Author: Julia Lawall <julia@diku.dk> If the NULL test is necessary, then the dereference should be moved below the NULL test. The semantic patch that makes this change is as follows: (http://www.emn.fr/x-info/coccinelle/). // @disable is_null@ identifier f; expression E; identifier fld; statement S; @@ + if (E == NULL) S f(…,E->fld,…); – if (E == NULL) …