[MPIWG Fortran] Another MPI_SIZEOF question

[Jeff Squyres (jsquyres)]

On Jun 6, 2014, at 9:27 PM, William Gropp <wgropp at illinois.edu> wrote:

> There's no (small) errata.  The Forum decided that MPI would no longer support Fortran 77 (and this was pretty clear from the discussions).  

To be clear: MPI has *never* supported Fortran 77.

> In MPI-2, MPI_SIZEOF was part of the extended support; the basic support did not include it and thus mpif.h could be implemented with Fortran 77 (see page 291, 10.2.4 in MPI-2.0).  

Ah, good point.

> This is no longer true; see 17.1.4 (mpif.h) which says the second set of function prototypes must be supported for all MPI functions, and page 621, where MPI_SIZEOF has a second set of function prototypes.  There are other references to overloading in mpif.h; see, for example, page 339, which would require an MPI implementation to provide different mpif.h files depending on which level of Fortran support is provided by the compiler (which might depend on a compiler switch!). 

Yeah, I kinda came to that same conclusion over the weekend (that OMPI's MPI_SIZEOF support in mpif.h would have to depend on which Fortran compiler is used).  Urrrgh...

-- 
Jeff Squyres
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