/* This testcase is part of GDB, the GNU debugger. Copyright (C) 2018-2020 Free Software Foundation, Inc. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see . */ enum cons_type { type_atom = 0, type_cons = 1 }; struct atom { int ival; }; struct cons { enum cons_type type; union { struct atom atom; struct cons *slots[2]; }; }; #define nil ((struct cons*)0); int main () { struct cons c1, c2, c3, c4; c1.type = type_cons; c1.slots[0] = &c4; c1.slots[1] = &c2; c2.type = type_cons; c2.slots[0] = nil; c2.slots[1] = &c3; c3.type = type_cons; c3.slots[0] = nil; c3.slots[1] = nil; c4.type = type_atom; c4.atom.ival = 13; return 0; /* next line */ }