Whilst John's example could certainly have been less flowery (though from the way it's written, I'm assuming it may be a variant of some more general set of such macros), your suggestion will fail if the source is coded as a literal. I know, because I had the same reaction, and tried it...
Of course, if the assembler were to support the L' construct for literals, this would not be a problem. Ray... Not (yet) a retired mainframer On 5/16/2012 3:04 PM, retired mainframer wrote:
:>: -----Original Message----- :>: From: IBM Mainframe Assembler List [mailto:ASSEMBLER- :>: [email protected]] On Behalf Of John Ehrman :>: Sent: Wednesday, May 16, 2012 9:48 AM :>: To: [email protected] :>: Subject: MVC with 2nd operand length :>: :>: This macro uses the length attribute of the second operand as the length :>: value in the MVC: :>: Macro :>:&Lab MVC2&Target,&Source :>:&Lab CLC 0(0,0),&Source X'D500 0000',S(&Source) :>: Org *-6 Back up to first byte of instruction :>: LA 0,&Target.(0) X'4100',S(&Target),S(&Source) :>: Org *-4 Back up to first byte of instruction :>: DC AL1(X'D2',L'&Source-1) First 2 bytes of instruction :>: Org *+4 Step to next instruction :>: MEnd :>: :>: Just write :>: MVC2 Target,=C'Whatever you like' I must be missing something obvious. Why not simply MACRO &Lab MVC2&Target,&Source &Lab MVC&Target(L'&Source-1),&Source MEND or avoid the macro completely with &Lab MVC Label1(L'Label2-1),Label2
