LISTING exit processing

You can use the LISTING exit to override the effect of the LIST assembler option. The exit does this by indicating to the assembler that it opens the listing data set and does all listing output processing. Then, as each listing record is passed to the exit, the exit can decide whether to print the record, and where it writes the record. For instance, the exit can write the listing records to a different data set than the assembler normally writes them.

The LISTING exit is not called if you specify the NOLIST assembler option. If you want to process the listing records in the exit but you do not want the assembler to write the records to the normal output data set, you can do one of these actions:

Instruct the assembler to discard the listing records by setting the exit return code.
Suppress the listing output by doing this action:
z/OS

Provide a //SYSPRINT DD DUMMY JCL statement.

CMS

Issue a FILEDEF SYSPRINT DUMMY command.

z/VSE

Assign the SYSLST to IGN.
Instruct the exit to issue an OPEN return code of 4.

The sections of the listing that are passed to the exit depend on the assembler options you specify. For instance, if you specify the NORLD option, then no Relocation Dictionary listing records are passed to the exit.

z/VM and z/OS: Although the assembler can write to a listing data set with a record format of variable-length, the exit is always presented with fixed-length records.

The assembler calls the LISTING exit with the following request types: