COBOL Manual for TNS/E Programs (H06.08+, J06.03+)

• If the compiler does not find the routine on the primary search list, it searches for the routine
in the files on the tertiary search list if one exists. (One or more CONSULT directives build the
tertiary search list; see Putting an Object File on the Tertiary Search List (page 818).)
• If the compiler does not find the routine in a file on the tertiary search list, it searches for the
routine in the file ECOBEXT, ZCOBDLL, and ZCREDLL.
• If the compiler does not find the routines in ECOBEXT, ZCOBDLL or ZCREDLL, it reports an
error.
If the compiler cannot validate the parameters of an ENTER statement in a program unit, it does
not produce an object file for that program unit.
When the compiler generates an implicit reference to one of its own run-time routines or to an
operating system routine, the compiler leaves these references unresolved so that the code of the
corresponding routines will execute in system code space.
Figure 35 How External References Are Resolved
Unresolved References
If an external reference in an object file refers to an entry point that is not among the code blocks
in that object file, the external reference is called unresolved. Unresolved external references cause
Concepts and Terms 815