About integers overflow: possible undefined behaviour

[alvoskov]

Is signed integer overflow an undefined behaviour in FreeOberon? I've tried to look at intermediate C sources generated by ofront+ and I've seen that it doesn't enforce wraparound behaviour during arithemtic operations. It means that implementation of algorithms that use integers overflow are impossible in FreeOberon.

[kekcleader]

The Oberon Report does not say anything about the integer overflow. That means, the behaviour is indeed undefined.

[alvoskov]

I agree. But is it implementation-defined behaviour or undefined behaviour in Oberon? In C the same arithmetical expression with signed overflow may give different results in different parts of the program because of undefined behaviour.