https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89692
--- Comment #14 from rguenther at suse dot de <rguenther at suse dot de> --- On Wed, 20 Mar 2019, jakub at gcc dot gnu.org wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89692 > > --- Comment #13 from Jakub Jelinek <jakub at gcc dot gnu.org> --- > (In reply to rguent...@suse.de from comment #12) > > All varaints have the same TYPE_CANONICAL, that of the main variant, and > > we never throw away the main variant. Basically > > > > gcc_assert (TYPE_CANONICAL (t) == TYPE_MAIN_VARIANT (TYPE_CANONICAL (t)) > > == TYPE_CANONICAL (TYPE_MAIN_VARAINT (t))) > > > > holds > > If it holds, then no objection from me, I just wonder how far we'd get in a > bootstrap (including say Ada) if we've added that assert somewhere. > But in that case the comment that > /* Do not walk TYPE_CANONICAL. We do not stream it and thus do not > and want not to reach unused types this way. */ > doesn't make much sense, because fld_worklist_push (TYPE_CANONICAL (t), fld); > wouldn't change anything. Theoretically TYPE_CANONICAL might point to an "unrelated" type, since we re-build TYPE_CANONICAL with LTO rules the comment does make sense. Of course the non-LTO compilation continues here so indeed that could leave types unvisited that are reached by TYPE_CANONICAL during the compilation up to stream-out (and into fat part compilation). So yes, we should probably visit TYPE_CANONICAL here.
