[Bug bootstrap/53798] [4.7] Bootstrap fails on Linux x86_64 with pre-built libmpc/mpfr/gmp due to multilib path problem

["windward at gmx dot com" <gcc-bugzilla@gcc.gnu.org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53798

--- Comment #8 from Martin <windward at gmx dot com> 2012-07-17 13:41:35 UTC ---
(In reply to comment #7)

> And what about when you put gmp, mpfr and mpc in the GCC source tree? That's
> what worked fine for me.  The same configure command without the
> --with-gmp/--with-mpfr/--with-mpc options?
Yep, tried that, failed with undefined references (see comment #3). To be
perfectly honest I did not investigate further since the workaround lets the
build run fine with the pre-compiled libs.

> The GCC binaries use GMP, MPFR and MPC internally and the GCC binaries are
> only built for a single arch, even if they are capable of producing multilib
> output.  I don't know but I guess libjava now uses them too, and so multilib
> libjava needs multilib support libs.
Seems so, I never had to provide 32 bit GMP, MPFR and MPC before.
But I rather had libtool in mind. I have never seen it providing a complete
path- and filename when calling the linker. I suppose fixing that will solve
the whole thing - at least with GNU ld, which will pick the right lib if 32 and
64 bit lib paths are given with -L.

> (In reply to comment #6)
> > --with-gnu-as --with-as=/opt/SP/gcc/gcc-4.7.1/bin/as \
> > --with-gnu-ld --with-ld=/opt/SP/gcc/gcc-4.7.1/bin/ld
> That's redundant, if configure finds an assembler and linker in the
> installation directory it will use them.
Errrm... well, yeah. I have _one_ rather large script to build GCC for Solaris
SPARC & x86 and Linux x86. In fact these parameters are env vars, and on
Solaris the linker settings would point to /usr/ccs/bin/ld (without-gnu-ld),
even though the GNU ld is present in the installation dir. Besides that there
are other versions in the PATH, so I prefer not to rely on smart configure
scripts. But thanks for pointing out.