Re: making the backend's json parser work in frontend code

On Tue, Jan 28, 2020 at 4:06 PM Robert Haas <robertmhaas@gmail.com> wrote:
>
> On Mon, Jan 27, 2020 at 2:02 PM Mahendra Singh Thalor
> <mahi6run@gmail.com> wrote:
> > I can see one warning on HEAD.
> >
> > jsonapi.c: In function ‘json_errdetail’:
> > jsonapi.c:1068:1: warning: control reaches end of non-void function
> > [-Wreturn-type]
> >  }
> >  ^
> >
> > Attaching a patch to fix warning.
>
> Hmm, I don't get a warning there. This function is a switch over an
> enum type with a case for every value of the enum, and every branch
> either does a "return" or an "elog," so any code after the switch
> should be unreachable. It's possible your compiler is too dumb to know
> that, but I thought there were other places in the code base where we
> assumed that if we handled every defined value of enum, that was good
> enough.
>
> But maybe not. I found similar coding in CreateDestReceiver(), and
> that ends with:
>
>         /* should never get here */
>         pg_unreachable();
>
> So perhaps we need the same thing here. Does adding that fix it for you?

FTR this has unfortunately the same result on Thomas' automatic patch
tester, e.g. https://travis-ci.org/postgresql-cfbot/postgresql/builds/642634195#L1968