Let us begin with the preliminaries. I assume that you have down loaded the source code of GCC. The different steps of installation of GCC are given with it. But I add it here for completeness.
Like most GNU software GCC must be configured before it is built. Let the GCC source code be in a directory called 'srcdir'. Create a new directory 'objdir' where the GCC is to be built. Create one more directory called 'local' where the tools will be accumulated. Let our current directory be /home/name. Now we have /home/name/srcdir, /home/name/objdir and /home/name/local.
To configure GCC use the command
cd objdir /home/name/srcdir/configure --prefix=/home/name/local/
When we complete the creation of our language add one more option,
--enable-languages=demo
where demo is the new language we are going to develop. The second step required is the building process. It is accomplished with the command
make bootstrap-lean
The last step is the final installation procedure. It is done with the command
make install
We can start our procedure of developing a new language.