I want to build and install a compiler at custom location in Red Hat v6 and I am facing a few problems with the environment variable setting. I have done installation on my Ubuntu 12.04 system successfully and want to do teh same on Red Hat. Please read the following for more information:

I have build gcc compiler (with cilk plus branch) in a custom location on my machine. The following environment variables are set before I compile any program in my system( Ubuntu 12.04 ):

export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/home/aman/intern/compiler/gmp-4.3.2/lib:/home/aman/intern/compiler/mpfr-2.4.2/lib:/home/aman/intern/compiler/mpc-0.8.1/lib:/home/aman/intern/compiler/gcc-cilkplus-install/lib

I have build mpfr, gmp, mpc in folder /home/aman/intern/compiler/ and their paths have been added to LD_LIBRARY_PATH. My compiler installation directory is /home/aman/intern/compiler/gcc-cilkplus-install/

export C_INCLUDE_PATH=/usr/include/x86_64-linux-gnu && export CPLUS_INCLUDE_PATH=$C_INCLUDE_PATH && export OBJC_INCLUDE_PATH=$C_INCLUDE_PATH

export LIBRARY_PATH=/usr/lib/x86_64-linux-gnu

All the environment variables which are exported were empty before I exported them.

Now I need to build the compiler on redhat. LD_LIBRARY_PATH can be easily translated as it belongs to the directory I created but I know not of what the paths are.

Note 1: I know stuff like C_INCLUDE_PATH is the directory where gcc looks for header files but my question is how to locate this on an arbitrary system specifically redhat V6.

Note 2: If you see the all env. variables other than LD_LIBRARY_PATH all correspond to /usr directory but in my installation I have not done anything there. So I may have made mistake in the first place itself and program is running on my system coincidently, just a thing I wanted to mention, if someone didn't notice.

Thanks!

see here: LD_LIBRARY_PATH should not be altered during build, it has no meaning. You need to set it on the target system depending on the actual environment.
The ...INCLUDE_PATH variables are not used on the target system, the compiler needs them to be able to build.