<Shrug> What do you want us to say?
Obviousy Macports is trying to build/install gcc but it can't without a compiler. Yes gcc can be built without a preexisting compiler, but good luck and why? Especially when XCode is a free download, click click let it start and a little while later it's done. At that point as pointed out elsewhere, gcc, g++ will work, but it's not actually gcc but clang in disguise.
If you want, you can use macports or brew or whatever later if you really want to, but again why? For programs that only work using gcc extensions? Doubt it. You just want a c/c++ compiler. If you ever want to do programs for the Mac or IPhone, you need XCode anyway, gcc won't do.