Re: Bogus reports from coverage.postgresql.org

On 2018-03-09 19:36:28 -0500, Tom Lane wrote:
> I happened to notice that if you look at
> https://coverage.postgresql.org/src/backend/optimizer/util/predtest.c.gcov.html
> it claims that the two occurrences of
>     elog(ERROR, "predicate_classify returned a bogus value");
> at lines 492 and 803 are reached.
> 
> This would be quite astonishing if true, but it isn't true, since
> the regression tests aren't reporting any such failure.
> 
> Needless to say, this puts quite a damper on my faith in the coverage
> reports.  Maybe that machine needs a software update?

Is it possible that the compiler figured that the patch is unreachable
and removed the code?

Greetings,

Andres Freund