Using X-macros

Some macro services, such as LINK and LINKX, offer two macros, one for callers in primary mode and one for callers in either primary or AR mode. The names of the two macros are the same, except the macro that supports both primary and AR mode caller ends with an "X". This information refers to these macros as "X-macros". The rules for using all X-macros, except ESTAEX, are:

Callers in primary mode can invoke either macro.
Some parameters on the X-macros, however, are not valid for callers in primary mode. Some parameters on the non X-macros are not valid for callers in AR mode. Check the macro descriptions in z/OS MVS Programming: Assembler Services Reference ABE-HSP or z/OS MVS Programming: Assembler Services Reference IAR-XCT for these exceptions.
Callers in AR mode should issue the X-macro after issuing the SYSSTATE ASCENV=AR macro.
If a caller in AR mode issues the non X-macro, the system substitutes the X-macro and issues a message during assembly that informs you of the substitution.

IBM® recommends you always use ESTAEX unless your program and your recovery routine are in 24-bit addressing mode, in which case, you should use ESTAE.

If your program issues macros while it is in AR mode, make sure the macros support AR mode callers and that SYSSTATE ASCENV=AR is coded.

If you rewrite programs and use the X-macro instead of the non X-macro, you must change both the list and execute forms of the macro. If you change only the execute form of the macro, the system will not generate the longer parameter list that the X-macro requires.

Note that an X-macro generates a larger parameter list than the corresponding non X-macro. A program using the X-macros must provide a larger parameter list than if it used the non X-macro.