08-222r3
To: J3
From: Van Snyder, originally Michael Ingrassia
Subject: Public Comment J32008
Date: 2008 August 15

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Commenter: Robert Corbett
Subject: "generic resolution"

Consider the program

       PROGRAM MAIN
         INTERFACE COS
           REAL FUNCTION MYCOS(X)
           END FUNCTION
         END INTERFACE
         CALL SUBR
       CONTAINS
         SUBROUTINE SUBR
           INTRINSIC COS
           PRINT *, COS(0.0)
         END SUBROUTINE
       END

       REAL FUNCTION MYCOS(X)
         MYCOS = 2.0
       END

When compiled using the compilers provided by Sun,
Cray, Intel, HP, and PathScale, the program prints
2.0.  When compiled using the compilers provided by
IBM, NAG, and GCC, the program prints 1.0.
Interpretations 90/000082 and 90/000086 require the
latter interpretation.  Text should be added to the
standard itself clarifying this point.

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J3 response:

Neither interpretation F90/000082 nor F90/000086, at least according to
http://j3-fortran.org/doc/archive/standing/006/96-006r2/96-006r2.b080,
mention the INTRINSIC attribute, and therefore do not appear to be
germane.

12.5.5.2p1 and 12.5.5.2p2 do not apply because the generic interface block
is not (defined) in the internal subroutine.  Although neither paragraph
includes the word "defined", the fact that host association is mentioned
in 12.5.5.2p4 makes it clear that the generic name is not accessed from
the host scoping unit, notwithstanding 16.5.1.5p2-3.  The relationship
between 12.5.5.2 and 16.5.1.5 should perhaps be clarified at a later time.

The program should print 1.0 because 12.5.5.2p3 specifies that the
intrinsic COS is referenced when 12.5.5.2p1-2 do not apply, and they do
not apply in this case.

An edit is supplied to clarify this.

[N1723:299:12.5.5.2p1-2]
Editor: Insert "defined" after "either is" twice, to make it clear that
host association is not under consideration.