http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50694
--- Comment #8 from Kazumoto Kojima <kkojima at gcc dot gnu.org> 2011-10-20 22:40:27 UTC --- (In reply to comment #7) This problem doesn't require the theoretical/mathematical completeness. There are many inappropriate combinations of options which don't get any warning when running compiler and configurations. The important thing is to warn very confusing ones from the user's point of view. So your patch in #6 or even one liner in #2 would be OK and enough for this PR, I think.
