Several restrictions apply to each input or output procedure called by SORT
and to each output procedure called by MERGE.
Observe these restrictions:
- The procedure must not contain any SORT
or MERGE statements.
- You can use ALTER, GO TO,
and PERFORM statements in the procedure to refer to
procedure-names outside the input or output procedure.
However, control must return to the input or output procedure after a
GO TO or PERFORM statement.
- The remainder of the PROCEDURE DIVISION must not contain any transfers of
control to points inside the input or output procedure (with the
exception of the return of control from a declarative
section).
- In an input or output procedure, you can call a
program.
However, the called program cannot issue a SORT
or MERGE statement, and the called program must return to the
caller.
- During a SORT
or MERGE operation, the SD data item is used.
You must not use it in the output
procedure before the first RETURN executes.
If you move data into this record area
before the first RETURN statement, the first record to be returned will be
overwritten.