[Info-vax] VMS Basic and quad by value

[Dave Froble]

On 9/23/2022 9:09 PM, Dave Froble wrote:
> On 9/23/2022 6:45 PM, Arne Vajhøj wrote:
>> On 9/23/2022 4:45 PM, Bill Gunshannon wrote:
>>> On 9/23/22 16:37, Arne Vajhøj wrote:
>>>> I am not good at Basic so I may be missing something obvious.
>>>>
>>>> As I read the manual then I should be able to pass a quad by value.
>>>>
>>>> But the compiler disagrees.
>>>>
>>>> Can anybody shed some light on this?
>>>>
>>>
>>> Can you show us the code?
>>
>> Sure.
>>
>> $ type z1.bas
>> program z1
>>
>> declare quad v
>>
>> v = 123
>> call f(v)
>
> You do realize, I hope, that you are passing the variable by reference?
>
>> end program
>> !
>>
>> sub f(quad a by value)
>
> I tried this.  It appears that Basic does not allow an argument to be declared
> QUAD and received By Value.  I'd consider this a bug.
>
> However, to demonstrate:
>
> AS800> t z5.bas,z6.bas
> 1       ! Program Z5
>
>         Declare Quad Q
>
>         Q = 123
>         Call Z6( Q )
>         Print Q
>
> End
>
> SYS$SYSDEVICE:[DFE]Z6.BAS;4
>
> 1       ! Program Z6
>
>         Sub Z6( Long L By Value )
>
>         Print L
>
>         End Sub
> AS800> run z5
>  2061851336
>  123
> AS800>
>
> As expected, the value of the argument is the address of the quadword variable
> in program Z5.
>

>>
>> This is on Alpha. There would be an obvious problem on VAX.

As a follow up, my test was using Alpha BASIC V1.7-000

I believe there are later versions of Basic.

I tried the test on VAX, and the Basic on the VAX, VAX BASIC V3.8-000, didn't 
seem to like Quad data types.  As expected.

-- 
David Froble                       Tel: 724-529-0450
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