Re: Pointer not set on returning from an RPG procedure to a

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     The following answer is directly from "Programming in RPG IV" by Judy 
     Yaeger, page 222-3
     
     RPGIV includes 2 kinds of pointer data types:  basing pointers and 
     procedure pointers...  Basing pointers reference storage locations of 
     variables while procedure pointers reference storage locations of 
     program modules.
     
     Both basing and procedure pointers are type *, with a fixed length of 
     16 bytes.
     
     Hope this helps...
     
     Bob Arlia, Nationwide Credit Inc.
______________________________ Reply Separator _________________________________
Subject: Pointer not set on returning from an RPG procedure to a CL o
Author:  MIDRANGE-L@midrange.com at unix
Date:    1/6/2000 12:36 PM


Hi all.
     
This is weird.
     
I was typing up this message, and before I completed it, I tried 
something out which fixed the problem.  But I thought I'd share it with 
the list anyway, as I don't understand it.
     
Here's my original question:
     
I have a simple RPG procedure which returns a one-character value (*on 
or *off, but that doesn't seem to be relevant, as I get the same problem 
if I code a literal '1' or '0').  I'm calling it from a CL procedure, 
using CALLPRC with the RTNVAL parameter.  The field for RTNVAL is 
defined as *CHAR 1.
     
I get MCH3601, pointer not set for location referenced, on the RETURN 
opcode.  Neither debug nor a dump tells me anything.
     
We are on V4R3.  Anybody got any ideas?
     
*** End of original question ***
     
And then I prompted CALLPRC and hit help on RTNVAL; it mentioned the 
return value being 'aligned on a sixteen-byte boundary'.  So on an 
impulse I redefined my return value field as *char 16.  And it worked.
     
I've come across this 'aligned on a sixteen-byte boundary' expression 
before, and never understood it; I eventually had concluded that it was 
a fancy way of saying pointers are sixteen bytes long; but I see that 
there's more to it than that.  Can anybody explain what's going on here?
     
Cheers,
     
Martin.
     
-- Martin McCallion                 
Midas-Kapiti International
Work:  mccallim@midas-kapiti.com
Home: martin.mccallion@ukonline.co.uk
     
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