Sayama P wrote: <snip> It looks like there is no practical way to detect unintentional run-time access to page zero. </snip>
Since the original post did not ask about "detecting" but rather about producing an access error (and you cannot do the latter), I disagree with this assertion. You cannot "detected unintentional" by scanning source and you often cannot know "unintentional" without mind-reading. But you can detect at run-time a class of errors - the most common class of errors - namely where a program picks up a field that contains an address, not realizing that sometimes that address is 0, and then uses that. ZAD (Zero Address Detection) detected that case. Yes, it's about "testing" (or simply normal running of work) because it can only detect what actually happens in running code. Sure, it's true that it does not detect the case where the address is not 0 but still within the first page. The case of 0 is orders of magnitude more likely. Peter Relson z/OS Core Technology Design
