Re: Service program signatures, and how to avoid unnecessarily recompiling programs that call service programs

"RPG400-L" <rpg400-l-bounces@xxxxxxxxxxxx> wrote on 09/13/2017 01:11:57
PM:

I've learned that I should add new exports only/always to the end of an
existing export list in my binder source. My understanding is that, by
doing so, programs that call existing procedures in the binder source do
not need to be recompiled. Correct?

Correct.

Also, if I change an existing procedure in a service program but do not
change the procedure interface, do I understand correctly that I won't

need

to recompile any programs that call that procedure?

Correct.

Is there a go-to reference for this topic?

Not sure. But, I can add (if you're not aware already) that there
are two ways to handle service program signatures (three, really, if you
count not providing any binder source member at all).

One method is to use a single signature in your binder source and
always add new procedures at the bottom of that existing signature. This
method also means that you can never delete the binder export statement
for an obsolete service procedure.

The second method is to only use a new signature group in your
binder source when you wish to begin obsoleting a service procedure. The
new singature group would omit the binder export for the obsolete
procedure(s). The old signature group would remain in your binder source
as *PREV to serve existing programs that have not yet been recompiled.
This method means that recompiled and new programs will not have access to
the obsolete procedure. Once all programs are eventually recompiled, then
the old signature group can be removed from the binder source and the
service procedure removed from the service program module source.

Sincerely,

Dave Clark