On 2016.11.03 at 13:32 +0100, Jakub Jelinek wrote: > On Thu, Nov 03, 2016 at 01:22:11PM +0100, Bernd Schmidt wrote: > > On 11/03/2016 12:58 PM, Jakub Jelinek wrote: > > >On Thu, Nov 03, 2016 at 12:51:15PM +0100, Bernd Schmidt wrote: > > >>I'm concerned about the number of false positives for this warning, and > > >>judging by previous discussions, I'm not alone in this. This patch limits > > >>it > > >>to level 1 (any comment before the case label disables the warning) for > > >>cases where the user specified no explicit level. It'll still generate > > >>enough noise that people will be aware of it and can choose whether to > > >>use a > > >>higher level or not. > > >> > > >>Bootstrapped and tested on x86_64-linux. Ok? > > > > > >I disagree, I'm ok with changing it to 2, but 1 is too much. > > > > Well, we have data from our own sources where we had to "fix" lots of > > perfectly good code, and also from the Linux kernel. From an earlier > > discussion: > > That data wasn't really convincing on this. All it proved is that most of > the cases are (likely) deliberate fall-throughs without any comment > whatsoever, the rest is in the noise. As one needs to deal with those > where comments are missing altogether, dealing with the noise is acceptable.
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. -- Markus
