Hi Tony,  

Thank you very much for bringing this issue to everyone's attention.  I too 
have a 'need to know when things like this are being changed'.  
Our initial macro lib scans have found appx. 60 occurrences where type 
attribute values of U or N are being evaluated and others where we create  
variables for checking downstream.   I'm guessing most, and maybe even all of 
these occurrences are unaffected by PH10081, but we still have to verify them 
all to be sure.  At least now we know about the potential exposure. 

This type of change, without any kind of TDM notice, is uncharacteristically 
poor form IMO.   

Thanks again, 
Mike 

-----Original Message-----
From: IBM Mainframe Assembler List <[email protected]> On Behalf 
Of Jonathan Scott
Sent: Thursday, July 7, 2022 12:39 PM
To: [email protected]
Subject: Re: Type attribute changes in a new HLASM version

Caution! This message was sent from outside your organization.

Tony H writes:
> In the old version, the type attribute (T') of a macro operand of -1 
> was U; in the new one it is, not unreasonably, N. This seems like a 
> positive change, but it actually broke a macro of ours ...

This particular change was APAR PH10081 in March 2019, which allowed decimal 
self-defining terms to be negative (making it possible to code -2147483648 as a 
valid operand) so all other checks for self-defining terms, including the type 
attribute, were affected as well.

As self-defining terms could already be signed, for example X'FFFFFFFF' for -1, 
we did not think this was going to cause any problems, as all we were doing was 
extending that notation to include decimal numbers.  However, we have since 
heard of other cases where macros were testing the type attribute specifically 
because they wanted to check for a positive decimal number, rather than 
generally for a self-defining term.

We are not aware of any other cases in recent years where an existing program 
that assembles without error could be affected by maintenance to HLASM.  Please 
let us know if you spot any!

A simple way to get a summary report of APARs applied is to run HLASM with the 
INFO option.

Jonathan Scott, HLASM
IBM Hursley, UK

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