The SYSDEFSD DD statement defines the location for the binder to write IMPORT statements for all exported entries of a DLL load module. Whenever entries are to be exported, the binder expects the SYSDEFSD data set and, if it is not present, will issue a warning message to indicate the missing data set. Product developers who supply DLLs do not always want or need the IMPORT statements associated with a DLL retained. In these instances, the SYSDEFSD would be better defined as either a temporary or DUMMY data set.

In each case, the SIDE DECK LIBRARY subentry of the LMOD entry will be set to SMPDUMMY. When needed for processing, SMPDUMMY will be dynamically allocated by SMP/E as a DUMMY data set.