Re: libtool --ltdl vs. autoreconf

[Ralf Wildenhues]

Hi Eric,

* Eric Blake wrote on Tue, May 09, 2006 at 02:04:23PM CEST:
> 
> As promised here,
> http://lists.gnu.org/archive/html/m4-patches/2006-05/msg00005.html, I
> noticed that m4 bootstrap invokes libtoolize --ltdl prior to autoreconf,
> which reinvokes libtoolize without --ltdl.  This seems like a bit of a
> waste of time, but when I tried removing the explicit libtoolize line, I
> got a bootstrap failure that a required file, ltmain.sh, was not found.  I
> thought that using LT_CONFIG_LTDL_DIR in configure.ac would take care of
> everything that --ltdl used to do on the command line, but I was obviously
> mistaken.

Bug in libtoolize, if you ask me.  If you use --ltdl, it detects that
LT_CONFIG_LTDL_DIR points you to use ltdl instead of libltdl as
subdirectory, but it doesn't infer the --ltdl itself yet.  I'm not so
sure if detecting it can break anything -- after all, I may reasonably
want to just update the non-ltdl files (in a different setting than CVS
M4).  OTOH adding more knowledge to autoreconf here seems maintenance-
intensive, too.

Since the order is wrong anyway: both aclocal and automake may have
already traced with different macro files in place, before libtoolize is
even run, it's necessary to first run libtoolize anyway.  One could move
libtoolize to be run before automake; but not before aclocal:
eventually, libtoolize and aclocal will again compete for each
installing the same macro files again, thanks to AC_CONFIG_MACRO_DIR and
"aclocal --install".

> Is there another libtool macro that I need to use in configure.ac to
> ensure that all needed libtool files are installed at autoreconf time?  Or
> should we enhance autoreconf to accept an --ltdl option to pass along to
> libtoolize?  It would be nice if we could avoid an explicit libtoolize
> pass outside of autoreconf.

There is another bootstrapping problem, independent of the one you
reported: before ltdl/m4 is populated,
  autom4te --trace=LT_INIT..

won't find the LT_INIT invocation, and thus will report "not using
Libtool"; this doesn't happen with AC_PROG_LIBTOOL, so I wonder where
we missed adding LT_INIT now..

Cheers,
Ralf