On 05/18/2010 03:06 AM, Bruno Haible wrote: > Hi Eric, > >> Typo in the ChangeLog; s/AM_DEFUN_ONCE/AC_DEFUN_ONCE/ > > Oops. Fixed now. Thanks. > >>> +m4_version_prereq([2.64],[AC_DEFUN_ONCE],[AC_DEFUN])([AM_ICONV], >> >> ... rather than have a version check, I'd rather see: >> >> m4_ifdef([AC_DEFUN_ONCE],[AC_DEFUN_ONCE],[AC_DEFUN])([AM_ICONV], > > Remember that AC_DEFUN_ONCE existed all the time in autoconf, since 2.52 > or earlier, but it was not really usable before 2.64. (See autoconf/NEWS.) > With this m4_ifdef, equivalent to an unconditional use of AC_DEFUN_ONCE, > users of autoconf < 2.64 without gnulib would encounter warnings that > they have not seen so far.
Good point. > I don't see how to test for a new vs. an old definition of AC_DEFUN_ONCE. You can use the existence of gnulib's witness macro (in 00gnulib.m4) as the proof of a working AC_DEFUN_ONCE prior to 2.64: m4_version_prereq([2.64],[AC_DEFUN_ONCE], [m4_ifdef([gl_00GNULIB],[AC_DEFUN_ONCE],[AC_DEFUN])])([AM_ICONV], -- Eric Blake ebl...@redhat.com +1-801-349-2682 Libvirt virtualization library http://libvirt.org
signature.asc
Description: OpenPGP digital signature
