RE: RPG & recursive call

[Hans Boldt <boldt@xxxxxxxxxx>]

Joe Giusto II wrote:
>Also be careful with recursive subroutine calls.  The compiler
>let me do it but I threw my program into an endless loop.  It
>seemed to me at the time that the subroutine "forgot" where it
>came from the first time.

Subroutines use an archaic form of linkage where the return
address is saved in a static variable.  On a recursive EXSR,
the return address for the first EXSR is replaced by the
return address for the second EXSR.  Thus, the subroutine
"forgets" the first return address.

The best way to implement a recursive solution is to use
procedures in ILE RPG.  (Personally, I'm a big fan of
recursion, which is certainly an advantage for a compiler
writer!)

Cheers!  Hans

Hans Boldt, ILE RPG Development, IBM Toronto Lab, boldt@ca.ibm.com
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