Installing gcc manually redhat - c

Question

I am working on a system on which I am a non-root user.
While trying to install gcc 5.1 in a custom directory as the present shared version of gcc isn't working for postgresql installation, I started out by
wget gcc 5.1.
After unzipping the folder, ran the commands below:
cd /seq/genome_portal/lib
mkdir bld
mkdir gcc
cd bld
/seq/genome_portal/lib/gcc-5.1/configure --prefix=/seq/genome_portal/lib/gcc
However config.log still shows this error:
/../../redhat_6_x86_64/pkgs/gcc_4.9.0/libexec/gcc/x86_64-redhat-linux/4.9.0/cc1: error while loading shared libraries: libmpfr.so.4: cannot open shared object file: No such file or directory
The prerequisites that come after
./contrib/download_prerequisites
are gmp,mpfr and mpc. I started with gmp and ended up in the same error as above. I somehow need to tell these programs that I do not want to use the existing gcc.
But I get the same error as mentioned before. Any advice as to how I can proceed to install it?

Answer 1

Building a compiler is much more complicated that building a straightforward utility; just running configure is not enough.
Primarily, you need to read the instructions; they are provided in the GCC source directory in the INSTALL subdirectory. They are in HTML so point your browser at it.
I know you didn't do this yet because the step on configuration makes very clear you should be using an out-of-source configuration; e.g., something like:
mkdir ../bld
cd ../bld
../gcc-5.1/configure ...
rather than running ./configure.
Regarding the missing dependencies, there's a "prerequisites" section in the docs. To get MPFR and other helpful things you can run:
cd gcc-5.1
./contrib/download_prerequisites
ETA: This should work:
rm -rf newgcc
mkdir newgcc
cd newgcc
tar xzf gcc-5.1.tar.gz
cd gcc-5.1
./contrib/download_prerequisites
mkdir ../bld
cd ../bld
../gcc-5.1/configure <configopts>
make -j8
make install
(or whatever -j you prefer).