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

Alvaro Herrera <alvherre@2ndquadrant.com> writes:
> I ended up using level 4 and dialling back to 3 for zic.c only
> (different make trickery though).

Meh ... if we're going to use level 4, I'm inclined to just change zic.c
to match.  It's not like we're using the upstream code verbatim anyway.
We could easily add s/fallthrough/FALLTHROUGH/ to the conversion recipe.

> I get no warnings with this (gcc 8), but ccache seems to save warnings
> in one run so that they can be thrown in a later one.  I'm not sure what
> to make of that, but ccache -d proved that beyond reasonable doubt and
> ccache -clear got rid of the lot.

Sounds like a ccache bug: maybe it's not accounting for different
fallthrough warning levels.  ccache knows a *ton* about gcc options,
so I'd not be surprised if it's doing something special with this one.

            regards, tom lane