Download an appropriate version of gcc:
http://www.ficksworkshop.com/blog/14-coding/65-installing-gcc-on-mac
You might have to say sudo /opt/local/bin/port install gcc47
if port is not found
You might have to go to the /opt/local/bin directory to do something like:
sudo ./port select --set gcc mp-gcc47


You might need an appropriate version (for your operating
system version)  of xcode:
https://developer.apple.com/downloads
