overly cautious or properly paranoid?
This is largely dependant upon the degree to which you control/trust the author of the calling code. If you are writing a service routine that can be called by anything written by anyone, then you must be absolutely paranoid in every way that you can think of! If you are coding to an IBM documented API, then you usually (BUT NOT ALWAYS!) can rely upon the fact that that that API will never change in an incompatible way. (In other words, you still have to be paranoid.) If you are coding for an API that you yourself will be writing, then the degree of paranoia depends upon how much you can trust your future (70 year old?) self. For myself, I am a very paranoid programmer, and I can't begin to tell you how many times that has saved my ass over the decades. In programming, paranoia is a good thing! Dave Cole At 8/11/2010 10:07 AM, McKown, John 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? 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? John McKown Systems Engineer IV IT Administrative Services Group HealthMarkets(r) 9151 Boulevard 26 * N. Richland Hills * TX 76010 (817) 255-3225 phone * (817)-691-6183 cell [email protected] * www.HealthMarkets.com Confidentiality Notice: This e-mail message may contain confidential or proprietary information. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. HealthMarkets(r) is the brand name for products underwritten and issued by the insurance subsidiaries of HealthMarkets, Inc. -The Chesapeake Life Insurance Company(r), Mid-West National Life Insurance Company of TennesseeSM and The MEGA Life and Health Insurance Company.SM
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