Re: Prototypes and parameters

[qsrvbas@xxxxxxxxxxxx (Tom Liotta)]

Barbara:

Can you clarify one thing? What do you mean by "which would not work" when you 
speak about a pointer for a varying length field? Is that to mean such an 
address cannot be passed? or that the called procedure could not correctly 
return a value without messing things up in the calling procedure? Would that 
still be strictly true even if both caller and callee used an agreed length, 
e.g., the caller set the length appropriately before the call? I've never 
looked at what would happen for a varying length field in this case; this makes 
me curious.

Thanks.

Tom Liotta

rpg400-l-request@midrange.com wrote:

>   1. Re: Prototypes and parameters (Barbara Morris)
>
>Tom Liotta wrote:
>>
>> When you prototype lookup() in the calling procedure, declare a pointer b=
>y value for the second parm. When you call lookup(), pass %addr(terms_code)=
> or %addr(sh_state). Inside lookup(), you _could_ declare the second parm a=
>s q_alpha_10 10A by reference if you really wish or you can again declare a=
> pointer and use it as a basing pointer for perhaps q_alpha_10. Just be sur=
>e you never use more than the maximum left-most positions of q_alpha_10 tha=
>n are indicated by FORMAT.
>>
>
>The trouble with passing a pointer is that it would be possible to pass
>the address of a varying length field, which would not work.  The
>compiler doesn't know that the pointer is supposed to point to a
>fixed-length character field.
>
>I would define the output parameter as character options(*varsize).
>There's still no protection against passing say a char(2) where the
>format indicates a char(3), but the pointer wouldn't help that case
>either.

--
Tom Liotta
The PowerTech Group, Inc.
19426 68th Avenue South
Kent, WA 98032
Phone  253-872-7788 x313
Fax    253-872-7904
http://www.powertechgroup.com


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