&SYSLIB_DSN System Variable Symbol

Use &SYSLIB_DSN in a macro definition to obtain name of the data set from which the assembler read the macro definition statements. If the macro definition is a source macro definition, &SYSLIB_DSN is assigned the same value as &SYSIN_DSN.

The local-scope system variable symbol &SYSLIB_DSN is assigned a read-only value each time a macro definition is called.

When the assembler runs on the z/OS operating systems, the value of the character string assigned to &SYSLIB_DSN is always the value stored in the JFCB for SYSLIB.

When the assembler runs on the CMS component of the VM operating systems, and the macro definition is a library macro definition, &SYSLIB_DSN is assigned the file name, file type, and file mode of the data set.

z/VSE: When the macro definition is a library macro definition, &SYSLIB_DSN is assigned the library name and sublibrary name of the z/VSE Librarian file.

Examples

Under z/OS, &SYSLIB_DSN might be assigned a value such as:

SYS1.MACLIB

Under CMS, &SYSLIB_DSN might be assigned a value such as:

DMSGPI MACLIB S2

Under z/VSE, &SYSLIB_DSN might be assigned a value such as:

IJSYSRS.SYSLIB

Notes:

If the LIBRARY user exit provides the data set information then the value in &SYSLIB_DSN is the value extracted from the Exit-Specific Information block described in the section "Exit-Specific Information Block" in the HLASM Programmer's Guide.
The value of the type attribute of &SYSLIB_DSN (T'&SYSLIB_DSN) is always U.
The value of the count attribute of &SYSLIB_DSN (K'&SYSLIB_DSN) is equal to the number of characters assigned as a value to &SYSLIB_DSN.
Throughout the use of a macro definition, the value of &SYSLIB_DSN is considered a constant.