J3/10-248
To: J3
From: Stan Whitlock
Subject: F03/0110 Restoring dropped restriction on ENTRY
Date: 2010 October 13

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NUMBER: F03/0110
TITLE: Restoring dropped restriction on ENTRY
KEYWORDS: ENTRY
DEFECT TYPE: Interpretation
STATUS: J3 consideration in progress

QUESTION:

It appears that a hard restriction found in ANSI X3.9-1978
was dropped when we published Fortran 90.  The restriction
on page 15-13 of the FORTRAN 77 standard says

>In a function subprogram, a variable name that is the same
>as an entry name must not appear in any statement that
>precedes the appearance of the entry name in an ENTRY
>statement, except in a type-statement.

so
	FUNCTION S()
	T = 13.0
	ENTRY T()
	END
is not standard-conforming.

The restriction appears to be missing from Fortran 90, 95,
2003.  Should it still be in force ?

ANSWER:

No, for whatever reason, the restriction was dropped a long time ago
and is not in F2008.  The above program does not violate the standard
with the placement of the assignment to T.  [10-007 10:5-8] Section
12.6.2.6 specifies that the results S and T in the above example share
the same memory so S() returns 13.0.  As is, the example is not standard-
conforming since no return value is set for T().

EDITS:

None

SUBMITTED BY: Michael Ingrassia

HISTORY: 07-341    m182  F03/0110 submitted
         10-xxx    m193  Draft answer for F2008