Building gcc

Download GCC, and extract the source to some location <gcc_src_dir>

    http://gcc.gnu.org/mirrors.html

Get makinfo via texinfo

    sudo yum install texinfo

build the gcc docs

    cd <gcc_src_dir>/gcc/doc
    ./install.texi2html

point your browser to the install docs, and have a look at the prerequisites

    <gcc_src_dir>/gcc/doc/HTML/index.html

Obtain the prerequisites and build; typically you build the prerequisites as follows:

        ./configure --help     : display possible configuration options
        ./configure            : configure with defaults
        make                   : build from source
        make html              : generate documentation
        sudo make install      : install

Prerequisites:

    gmp: http://gmplib.org/
        I used gmp-5.0.5
        make sure you enable the C++ interface
            ./configure --enable-cxx

    mpfr: http://www.mpfr.org/
        I used mpfr-3.1.1

    mpc: http://www.multiprecision.org/
        I used mpc-1.0

    ppl: http://bugseng.com/products/ppl/Download/
        I used ppl-0.11.2

        tell it where gmp is  (not sure why this didn't get picked up automatically - perhaps a clash with an existing version in /usr?)
            ./configure --with-gmp=/usr/local

    polylib: http://icps.u-strasbg.fr/polylib/
        I used polylib-5.22.5

    cloog-ppl: ftp://gcc.gnu.org/pub/gcc/infrastructure/
        I used cloog-ppl-0.15

configuring gcc

    ../gcc-4.7.1/configure --with-pkgversion='Lori build 04/08/2012' --disable-multilib --disable-libgcj --build x86_64-fedora-linux --with-mpc=/usr/local --with-mpfr=/usr/local --with-cloog=/usr/local --with-gmp=/usr/local --with-ppl=/usr/local