Re: New string-truncation warnings from GCC 15

Hi,

On 2025-09-17 16:38:56 -0400, Tom Lane wrote:
> Peter Eisentraut <peter(at)eisentraut(dot)org> writes:
> > On 17.09.25 00:48, Tom Lane wrote:
> >> Several of the buildfarm animals seem to have been updated to
> >> GCC 15 over the past week or so. They are now moaning about
> >> various places where we're intentionally omitting a string
> >> terminator, eg these warnings from scorpion:
> >>
> >> scorpion | 2025-09-16 18:39:03 | ../pgsql/src/backend/commands/copyfromparse.c:139:41: warning: initializer-string for array of 'char' truncates NUL terminator but destination lacks 'nonstring' attribute (12 chars into 11 available) [-Wunterminated-string-initialization]
>
> > Note that this is not a default warning option in gcc or an option put
> > in by PostgreSQL. This comes from -Wextra, which that buildfarm member
> > has added by itself. So there is also an option C in having that
> > buildfarm member turn off that option.
>
> Oh! Hmm... I am not sure that we want to commit to being -Wextra
> clean across-the-board.

We've been -Wextra clean for years, with a few temporary exceptions. IME a lot
of warnings added to -Wextra in one year, get promoted to -Wall a few releases
later. I found plenty mistakes with -Wextra stuff, so I'd be sad if we decided
we're not trying to fix them...

Greetings,

Andres Freund