On Mon, Mar 27, 2017 at 09:27:34AM -0700, Steve Kargl wrote: > On Mon, Mar 27, 2017 at 05:22:12PM +0200, Markus Trippelsdorf wrote: > > On 2017.03.27 at 06:49 -0700, Steve Kargl wrote: > > > > > > Go scan the gcc-patches mailing list for "fallthrough". I'll > > > note other have concerns. Here's one example: > > > > > > https://gcc.gnu.org/ml/gcc-patches/2016-11/msg00300.html > > > > > > Without Bernd's patch to set the default to 1 you will drown > > > in false positives once you start using gcc-7 to build a whole > > > distro. On my Gentoo test box anything but level 1 is simply > > > unacceptable, because you will miss important other warnings > > > in the -Wimplicit-fallthrough noise otherwise. > > > > The quotation doesn't have anything to do with the current discussion, > > which is the general usefulness of the warning. > > It only talks about one of the (admittedly over-engineered) six > > different levels of the warning. > > > > Yes, it does. See the part about "... drown in false positives ..." > Whoever turned this option on should have been prepared to deal > with the fallout by investigating each and every warning (i.e., > either fix a real bug or (un)fix valid code to prevent the false > positive). Having spent hours on fixing various fallthrough cases throughout the codebase, deciding whether or not a particular case is an intentional fallthru, and pursuing various maintainers if I couldn't make a call, I find your statement, erm, incorrect . I'm sorry that apparently something has slipped through. I would've fixed it if I'd hit it.
The warning had been discussed extensively on the ML, and you had the chance to chime in, too. There's a reason why the warning is only enabled by -Wextra and not by -Wall. > But that's okay. I now understand that it is acceptable for > a developer to commit a change that causes issues for other > developers, and said developer can turn a blind eye. Nonsense. Marek