[Bug bootstrap/44455] New: GCC fails to build if MPFR 3.0.0 (Release Candidate) is used

["Denis dot Excoffier at airbus dot com" <gcc-bugzilla@gcc.gnu.org>]

I have compiled sucessfully GCC 4.5.0 under various systems (solaris, cygwin,
darwin), using gmp-5.0.1, mpfr-2.4.2 and mpc-0.8.2 installed in the source tree
before compilation.

I've tried recently a new MPFR Release Candidate 2 (from
http://www.mpfr.org/mpfr-3.0.0/mpfr-3.0.0-rc2.tar.bz2) as a replacement for
mpfr-2.4.2.tar.bz2.

But It failed within stage 1 of mpfr, at least under darwin and solaris, with
the following message:

"header files gmp-impl.h and longlong.h not found"

It seems:
- that GCC compiles mpfr by passing the --with-gmp-build option to its
configure,
- that the new mpfr-3.0.0 now detects that the directory given under
--with-gmp-build does not contain the necessary files and aborts in this case
- that the same detection was performed under mpfr-2.4.2, albeit with no abort
- the two missing header files are present in the source directory, but not in
the build directory (the one given to --with-gmp-build)

I then tried to patch the mpfr/configure in order to skip this test (and the
following one "checking for valid GMP_NUMB_BITS"), and it seems to work: GCC is
built, and i can use this GCC like before. However i cannot say whether the
MPFR part is fully functioning or not.

See also http://websympa.loria.fr/wwsympa/arc/mpfr/2010-06/msg00003.html (the
french part of this message is summarized above). According to MPFR people, the
bug would reside in GCC.

Hope this helps (the future).

NB. I categorized this problem as more severe as "Normal", since it is likely
to affect many targets, and also affect all users that would want to upgrade
(blindly) to the last MPFR (within the GCC source directory).


-- 
           Summary: GCC fails to build if MPFR 3.0.0 (Release Candidate) is
                    used
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Severity: major
          Priority: P3
         Component: bootstrap
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: Denis dot Excoffier at airbus dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44455