Document Number:     J4/02-0251

2002-11-22 

 

DF-1.2           Page    1  of   3

Subject: 

Restricted program pointer with AS phrase on CALL stmt

Author: 

Artur Reimann, Thane Hubbell

Previous Version: 

02-0116 

http://www.cobolstandard.info/j4020116.htm

References:

1.

ISO/IEC FDIS 1989:2002, Programming language

COBOL:

Page 420, 14.8.4 CALL statement

02-0070  –Restricted program pointer with AS phrase on

CALL stmt (Schricker)

 

http://www.cobolstandard.info/j4020070.htm

Is the AS phrase allowed to override a restricted program pointer?  There is no rule that prohibits

it.

Consider, for example:

Should this CALL statement be legal?

Document Number:     J4/02-0251

2002-11-22 

 

DF-1.2           Page    2  of   3

Note that

 

SET pp-1 TO ADDRESS OF PROGRAM program-2

is invalid according to the syntax rules of the SET statement unless the signatures of program-1

and program-2 are the same.  Therefore, it would seem that this AS phrase should not be allowed

on the CALL statement unless the two signatures are the same, and in that case there is no need

for the AS phrase.

General rule 7 of the CALL statement, which applies to the format 3 (the program-prototype for-

mat) reads:

7) If the NESTED phrase is not specified, program-prototype-name-1, or the program prototype

specified in the definition of identifier-1 if it is defined as a restricted program-pointer, is used to de-

termine the characteristics of the called program.

This implies that specifying program-prototype-name-1 and specifying a restricted program-

pointer for identifier-1 are mutually exclusive.  Taken literally, it means that program-prototype-

name-1 is ignored if identifer-1 is a restricted program-pointer.  Why require program-prototype-

name-1 to be specified if it is to be ignored?  This seems like an error.

There are a couple of solutions that come to mind:

Solution 1 – New syntax

change the syntax diagram for format 3 of the CALL statement so that the first line reads:

 identifier-1

NESTED

AS

 literal-1

 program-prototype-name-1

 

CALL

 identifier-5

update the syntax rules so that

- identifier-5 is required to be a restricted program-pointer

- if identifier-1 is a program-pointer, it is not a restricted program-pointer.

Solution 2 – no change to the syntax, new syntax rule

Add a syntax rule so that when identifer-1 is a restricted program-pointer, it must be restricted to

program-prototype-name-1.  This seems very ugly.  There's no reason to specify the program

prototype when one has no choice as to what it is.

Summary

If we do nothing, either typing for program-pointers is broken or the user is required to specify

syntax that is ignored.  Implementations may differ in their interpretation.

I favor solution 1.

Document Number:     J4/02-0251

2002-11-22 

 

DF-1.2           Page    3  of   3

Mr. Hubbell moved and Mr. Stevens seconded:  To approve the Proposed Response and

Changes Needed sections of 02-0116, and to request that Mr. Hubbell prepare an ISO-format

defect report based on this document,   Passed;  Yes – 7; No – 0; Abstain – 0.