Mixing Static and Dynamic Linking

If you want to link some modules statically and others dynamically, you need to:

• Specify the Linker directive CALL when you build the executable program. To do this:
  • Check Resolve external calls at link time on the Compiler tab on your project properties page.

  With CALL set, the linker attempts to resolve all external references.

• Ensure that for each module that you want to call dynamically, you include an INCLUDE command in the link file with the operand TYPE=COBOL or TYPE=ASM. When the Linker processes the INCLUDE command, it does not actually include the module, but instead generates and includes a small Assembler module to dynamically call that entry point. When the CALL is executed at run time, the Assembler module asks the cobol run time to load the module and transfer control to it.

If there are any entry points defined in the statically linked modules that match entry points in the dynamically linked modules, you must also use the Linker directive NOEXPORT, to prevent the linker from making any of the entries in the executable program available to calling programs after it is loaded into memory. By default any ENTRY or CSECT or START symbol in all Assembler modules are normally loaded into the cobol run time system’s entry point table so NOEXPORT will prevent this behavior. Also use an ALIAS link file commands for the statically linked modules, including the main executable program. This technique gives you precise control over the type of linking you use for each module.