On 2016.10.12 at 11:52 +0200, Bernd Schmidt wrote:
> On 10/12/2016 11:31 AM, Markus Trippelsdorf wrote:
> > On 2016.10.12 at 00:34 +0200, Bernd Schmidt wrote:
> > > 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.
>
> And that's for a codebase that was written in English to begin with. Would
> you mind posting one or two examples if you saw interesting ones, for
> reference?
Actually looking more closely it appears that all of the 136 additional
warnings for level 2 are bogus, too. Here is an example:
switch (class) {
case ATA_DEV_SEMB:
class = ATA_DEV_ATA; /* some hard drives report SEMB sig */
case ATA_DEV_ATA:
case ATA_DEV_ZAC:
tf.command = ATA_CMD_ID_ATA;
break;
> This result suggests that we should probably collapse levels 3-5 into a
> single strict one that doesn't try to be clever, and definitely make at most
> level 1 the default.
Yes, I agree.
--
Markus
