https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77327
--- Comment #3 from Fritz Reese <fritzoreese at gmail dot com> --- > interface.c:403 is > if ( (d1 && (d1->attr.flavor == FL_STRUCT || d1->attr.flavor == FL_UNION) > > and I believe d->attr.flavor is the item used after freed. This is correct, and the reason is clear when you look up a few lines and realize I did not check the type of cmp1 or cmp2 before jumping straight to checking properties about their derived type declarations (in cmp->ts.u.derived). Unless cmp->ts.type == BT_DERIVED or cmp->ts.type == BT_UNION, the cmp->ts.u.derived pointer is garbage. I have a patch which implements that part of code in a different way - also correctly and more reliably. It fixes this PR and I hope to commit it over the weekend: https://gcc.gnu.org/ml/fortran/2016-08/msg00144.html However I am not sure how one would observe that no invalid memory references occur for your code via a DejaGNU testcase. I would appreciate ideas for a testcase I can commit with the aforementioned patch to ensure this PR isn't regressed.
