Robert Young <yayooo@gmail.com> writes:
> As I tested, if you explicit appoint a union tag, the OpenBSD m4 and
> GNU m4 work identically.
> And This explicit definition just corresponding to the forward-declaration.
> As mentioned in
> http://www.gnu.org/s/bison/manual/html_node/Union-Decl.html
> This feature is a POSIX extension.
> I don't know what impact to other platform.
> So I suppose this should be the appropriate patch to solve this problem
I don't think we're going to worry too much about making plpgsql cope
with an m4 that's too old to support autoconf, which I gather is the
case from the bison bug report thread I mentioned before. If you're
going to be changing the source code or working from a git pull, you
need to have reasonably non-broken tools. We do provide pre-made bison
output in release tarballs, if you don't want to take the responsibility
of having a non-buggy bison available.
regards, tom lane