Multiple compilation units in a single assembly

z/OS® Debugger treats each assembler CSECT as a separate compilation unit (CU). If your assembler source contains more than one CSECT, then the EQALANGX file that you create will contain debug information for all the CSECTs.

In most cases, all of the CSECTs in the assembly will be present in the load module or program object. However, in some cases, one or more of the assemblies might not be present or might be replaced by other CSECTs of the same name. There are, therefore, two ways of loading the debug data for assemblies containing multiple CSECTs:

• When SET LDD ALL is in effect, the debug data for all CSECTs (CUs) in the assembly is loaded as the result of a single LOADDEBUGDATA (LDD) command.
• When SET LDD SINGLE is in effect, a separate LDD command must be issued for each CSECT (CU). This form must be used when one or more of the CSECTs in the assembly are not present in the load module or program object or when one or more of the CSECTs have been replaced by other CSECTs of the same name.

The following sections use an example assembly that generates two CSECTs: MYPROG and MYPROGA. The debug information for both of these CSECTs is in the data set yourid.EQALANGX(MYPROG).