[MPIWG Fortran] MPI_SIZEOF: Errata required (was: Another MPI_SIZEOF question)

[Rolf Rabenseifner]

Only a remark on the impossibility of
continuation lines in mpif.h:

MPI-3.0 Errata from May 14, 2014, page 13, lines 38-43 tell:

"In principle, continuation lines would be possible in mpif.h 
(spaces in columns 73-131, & in column 132, and in column 6 
of the continuation line) but this would not be valid if the
source line length is extended with a compiler flag to 132
characters. Column 133 is also not available for the 
continuation character because lines longer than 132 
characters are invalid with some compilers by default."

Best regards
Rolf

----- Original Message -----
> From: "Bill Long" <longb at cray.com>
> To: "MPI-WG Fortran working group" <mpiwg-fortran at lists.mpi-forum.org>
> Sent: Thursday, June 12, 2014 9:33:26 PM
> Subject: Re: [MPIWG Fortran] MPI_SIZEOF: Errata	required	(was:	Another	MPI_SIZEOF question)
> 
> 
> On Jun 12, 2014, at 2:19 PM, Jeff Squyres (jsquyres)
> <jsquyres at cisco.com> wrote:
> 
> > On Jun 11, 2014, at 4:25 PM, Bill Long <longb at cray.com> wrote:
> > 
> >>> Actually, this doesn't work, either.  If you have an mpif.h that
> >>> contains an "INTERFACE MPI_Sizeof", the compiler will treat it
> >>> differently depending on whether it is included from source.f or
> >>> source.f90 (and probably other variants, too).  Gaahhh!
> >> 
> >> Not sure why you say this.  Unless the lines get too long because
> >> of long names, you can write an include file so that it works for
> >> both fixed and free source forms.  The assumed source form is the
> >> only distinction to the compiler between source files that end in
> >> .f and .f90.
> > 
> > Argh -- my Fortran ignorance rears its ugly head.  Yes, indenting
> > properly makes that problem go away.
> > 
> > It's a tight squeeze, but the longest interface I can find is with
> > COMPLEX(REAL128) and DIMENSION for 15 ranks; it barely fits into
> > 72 columns:
> 
> It is possible to have continuation lines by putting & in column 73
> of the line to be continued (which fixed-source rules will see in
> the “comment” part of the line, and free-source will see as a
> continuation sentinel) and also a & in column 6 of the following
> continuation line (which fixed-source rules will see as the normal
> continuation character, and free-source allows and represents
> removal of any spaces between the two & characters).   This CAN get
> foiled if the fixed-source compilation violates the “column 73-80 is
> a comment” rule by specifying a longer length for statement content.
> Some compilers do allow that.  You can help avoid that by moving the
> trailing & out farther - say column 132.  But there is always some
> risk from non-conforming compilers.
> 
> > 
> >      COMPLEX(REAL128),DIMENSION(1,1,1,1,1,1,1,1,1,1,1,1,1,1,*)::x
> > 
> > Quite ugly, of course.  But with a perl script to generate all the
> > possibilities (for maximum portability), it works.  Yuck.
> > 
> >> As you might recall from earlier conference calls,  I prefer that
> >> nothing be added to mpif.h that was not there before.  None of
> >> the new functions or constants.  It should be frozen at MPI 2.2
> >> for compatibility with legacy codes.  If programmers want to use
> >> new features, they have to modify their sources anyway, and
> >> should change to using a module at the same time.
> > 
> > There was unfortunately pushback from the Forum on this issue; we
> > lost that battle.
> 
> I seem to recall.  But I interpreted the question as for what was
> desired for MPI 4.0, and my opinion on that question is still the
> same as before.
> 
> Cheers,
> Bill
> 
> 
> > 
> > --
> > Jeff Squyres
> > jsquyres at cisco.com
> > For corporate legal information go to:
> > http://www.cisco.com/web/about/doing_business/legal/cri/
> > 
> > _______________________________________________
> > mpiwg-fortran mailing list
> > mpiwg-fortran at lists.mpi-forum.org
> > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-fortran
> 
> Bill Long
>                                                                       longb at cray.com
> Fortran Technical Suport  &                                  voice:
>  651-605-9024
> Bioinformatics Software Development                     fax:
>  651-605-9142
> Cray Inc./ Cray Plaza, Suite 210/ 380 Jackson St./ St. Paul, MN 55101
> 
> 
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-- 
Dr. Rolf Rabenseifner . . . . . . . . . .. email rabenseifner at hlrs.de
High Performance Computing Center (HLRS) . phone ++49(0)711/685-65530
University of Stuttgart . . . . . . . . .. fax ++49(0)711 / 685-65832
Head of Dpmt Parallel Computing . . . www.hlrs.de/people/rabenseifner
Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room 1.307)