I think the author knows very well what UB is and means. But he’s thinking critically about the whole system.
UB is meant to add value. It’s possible to write a language without it, so why do we have any UB at all? We do because of portability and because it gives flexibility to compilers writers.
The post is all about whether this flexibility is worth it when compared with the difficulty of writing programs without UB.
The author makes the case that (1) there seem to be more money lost on bugs than money saved on faster bytecode and (2) there’s an unwillingness to do something about it because compiler writers have a lot of weight when it comes to what goes into language standards.
UB is meant to add value. It’s possible to write a language without it, so why do we have any UB at all? We do because of portability and because it gives flexibility to compilers writers.
The post is all about whether this flexibility is worth it when compared with the difficulty of writing programs without UB.
The author makes the case that (1) there seem to be more money lost on bugs than money saved on faster bytecode and (2) there’s an unwillingness to do something about it because compiler writers have a lot of weight when it comes to what goes into language standards.