HLASM Language Reference

&SYSADATA_MEMBER System Variable Symbol
When the assembler runs on the CMS component of the VM operating
systems, the value of the character string assigned to &SYSADATA_DSN is
determined as follows:
Figure 66. Contents of &SYSADATA_DSN on CMS
SYSADATA Allocated To:
CMS file
Dummy file (no physical I/O)
Labeled tape file
Contents of &SYSADATA_DSN:
The 8-character filename, the
8-character filetype, and the
2-character filemode of the file, each
separated by a space
DUMMY
The data set name of the tape file
Unlabeled tape file TAPn, where n is a value from 0 to 9,
or A to F.
For example, &SYSADATA_DSN might be assigned a value such as:
SAMPLE SYSADATA A1
The value of the character string assigned to &SYSADATA_DSN is the
file id from the SYSADAT dlbl.
For example, &SYSADATA_DSN might be assigned a value such as:
MYDATA
Notes:
1. The value of the type attribute of &SYSADATA_DSN (T'&SYSADATA_DSN) is
always U.
2. The value of the count attribute of &SYSADATA_DSN (K'&SYSADATA_DSN)
is equal to the number of characters assigned as a value to
&SYSADATA_DSN. In the CMS example above, the count attribute of
&SYSADATA_DSN is 20.
&SYSADATA_MEMBER System Variable Symbol
The value of &SYSADATA_MEMBER is always null. The value of the
type attribute is O, and the value of the count attribute is 0.
You can use &SYSADATA_MEMBER in a macro definition to obtain
the name of the data set member to which the assembler is writing the associated
data.
The local-scope system variable symbol &SYSADATA_MEMBER is assigned a
read-only value each time a macro definition is called.
264 HLASM V1R5 Language Reference