Every once in a while I hear the "we did this code generation stuff in LISP 40 years ago". So I track back to the person and ask them to tell me about it. It hasn't worked out yet. I have no doubt that code generation was done then as it is done now. I read "we did the same thing 40 years ago" as "you had a great idea 40 years ago and you neglected to communicate it properly." Code generation is taught, if it is taught at all, as a graduate course.
I'd love to learn the technical lessons from the LISP macro code generation. But I have already learned the most important lesson from this experience, which is when you have a good idea you should feel obligated to pass it on for the good of the profession.