Re: PG 15 (and to a smaller degree 14) regression due to ExprEvalStep size

On Wed, Feb 22, 2023 at 5:47 PM Andres Freund <andres(at)anarazel(dot)de> wrote:

> Hi,
>
> On 2023-02-22 16:34:44 -0500, Tom Lane wrote:
> > I wrote:
> > > Andres Freund <andres(at)anarazel(dot)de> writes:
> > >> Maybe it's worth sticking a StaticAssert() for the struct size
> > >> somewhere.
> >
> > > Indeed. I thought we had one already.
> >
> > >> I'm a bit wary about that being too noisy, there are some machines
> with
> > >> odd alignment requirements. Perhaps worth restricting the assertion to
> > >> x86-64 + armv8 or such?
> >
> > > I'd put it in first and only reconsider if it shows unfixable problems.
> >
> > Now that we've got the sizeof(ExprEvalStep) under control, shouldn't
> > we do the attached?
>
> Indeed. Pushed.
>
> Let's hope there's no rarely used architecture with odd alignment rules.
>
> Greetings,
>
> Andres Freund
>
>
>
I have a question about this that may affect some of my future work.

My not-ready-for-16 work on CAST( ... ON DEFAULT ... ) involved making
FuncExpr/IoCoerceExpr/ArrayCoerceExpr have a safe_mode flag, and that
necessitates adding a reserror boolean to ExprEvalStep for subsequent steps
to test if the error happened.

Will that change be throwing some architectures over the 64 byte count?