Components used to build GCC

[Jonathan Wakely]

On Mon, 7 Mar 2022 at 22:27, vicentesmith via Gcc-help
<gcc-help@gcc.gnu.org> wrote:
>
> Hello,
> I'm building GCC11 on a system running Ubuntu20.04 (that includes GCC 9.3.0). After downloading the prerequisites, the system is stating:
> ...
> gmp-6.1.0.tar.bz2: OK
> mpfr-3.1.6.tar.bz2: OK
> mpc-1.0.3.tar.gz: OK
> isl-0.18.tar.bz2: OK
> All prerequisites downloaded successfully.
> My question is whether the GCC build is going to use these versions of GMP, MPFR and MPC or the ones already installed in the system, which are more recent. Thanks.

When the sources are present in the GCC source tree (which is what the
download_prerequisites script does) then those ones will be used.

If you want to use the system versions, just remove the "gmp", "mpfr",
"mpc" and "isl" symlinks in the GCC source tree. You can also remove
the gmp-6.1.0, mpfr-3.1.6 etc. directories, but doing so isn't
necessary. The configure script only looks for the unversioned names,
so removing the symlinks is sufficient.