var SyscallsLibrary = {
  $SYSCALLS__deps: [
#if NO_FILESYSTEM == 0
                   '$FS', '$ERRNO_CODES', '$PATH',
#endif
#if SYSCALL_DEBUG
                   '$ERRNO_MESSAGES'
#endif
  ],
  $SYSCALLS: {
#if NO_FILESYSTEM == 0
    // global constants
    DEFAULT_POLLMASK: {{{ cDefine('POLLIN') }}} | {{{ cDefine('POLLOUT') }}},

    // global state
    mappings: {},
    umask: 0x1FF,  // S_IRWXU | S_IRWXG | S_IRWXO

    // shared utilities
    calculateAt: function(dirfd, path) {
      if (path[0] !== '/') {
        // relative path
        var dir;
        if (dirfd === {{{ cDefine('AT_FDCWD') }}}) {
          dir = FS.cwd();
        } else {
          var dirstream = FS.getStream(dirfd);
          if (!dirstream) throw new FS.ErrnoError(ERRNO_CODES.EBADF);
          dir = dirstream.path;
        }
        path = PATH.join2(dir, path);
      }
      return path;
    },

    doStat: function(func, path, buf) {
      try {
        var stat = func(path);
      } catch (e) {
        if (e && e.node && PATH.normalize(path) !== PATH.normalize(FS.getPath(e.node))) {
          // an error occurred while trying to look up the path; we should just report ENOTDIR
          return -ERRNO_CODES.ENOTDIR;
        }
        throw e;
      }
      {{{ makeSetValue('buf', C_STRUCTS.stat.st_dev, 'stat.dev', 'i32') }}};
      {{{ makeSetValue('buf', C_STRUCTS.stat.__st_dev_padding, '0', 'i32') }}};
      {{{ makeSetValue('buf', C_STRUCTS.stat.__st_ino_truncated, 'stat.ino', 'i32') }}};
      {{{ makeSetValue('buf', C_STRUCTS.stat.st_mode, 'stat.mode', 'i32') }}};
      {{{ makeSetValue('buf', C_STRUCTS.stat.st_nlink, 'stat.nlink', 'i32') }}};
      {{{ makeSetValue('buf', C_STRUCTS.stat.st_uid, 'stat.uid', 'i32') }}};
      {{{ makeSetValue('buf', C_STRUCTS.stat.st_gid, 'stat.gid', 'i32') }}};
      {{{ makeSetValue('buf', C_STRUCTS.stat.st_rdev, 'stat.rdev', 'i32') }}};
      {{{ makeSetValue('buf', C_STRUCTS.stat.__st_rdev_padding, '0', 'i32') }}};
      {{{ makeSetValue('buf', C_STRUCTS.stat.st_size, 'stat.size', 'i32') }}};
      {{{ makeSetValue('buf', C_STRUCTS.stat.st_blksize, '4096', 'i32') }}};
      {{{ makeSetValue('buf', C_STRUCTS.stat.st_blocks, 'stat.blocks', 'i32') }}};
      {{{ makeSetValue('buf', C_STRUCTS.stat.st_atim.tv_sec, '(stat.atime.getTime() / 1000)|0', 'i32') }}};
      {{{ makeSetValue('buf', C_STRUCTS.stat.st_atim.tv_nsec, '0', 'i32') }}};
      {{{ makeSetValue('buf', C_STRUCTS.stat.st_mtim.tv_sec, '(stat.mtime.getTime() / 1000)|0', 'i32') }}};
      {{{ makeSetValue('buf', C_STRUCTS.stat.st_mtim.tv_nsec, '0', 'i32') }}};
      {{{ makeSetValue('buf', C_STRUCTS.stat.st_ctim.tv_sec, '(stat.ctime.getTime() / 1000)|0', 'i32') }}};
      {{{ makeSetValue('buf', C_STRUCTS.stat.st_ctim.tv_nsec, '0', 'i32') }}};
      {{{ makeSetValue('buf', C_STRUCTS.stat.st_ino, 'stat.ino', 'i32') }}};
      return 0;
    },
    doMsync: function(addr, stream, len, flags) {
      var buffer = new Uint8Array(HEAPU8.subarray(addr, addr + len));
      FS.msync(stream, buffer, 0, len, flags);
    },
    doMkdir: function(path, mode) {
      // remove a trailing slash, if one - /a/b/ has basename of '', but
      // we want to create b in the context of this function
      path = PATH.normalize(path);
      if (path[path.length-1] === '/') path = path.substr(0, path.length-1);
      FS.mkdir(path, mode, 0);
      return 0;
    },
    doMknod: function(path, mode, dev) {
      // we don't want this in the JS API as it uses mknod to create all nodes.
      switch (mode & {{{ cDefine('S_IFMT') }}}) {
        case {{{ cDefine('S_IFREG') }}}:
        case {{{ cDefine('S_IFCHR') }}}:
        case {{{ cDefine('S_IFBLK') }}}:
        case {{{ cDefine('S_IFIFO') }}}:
        case {{{ cDefine('S_IFSOCK') }}}:
          break;
        default: return -ERRNO_CODES.EINVAL;
      }
      FS.mknod(path, mode, dev);
      return 0;
    },
    doReadlink: function(path, buf, bufsize) {
      if (bufsize