J3/04-319

To: J3
From: Dan Nagle
Subject: Enhanced STOP
Date: 2004 May 14

The spreadsheet 265r1 lists "Enhanced STOP" as a trivial
item.  This paper attempts to provide edits against 04-007
to put Enhanced STOP into the next standard.

Number:

Title: Enhanced STOP

Submitted By: J3

Status: For Consideration

References: 04-007 8.4 STOP Statement page 170

Basic Functionality: Trivially enhance the STOP statement
                     for modern processors

Rationale:  The current STOP statement is vaguely defined, apparently
            to allow some (older) processors to conform to the standard.
            This paper attempts to provide edits to enhance
            the STOP statement for modern practice.

Estimated Impact: At 167, J3/JoR estimated the impact as "Trivial".
                  This is recorded in 04-265r1.

Detailed Specification: Allow scalar-default-integer-constants to be
                        the <stop-code>.  Suggest writing to stderr
                        as the preferred meaning of "made available"
                        and suggest that when the <stop-code> is
                        an integer constant that it be used as the process
                        exit status if possible.

                        Edits:

                        [170:23]
                        replace "<digit [ digit [ digit [ digit [ digit ]]]]>"
                        by "<scalar-int-constant>"

                        [170:24+] add
                        "C834+ (R850) The <scalar-int-constant> shall be
                        of default kind.

                        Note 8.21+ When the <stop-code> is an integer constant,
                        it is recommended that the value be used
                        as the process exit status,
                        if the operating system supports that concept.
                        If the integer <stop-code> is used as the process
                        exit status, the operating system might be able
                        to interpret only values within a limited range,
                        or only a limited portion (for example,
                        the lower 8 bits) of the integer value."

                        [170:29+] add
                        "Note 8.21++  The 'processor-dependent manner'
                        by which a <stop-code> is made available is
                        recommended to be by means of formatted output
                        to the processor-dependent external unit
                        identified by the named constant ERROR_UNIT
                        of the ISO_FORTRAN_ENV intrinsic module (Section 9.4)."

History: Submitted by paper 04-102 at meeting 167.