Linking DLLs

You can link DLL-enabled object modules into separate DLL program objects, or you can link them together statically. You can decide whether to package the application as one module or as several DLL modules at link time.

The DLL support in the z/OS® binder is recommended for linking DLL applications. The binder can directly receive the output of COBOL compilers.

Start of changeA binder-based DLL must reside in a PDSE or in a z/OS UNIX file.End of change

When using the binder to link a DLL application, use the following options:

Table 1. Binder options for DLL applications
Type of code Link using binder parameters:
DLL applications DYNAM(DLL), RENT
Applications that use mixed-case exported program-names

Class definitions or INVOKE statements

CASE(MIXED)

You must specify a SYSDEFSD DD statement to indicate the data set in which the binder should create a DLL definition side file. This side file contains IMPORT control statements for each symbol exported by a DLL. The binder SYSLIN input (the binding code that references the DLL code) must include the DLL definition side files for DLLs that are to be referenced from the module being linked.

If there are programs in the module that you do not want to make available with DLL linkage, you can edit the definition side file to remove these programs.

Example: sample JCL for a procedural DLL application

related references  
MVS™ Program Management: User's Guide and Reference (Binder support for DLLs)