[Info-vax] Returning data from Cobol AST routine.

[Arne Vajhøj]

On 9/22/2021 3:41 AM, Jan-Erik Söderholm wrote:
> Den 2021-09-22 kl. 03:37, skrev Arne Vajhøj:
>> On 9/21/2021 8:31 PM, Jan-Erik Söderholm wrote:
>>> 01  reqidt              pic 9(9)    comp.
>>> ...
>>>      move 1234 to reqidt
>>>      call "sys$setimr"
>>>          using omitted
>>>                by reference delta-time
>>>                by value ast-proc-addr
>>>                by reference reqidt    <<==
>>>                omitted
>>>          giving return-value
>>>      end-call
>>>
>>> Replaced "by value reqidt" with "by reference reqidt".
>>> That will pass the address (pointer) to reqidt.
>>> Silly not thinking about that...
>>>
>>> The AST routine just uses the paramater as-is as before
>>> an now prints "reqidt: 1234" as expected.
>>
>> I would probably have preferred to keep the formal
>> argument as by val and stuffed the address into an integer
>> and passed that. Slightly more complicated but I just
>> don't like faking the passing mechanism of a system
>> service.
> 
> Not that much more complicated, one additional pointer definition:
> 
> 01  reqidt_addr         pointer     value reference reqidt.
> 01  reqidt              pic 9(9)    comp.
> ...
>      move 1234 to reqidt
> 
>      call "sys$setimr"
>          using omitted
>                by reference delta-time
>                by value ast-proc-addr
>                by value reqidt_addr
>                omitted
>          giving return-value
>      end-call
> 
> This also works. A matter of taste, I guess. :-)

Yes. They do the same thing.

It just bother me to see a by reference when the documentation
says by value even though there is a good reason.

Arne