On Fri, 13 Feb 2026 10:31:43 -0500, David Clark <[email protected]> wrote:
>I'm guessing a lot of you are not comfortable with my idea for backward >compatibility In the professional world, backwards compatibility is always guaranteed using macros. If there are 3 versions of those macros, then we verify each remains compatible. >when 16 legacy functions are dependent upon one parameter format >and now you want those same 16 functions to also support >a new parameter format? This is not unusual and you will see various solutions scattered throughout SYS1.MACLIB. Ever see SYSSTATE in a macro? Have you ever coded DCB or DCBD? It should take long to find a macro with compatibility code in many forms albeit they may not be obvious. How you determine compatibility (to or from) is up to the person writing the code. >I'm guessing that you would rather add the new fields to the end of the DSECT. This is a common practice by professional developers to avoid coding errors (e.g. alignment). QA might not think about testing requirements on fields that follow the change. >But let's say marketing demanded the above format and then >let's talk about maintaining backward compatibility. When has marketing ever made a DSECT demand that is hidden in a macro (e.g. DCB)?
