llvm/lib/Support/Unix/Path.inc
Mehdi Amini dbca62ee4e [ThinLTO] Add an API to trigger file-based API for returning objects to the linker
Summary:
The motivation is to support better the -object_path_lto option on
Darwin. The linker needs to write down the generate object files on
disk for later use by lldb or dsymutil (debug info are not present
in the final binary). We're moving this into libLTO so that we can
be smarter when a cache is enabled and hard-link when possible
instead of duplicating the files.

Reviewers: tejohnson, deadalnix, pcc

Subscribers: dexonsmith, llvm-commits

Differential Revision: https://reviews.llvm.org/D27507

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289631 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-14 04:56:42 +00:00

795 lines
24 KiB
C++

//===- llvm/Support/Unix/Path.inc - 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 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
#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
#ifdef __APPLE__
#include <mach-o/dyld.h>
#include <sys/attr.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
#endif
#include <sys/types.h>
#if !defined(__APPLE__) && !defined(__OpenBSD__) && !defined(__ANDROID__)
#include <sys/statvfs.h>
#define STATVFS statvfs
#define STATVFS_F_FRSIZE(vfs) vfs.f_frsize
#else
#ifdef __OpenBSD__
#include <sys/param.h>
#include <sys/mount.h>
#elif defined(__ANDROID__)
#include <sys/vfs.h>
#else
#include <sys/mount.h>
#endif
#define STATVFS statfs
#define STATVFS_F_FRSIZE(vfs) static_cast<uint64_t>(vfs.f_bsize)
#endif
using namespace llvm;
namespace llvm {
namespace sys {
namespace fs {
#if defined(__FreeBSD__) || defined (__NetBSD__) || defined(__Bitrig__) || \
defined(__OpenBSD__) || defined(__minix) || defined(__FreeBSD_kernel__) || \
defined(__linux__) || defined(__CYGWIN__) || defined(__DragonFly__) || \
defined(_AIX)
static int
test_dir(char ret[PATH_MAX], const char *dir, const char *bin)
{
struct stat sb;
char fullpath[PATH_MAX];
snprintf(fullpath, PATH_MAX, "%s/%s", dir, bin);
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)
{
char *pv, *s, *t;
/* 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 */
if ((pv = getenv("PATH")) == nullptr)
return nullptr;
s = pv = strdup(pv);
if (!pv)
return nullptr;
while ((t = strsep(&s, ":")) != nullptr) {
if (test_dir(ret, t, bin) == 0) {
free(pv);
return ret;
}
}
free(pv);
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(__Bitrig__) || \
defined(__OpenBSD__) || defined(__minix) || defined(__DragonFly__) || \
defined(__FreeBSD_kernel__) || defined(_AIX)
char exe_path[PATH_MAX];
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 std::string(exe_path, len);
} else {
// Fall back to the classical detection.
if (getprogpath(exe_path, argv0))
return exe_path;
}
#elif defined(HAVE_DLFCN_H)
// 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<> file_status::getLastAccessedTime() const {
return toTimePoint(fs_st_atime);
}
TimePoint<> file_status::getLastModificationTime() const {
return toTimePoint(fs_st_mtime);
}
UniqueID file_status::getUniqueID() const {
return UniqueID(fs_st_dev, fs_st_ino);
}
ErrorOr<space_info> disk_space(const Twine &Path) {
struct STATVFS Vfs;
if (::STATVFS(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 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();
}
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))
return std::error_code(Err, std::generic_category());
#else
// 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());
#endif
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 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;
}
file_type Type = file_type::type_unknown;
if (S_ISDIR(Status.st_mode))
Type = file_type::directory_file;
else if (S_ISREG(Status.st_mode))
Type = file_type::regular_file;
else if (S_ISBLK(Status.st_mode))
Type = file_type::block_file;
else if (S_ISCHR(Status.st_mode))
Type = file_type::character_file;
else if (S_ISFIFO(Status.st_mode))
Type = file_type::fifo_file;
else if (S_ISSOCK(Status.st_mode))
Type = file_type::socket_file;
perms Perms = static_cast<perms>(Status.st_mode);
Result =
file_status(Type, Perms, Status.st_dev, Status.st_ino, Status.st_atime,
Status.st_mtime, Status.st_uid, Status.st_gid,
Status.st_size);
return std::error_code();
}
std::error_code status(const Twine &Path, file_status &Result) {
SmallString<128> PathStorage;
StringRef P = Path.toNullTerminatedStringRef(PathStorage);
struct stat Status;
int StatRet = ::stat(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);
}
std::error_code setLastModificationAndAccessTime(int FD, TimePoint<> Time) {
#if defined(HAVE_FUTIMENS)
timespec Times[2];
Times[0] = Times[1] = sys::toTimeSpec(Time);
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] = Times[1] = sys::toTimeVal(
std::chrono::time_point_cast<std::chrono::microseconds>(Time));
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);
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, uint64_t length,
uint64_t offset, std::error_code &ec)
: 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, offset, mode);
if (ec)
Mapping = nullptr;
}
mapped_file_region::~mapped_file_region() {
if (Mapping)
::munmap(Mapping, Size);
}
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!");
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::getPageSize();
}
std::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)
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());
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();
}
std::error_code detail::directory_iterator_increment(detail::DirIterState &it) {
errno = 0;
dirent *cur_dir = ::readdir(reinterpret_cast<DIR *>(it.IterationHandle));
if (cur_dir == nullptr && errno != 0) {
return std::error_code(errno, std::generic_category());
} else if (cur_dir != nullptr) {
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 std::error_code();
}
#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
std::error_code openFileForRead(const Twine &Name, int &ResultFD,
SmallVectorImpl<char> *RealPath) {
SmallString<128> Storage;
StringRef P = Name.toNullTerminatedStringRef(Storage);
while ((ResultFD = open(P.begin(), O_RDONLY)) < 0) {
if (errno != EINTR)
return std::error_code(errno, std::generic_category());
}
// 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 {
// 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();
}
std::error_code openFileForWrite(const Twine &Name, int &ResultFD,
sys::fs::OpenFlags Flags, unsigned Mode) {
// Verify that we don't have both "append" and "excl".
assert((!(Flags & sys::fs::F_Excl) || !(Flags & sys::fs::F_Append)) &&
"Cannot specify both 'excl' and 'append' file creation flags!");
int OpenFlags = O_CREAT;
if (Flags & F_RW)
OpenFlags |= O_RDWR;
else
OpenFlags |= O_WRONLY;
if (Flags & F_Append)
OpenFlags |= O_APPEND;
else
OpenFlags |= O_TRUNC;
if (Flags & F_Excl)
OpenFlags |= O_EXCL;
SmallString<128> Storage;
StringRef P = Name.toNullTerminatedStringRef(Storage);
while ((ResultFD = open(P.begin(), OpenFlags, Mode)) < 0) {
if (errno != EINTR)
return std::error_code(errno, std::generic_category());
}
return std::error_code();
}
std::error_code getPathFromOpenFD(int FD, SmallVectorImpl<char> &ResultPath) {
if (FD < 0)
return make_error_code(errc::bad_file_descriptor);
#if defined(F_GETPATH)
// When F_GETPATH is availble, it is the quickest way to get
// the path from a file descriptor.
ResultPath.reserve(MAXPATHLEN);
if (::fcntl(FD, F_GETPATH, ResultPath.begin()) == -1)
return std::error_code(errno, std::generic_category());
ResultPath.set_size(strlen(ResultPath.begin()));
#else
// If we have a /proc filesystem mounted, we can quickly establish the
// real name of the file with readlink. Otherwise, we don't know how to
// get the filename from a file descriptor. Give up.
if (!fs::hasProcSelfFD())
return make_error_code(errc::function_not_supported);
ResultPath.reserve(PATH_MAX);
char ProcPath[64];
snprintf(ProcPath, sizeof(ProcPath), "/proc/self/fd/%d", FD);
ssize_t CharCount = ::readlink(ProcPath, ResultPath.begin(), ResultPath.capacity());
if (CharCount < 0)
return std::error_code(errno, std::generic_category());
// Was the filename truncated?
if (static_cast<size_t>(CharCount) == ResultPath.capacity()) {
// Use lstat to get the size of the filename
struct stat sb;
if (::lstat(ProcPath, &sb) < 0)
return std::error_code(errno, std::generic_category());
ResultPath.reserve(sb.st_size + 1);
CharCount = ::readlink(ProcPath, ResultPath.begin(), ResultPath.capacity());
if (CharCount < 0)
return std::error_code(errno, std::generic_category());
// Test for race condition: did the link size change?
if (CharCount > sb.st_size)
return std::error_code(ENAMETOOLONG, std::generic_category());
}
ResultPath.set_size(static_cast<size_t>(CharCount));
#endif
return std::error_code();
}
} // end namespace fs
namespace path {
bool home_directory(SmallVectorImpl<char> &result) {
if (char *RequestedDir = getenv("HOME")) {
result.clear();
result.append(RequestedDir, RequestedDir + strlen(RequestedDir));
return true;
}
return false;
}
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 bool getUserCacheDir(SmallVectorImpl<char> &Result) {
// First try using XDG_CACHE_HOME env variable,
// as specified in XDG Base Directory Specification at
// http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html
if (const char *XdgCacheDir = std::getenv("XDG_CACHE_HOME")) {
Result.clear();
Result.append(XdgCacheDir, XdgCacheDir + strlen(XdgCacheDir));
return true;
}
// Try Darwin configuration query
if (getDarwinConfDir(false, Result))
return true;
// Use "$HOME/.cache" if $HOME is available
if (home_directory(Result)) {
append(Result, ".cache");
return true;
}
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
} // end namespace sys
} // end namespace llvm