alt Hacker NewsIf you don't want UB to mean "Absolutely anything might happen" which necessarily has to include "... forever" then you need Fil-C or similar runtime handling so that any time its behaviour would become undefined the program exits instead.
To some extent in C and even more in C++ there's a much worse problem, IFNDR [Ill-formed No Diagnostic Required]. Programs which the language specification insists mean nothing at all, but your tools won't (in many cases can't) notice so the result might do anything. It's not Undefined Behaviour, your program never had any defined behaviour at all.
> Fil-C or similar runtime handling so that any time its behaviour would become undefined the program exits instead
It’s worth being clear here that this is not what Fil-C does, it still has UB, and can still explode in many of the same ways as C and all (after all, it’s a clang fork). Fil-C takes one particular class of allocation related bugs and UB off the table, but leaves many of them behind.