On Wed, 15 Nov 2023 at 15:03, Paul Gilmartin < [email protected]> wrote: [...]
> In the REXX Ref. I see: > Register 0 > Address of an environment block (optional) > > "optional" should never be specified as a register content. I read that > as: > Address of an environment block (if not, it doesn't matter) > Yeah - this offended my sense of design when I saw it 20+ years ago. REXX uses some undocumented algorithm to decide if R0 points to a "valid" env block, and doesn't abend if R0 isn't even a pointer to anything. So there is presumably an ESTAE in there as well as the undocumented test(s). Or conceivably it does some indefensible stuff with validating the R0 content (VSMLOC or TPROT or something?) before trying to deference it. Are all ENVBLOKs on a list somewhere? I guess that'd be the easiest approach. Yuck whichever way... Tony H. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
