[PPL-devel] Re: ac_check_gmp.m4 in ppl

[Roberto Bagnara]

Bruno Haible wrote:
> Roberto Bagnara wrote:
> 
>>Moreover all the generated Makefile's have
>>
>>CPPFLAGS =
>>
>>so that compilation fails miserably because gmpxx.h cannot
>>be found.
> 
> 
> This is because two other .m4 macros reset CPPFLAGS to empty. This patch
> fixes it:
> 
> [...]

Thanks Bruno!

> Also, with the current macro, it's apparently needed to specify both
> --with-libgmp-prefix=/tmp/jank and --with-libgmpxx-prefix=/tmp/jank.
> The following two patches let the user get away with just one of these.
> 
> The first one should be used if some of your programs need only libgmp
> but not libgmpxx. The second one can be used if all you ever link with
> is libgmpxx. (I've tested the second one in three configurations:
> with libgmp installed as shared libs, installed as static libs, and
> installed as static libs with .la files removed.)
> 
> [...]

I think the first one is what we need.  We test first for libgmp and
then for libgmpxx so that we can detect the (quite common) situation
whereby the user has compiled GMP without the --enable-cxx option.
That way we are able to print a more informative error message.
Thanks again!
Cheers,

     Roberto

-- 
Prof. Roberto Bagnara
Computer Science Group
Department of Mathematics, University of Parma, Italy
http://www.cs.unipr.it/~bagnara/
mailto:bagnara at cs.unipr.it