Re: Add "-Wimplicit-fallthrough" to default flags (was Re: pgsql: Support FETCH FIRST WITH TIES)

On Mon, May 11, 2020 at 6:47 AM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>
> Alvaro Herrera <alvherre(at)2ndquadrant(dot)com> writes:
> > On 2020-May-06, Alvaro Herrera wrote:
> >> This doesn't allow whitespace between "fall" and "through", which means
> >> we generate 217 such warnings currently. Or we can just use
> >> -Wimplicit-fallthrough=3, which does allow whitespace (among other
> >> detritus).
>
> > If we're OK with patching all those places, I volunteer to do so. Any
> > objections? Or I can keep it at level 3, which can be done with minimal
> > patching.
>
> If we're gonna do it at all, I think we should go for the level 4
> warnings. Level 3's idea of a fallthrough comment is too liberal
> for my tastes...

Here's a patch that also takes care of cleaning all warning due to the
level 4 setting (at least the one I got with my other config options).
I went with "FALLTHRU" as this seemed more used.

Note that timezone/zic.c would also have to be changed.