Re: meson: Specify -Wformat as a common warning flag for extensions

On 08.03.24 17:05, Tristan Partin wrote:
> Ok, I figured this out. -Wall implies -Wformat=1. We set warning_level 
> to 1 in the Meson project() call, which implies -Wall, and set -Wall in 
> CFLAGS for autoconf. That's the reason we don't get issues building 
> Postgres. A user making use of the pg_config --cflags option, as Sutou 
> is, *will* run into the aforementioned issues, since we don't propogate 
> -Wall into pg_config.

(The actual mechanism for extensions is that they get CFLAGS from 
Makefile.global, but pg_config has the same underlying issue.)

I think the fix then is to put -Wall into CFLAGS in Makefile.global. 
Looking at a diff of Makefile.global between an autoconf and a meson 
build, I also see that under meson, CFLAGS doesn't get -O2 -g (or 
similar, depending on settings).  This presumably has the same 
underlying issue that meson handles those flags internally.

For someone who wants to write a fix for this, the relevant variable is 
var_cflags in our meson scripts.  And var_cxxflags as well.