upgrading gcc/gfortran on linux, glibc=2.5

[Tom Roche]

Paul Richard Thomas Wed, 28 Mar 2012 16:26:17 +0200
> I believe that I have RHEL5.4 as a virtual machine at home. If so,
> I'll build a release version of 4.7.0 on it.

Thanks!

> It'll take a few days because I know that some of the dependencies
> will need updating and all the usual good stuff. I have to say that,
> whilst I am a gfortran maintainer and would say this :-), building
> your own is very straight forward on linices

Except we lack root :-( Our cluster (which is currently running

$ lsb_release -ds
"Red Hat Enterprise Linux Server release 5.4 (Tikanga)"
$ gfortran --version
GNU Fortran (GCC) 4.1.2 20080704 (Red Hat 4.1.2-46)
$ ldd --version
ldd (GNU libc) 2.5

) is maintained by contractors for a larger group, who dissuade us
from building dependencies as fundamental as gcc. While there are
plans to upgrade the cluster to RHEL 6 "soon," that may not be for
months, and anyway that would only get us to gcc-4.4 (IIUC). However,
one of the admins has stated

> I tried to compile the 4.6 version of GCC from source and could not
> get it to work. If you have a working version, I would be happy to
> put it [up]

so if you can build gcc-4.7, that should work. However I also note

http://gfortran.com/download/x86_64/PLEASE_README.txt
> this directory

http://gfortran.com/download/x86_64/

> [provides] GCC builds for linux x86_64 systems[, including]
> compilers for the c, c++ and fortran languages built on a linux
> system with glibc 2.6.1.

> The provided [compilers] need glibc 2.4 or newer, however the
> library libgomp needs glibc 2.6,

Unfortunately we do need OMP for the parallel versions of our model,
though being able to build/test serial with a newer gcc/gfortran would
be good for us. I note

$ ldconfig -p | fgrep -ie 'omp'
-bash: ldconfig: command not found
$ locate *gomp* | fgrep -e '.so'
/usr/lib/gcc/x86_64-redhat-linux/4.1.1/libgomp.so
/usr/lib/gcc/x86_64-redhat-linux/4.1.1/32/libgomp.so
/usr/lib64/libgomp.so.1
/usr/lib64/libgomp.so.1.0.0

So I'm wondering,

1 Can we also get or build glibc >= 2.6 for RHEL 5.4?

2 If we cannot build/get a glibc >= 2.6: what is the latest gcc with a
  libgomp that works with glibc == 2.5?

TIA, Tom Roche <Tom_Roche@pobox.com>