On Nov 17, 2021, at 02:36:12, Jonathan Scott wrote:
> ...
> When we resumed this item recently, we found that the logic to
> handle the dependent USING base address and range in the Using
> Map and Active Usings headings incorrectly assumed that any
> dependent USING would be basing the start of a section, which
> meant that various fields were being incorrectly calculated.
> This has now been fixed.
>
Does that affect generated code, or even ASMADATA? Might
any users depend on the misbehavior? I recall many years
ago IBM fixed a clear code generation bug which we had
Been deliberately avoiding. But our development manager
required that we compare all our SYSLINI after and before
the APAR to prove we hadn't unwittingly depended on the
defect.
Also, decades ago, I found that (something like):
PSWMAP DSECT
...
USING PSWMAP-SVCOPSW,R0
quietly behaved as if I had coded:
USING PSWMAP,R0
Experts conceded that the behavior is indefensible except
on grounds of compatibility with existing art.
Nowadays it's no longer quiet, but:
ASMA302W USING specifies register 0 with a non-zero absolute or relocatable
base address
Feckless. A more honest message text would be:
ASMA302W USING interpreted incorrectly for compatibility with historic
behavior
XR R2,R2
USING PSWMAP-SVCOPSW,R2
... ehaves correctly.
> https://www.ibm.com/support/pages/apar/PH4205
-- gil
