// Copyright: (C) 2009 Gilles Muller, Julia Lawall, INRIA, DIKU. GPLv2. @r@ expression E1,E2; identifier fld; statement S1,S2; @@ E1 = E2->fld; ( if (E1 == NULL) S1 else S2 | *if (E2 == NULL) S1 else S2 )