X 5.3.16.7 PROCEDURE-POINTER Phrase
X A procedure-pointer data item can contain the address of a procedure entry
X point. Procedure-pointer data items can be compared for equality or moved
X to other procedure-pointer data items.
X >_Host_> Under OS/390 and VM, a procedure-pointer data item is an 8-byte
X elementary item. <_Host_<
X >_Workstation_> Under AIX, OS/2, and Windows, a procedure-pointer data
X item is a 4-byte elementary item. <_Workstation_<
X The entry point for a procedure-pointer data item can be:
- X The primary entry point of a COBOL program as defined by the
X PROGRAM-ID statement of the outermost program of a compilation unit;
X it must not be the PROGRAM-ID of a nested program.
- X An alternate entry point of a COBOL program as defined by a COBOL
X ENTRY statement
- X An entry point in a non-COBOL program.
X The entry point address and code address are contained in the first word.
X The second word is binary zero.
X A procedure-pointer data item can only be used:
- X In a SET statement (Format 6 only)
- X In a CALL statement
- X In a relation condition
- X In the USING phrase of an ENTRY statement or the Procedure Division
X header
X The USAGE IS PROCEDURE-POINTER clause can be written at any level except
X level 88. If a group item is described with the USAGE IS
X PROCEDURE-POINTER clause, the elementary items within the group are
X procedure-pointer data items; the group itself is not a procedure-pointer
X and cannot be used in the syntax where a procedure-pointer data item is
X allowed. The USAGE clause of an elementary item cannot contradict the
X USAGE clause of a group to which the item belongs.
X Procedure-pointer data items can be part of a group that is referred to in
X a MOVE statement or an input/output statement. However, there is no
X conversion of values when the statement is executed. If a
X procedure-pointer data item is written to a data set, subsequent reading
X of the record containing the procedure-pointer can result in an invalid
X value in the procedure-pointer.
X A procedure-pointer data item can be the subject or object of a REDEFINES
X clause.
X SYNCHRONIZED can be used with USAGE IS PROCEDURE-POINTER to obtain
X efficient alignment of the procedure-pointer data item.
X The GLOBAL, EXTERNAL, and OCCURS clause can be used with USAGE IS
X PROCEDURE-POINTER.
X A VALUE clause for a procedure-pointer data item can contain only NULL or
X NULLS.
X The DATE FORMAT, JUSTIFIED, PICTURE, and BLANK WHEN ZERO clauses cannot be
X used to describe group or elementary items defined with the USAGE IS
X PROCEDURE-POINTER clause.
X A procedure-pointer data item cannot be a conditional variable.
X A procedure-pointer data item does not belong to any class or category.
X Procedure-pointer data items are ignored in CORRESPONDING operations.
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