Re: FYI: 17-gary-evalmp-libgmp-autoconfiscation.patch

[Gary V. Vaughan]

On Tue, Sep 25, 2001 at 09:46:29AM +0200, Akim Demaille wrote:
> 
> | Index: config/gmp.m4
> | ===================================================================
> | RCS file: /cvsroot/m4/m4/config/gmp.m4,v
> | retrieving revision 1.3
> | diff -u -p -u -r1.3 gmp.m4
> | --- config/gmp.m4 2001/09/20 08:49:31 1.3
> | +++ config/gmp.m4 2001/09/21 00:12:58
> | @@ -16,44 +16,52 @@
> |  # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
> |  # 02111-1307  USA
> |  
> | -# serial 4
> | +# serial 5
> |  
> |  m4_define([_AC_LIB_GMP],
> | -[AC_ARG_WITH(gmp,
> | -[  --without-gmp           don't use GNU multiple precision arithmetic 
> library],
> | -[use_gmp=$withval], [use_gmp=yes])
> | -
> 
> Hm... Considering that I would also like to find some general
> scheme/approach to macros for such libraries, considering that I would
> like to promote generic macros (in the sense of `valid for several
> packages') vs dedicated macros, I would have preferred keeping the
> --with.

Okay.  I made the change before I saw your RFC post.  Sorry about that.

> +#if !USE_GMP
>  
> +M4INIT_HANDLER (mpeval)
> +{
> +  const char s[] = "libgmp support was not compiled in";
> +
> +  if (obs)
> +    obstack_grow (obs, s, strlen(s));
> +}
> +
> +#else /* USE_GMP */
> 
> This I don't understand too well.  Why building a fake module instead
> of not building it.

Err.  Lapse of concentration :-(  But seriously, you're right... this
is pretty sucky.  Feel free to change that, or add a comment to the
TODO to remind me to get back to it.

> The current module interface is lacking, IMHO, one feature: the
> ability to ask whether a module *exists*.  Or a means to load and
> catch error when loading fails.

I like the sound of this... especially as it may fuel some nice
generic support for that feature inside libltdl.  As a matter of
interest, most of the development in libltdl in the last 2 years has
been fed by requirements in the M4 module loader :-)

Do you have any thoughts on what form this feature should take at the
M4 level?  And at the libm4 API level?

> But then, if you create a broken module, there is no use.

Indeed.


> Also, why should an error message such `as libgmp support was not
> compiled in' be in regular output instead of stderr?

It was late, and I was concentrating on getting it to compile, rather
than thinking about the big picture.  This is just plain wrong.
Thanks for pointing it out :-)

Cheers,
        Gary.
-- 
  ())_. Gary V. Vaughan     gary@(oranda.demon.co.uk|gnu.org)
  ( '/  Research Scientist  http://www.oranda.demon.co.uk       ,_())____
  / )=  GNU Hacker          http://www.gnu.org/software/libtool  \'      `&
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