Re: build failure, GMP not available

["Kaveh R. GHAZI" <ghazi at caip dot rutgers dot edu>]

On Mon, 30 Oct 2006, Geoffrey Keating wrote:

> Hi Kaveh,
>
> Since your patch
>
> ------------------------------------------------------------------------
> r117933 | ghazi | 2006-10-21 06:58:13 -0700 (Sat, 21 Oct 2006) | 16
> lines
>
>          * configure.in: Require GMP-4.1+ and MPFR-2.2+.  Don't check
>          need_gmp anymore.
>
> I'm getting
>
> configure: error: Building GCC requires GMP 4.1+ and MPFR 2.2+.  Try
> the --with-gmp and/or --with-mpfr options.

Hi Geoff,

I believe most of your questions were already answered.  But I'll try and
fill in some additional info.


> 1. Is this intentional?
> 2. Is it supposed to apply to the host, the target, or both?
> 3. If it's intentional, what is the list of platforms that you
> intended to prevent building, that is, platforms which GCC used to
> support but on which GMP or MPFR does not build?

It should be possible to build gmp and mpfr on (at least) all the primary
and secondary platforms.  Before installing my patch, I did a search for
testsuite posts with gfortran results on the major systems.  I assumed
that I could use gfortran results as a proxy for gmp/mpfr working since
that language already requires those libraries.  See:
http://gcc.gnu.org/ml/gcc/2006-10/msg00224.html

Note that x86-darwin was among those results.  In addition to my posting,
Francois posted a followup with several more platforms, and the MPFR page
in my posting lists many more platforms where it is supposed to work.


> 4. Are you aware that the GMP home page says
>
> [2006-05-04] GMP does not build on MacInteltosh machines. No fix
> planned for GMP 4.x.
>
> and indeed it does not appear to build correctly when configured on
> my MacBook Pro?
>
> 5. Are you aware that the GMP home page says
>
> Note that we chose not to work around all new GCC bugs in this
> release. Never forget to do  make check  after building the library
> to make likely it was not miscompiled!
>
> and therefore this library needs to be part of the bootstrap, not
> built separately?

As was noted, you should be able to build GMP with generic C sources as
opposed to optimized assembly using the "none" CPU type.


> 6. The regression tester does actually have GMP installed, but it is,
> not in /usr/local.  Should this code be searching for GMP and mpfr in
> more places if it is not found?

We already have --with-* options so you can specify the directory where
you have gmp and/or mpfr installed.  I don't think we need to probe
additional directories automatically, that list could get rather large
pretty fast and introduce unexpected wierdness if unintended stuff gets
sucked in.

>
> Because of the severe nature of this problem (everything doesn't
> build, multiple hosts affected), I'd like you to consider backing out
> this patch until the problems are fixed.  I'll work on a patch which
> just disables the check for Darwin.

As was noted, if you disable the check, you'll simply get a build failure
in the middle-end which now uses gmp/mpfr.  Let's see if you can get these
libraries installed before going down that road.

		--Kaveh
--
Kaveh R. Ghazi			ghazi@caip.rutgers.edu