procptr works as system pointer. hack or feature?

[Steve Richter <stephenrichter@xxxxxxxxx>]

If you want to use the fndinxen procedure to read from a user index
you need a system pointer that is set to the user index.  For that you
use the rslvsp2 procedure call.

** ---------------- miFndinxen ---------------------------
dmiFndinxen       pr                  extproc('_FNDINXEN')
d pInBuf                          *   value
d spInIdx                         *   const procptr
d pOptions                        *   value
d pArgs                           *   value

** -------------------- miRslvsp2 -------------------------
dmiRslvsp2        pr                  extproc('_RSLVSP2')
d pOutSysPtr                      *   procptr
d InObj                               const likeds(miObject)

These two prototypes work whether the system pointer parameter is
declared as a procptr or a regular pointer. But that is only because
the system pointer is passed by reference.

In RPG, when you assign one pointer to another:
 d ptr1         s          *
 d ptr2         s          *
   ptr1  = ptr2 ;

the assignment works, even if the pointer is a system pointer.

But when a pointer that contains a system pointer is passed by value
to a procedure, the pointer arrives in the called procedure as *null.
not good.

When the pointer is declared as a PROCPTR a system pointer passed by
value to such a parm arrives ok.  It does not lose its system pointer
value.

I would like to know if system pointers and procedure pointers are the
same thing. Or will code that relies on a procedure to correctly
return a system pointer possibly not work in a future release?

thanks,

-Steve