Re: AC_DEFUN_ONCE semantics

[Ralf Wildenhues]

* Eric Blake wrote on Mon, Jan 26, 2009 at 10:06:12PM CET:
> I guess this also means that we have an additional rule of thumb: if
> there is ever any reason why the macro should _not_ be blindly hoisted
> outside of all other defun'd macros, then don't use AC_DEFUN_ONCE,
> because the macro is not truly one-shot if it is not safe to hoist.
> Do you want me to add text along these lines to the AC_DEFUN_ONCE
> documentation?

Yes, that sounds good.

What I'm more concerned about is all the macros that will now be turned
into being AC_DEFUN_ONCE, and which users have been using for a long
time and won't expect to have their semantics changed.  I hope this set
will be small.  AC_PROG_* shouldn't be in it, for compatibility reasons.

Thanks,
Ralf