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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 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 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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