https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63880
--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> --- Indeed this is a case we don't handle as QOI special-case (we accept other cases of strictly undefined code though). In this case it is recommended to just do arglist *p = malloc (sizeof (arglist) + sizeof (char *) * 1000); and as Andrew said not wrap arglist inside another struct which appends a member.
