On 2016.10.12 at 00:34 +0200, Bernd Schmidt wrote: > On 10/11/2016 11:52 PM, Jakub Jelinek wrote: > > The following patch introduces difference warning levels for > > -Wimplicit-fallthrough warning, so projects can choose if they want to > > honor only attributes (-Wimplicit-fallthrough=5), or what kind of comments. > > =4 is very picky and accepts only very small amount of comments, =3 is what > > we had before this patch, =2 looks case insensitively for falls?[ > > \t-]*thr(u|ough) > > anywhere in the comment, =1 accepts any comment, =0 is the same as > > -Wno-implicit-fallthrough - disables the warning. > > > > Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? > > I think this is ok, and thank you very much for doing this. > > > The patch keeps as the default the current forms, I'm not against changing > > it to =2 if there is consensus on it, but would strongly prefer doing that > > incrementally, as e.g. we'll need to adjust the testsuite for that, and > > perhaps also use =3 as the warning for gcc bootstraps when we are already =3 > > mode clear. > > It's a discussion we should have, but I agree it should be done > incrementally. I would argue for =1 as the default.
Here are some numbers for an allmodconfig Linux kernel on pcc64le: -Wimplicit-fallthrough=1 : 951 warnings -Wimplicit-fallthrough=2 : 1087 warnings -Wimplicit-fallthrough=3 : 1209 warnings I randomly looked at the differences and almost all additional -Wimplicit-fallthrough=2 warnings are bogus (~5% are genuine). And _all_ additional -Wimplicit-fallthrough=3 warnings appear to be bogus. -- Markus
