09-267
To: J3
From: Malcolm Cohen
Subject: Interpretation request
Date: 2009 July 27


1. Introduction

This paper contains an interpretation request to handle the situation
mentioned in 09-261.  Although 09-261 contains a fix for this, that
interpretation request is actually on a different topic thus the separate
request.

The edit contained in the proposed answer to this request makes a
slightly stricter requirement than that of the edit in 09-261.


2. Interpretation Request

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NUMBER: F03/?
TITLE: Dummy procedure type compatibility
KEYWORDS: Dummy function, implicit interface
DEFECT TYPE: Interpretation
STATUS: J3 consideration in progress

QUESTION:

Consider
  PROGRAM EXAMPLE
  REAL,EXTERNAL :: F
  CALL S(F)
  END
  SUBROUTINE S(A)
  INTEGER,EXTERNAL :: A
  PRINT *,A()
  END SUBROUTINE
  REAL FUNCTION F()
    F = HUGE(0.0)
  END FUNCTION

Subclause 12.4.1.3 (pages 271-272) appear to require that the actual
argument corresponding to a procedure dummy argument must be a
function if the dummy procedure is referenced as a function, but there
seems to be no visible requirement for it to have the same type and
type parameters.  That would seem to make the above program standard
conforming.

Is there intended to be such a requirement?

ANSWER:

Yes, there should be such a requirement.
An edit is supplied to correct this oversight.

EDIT:

[271:28] Append new sentences to the end of paragraph 5 of 12.4.1.3
  "If both the actual argument and dummy argument are known to be
   functions, they shall have the same type and type parameters.
   If only the dummy argument is known to be a function, the function
   that would be invoked by a reference to the dummy argument shall
   have the same type and type parameters, \obs{except that an
   external function with assumed character length may be associated
   with a dummy argument with explicit character length}".
{The second sentence is there to catch an argument association chain,
 and this case needs to allow the obsolescent assumed-length character
 function.  In the case in the first sentence, the actual argument
 already is prevented from having assumed length by our other rules.}

SUBMITTED BY: Malcolm Cohen

HISTORY: 09-267    m189  Submitted

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