Static Analysis

Instead of giving up, compiler writers resort to static analysis:

• Don't try to decide the question exactly
• Settle for an approximative answer
• Only give safe (=conservative/sound) answers

For the Halting Problem, the answers would be:

• "Yes, your program definitely always terminates"
• "I don't think your program always terminates, but I'm not really sure"

The engineering challenge is to give useful answers as often as possible - and be efficient