Comment by brynet

OpenBSD's base gcc is a fork of the last GPLv2 version, like Apple and embedded except with many local changes, e.g. gcc-local(1):

http://man.openbsd.org/OpenBSD-current/man1/gcc-local.1

There's newer versions of gcc in ports, llvm/clang was recently updated to 3.7.1, post 5.9.