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Diffstat (limited to 'lib/Support/Unix/Path.inc')
| -rw-r--r-- | lib/Support/Unix/Path.inc | 887 | 
1 files changed, 887 insertions, 0 deletions
diff --git a/lib/Support/Unix/Path.inc b/lib/Support/Unix/Path.inc new file mode 100644 index 000000000000..0f6e800505e1 --- /dev/null +++ b/lib/Support/Unix/Path.inc @@ -0,0 +1,887 @@ +//===- llvm/Support/Unix/Path.cpp - Unix Path Implementation -----*- C++ -*-===// +// +//                     The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file implements the Unix specific portion of the Path class. +// +//===----------------------------------------------------------------------===// + +//===----------------------------------------------------------------------===// +//=== WARNING: Implementation here must contain only generic UNIX code that +//===          is guaranteed to work on *all* UNIX variants. +//===----------------------------------------------------------------------===// + +#include "Unix.h" +#if HAVE_SYS_STAT_H +#include <sys/stat.h> +#endif +#if HAVE_FCNTL_H +#include <fcntl.h> +#endif +#ifdef HAVE_SYS_MMAN_H +#include <sys/mman.h> +#endif +#ifdef HAVE_SYS_STAT_H +#include <sys/stat.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 + +#if HAVE_DLFCN_H +#include <dlfcn.h> +#endif + +#ifdef __APPLE__ +#include <mach-o/dyld.h> +#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; + +const char sys::PathSeparator = ':'; + +StringRef Path::GetEXESuffix() { +  return StringRef(); +} + +Path::Path(StringRef p) +  : path(p) {} + +Path::Path(const char *StrStart, unsigned StrLen) +  : path(StrStart, StrLen) {} + +Path& +Path::operator=(StringRef that) { +  path.assign(that.data(), that.size()); +  return *this; +} + +bool +Path::isValid() const { +  // Empty paths are considered invalid here. +  // This code doesn't check MAXPATHLEN because there's no need. Nothing in +  // LLVM manipulates Paths with fixed-sizes arrays, and if the OS can't +  // handle names longer than some limit, it'll report this on demand using +  // ENAMETOLONG. +  return !path.empty(); +} + +bool +Path::isAbsolute(const char *NameStart, unsigned NameLen) { +  assert(NameStart); +  if (NameLen == 0) +    return false; +  return NameStart[0] == '/'; +} + +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[] = "/tmp/llvm_XXXXXX"; +  if (0 == mkdtemp(pathname)) { +    MakeErrMsg(ErrMsg, +               std::string(pathname) + ": can't create temporary directory"); +    return Path(); +  } +  return Path(pathname); +#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[] = "/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(); +  } +  return Path(pathname); +#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[] = "/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(); +  } +  return Path(TmpName); +#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(); +  } +  return Path(pathname); +#endif +} + +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::GetBitcodeLibraryPaths(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"); +  Path result; +  if (home && result.set(home)) +    return result; +  result.set("/"); +  return result; +} + +Path +Path::GetCurrentDirectory() { +  char pathname[MAXPATHLEN]; +  if (!getcwd(pathname,MAXPATHLEN)) { +    assert (false && "Could not query current working directory."); +    return Path(); +  } + +  return Path(pathname); +} + +#if defined(__FreeBSD__) || defined (__NetBSD__) || \ +    defined(__OpenBSD__) || defined(__minix) +static int +test_dir(char buf[PATH_MAX], char ret[PATH_MAX], +    const char *dir, const char *bin) +{ +  struct stat sb; + +  snprintf(buf, PATH_MAX, "%s/%s", dir, bin); +  if (realpath(buf, ret) == NULL) +    return (1); +  if (stat(buf, &sb) != 0) +    return (1); + +  return (0); +} + +static char * +getprogpath(char ret[PATH_MAX], const char *bin) +{ +  char *pv, *s, *t, buf[PATH_MAX]; + +  /* First approach: absolute path. */ +  if (bin[0] == '/') { +    if (test_dir(buf, ret, "/", bin) == 0) +      return (ret); +    return (NULL); +  } + +  /* Second approach: relative path. */ +  if (strchr(bin, '/') != NULL) { +    if (getcwd(buf, PATH_MAX) == NULL) +      return (NULL); +    if (test_dir(buf, ret, buf, bin) == 0) +      return (ret); +    return (NULL); +  } + +  /* Third approach: $PATH */ +  if ((pv = getenv("PATH")) == NULL) +    return (NULL); +  s = pv = strdup(pv); +  if (pv == NULL) +    return (NULL); +  while ((t = strsep(&s, ":")) != NULL) { +    if (test_dir(buf, ret, t, bin) == 0) { +      free(pv); +      return (ret); +    } +  } +  free(pv); +  return (NULL); +} +#endif // __FreeBSD__ || __NetBSD__ + +/// GetMainExecutable - Return the path to the main executable, given the +/// value of argv[0] from program startup. +Path Path::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 Path(link_path); +  } +#elif defined(__FreeBSD__) || defined (__NetBSD__) || \ +      defined(__OpenBSD__) || defined(__minix) +  char exe_path[PATH_MAX]; + +  if (getprogpath(exe_path, argv0) != NULL) +    return Path(exe_path); +#elif defined(__linux__) || defined(__CYGWIN__) +  char exe_path[MAXPATHLEN]; +  ssize_t len = readlink("/proc/self/exe", exe_path, sizeof(exe_path)); +  if (len >= 0) +    return Path(StringRef(exe_path, len)); +#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 Path(); + +  // 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 Path(link_path); +#else +#error GetMainExecutable is not implemented on this host yet. +#endif +  return Path(); +} + + +StringRef Path::getDirname() const { +  return getDirnameCharSep(path, "/"); +} + +StringRef +Path::getBasename() const { +  // Find the last slash +  std::string::size_type slash = path.rfind('/'); +  if (slash == std::string::npos) +    slash = 0; +  else +    slash++; + +  std::string::size_type dot = path.rfind('.'); +  if (dot == std::string::npos || dot < slash) +    return StringRef(path).substr(slash); +  else +    return StringRef(path).substr(slash, dot - slash); +} + +StringRef +Path::getSuffix() const { +  // Find the last slash +  std::string::size_type slash = path.rfind('/'); +  if (slash == std::string::npos) +    slash = 0; +  else +    slash++; + +  std::string::size_type dot = path.rfind('.'); +  if (dot == std::string::npos || dot < slash) +    return StringRef(); +  else +    return StringRef(path).substr(dot + 1); +} + +bool Path::getMagicNumber(std::string &Magic, unsigned len) const { +  assert(len < 1024 && "Request for magic string too long"); +  char Buf[1025]; +  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) +    return false; +  Magic.assign(Buf, len); +  return true; +} + +bool +Path::exists() const { +  return 0 == access(path.c_str(), F_OK ); +} + +bool +Path::isDirectory() const { +  struct stat buf; +  if (0 != stat(path.c_str(), &buf)) +    return false; +  return ((buf.st_mode & S_IFMT) == S_IFDIR) ? true : false; +} + +bool +Path::isSymLink() const { +  struct stat buf; +  if (0 != lstat(path.c_str(), &buf)) +    return false; +  return S_ISLNK(buf.st_mode); +} + + +bool +Path::canRead() const { +  return 0 == access(path.c_str(), R_OK); +} + +bool +Path::canWrite() const { +  return 0 == access(path.c_str(), W_OK); +} + +bool +Path::isRegularFile() const { +  // Get the status so we can determine if it's a file or directory +  struct stat buf; + +  if (0 != stat(path.c_str(), &buf)) +    return false; + +  if (S_ISREG(buf.st_mode)) +    return true; + +  return false; +} + +bool +Path::canExecute() const { +  if (0 != access(path.c_str(), R_OK | X_OK )) +    return false; +  struct stat buf; +  if (0 != stat(path.c_str(), &buf)) +    return false; +  if (!S_ISREG(buf.st_mode)) +    return false; +  return true; +} + +StringRef +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 StringRef(path).substr(0,pos); +    else +      return StringRef(path).substr(pos2+1,pos-pos2-1); +  } +  // Return everything after the last slash +  return StringRef(path).substr(pos+1); +} + +const FileStatus * +PathWithStatus::getFileStatus(bool update, std::string *ErrStr) const { +  if (!fsIsValid || update) { +    struct stat buf; +    if (0 != stat(path.c_str(), &buf)) { +      MakeErrMsg(ErrStr, path + ": can't get status of file"); +      return 0; +    } +    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); +    fsIsValid = true; +  } +  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. +  struct stat buf; +  if (0 != stat(File.c_str(), &buf)) +    return false; +  // Change the file to have whichever permissions bits from 'bits' +  // that the umask would not disable. +  if ((chmod(File.c_str(), (buf.st_mode | (bits & ~mask)))) == -1) +      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(StringRef a_path) { +  if (a_path.empty()) +    return false; +  path = a_path; +  return true; +} + +bool +Path::appendComponent(StringRef name) { +  if (name.empty()) +    return false; +  if (!lastIsSlash(path)) +    path += '/'; +  path += name; +  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::eraseSuffix() { +  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; +    } +  } +  return false; +} + +static bool createDirectoryHelper(char* beg, char* end, bool create_parents) { + +  if (access(beg, R_OK | W_OK) == 0) +    return false; + +  if (create_parents) { + +    char* c = end; + +    for (; c != beg; --c) +      if (*c == '/') { + +        // Recurse to handling the parent directory. +        *c = '\0'; +        bool x = createDirectoryHelper(beg, c, create_parents); +        *c = '/'; + +        // Return if we encountered an error. +        if (x) +          return true; + +        break; +      } +  } + +  return mkdir(beg, S_IRWXU | S_IRWXG) != 0; +} + +bool +Path::createDirectoryOnDisk( bool create_parents, std::string* ErrMsg ) { +  // Get a writeable copy of the path name +  std::string pathname(path); + +  // Null-terminate the last component +  size_t lastchar = path.length() - 1 ; + +  if (pathname[lastchar] != '/') +    ++lastchar; + +  pathname[lastchar] = '\0'; + +  if (createDirectoryHelper(&pathname[0], &pathname[lastchar], create_parents)) +    return MakeErrMsg(ErrMsg, 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 { +  // Get the status so we can determine if it's a file or directory. +  struct stat buf; +  if (0 != stat(path.c_str(), &buf)) { +    MakeErrMsg(ErrStr, path + ": can't get status of file"); +    return true; +  } + +  // 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)) { +    if (unlink(path.c_str()) != 0) +      return MakeErrMsg(ErrStr, path + ": can't destroy file"); +    return false; +  } + +  if (!S_ISDIR(buf.st_mode)) { +    if (ErrStr) *ErrStr = "not a file or directory"; +    return true; +  } + +  if (remove_contents) { +    // Recursively descend the directory to remove its contents. +    std::string cmd = "/bin/rm -rf " + path; +    if (system(cmd.c_str()) != 0) { +      MakeErrMsg(ErrStr, path + ": failed to recursively remove directory."); +      return true; +    } +    return false; +  } + +  // Otherwise, try to just remove the one directory. +  std::string pathname(path); +  size_t lastchar = path.length() - 1; +  if (pathname[lastchar] == '/') +    pathname[lastchar] = '\0'; +  else +    pathname[lastchar+1] = '\0'; + +  if (rmdir(pathname.c_str()) != 0) +    return MakeErrMsg(ErrStr, 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.str() + "'"); +  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.str() + +      ": 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.str() + +      ": 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.str()+": 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.str() + +              ": 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) { +  bool Exists; +  if (reuse_current && (fs::exists(path, Exists) || !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. +  // This uses std::vector instead of SmallVector to avoid a dependence on +  // libSupport. And performance isn't critical here. +  std::vector<char> Buf; +  Buf.resize(path.size()+8); +  char *FNBuffer = &Buf[0]; +    path.copy(FNBuffer,path.size()); +  bool isdir; +  if (!fs::is_directory(path, isdir) && isdir) +    strcpy(FNBuffer+path.size(), "/XXXXXX"); +  else +    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; +  // Try to initialize with unique value. +  if (FCounter == 0) FCounter = ((unsigned)getpid() & 0xFFFF) << 8; +  char* pos = strstr(FNBuffer, "XXXXXX"); +  do { +    if (++FCounter > 0xFFFFFF) { +      return MakeErrMsg(ErrMsg, +        path + ": can't make unique filename: too many files"); +    } +    sprintf(pos, "%06X", FCounter); +    path = FNBuffer; +  } while (exists()); +  // POSSIBLE SECURITY BUG: An attacker can easily guess the name and exploit +  // LLVM. +#endif +  return false; +} + +const char *Path::MapInFilePages(int FD, uint64_t FileSize) { +  int Flags = MAP_PRIVATE; +#ifdef MAP_FILE +  Flags |= MAP_FILE; +#endif +  void *BasePtr = ::mmap(0, FileSize, PROT_READ, Flags, FD, 0); +  if (BasePtr == MAP_FAILED) +    return 0; +  return (const char*)BasePtr; +} + +void Path::UnMapFilePages(const char *BasePtr, uint64_t FileSize) { +  ::munmap((void*)BasePtr, FileSize); +} + +} // end llvm namespace  | 
