Re: PR/57807 CVS commit: src/sys/sys

[Taylor R Campbell <riastradh%NetBSD.org@localhost>]

> Date: Thu, 26 Sep 2024 06:23:23 +0700
> From: Robert Elz <kre%munnari.OZ.AU@localhost>
> 
>     Date:        Wed, 25 Sep 2024 22:29:53 +0000
>     From:        Taylor R Campbell <riastradh%NetBSD.org@localhost>
>     Message-ID:  <20240925222957.A369A84D21%mail.netbsd.org@localhost>
> 
>   | If christos's change doesn't fix it, can you find where _NETBSD_SOURCE
>   | is getting defined so we can fix that too?
> 
> It gets defined in <sys/featuretest.h> when none of the other
> relevant symbols (_POSIX_C_SOURCE etc) are defined.
> 
> Things like the old gmake that are built as a tool don't define
> any of those, so get __NetBSD_SOURCE ... we cannot really simply
> pick one of the others to define for things like this, as there's
> no particular reason they all need the same one.

If old gmake doesn't use nbtool_config.h / compat_defs.h, then perhaps
it sounds like we should arrange to build old gmake with
-D_XOPEN_SOURCE=600 (and maybe the others too), just like
compat_defs.h.  It is a bug for anything in tools to be built with
_NETBSD_SOURCE, even implicitly.

But it's not clear that's what's happening with tools/libctf, because
the excerpt quoted goes through nbtool_config.h, so it should pick up
the _XOPEN_SOURCE &c. definitions.  So I'm puzzled where
_NETBSD_SOURCE could be coming from in that case.