What the prelinker does

The prelinker performs the following functions:

• Collects information for runtime initialization, including data initialization for C/C++, constructor/destructor calls for static objects in C++, and DLL initialization information.
• For C object modules compiled with RENT, C++ programs, Enterprise PL/I for z/OS programs, or COBOL programs with OO extensions, the prelinker:
  • Combines writable static initialization information
  • Assigns relative offsets to objects in writable static storage
  • Removes writable static name and relocation information
• For programs containing longnames, such as C programs compiled with LONGNAME, C++ programs, Enterprise PL/I for z/OS programs, and COBOL programs compiled with PGMNAME(LONGMIXED) or PGMNAME(LONGUPPER), the prelinker maps LONGNAME option to SHORTNAME option on output.
• For programs that use DLLs, the prelinker:
  • Generates a function descriptor in writable static for each DLL referenced function
  • Generates a variable descriptor for each DLL referenced variable
  • Generates an IMPORT control statement for each exported function and variable
  • Generates internal information for the load module that describes symbols that are exported to and imported from other load modules
  • Combines static DLL initialization information
  • Uses longnames to resolve exported and imported symbols