extern void abort(void); #include void reach_error() { assert(0); } #include int main() { union { void *p0; struct { char c[2]; void *p1; void *p2; } str; } data; // alloc 37B on heap data.p0 = malloc(37U); // this should be fine data.str.p2 = &data; // this introduces a memleak data.str.c[1] = sizeof data.str.p1; return 0; }