Re: [PATCH] Fix OAuth feature detection on OpenBSD+Meson

On Tue, Jun 24, 2025 at 1:29 PM Peter Eisentraut <peter@eisentraut.org> wrote:
> Note that Autoconf uses a compilation test, not a preprocessor test, for
> its AC_CHECK_HEADERS, so it uses .check_header() semantics.  And this
> was the result of a long transition, because the compile test was
> ultimately deemed to be better.  So in general, I would be wary about
> moving away from .check_header() toward .has_header().  But it looks
> like meson.build mixes those without much of a pattern, so maybe it
> doesn't matter for now.

I don't mind moving in that direction, but I do want the two sides to
match. So if it was good enough up to this point to use has_header()
for our feature macros, I don't think I want to try to change that for
18.

> But I'm also suspicious, because by this explanation, the
> AC_CHECK_HEADERS calls on sys/event.h should fail on OpenBSD, but they
> do not on the existing buildfarm members.

I think Andres tracked that discrepancy down [1]:

> Gah, configure does pass - because AC_CHECK_HEADER(), if includes is not passed
> in, first includes what's defined in AC_INCLUDES_DEFAULT.

Thanks!
--Jacob

[1] https://www.postgresql.org/message-id/637haqqyhg2wlz7q6wq25m2qupe67g7f2uupngzui64zypy4x2%40ysr2xnmynmu4