Successful build of GCC 4.9.0 on OS X 10.9.3.

build_gcc.sh

# setup:
# installed ports are listed at http://goo.gl/x0tTpu
# almost clean /usr/local

# download the source tarballs
# cloog, gmp, isl, mpc, mpfr, and most importantly, gcc
cd ~/src/tarballs
wget -q ftp://gcc.gnu.org/pub/gcc/infrastructure/cloog-0.18.1.tar.gz
wget -q ftp://gcc.gnu.org/pub/gcc/infrastructure/gmp-4.3.2.tar.bz2
wget -q ftp://gcc.gnu.org/pub/gcc/infrastructure/isl-0.12.2.tar.bz2
wget -q ftp://gcc.gnu.org/pub/gcc/infrastructure/mpc-0.8.1.tar.gz
wget -q ftp://gcc.gnu.org/pub/gcc/infrastructure/mpfr-2.4.2.tar.bz2
wget -q ftp://ftp.gnu.org/gnu/gcc/gcc-4.9.0/gcc-4.9.0.tar.gz

# extract the tarballs, dependencies into the gcc source directory
# gcc extraction is likely to take long due to size and file count
tar -xzf gcc-4.9.0.tar.gz
mv gcc-4.9.0 ~/src/gcc
tar -xzf cloog-0.18.1.tar.gz
mv cloog-0.18.1 ~/src/gcc/cloog
tar -xzf gmp-4.3.2.tar.bz2
mv gmp-4.3.2 ~/src/gcc/gmp
tar -xzf isl-0.12.2.tar.bz2
mv isl-0.12.2 ~/src/gcc/isl
tar -xzf mpc-0.8.1.tar.gz
mv mpc-0.8.1 ~/src/gcc/mpc
tar -xzf mpfr-2.4.2.tar.bz2
mv mpfr-2.4.2 ~/src/gcc/mpfr

# all set, ready to build
cd ~/build
mkdir gcc; cd gcc
~/src/gcc/configure --enable-languages=c,c++ | tee configure_output
# output omitted, see configure_output at http://goo.gl/D7a0R4
make -j4 | tee make_output
# took me more than an hour on 2.9 GHz Intel Core i7 (MacBook Pro 13''
# mid-2012)
# output omitted, see make_output at http://goo.gl/1HpW9x
sudo make -j4 install | tee make_install_output
# output omitted, see make_install_output at http://goo.gl/tQww7N