The halting problem only means that the problem "does this line ever run" is not computable for every case, since it's possible to construct undecidable cases.

The halting problem only means that the problem "does this line ever run" is not computable for every case, since it's possible to construct undecidable cases. However, not all cases are undecidable and for most lines of most programs simple static analysis can indeed determine that certain lines will definitely run and certain lines won't. As long as you accept that the solution won't give a yes/no answer but yes/no/maybe, an automated system definitely can opiniate on what the program does; for example, by actually attempting to run the involved fragments for a limited time.