a stat() to get the type.
return file_type::type_unknown;
#endif
}
std::error_code detail::directory_iterator_increment(detail::DirIterState &It) {
errno = 0;
dirent *CurDir = ::readdir(reinterpret_cast<DIR *>(It.IterationHandle));
if (CurDir == nullptr && errno != 0) {
return std::error_code(errno, std::generic_category());
} else if (CurDir != nullptr) {
StringRef Name(CurDir->d_name);
if ((Name.size() == 1 && Name[0] == '.') ||
(Name.size() == 2 && Name[0] == '.' && Name[1] == '.'))
return directory_iterator_increment(It);
It.CurrentEntry.replace_filename(Name, direntType(CurDir));
} else
return directory_iterator_destruct(It);
return std::error_code();
}
ErrorOr<basic_file_status> directory_entry::status() const {
file_status s;
if (auto EC = fs::status(Path, s, FollowSymlinks))
return EC;
return s;
}
#if !defined(F_GETPATH)
static bool hasProcSelfFD() {
// If we have a /proc filesystem mounted, we can quickly establish the
// real name of the file with readlink
static const bool Result = (::access("/proc/self/fd", R_OK) == 0);
return Result;
}
#endif
static int nativeOpenFlags(CreationDisposition Disp, OpenFlags Flags,
FileAccess Access) {
int Result = 0;
if (Access == FA_Read)
Result |= O_RDONLY;
else if (Access == FA_Write)
Result |= O_WRONLY;
else if (Access == (FA_Read | FA_Write))
Result |= O_RDWR;
// This is for compatibility with old code that assumed F_Append implied
// would open an existing file. See Windows/Path.inc for a longer comment.
if (Flags & F_Append)
Disp = CD_OpenAlways;
if (Disp == CD_CreateNew) {
Result |= O_CREAT; // Create if it doesn't exist.
Result |= O_EXCL; // Fail if it does.
} else if (Disp == CD_CreateAlways) {
Result |= O_CREAT; // Create if it doesn't exist.
Result |= O_TRUNC; // Truncate if it does.
} else if (Disp == CD_OpenAlways) {
Result |= O_CREAT; // Create if it doesn't exist.
} else if (Disp == CD_OpenExisting) {
// Nothing special, just don't add O_CREAT and we get these semantics.
}
if (Flags & F_Append)
Result |= O_APPEND;
#ifdef O_CLOEXEC
if (!(Flags & OF_ChildInherit))
Result |= O_CLOEXEC;
#endif
return Result;
}
std::error_code openFile(const Twine &Name, int &ResultFD,
CreationDisposition Disp, FileAccess Access,
OpenFlags Flags, unsigned Mode) {
int OpenFlags = nativeOpenFlags(Disp, Flags, Access);
SmallString<128> Storage;
StringRef P = Name.toNullTerminatedStringRef(Storage);
// Call ::open in a lambda to avoid overload resolution in RetryAfterSignal
// when open is overloaded, such as in Bionic.
auto Open = [&]() { return ::open(P.begin(), OpenFlags, Mode); };
if ((ResultFD = sys::RetryAfterSignal(-1, Open)) < 0)
return std::error_code(errno, std::generic_category());
#ifndef O_CLOEXEC
if (!(Flags & OF_ChildInherit)) {
int r = fcntl(ResultFD, F_SETFD, FD_CLOEXEC);
(void)r;
assert(r == 0 && "fcntl(F_SETFD, FD_CLOEXEC) failed");
}
#endif
return std::error_code();
}
Expected<int> openNativeFile(const Twine &Name, CreationDisposition Disp,
FileAccess Access, OpenFlags Flags,
unsigned Mode) {
int FD;
std::error_code EC = openFile(Name, FD, Disp, Access, Flags, Mode);
if (EC)
return errorCodeToError(EC);
return FD;
}
std::error_code openFileForRead(const Twine &Name, int &ResultFD,
OpenFlags Flags,
SmallVectorImpl<char> *RealPath) {
std::error_code EC =
openFile(Name, ResultFD, CD_OpenExisting, FA_Read, Flags, 0666);
if (EC)
return EC;
// Attempt to get the real name of the file, if the user asked
if(!RealPath)
return std::error_code();
RealPath->clear();
#if defined(F_GETPATH)
// When F_GETPATH is availble, it is the quickest way to get
// the real path name.
char Buffer[MAXPATHLEN];
if (::fcntl(ResultFD, F_GETPATH, Buffer) != -1)
RealPath->append(Buffer, Buffer + strlen(Buffer));
#else
char Buffer[PATH_MAX];
if (hasProcSelfFD()) {
char ProcPath[64];
snprintf(ProcPath, sizeof(ProcPath), "/proc/self/fd/%d", ResultFD);
ssize_t CharCount = ::readlink(ProcPath, Buffer, sizeof(Buffer));
if (CharCount > 0)
RealPath->append(Buffer, Buffer + CharCount);
} else {
SmallString<128> Storage;
StringRef P = Name.toNullTerminatedStringRef(Storage);
// Use ::realpath to get the real path name
if (::realpath(P.begin(), Buffer) != nullptr)
RealPath->append(Buffer, Buffer + strlen(Buffer));
}
#endif
return std::error_code();
}
Expected<file_t> openNativeFileForRead(const Twine &Name, OpenFlags Flags,
SmallVectorImpl<char> *RealPath) {
file_t ResultFD;
std::error_code EC = openFileForRead(Name, ResultFD, Flags, RealPath);
if (EC)
return errorCodeToError(EC);
return ResultFD;
}
void closeFile(file_t &F) {
::close(F);
F = kInvalidFile;
}
template <typename T>
static std::error_code remove_directories_impl(const T &Entry,
bool IgnoreErrors) {
std::error_code EC;
directory_iterator Begin(Entry, EC, false);
directory_iterator End;
while (Begin != End) {
auto &Item = *Begin;
ErrorOr<basic_file_status> st = Item.status();
if (!st && !IgnoreErrors)
return st.getError();
if (is_directory(*st)) {
EC = remove_directories_impl(Item, IgnoreErrors);
if (EC && !IgnoreErrors)
return EC;
}
EC = fs::remove(Item.path(), true);
if (EC && !IgnoreErrors)
return EC;
Begin.increment(EC);
if (EC && !IgnoreErrors)
return EC;
}
return std::error_code();
}
std::error_code remove_directories(const Twine &path, bool IgnoreErrors) {
auto EC = remove_directories_impl(path, IgnoreErrors);
if (EC && !IgnoreErrors)
return EC;
EC = fs::remove(path, true);
if (EC && !IgnoreErrors)
return EC;
return std::error_code();
}
std::error_code real_path(const Twine &path, SmallVectorImpl<char> &dest,
bool expand_tilde) {
dest.clear();
if (path.isTriviallyEmpty())
return std::error_code();
if (expand_tilde) {
SmallString<128> Storage;
path.toVector(Storage);
expandTildeExpr(Storage);
return real_path(Storage, dest, false);
}
SmallString<128> Storage;
StringRef P = path.toNullTerminatedStringRef(Storage);
char Buffer[PATH_MAX];
if (::realpath(P.begin(), Buffer) == nullptr)
return std::error_code(errno, std::generic_category());
dest.append(Buffer, Buffer + strlen(Buffer));
return std::error_code();
}
} // end namespace fs
namespace path {
bool home_directory(SmallVectorImpl<char> &result) {
char *RequestedDir = getenv("HOME");
if (!RequestedDir) {
struct passwd *pw = getpwuid(getuid());
if (pw && pw->pw_dir)
RequestedDir = pw->pw_dir;
}
if (!RequestedDir)
return false;
result.clear();
result.append(RequestedDir, RequestedDir + strlen(RequestedDir));
return true;
}
static bool getDarwinConfDir(bool TempDir, SmallVectorImpl<char> &Result) {
#if defined(_CS_DARWIN_USER_TEMP_DIR) && defined(_CS_DARWIN_USER_CACHE_DIR)
// On Darwin, use DARWIN_USER_TEMP_DIR or DARWIN_USER_CACHE_DIR.
// macros defined in <unistd.h> on darwin >= 9
int ConfName = TempDir ? _CS_DARWIN_USER_TEMP_DIR
: _CS_DARWIN_USER_CACHE_DIR;
size_t ConfLen = confstr(ConfName, nullptr, 0);
if (ConfLen > 0) {
do {
Result.resize(ConfLen);
ConfLen = confstr(ConfName, Result.data(), Result.size());
} while (ConfLen > 0 && ConfLen != Result.size());
if (ConfLen > 0) {
assert(Result.back() == 0);
Result.pop_back();
return true;
}
Result.clear();
}
#endif
return false;
}
static const char *getEnvTempDir() {
// Check whether the temporary directory is specified by an environment
// variable.
const char *EnvironmentVariables[] = {"TMPDIR", "TMP", "TEMP", "TEMPDIR"};
for (const char *Env : EnvironmentVariables) {
if (const char *Dir = std::getenv(Env))
return Dir;
}
return nullptr;
}
static const char *getDefaultTempDir(bool ErasedOnReboot) {
#ifdef P_tmpdir
if ((bool)P_tmpdir)
return P_tmpdir;
#endif
if (ErasedOnReboot)
return "/tmp";
return "/var/tmp";
}
void system_temp_directory(bool ErasedOnReboot, SmallVectorImpl<char> &Result) {
Result.clear();
if (ErasedOnReboot) {
// There is no env variable for the cache directory.
if (const char *RequestedDir = getEnvTempDir()) {
Result.append(RequestedDir, RequestedDir + strlen(RequestedDir));
return;
}
}
if (getDarwinConfDir(ErasedOnReboot, Result))
return;
const char *RequestedDir = getDefaultTempDir(ErasedOnReboot);
Result.append(RequestedDir, RequestedDir + strlen(RequestedDir));
}
} // end namespace path
namespace fs {
#ifdef __APPLE__
/// This implementation tries to perform an APFS CoW clone of the file,
/// which can be much faster and uses less space.
/// Unfortunately fcopyfile(3) does not support COPYFILE_CLONE, so the
/// file descriptor variant of this function still uses the default
/// implementation.
std::error_code copy_file(const Twine &From, const Twine &To) {
uint32_t Flag = COPYFILE_DATA;
#if __has_builtin(__builtin_available)
if (__builtin_available(macos 10.12, *)) {
bool IsSymlink;
if (std::error_code Error = is_symlink_file(From, IsSymlink))
return Error;
// COPYFILE_CLONE clones the symlink instead of following it
// and returns EEXISTS if the target file already exists.
if (!IsSymlink && !exists(To))
Flag = COPYFILE_CLONE;
}
#endif
int Status =
copyfile(From.str().c_str(), To.str().c_str(), /* State */ NULL, Flag);
if (Status == 0)
return std::error_code();
return std::error_code(errno, std::generic_category());
}
#endif // __APPLE__
} // end namespace fs
} // end namespace sys
} // end namespace llvm
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