XREF

Syntax:

>>-.---.-.----.--XREF----------------------><
   +-/-+ +-NO-+

Parameters:

None

Properties:

Default: NOXREF
Phase: Syntax check
$SET: Initial

Dependencies:

XREF sets RESEQ immediately.

Set to NOXREF at end by NOLIST.

Comments:

This directive has no effect if the LIST directive is not specified.

To produce the cross-reference listing the Compiler needs extra work space on the disk. The space needed depends on the number of data items and procedure-names and the number of times they are referenced.

On UNIX, to produce the message "*End of cross reference listing" in the cross reference listing you must also specify the verbose compiler option, -v.

When the XREF directive is specified, extra information is added to the end of the .lst file produced:

  • Name of the data item
  • Type of the data item
  • Line number where the data item was defined, shown as n#
  • Line numbers where the data item was updated, shown as n*
  • Line numbers where the data item was tested, shown as n?
  • Number of times the data item appeared in the cross-reference listing, shown as (X n)
  • Procedure-name
  • Type of procedure

Example:

The following is an extract from a .lst file for a simple program:

     1 working-storage section.
     2 01 a  pic 9(2).
     3
     4 procedure division.
     5 main section.
     6     move 1 to a
     7     if a = 1 display "HELLO" end-if
     8     stop run.
     ...
* A                              Numeric DISPLAY
*          2#      6*      7?                           (X    3)
*
*               1 data-names
*
* MAIN                           Section
*          5#                                           (X    1)
*
*
*               1 procedure-names
* End of cross reference listing

The cross-referencing information shows that there is one data item, a, of type numeric display, which is defined on line 2, updated on line 6, and tested on line 7. The (X 3) at the end of the line refers to the number of times the data item appears in the cross-reference listing. The procedure-name main also appears in the listing, as a section which is referenced only once.