Detecting division by zero with 100% accuracy in a general C or C++ program without assistance is equivalent to the halting problem.

Now I'm not saying that they solved the halting problem, as that is not possible. Rather that there is missing information on the linked page. Either:

1. The tool requires the an external machine-checkable proof that no division by zero happens.

2. Certain language constructs are disallowed. They probably just ban goto (this is fine), possibly also recursion, multiple return statements, loops without a hard bound of iteration, etc... .

Or both. Where can I find information about this?