On Thu, Jun 20, 2019 at 6:02 PM Chuck Arney <ch...@arneycomputer.com> wrote:
> The TRAP facility was originally implemented in the hardware for Y2K
> support. It was to be used by products to overlay clock related
> instructions so different clocks/dates could be simulated. At least that
> is what I was told many years ago.
>
That's what I heard too. But it appears that the hardware people have
enhanced it for other "exceptional" processing, such as C language NULL
pointer testing. At present, as far as I can tell in z/OS, it is not being
used for anything. It would require z/OS support as well as HLL (C/C++)
support. Given some comments in another thread on ASSEMBLER-LIST, I am
guess most HLASM programmers would prefer coding like:
LT R10,POINTER
JZ NULL_REFERENCE
instead of using some API (perhaps akin to an ESTAEX or ESPIE type
situation) and using
LAT R10,POINTER #TRAP IF NULL POINTER
Of course, using this would require more, non-ISO, changes to the C/C++
compiler so that programmers would have some way to "trap" the exception.
Which would make the code non-portable.
So I guess I am once again, out in the parking lot at the wrong stadium.
--
Money is the root of all evil.
Evil is the root of all money.
With that in mind, money is made by the government ...
Maranatha! <><
John McKown
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