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llvm-mirror/lib/Support/Unix/Path.inc
Michał Górny 1cdecf37fe [llvm] [Support] Fix segv if argv0 is null in getMainExecutable() 
When LLDB Python bindings are used and stack backtraces are enabled
for logging, getMainExecutable() is called with argv0 being null.
This caused the fallback function getprogpath() (used on FreeBSD, NetBSD
and Linux) to segfault.  Make it handle null executable name gracefully.

Differential Revision: https://reviews.llvm.org/D91012
2020-11-09 11:35:11 +01:00

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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>
#include <sys/file.h>
#ifdef __APPLE__
#include <mach-o/dyld.h>
#include <sys/attr.h>
#include <copyfile.h>
#elif defined(__FreeBSD__)
#include <osreldate.h>
#if __FreeBSD_version >= 1300057
#include <sys/auxv.h>
#else
#include <machine/elf.h>
extern char **environ;
#endif
#elif defined(__DragonFly__)
#include <sys/mount.h>
#elif defined(__MVS__)
#include <sys/ps.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
#if !defined(PATH_MAX)
// For GNU Hurd
#if defined(__GNU__)
#define PATH_MAX 4096
#elif defined(__MVS__)
#define PATH_MAX _XOPEN_PATH_MAX
#endif
#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__) || \
defined(__MVS__)
#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)
{
if (bin == nullptr)
return nullptr;
/* 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[PATH_MAX];
uint32_t size = sizeof(exe_path);
if (_NSGetExecutablePath(exe_path, &size) == 0) {
char link_path[PATH_MAX];
if (realpath(exe_path, link_path))
return link_path;
}
#elif defined(__FreeBSD__)
// On FreeBSD if the exec path specified in ELF auxiliary vectors is
// preferred, if available. /proc/curproc/file and the KERN_PROC_PATHNAME
// sysctl may not return the desired path if there are multiple hardlinks
// to the file.
char exe_path[PATH_MAX];
#if __FreeBSD_version >= 1300057
if (elf_aux_info(AT_EXECPATH, exe_path, sizeof(exe_path)) == 0)
return exe_path;
#else
// elf_aux_info(AT_EXECPATH, ... is not available in all supported versions,
// fall back to finding the ELF auxiliary vectors after the process's
// environment.
char **p = ::environ;
while (*p++ != 0)
;
// Iterate through auxiliary vectors for AT_EXECPATH.
for (; *(uintptr_t *)p != AT_NULL; p++) {
if (*(uintptr_t *)p++ == AT_EXECPATH)
return *p;
}
#endif
// Fall back to argv[0] if auxiliary vectors are not available.
if (getprogpath(exe_path, argv0) != NULL)
return exe_path;
#elif defined(__NetBSD__) || defined(__OpenBSD__) || defined(__minix) || \
defined(__DragonFly__) || defined(__FreeBSD_kernel__) || defined(_AIX)
const char *curproc = "/proc/curproc/file";
char exe_path[PATH_MAX];
if (sys::fs::exists(curproc)) {
ssize_t len = readlink(curproc, 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__) || defined(__gnu_hurd__)
char exe_path[PATH_MAX];
const char *aPath = "/proc/self/exe";
if (sys::fs::exists(aPath)) {
// /proc is not always mounted under Linux (chroot for example).
ssize_t len = readlink(aPath, 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[PATH_MAX];
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(__MVS__)
int token = 0;
W_PSPROC buf;
char exe_path[PS_PATHBLEN];
pid_t pid = getpid();
memset(&buf, 0, sizeof(buf));
buf.ps_pathptr = exe_path;
buf.ps_pathlen = sizeof(exe_path);
while (true) {
if ((token = w_getpsent(token, &buf, sizeof(buf))) <= 0)
break;
if (buf.ps_pid != pid)
continue;
char real_path[PATH_MAX];
if (realpath(exe_path, real_path))
return std::string(real_path);
break; // Found entry, but realpath failed.
}
#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[PATH_MAX];
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();
}
result.reserve(PATH_MAX);
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 = std::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;
#elif defined(__MVS__)
// The file system can have an arbitrary structure on z/OS; must go with 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) {
SmallString<128> PathStorage;
StringRef P = Path.toNullTerminatedStringRef(PathStorage);
if (::chmod(P.begin(), Permissions))
return std::error_code(errno, std::generic_category());
return std::error_code();
}
std::error_code setPermissions(int FD, perms Permissions) {
if (::fchmod(FD, 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();
#elif defined(__MVS__)
attrib_t Attr;
memset(&Attr, 0, sizeof(Attr));
Attr.att_atimechg = 1;
Attr.att_atime = sys::toTimeT(AccessTime);
Attr.att_mtimechg = 1;
Attr.att_mtime = sys::toTimeT(ModificationTime);
if (::__fchattr(FD, &Attr, sizeof(Attr)) != 0)
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.
// Note that while glibc provides a macro to see if this is supported,
// _DIRENT_HAVE_D_TYPE, it's not defined on BSD/Mac, so we test for the
// d_type-to-mode_t conversion macro instead.
#if 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 OF_Append implied
// would open an existing file. See Windows/Path.inc for a longer comment.
if (Flags & OF_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 & OF_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[PATH_MAX];
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;
}
file_t getStdinHandle() { return 0; }
file_t getStdoutHandle() { return 1; }
file_t getStderrHandle() { return 2; }
Expected<size_t> readNativeFile(file_t FD, MutableArrayRef<char> Buf) {
#if defined(__APPLE__)
size_t Size = std::min<size_t>(Buf.size(), INT32_MAX);
#else
size_t Size = Buf.size();
#endif
ssize_t NumRead =
sys::RetryAfterSignal(-1, ::read, FD, Buf.data(), Size);
if (ssize_t(NumRead) == -1)
return errorCodeToError(std::error_code(errno, std::generic_category()));
return NumRead;
}
Expected<size_t> readNativeFileSlice(file_t FD, MutableArrayRef<char> Buf,
uint64_t Offset) {
#if defined(__APPLE__)
size_t Size = std::min<size_t>(Buf.size(), INT32_MAX);
#else
size_t Size = Buf.size();
#endif
#ifdef HAVE_PREAD
ssize_t NumRead =
sys::RetryAfterSignal(-1, ::pread, FD, Buf.data(), Size, Offset);
#else
if (lseek(FD, Offset, SEEK_SET) == -1)
return errorCodeToError(std::error_code(errno, std::generic_category()));
ssize_t NumRead =
sys::RetryAfterSignal(-1, ::read, FD, Buf.data(), Size);
#endif
if (NumRead == -1)
return errorCodeToError(std::error_code(errno, std::generic_category()));
return NumRead;
}
std::error_code tryLockFile(int FD, std::chrono::milliseconds Timeout) {
auto Start = std::chrono::steady_clock::now();
auto End = Start + Timeout;
do {
struct flock Lock;
memset(&Lock, 0, sizeof(Lock));
Lock.l_type = F_WRLCK;
Lock.l_whence = SEEK_SET;
Lock.l_start = 0;
Lock.l_len = 0;
if (::fcntl(FD, F_SETLK, &Lock) != -1)
return std::error_code();
int Error = errno;
if (Error != EACCES && Error != EAGAIN)
return std::error_code(Error, std::generic_category());
usleep(1000);
} while (std::chrono::steady_clock::now() < End);
return make_error_code(errc::no_lock_available);
}
std::error_code lockFile(int FD) {
struct flock Lock;
memset(&Lock, 0, sizeof(Lock));
Lock.l_type = F_WRLCK;
Lock.l_whence = SEEK_SET;
Lock.l_start = 0;
Lock.l_len = 0;
if (::fcntl(FD, F_SETLKW, &Lock) != -1)
return std::error_code();
int Error = errno;
return std::error_code(Error, std::generic_category());
}
std::error_code unlockFile(int FD) {
struct flock Lock;
Lock.l_type = F_UNLCK;
Lock.l_whence = SEEK_SET;
Lock.l_start = 0;
Lock.l_len = 0;
if (::fcntl(FD, F_SETLK, &Lock) != -1)
return std::error_code();
return std::error_code(errno, std::generic_category());
}
std::error_code closeFile(file_t &F) {
file_t TmpF = F;
F = kInvalidFile;
return Process::SafelyCloseFileDescriptor(TmpF);
}
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;
}
bool user_config_directory(SmallVectorImpl<char> &result) {
#ifdef __APPLE__
// Mac: ~/Library/Preferences/
if (home_directory(result)) {
append(result, "Library", "Preferences");
return true;
}
#else
// XDG_CONFIG_HOME as defined in the XDG Base Directory Specification:
// http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html
if (const char *RequestedDir = getenv("XDG_CONFIG_HOME")) {
result.clear();
result.append(RequestedDir, RequestedDir + strlen(RequestedDir));
return true;
}
#endif
// Fallback: ~/.config
if (!home_directory(result)) {
return false;
}
append(result, ".config");
return true;
}
bool cache_directory(SmallVectorImpl<char> &result) {
#ifdef __APPLE__
if (getDarwinConfDir(false/*tempDir*/, result)) {
return true;
}
#else
// XDG_CACHE_HOME as defined in the XDG Base Directory Specification:
// http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html
if (const char *RequestedDir = getenv("XDG_CACHE_HOME")) {
result.clear();
result.append(RequestedDir, RequestedDir + strlen(RequestedDir));
return true;
}
#endif
if (!home_directory(result)) {
return false;
}
append(result, ".cache");
return true;
}
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) && defined(COPYFILE_CLONE)
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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