Hi,
On 2021-06-17 13:16:17 -0400, Tom Lane wrote:
> > Then again, why would pg_config.h be absent?
>
> Likely because somebody decided it was a server-side include rather
> than an application-side include.
Which is the right call - pg_config.h can't easily be included in
applications that themselves use autoconf. Most problematically it
defines all the standard autotools PACKAGE_* macros that are guaranteed
to conflict in any autotools using project. There's obviously also a lot
of other defines in there that quite possibly could conflict.
We probably split pg_config.h at some point. Even for extensions it can
be annoying because pg_config.h is always included in server code, which
means that the extension can't easily include an autoheader style header
itself.
I'm not sure I understand why you think that exposing the version number
for libpq is such a bad idea?
I think it'd be reasonable to add a few more carefully chosen macros to
pg_config_ext.h.
Greetings,
Andres Freund