int
whatever()
{
        int error;

        do_stuff();
        keep_doing_stuff();
        if (!this_is_right())
        {
                error = EINVAL;
                goto err;
        }
        bla();
        if (this_is_wrong())
        {
                error = EPERM;
                goto err;
        }
        while (...)
        {
                stuff();
                if (stuff2())
                {
                        error = EFAULT;
                        goto err;
                }
        }
        ...
err:
        do_this();
        do_that();
        do_whatever();
        return -error;
}