On Wed, 11 Aug 2010 09:07:34 -0500 "McKown, John" <[email protected]> wrote:
:>This is just curiousity on my part. I was thinking about standard parameter passing in z/OS. That's where R1 points to a list of fullwords containing address of parameters, with the last address having the high order bit set and all previous addresses having the high order bit unset. So I was wondering the following: :>1) do you check to make sure that R1 actually points to a fullword boundry. I.e. bits 30&31 are '0'b? Is this necessary or not? If R1 doesn't point to a fullword boundry, is that actually an error? That is, do you feel that a proper parameter list must be fullword aligned? When I complained to IBM (some years ago) that the USS SAF ROUTER exit (the exit where you get no save area, must restore all registers and ARs except 0 & 15 - but get a work area passed) did not always get a word aligned work area and my STAM got an 0C6 they said that the work area was not documented to be aligned. :>2) do you always verify bit 0 of every fullword in the list of addresses to make sure that you get the expected number of parameters? What do you do if you get too few or too many? I tend to check only when variable number is permitted and then only from the minimum required. Some IBM services check all. -- Binyamin Dissen <[email protected]> http://www.dissensoftware.com Director, Dissen Software, Bar & Grill - Israel Should you use the mailblocks package and expect a response from me, you should preauthorize the dissensoftware.com domain. I very rarely bother responding to challenge/response systems, especially those from irresponsible companies.
