J *+1 isn't even possible, as the hardware offset for relative
addressing is in halfwords.
For many years I have been using a conditional TRAP macro which
is equivalent to
BC cond,*+1
but which is coded using LA with an ORG back to change the
opcode, to avoid getting an error message. This avoids a branch
in the normal case. It is primarily used for integrity and
consistency checks, and my recovery routine recognizes this
convention and reports it as "TRAP occurred at offset &1 in &2".
Martin Ward writes:
> On 06/08/2018 02:30, Robin Vowels wrote:
> > And anyway, why would you want to EX an EX?
>
> To cause an ABEND after an error, of course!
> I have seen "EX 0,*" in production code to do this
> (along with "J *+1")
Jonathan Scott, HLASM
IBM Hursley, UK
