Re: compiler warnings with gcc 4.8 and -Og

Hi,

On 2022-06-02 01:09:58 -0400, Tom Lane wrote:
> Justin Pryzby <pryzby(at)telsasoft(dot)com> writes:
> > forking: <20220302205058(dot)GJ15744(at)telsasoft(dot)com>: Re: Adding CI to our tree
> > On Wed, Mar 02, 2022 at 02:50:58PM -0600, Justin Pryzby wrote:
> >> BTW (regarding the last patch), I just noticed that -Og optimization can cause
> >> warnings with gcc-4.8.5-39.el7.x86_64.
>
> I'm a little dubious about whether -Og is a case we should pay special
> attention to? Our standard optimization setting for gcc is -O2, and
> once you go away from that there are any number of weird cases that
> may or may not produce warnings. I'm not entirely willing to buy
> the proposition that we must suppress warnings on
> any-random-gcc-version combined with any-random-options.

I think it'd be useful to have -Og in a usable state, despite my nearby
griping about it. It makes our tests use noticably fewer CPU cycles, and
debugging is less annoying than with -O2. It's also faster to compile.

However, making that effort for compiler versions for a compiler that went out
of support in 2015 doesn't seem useful. It may be useful to pay some attention
to not producint too many warnings on LTS distribution compilers when
compiling with production oriented flags, but nobody should develop on them.

Greetings,

Andres Freund