Hello Paul and Eric, in short, I have changed my mind, and I think we should install Eric's patch. On Thu, Jun 15, 2006 at 05:47:04AM -0600, Eric Blake wrote: > According to Paul Eggert on 6/15/2006 1:28 AM: > > Sorry, I'm lost. If Autoconf doesn't need a wrapper, then why does a > > build break with a 2.0-like m4? I apologize for the confusion. Let me correct it: Autoconf 2.60 requires LIFO, and will break with m4 2.0. The most evil scenario is the one described by Ralf: m4 < 2.0 is used to build Autoconf 2.60, but then m4 is upgraded to 2.0 and autoconf stops working. I can see two ways to fix the problem: 1) autoconf will check for m4 >= 2.0 at startup and will refuse to run with m4 >= 2.0 2) m4_wrap in m4sugar.m4 will ensure the LIFO order. The (1) is slightly more reliable, because it protects us from other possible incompatibilities with m4-2.0, not yet known. But (2) is less intrusive, and the implementation is right at our hand, written by Eric: > I already provided such a patch, that guarantees LIFO order in m4_wrap ... > http://lists.gnu.org/archive/html/autoconf-patches/2006-06/msg00060.html On a second thought, this is probably the best solution, let's accept a variant of this patch (I have not reviewed it yet, sorry). But I don't think we should document that m4_wrap is LIFO, because it may not be necessarily true. <dreams> In future, I think some code around m4_diversion_push and _pop should be cleaned up. The Autoconf itself will then become independent on the fact that m4_wrap is LIFO. Than we can remove the LIFO wrapper again. </dreams> I don't think we need to discuss about the above dream, but please let the question open: do not document that m4_wrap is LIFO. I hope this mail is less confusing than the previous one. Stepan _______________________________________________ Autoconf mailing list Autoconf@xxxxxxx http://lists.gnu.org/mailman/listinfo/autoconf
