> static void
> s1_free (/*@only@*/ /*@null@*/ struct s1 * f) {
> if ( f == NULL )
> return;
> free(f);
> }
By the way: The check for the null pointer can be omitted in this example.
http://opengroup.org/onlinepubs/009695399/functions/free.html
Regards,
Markus