About prelinking, linking, and binding

When describing the process to build an application, this document refers to the bind step.

Normally, the program management binder is used to perform the bind step. However, in many cases the prelink and link steps can be used in place of the bind step. When they cannot be substituted, and the program management binder alone must be used, it will be stated.

The terms bind and link have multiple meanings.

With respect to building an application:
In both instances, the program management binder is performing the actual processing of converting the object file(s) into the application executable module.

Object files with longname symbols, reentrant writable static symbols, and DLL-style function calls require additional processing to build global data for the application.
The term link refers to the case where the binder does not perform this additional processing, due to one of the following:
- The processing is not required, because none of the object files in the application use constructed reentrancy, use long names, are DLL or are C++.
- The processing is handled by executing the prelinker step before running the binder.
The term bind refers to the case where the binder is required to perform this processing.
With respect to executing code in an application:
The linkage definition refers to the program call linkage between program functions and methods. This includes the passing of control and parameters. Refer to "Program Linkage" in z/OS XL C/C++ Language Reference for more information about linkage specification.

Some platforms have a single linkage convention. z/OS® has a number of linkage conventions, including standard operating system linkage, Extra Performance Linkage (XPLINK), and different non-XPLINK linkage conventions for C and C++.