Single pass generally means one crack at each compilation unit. it's ok to keep a list of unresolved forward references and go back and inject (fix-up) the addr

Single pass generally means one crack at each compilation unit. it's ok to keep a list of unresolved forward references and go back and inject (fix-up) the address once it's known. I mean, that would still count as a single pass. If they're not in the same file, the linker does it.