Thw C standard has a list of all known UBs. We don't know if the list is complete, because the C standard makes anything not defined by omission UB, so its poss

Thw C standard has a list of all known UBs. We don't know if the list is complete, because the C standard makes anything not defined by omission UB, so its possible to discover new UB. The language is however pretty thoroughly explored.