uid_t newgen[_hurd_id.gen.nuids + 1]; uid_t newaux[_hurd_id.aux.nuids];  newgen[0] = uid; memcpy (&newgen[1], _hurd_id.gen.uids, _hurd_id.gen.nuids * sizeof (uid_t)); newaux[0] = uid; memcpy (&newaux[1], _hurd_id.aux.uids + 1, (_hurd_id.aux.nuids - 1) * sizeof (uid_t));
uid_t *newgen, *newaux, auxbuf[2]; size_t ngen, naux;  newaux = _hurd_id.aux.uids; naux = _hurd_id.aux.nuids; if (_hurd_id.gen.nuids == 0) {  newgen = &uid; ngen = 1; } else if (_hurd_id.gen.uids[0] == 0) {  _hurd_id.gen.uids[0] = uid; _hurd_id.valid = 0; newgen = _hurd_id.gen.uids; ngen = _hurd_id.gen.nuids; if (_hurd_id.aux.nuids < 2) { newaux = auxbuf; naux = 2; } _hurd_id.aux.uids[0] = _hurd_id.aux.uids[1] = uid; } else {  _hurd_id.gen.uids[0] = uid; _hurd_id.valid = 0; newgen = _hurd_id.gen.uids; ngen = _hurd_id.gen.nuids; }
DEFUN(__setuid, (uid), uid_t uid){  auth_t newauth;  error_t err;  HURD_CRITICAL_BEGIN;  __mutex_lock (&_hurd_id.lock);  err = _hurd_check_ids ();  if (!err)    {      /* Make a new auth handle which has UID as the real uid,	 and as the first element in the list of effective uids.  */      uid_t newgen[_hurd_id.gen.nuids + 1];      uid_t newaux[_hurd_id.aux.nuids];            newgen[0] = uid;      memcpy (&newgen[1], _hurd_id.gen.uids,	      _hurd_id.gen.nuids * sizeof (uid_t));      newaux[0] = uid;      memcpy (&newaux[1], _hurd_id.aux.uids + 1,	      (_hurd_id.aux.nuids - 1) * sizeof (uid_t));      err = __USEPORT (AUTH, __auth_makeauth		       (port, NULL, MACH_MSG_TYPE_COPY_SEND, 0,			newgen, 1 + _hurd_id.gen.nuids,			newaux, _hurd_id.aux.nuids,			_hurd_id.gen.gids, _hurd_id.gen.ngids,			_hurd_id.aux.gids, _hurd_id.aux.ngids,			&newauth));    }  __mutex_unlock (&_hurd_id.lock);  HURD_CRITICAL_END;  if (err)    return __hurd_fail (err);  /* Install the new handle and reauthenticate everything.  */  err = __setauth (newauth);  __mach_port_deallocate (__mach_task_self (), newauth);  return err;}