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

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//===- llvm/System/Unix/Path.cpp - Unix Path Implementation -----*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by Reid Spencer and is distributed under the
// University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the Unix specific portion of the Path class.
//
//===----------------------------------------------------------------------===//
//===----------------------------------------------------------------------===//
//=== WARNING: Implementation here must contain only generic UNIX code that
//=== is guaranteed to work on *all* UNIX variants.
//===----------------------------------------------------------------------===//
#include "llvm/Config/alloca.h"
#include "Unix.h"
#if HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#if HAVE_FCNTL_H
#include <fcntl.h>
#endif
#if HAVE_UTIME_H
#include <utime.h>
#endif
#if HAVE_TIME_H
#include <time.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
// Put in a hack for Cygwin which falsely reports that the mkdtemp function
// is available when it is not.
#ifdef __CYGWIN__
# undef HAVE_MKDTEMP
#endif
namespace {
inline bool lastIsSlash(const std::string& path) {
return !path.empty() && path[path.length() - 1] == '/';
}
}
namespace llvm {
using namespace sys;
bool
Path::isValid() const {
// Check some obvious things
if (path.empty())
return false;
else if (path.length() >= MAXPATHLEN)
return false;
// Check that the characters are ascii chars
size_t len = path.length();
unsigned i = 0;
while (i < len && isascii(path[i]))
++i;
return i >= len;
}
bool
Path::isAbsolute() const {
if (path.empty())
return false;
return path[0] == '/';
}
Path
Path::GetRootDirectory() {
Path result;
result.set("/");
return result;
}
Path
Path::GetTemporaryDirectory(std::string* ErrMsg ) {
#if defined(HAVE_MKDTEMP)
// The best way is with mkdtemp but that's not available on many systems,
// Linux and FreeBSD have it. Others probably won't.
char pathname[MAXPATHLEN];
strcpy(pathname,"/tmp/llvm_XXXXXX");
if (0 == mkdtemp(pathname)) {
MakeErrMsg(ErrMsg,
std::string(pathname) + ": can't create temporary directory");
return Path();
}
Path result;
result.set(pathname);
assert(result.isValid() && "mkdtemp didn't create a valid pathname!");
return result;
#elif defined(HAVE_MKSTEMP)
// If no mkdtemp is available, mkstemp can be used to create a temporary file
// which is then removed and created as a directory. We prefer this over
// mktemp because of mktemp's inherent security and threading risks. We still
// have a slight race condition from the time the temporary file is created to
// the time it is re-created as a directoy.
char pathname[MAXPATHLEN];
strcpy(pathname, "/tmp/llvm_XXXXXX");
int fd = 0;
if (-1 == (fd = mkstemp(pathname))) {
MakeErrMsg(ErrMsg,
std::string(pathname) + ": can't create temporary directory");
return Path();
}
::close(fd);
::unlink(pathname); // start race condition, ignore errors
if (-1 == ::mkdir(pathname, S_IRWXU)) { // end race condition
MakeErrMsg(ErrMsg,
std::string(pathname) + ": can't create temporary directory");
return Path();
}
Path result;
result.set(pathname);
assert(result.isValid() && "mkstemp didn't create a valid pathname!");
return result;
#elif defined(HAVE_MKTEMP)
// If a system doesn't have mkdtemp(3) or mkstemp(3) but it does have
// mktemp(3) then we'll assume that system (e.g. AIX) has a reasonable
// implementation of mktemp(3) and doesn't follow BSD 4.3's lead of replacing
// the XXXXXX with the pid of the process and a letter. That leads to only
// twenty six temporary files that can be generated.
char pathname[MAXPATHLEN];
strcpy(pathname, "/tmp/llvm_XXXXXX");
char *TmpName = ::mktemp(pathname);
if (TmpName == 0) {
MakeErrMsg(ErrMsg,
std::string(TmpName) + ": can't create unique directory name");
return Path();
}
if (-1 == ::mkdir(TmpName, S_IRWXU)) {
MakeErrMsg(ErrMsg,
std::string(TmpName) + ": can't create temporary directory");
return Path();
}
Path result;
result.set(TmpName);
assert(result.isValid() && "mktemp didn't create a valid pathname!");
return result;
#else
// This is the worst case implementation. tempnam(3) leaks memory unless its
// on an SVID2 (or later) system. On BSD 4.3 it leaks. tmpnam(3) has thread
// issues. The mktemp(3) function doesn't have enough variability in the
// temporary name generated. So, we provide our own implementation that
// increments an integer from a random number seeded by the current time. This
// should be sufficiently unique that we don't have many collisions between
// processes. Generally LLVM processes don't run very long and don't use very
// many temporary files so this shouldn't be a big issue for LLVM.
static time_t num = ::time(0);
char pathname[MAXPATHLEN];
do {
num++;
sprintf(pathname, "/tmp/llvm_%010u", unsigned(num));
} while ( 0 == access(pathname, F_OK ) );
if (-1 == ::mkdir(pathname, S_IRWXU)) {
MakeErrMsg(ErrMsg,
std::string(pathname) + ": can't create temporary directory");
return Path();
}
Path result;
result.set(pathname);
assert(result.isValid() && "mkstemp didn't create a valid pathname!");
return result;
#endif
}
static void getPathList(const char*path, std::vector<sys::Path>& Paths) {
const char* at = path;
const char* delim = strchr(at, ':');
Path tmpPath;
while( delim != 0 ) {
std::string tmp(at, size_t(delim-at));
if (tmpPath.set(tmp))
if (tmpPath.canRead())
Paths.push_back(tmpPath);
at = delim + 1;
delim = strchr(at, ':');
}
if (*at != 0)
if (tmpPath.set(std::string(at)))
if (tmpPath.canRead())
Paths.push_back(tmpPath);
}
void
Path::GetSystemLibraryPaths(std::vector<sys::Path>& Paths) {
#ifdef LTDL_SHLIBPATH_VAR
char* env_var = getenv(LTDL_SHLIBPATH_VAR);
if (env_var != 0) {
getPathList(env_var,Paths);
}
#endif
// FIXME: Should this look at LD_LIBRARY_PATH too?
Paths.push_back(sys::Path("/usr/local/lib/"));
Paths.push_back(sys::Path("/usr/X11R6/lib/"));
Paths.push_back(sys::Path("/usr/lib/"));
Paths.push_back(sys::Path("/lib/"));
}
void
Path::GetBytecodeLibraryPaths(std::vector<sys::Path>& Paths) {
char * env_var = getenv("LLVM_LIB_SEARCH_PATH");
if (env_var != 0) {
getPathList(env_var,Paths);
}
#ifdef LLVM_LIBDIR
{
Path tmpPath;
if (tmpPath.set(LLVM_LIBDIR))
if (tmpPath.canRead())
Paths.push_back(tmpPath);
}
#endif
GetSystemLibraryPaths(Paths);
}
Path
Path::GetLLVMDefaultConfigDir() {
return Path("/etc/llvm/");
}
Path
Path::GetUserHomeDirectory() {
const char* home = getenv("HOME");
if (home) {
Path result;
if (result.set(home))
return result;
}
return GetRootDirectory();
}
std::string
Path::getBasename() const {
// Find the last slash
size_t slash = path.rfind('/');
if (slash == std::string::npos)
slash = 0;
else
slash++;
size_t dot = path.rfind('.');
if (dot == std::string::npos || dot < slash)
return path.substr(slash);
else
return path.substr(slash, dot - slash);
}
bool Path::hasMagicNumber(const std::string &Magic) const {
size_t len = Magic.size();
assert(len < 1024 && "Request for magic string too long");
char* buf = (char*) alloca(1 + len);
int fd = ::open(path.c_str(), O_RDONLY);
if (fd < 0)
return false;
size_t read_len = ::read(fd, buf, len);
close(fd);
if (len != read_len)
return false;
buf[len] = '\0';
return Magic == buf;
}
bool Path::getMagicNumber(std::string& Magic, unsigned len) const {
assert(len < 1024 && "Request for magic string too long");
char* buf = (char*) alloca(1 + len);
int fd = ::open(path.c_str(), O_RDONLY);
if (fd < 0)
return false;
ssize_t bytes_read = ::read(fd, buf, len);
::close(fd);
if (ssize_t(len) != bytes_read) {
Magic.clear();
return false;
}
Magic.assign(buf,len);
return true;
}
bool
Path::isBytecodeFile() const {
char buffer[4];
buffer[0] = 0;
int fd = ::open(path.c_str(), O_RDONLY);
if (fd < 0)
return false;
ssize_t bytes_read = ::read(fd, buffer, 4);
::close(fd);
if (4 != bytes_read)
return false;
return (buffer[0] == 'l' && buffer[1] == 'l' && buffer[2] == 'v' &&
(buffer[3] == 'c' || buffer[3] == 'm'));
}
bool
Path::exists() const {
return 0 == access(path.c_str(), F_OK );
}
bool
Path::canRead() const {
return 0 == access(path.c_str(), F_OK | R_OK );
}
bool
Path::canWrite() const {
return 0 == access(path.c_str(), F_OK | W_OK );
}
bool
Path::canExecute() const {
if (0 != access(path.c_str(), R_OK | X_OK ))
return false;
if (const FileStatus *fs = getFileStatus(true, 0)) {
if (!S_ISREG(fs->mode))
return false;
} else
return false;
return true;
}
std::string
Path::getLast() const {
// Find the last slash
size_t pos = path.rfind('/');
// Handle the corner cases
if (pos == std::string::npos)
return path;
// If the last character is a slash
if (pos == path.length()-1) {
// Find the second to last slash
size_t pos2 = path.rfind('/', pos-1);
if (pos2 == std::string::npos)
return path.substr(0,pos);
else
return path.substr(pos2+1,pos-pos2-1);
}
// Return everything after the last slash
return path.substr(pos+1);
}
const FileStatus*
Path::getFileStatus(bool update, std::string *ErrStr) const {
if (status == 0 || update) {
struct stat buf;
if (0 != stat(path.c_str(), &buf)) {
MakeErrMsg(ErrStr, path + ": can't get status of file");
return 0;
}
if (status == 0)
status = new FileStatus;
status->fileSize = buf.st_size;
status->modTime.fromEpochTime(buf.st_mtime);
status->mode = buf.st_mode;
status->user = buf.st_uid;
status->group = buf.st_gid;
status->uniqueID = uint64_t(buf.st_ino);
status->isDir = S_ISDIR(buf.st_mode);
status->isFile = S_ISREG(buf.st_mode);
}
return status;
}
static bool AddPermissionBits(const Path &File, int bits) {
// Get the umask value from the operating system. We want to use it
// when changing the file's permissions. Since calling umask() sets
// the umask and returns its old value, we must call it a second
// time to reset it to the user's preference.
int mask = umask(0777); // The arg. to umask is arbitrary.
umask(mask); // Restore the umask.
// Get the file's current mode.
if (const FileStatus *fs = File.getFileStatus()) {
// Change the file to have whichever permissions bits from 'bits'
// that the umask would not disable.
if ((chmod(File.c_str(), (fs->getMode() | (bits & ~mask)))) == -1)
return false;
} else
return false;
return true;
}
bool Path::makeReadableOnDisk(std::string* ErrMsg) {
if (!AddPermissionBits(*this, 0444))
return MakeErrMsg(ErrMsg, path + ": can't make file readable");
return false;
}
bool Path::makeWriteableOnDisk(std::string* ErrMsg) {
if (!AddPermissionBits(*this, 0222))
return MakeErrMsg(ErrMsg, path + ": can't make file writable");
return false;
}
bool Path::makeExecutableOnDisk(std::string* ErrMsg) {
if (!AddPermissionBits(*this, 0111))
return MakeErrMsg(ErrMsg, path + ": can't make file executable");
return false;
}
bool
Path::getDirectoryContents(std::set<Path>& result, std::string* ErrMsg) const {
DIR* direntries = ::opendir(path.c_str());
if (direntries == 0)
return MakeErrMsg(ErrMsg, path + ": can't open directory");
std::string dirPath = path;
if (!lastIsSlash(dirPath))
dirPath += '/';
result.clear();
struct dirent* de = ::readdir(direntries);
for ( ; de != 0; de = ::readdir(direntries)) {
if (de->d_name[0] != '.') {
Path aPath(dirPath + (const char*)de->d_name);
struct stat st;
if (0 != lstat(aPath.path.c_str(), &st)) {
if (S_ISLNK(st.st_mode))
continue; // dangling symlink -- ignore
return MakeErrMsg(ErrMsg,
aPath.path + ": can't determine file object type");
}
result.insert(aPath);
}
}
closedir(direntries);
return false;
}
bool
Path::set(const std::string& a_path) {
if (a_path.empty())
return false;
std::string save(path);
path = a_path;
if (!isValid()) {
path = save;
return false;
}
return true;
}
bool
Path::appendComponent(const std::string& name) {
if (name.empty())
return false;
std::string save(path);
if (!lastIsSlash(path))
path += '/';
path += name;
if (!isValid()) {
path = save;
return false;
}
return true;
}
bool
Path::eraseComponent() {
size_t slashpos = path.rfind('/',path.size());
if (slashpos == 0 || slashpos == std::string::npos) {
path.erase();
return true;
}
if (slashpos == path.size() - 1)
slashpos = path.rfind('/',slashpos-1);
if (slashpos == std::string::npos) {
path.erase();
return true;
}
path.erase(slashpos);
return true;
}
bool
Path::appendSuffix(const std::string& suffix) {
std::string save(path);
path.append(".");
path.append(suffix);
if (!isValid()) {
path = save;
return false;
}
return true;
}
bool
Path::eraseSuffix() {
std::string save = path;
size_t dotpos = path.rfind('.',path.size());
size_t slashpos = path.rfind('/',path.size());
if (dotpos != std::string::npos) {
if (slashpos == std::string::npos || dotpos > slashpos+1) {
path.erase(dotpos, path.size()-dotpos);
return true;
}
}
if (!isValid())
path = save;
return false;
}
bool
Path::createDirectoryOnDisk( bool create_parents, std::string* ErrMsg ) {
// Get a writeable copy of the path name
char pathname[MAXPATHLEN];
path.copy(pathname,MAXPATHLEN);
// Null-terminate the last component
int lastchar = path.length() - 1 ;
if (pathname[lastchar] == '/')
pathname[lastchar] = 0;
else
pathname[lastchar+1] = 0;
// If we're supposed to create intermediate directories
if ( create_parents ) {
// Find the end of the initial name component
char * next = strchr(pathname,'/');
if ( pathname[0] == '/')
next = strchr(&pathname[1],'/');
// Loop through the directory components until we're done
while ( next != 0 ) {
*next = 0;
if (0 != access(pathname, F_OK | R_OK | W_OK))
if (0 != mkdir(pathname, S_IRWXU | S_IRWXG)) {
return MakeErrMsg(ErrMsg,
std::string(pathname) + ": can't create directory");
}
char* save = next;
next = strchr(next+1,'/');
*save = '/';
}
}
if (0 != access(pathname, F_OK | R_OK))
if (0 != mkdir(pathname, S_IRWXU | S_IRWXG)) {
return MakeErrMsg(ErrMsg,
std::string(pathname) + ": can't create directory");
}
return false;
}
bool
Path::createFileOnDisk(std::string* ErrMsg) {
// Create the file
int fd = ::creat(path.c_str(), S_IRUSR | S_IWUSR);
if (fd < 0)
return MakeErrMsg(ErrMsg, path + ": can't create file");
::close(fd);
return false;
}
bool
Path::createTemporaryFileOnDisk(bool reuse_current, std::string* ErrMsg) {
// Make this into a unique file name
if (makeUnique( reuse_current, ErrMsg ))
return true;
// create the file
int fd = ::open(path.c_str(), O_WRONLY|O_CREAT|O_TRUNC, 0666);
if (fd < 0)
return MakeErrMsg(ErrMsg, path + ": can't create temporary file");
::close(fd);
return false;
}
bool
Path::eraseFromDisk(bool remove_contents, std::string *ErrStr) const {
FileStatus Status;
if (const FileStatus *Status = getFileStatus(false, ErrStr)) {
// 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 (Status->isFile) {
if (unlink(path.c_str()) != 0)
return MakeErrMsg(ErrStr, path + ": can't destroy file");
return false;
}
if (!Status->isDir) {
if (ErrStr) *ErrStr = "not a file or directory";
return true;
}
} else
return true;
if (remove_contents) {
// Recursively descend the directory to remove its contents.
std::string cmd = "/bin/rm -rf " + path;
system(cmd.c_str());
return false;
}
// Otherwise, try to just remove the one directory.
char pathname[MAXPATHLEN];
path.copy(pathname, MAXPATHLEN);
int lastchar = path.length() - 1 ;
if (pathname[lastchar] == '/')
pathname[lastchar] = 0;
else
pathname[lastchar+1] = 0;
if (rmdir(pathname) != 0)
return MakeErrMsg(ErrStr,
std::string(pathname) + ": can't erase directory");
return false;
}
bool
Path::renamePathOnDisk(const Path& newName, std::string* ErrMsg) {
if (0 != ::rename(path.c_str(), newName.c_str()))
return MakeErrMsg(ErrMsg, std::string("can't rename '") + path + "' as '" +
newName.toString() + "' ");
return false;
}
bool
Path::setStatusInfoOnDisk(const FileStatus &si, std::string *ErrStr) const {
struct utimbuf utb;
utb.actime = si.modTime.toPosixTime();
utb.modtime = utb.actime;
if (0 != ::utime(path.c_str(),&utb))
return MakeErrMsg(ErrStr, path + ": can't set file modification time");
if (0 != ::chmod(path.c_str(),si.mode))
return MakeErrMsg(ErrStr, path + ": can't set mode");
return false;
}
bool
sys::CopyFile(const sys::Path &Dest, const sys::Path &Src, std::string* ErrMsg){
int inFile = -1;
int outFile = -1;
inFile = ::open(Src.c_str(), O_RDONLY);
if (inFile == -1)
return MakeErrMsg(ErrMsg, Src.toString() +
": can't open source file to copy");
outFile = ::open(Dest.c_str(), O_WRONLY|O_CREAT, 0666);
if (outFile == -1) {
::close(inFile);
return MakeErrMsg(ErrMsg, Dest.toString() +
": can't create destination file for copy");
}
char Buffer[16*1024];
while (ssize_t Amt = ::read(inFile, Buffer, 16*1024)) {
if (Amt == -1) {
if (errno != EINTR && errno != EAGAIN) {
::close(inFile);
::close(outFile);
return MakeErrMsg(ErrMsg, Src.toString()+": can't read source file: ");
}
} else {
char *BufPtr = Buffer;
while (Amt) {
ssize_t AmtWritten = ::write(outFile, BufPtr, Amt);
if (AmtWritten == -1) {
if (errno != EINTR && errno != EAGAIN) {
::close(inFile);
::close(outFile);
return MakeErrMsg(ErrMsg, Dest.toString() +
": can't write destination file: ");
}
} else {
Amt -= AmtWritten;
BufPtr += AmtWritten;
}
}
}
}
::close(inFile);
::close(outFile);
return false;
}
bool
Path::makeUnique(bool reuse_current, std::string* ErrMsg) {
if (reuse_current && !exists())
return false; // File doesn't exist already, just use it!
// Append an XXXXXX pattern to the end of the file for use with mkstemp,
// mktemp or our own implementation.
char *FNBuffer = (char*) alloca(path.size()+8);
path.copy(FNBuffer,path.size());
strcpy(FNBuffer+path.size(), "-XXXXXX");
#if defined(HAVE_MKSTEMP)
int TempFD;
if ((TempFD = mkstemp(FNBuffer)) == -1)
return MakeErrMsg(ErrMsg, path + ": can't make unique filename");
// We don't need to hold the temp file descriptor... we will trust that no one
// will overwrite/delete the file before we can open it again.
close(TempFD);
// Save the name
path = FNBuffer;
#elif defined(HAVE_MKTEMP)
// If we don't have mkstemp, use the old and obsolete mktemp function.
if (mktemp(FNBuffer) == 0)
return MakeErrMsg(ErrMsg, path + ": can't make unique filename");
// Save the name
path = FNBuffer;
#else
// Okay, looks like we have to do it all by our lonesome.
static unsigned FCounter = 0;
unsigned offset = path.size() + 1;
while ( FCounter < 999999 && exists()) {
sprintf(FNBuffer+offset,"%06u",++FCounter);
path = FNBuffer;
}
if (FCounter > 999999)
return MakeErrMsg(ErrMsg,
path + ": can't make unique filename: too many files");
#endif
return false;
}
} // end llvm namespace
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