Re: RPG Refactoring - removing GOTO - tips & techniques?

Yo might want to try a test drive of Arcad's tooling Charles. They remove GOTOs reasonably well - at least the code they generate is comprehensible and the beauty of using a tool is that the changes are constant. Even if you don't use the tool long term it will give you ideas as to how to make your own conversions.


Jon Paris

www.partner400.com
www.SystemiDeveloper.com

On Oct 12, 2017, at 1:43 PM, Charles Wilt <charles.wilt@xxxxxxxxx> wrote:

Looking at an old program that using GOTO...I'd like to get rid of it.

In this case, it's a relatively simple usage

//mainline part1
if something goto @end
//mainline part2
if somethingelse goto @end
//mainline part 3
...
TAG @END
eval parm12 = *IN12;
return;

I see two options
1) dou loop
2) add an end_program subroutine

---Option 1---

dou *on = *on; //run once
//mainline part1
if something leave
//mainline part2
if somethingelse leave
//mainline part 3
enddo;
eval parm12 = *IN12;
return;

---Option 2---

//mainline part1
if something exsr @END_PROGRAM
//mainline part2
if somethingelse exsr @END_PROGRAM
//mainline part 3
...
exsr @END_PROGRAM
//shouldn't get here, but to be safe
return;

begsr @END_PROGRAM;
eval parm12 = *IN12;
return;
endsr;


Advantages to option 2 as I see them...
- works even if GOTO exists in a loop in the mainline
- works if GOTO is in an subroutine

note that the "eval parm12 = *IN12" line is due to refactoring a *ENTRY
PLIST into a PR/PI. *IN12 was specified as the factor 2 on the PARM
op-code for parm12. So I can't just change GOTO @END to RETURN.

Thoughts / comments on either of the above options?
Any additional tips or techniques?

Thanks!
Charles
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