The halting problem is exhaustive, there isn't an algorithm that is valid for all programs. You can still check for some kinds of infinite loops though!
More specifically, you can accept a set of programs that you are certain do halt, and reject all others, at the expense of rejecting some that will halt. As long as that set is large enough to be practical, the result can be useful. If you eg forbid code paths that jump "backwards", you can't really loop at all. Or require loops to be bounded by constants.
