On the last point, the real answer is that since the attributes behave as if they were set by the now deprecated functions, they should themselves be deprecated, since we must not change their behavior. This is also the source of the int/MPI_Fint issue - there was no MPI_Fint in MPI-1. Bill On Jan 27, 2009, at 4:09 PM, MPI Forum wrote:

#55: MPI-2.1 Cross-language attribute example is wrong ----------------------------------- +---------------------------------------- Reporter: jsquyres | Owner: jsquyres Type: Correction to standard | Status: new Priority: Waiting for reviews | Milestone: 2008/12/15 Menlo Park Version: MPI 2.2 | Resolution: Keywords: | ----------------------------------- +----------------------------------------

Comment(by jsquyres):

I am re-working this proposal and will post a new one soon. Some things that have been consistently missed by multiple reviewers:

* The original example is '''definitely wrong'''. MPI_COMM_PUT_ATTR does not exist; the correct call is MPI_COMM_SET_ATTR. * The original example is '''definitely wrong'''. Example B sets an INTEGER(KIND=MPI_ADDRESS_KIND) value, and therefore the output C type must be MPI_Aint* (not (int*)) -- regardless of the behavior of predefined attributes. * If predefined attributes are supposed to behave as if they were set via the (deprecated!) Fortran MPI-1 function, then the value when retrieved in C (e.g., MPI_TAG_UB) should actually be of type MPI_Fint, not int. I think that the text in MPI-2.1 p488:3 is wrong on this point (i.e., s/int/MPI_Fint/).

Per the last point, I think it is pretty good luck that existing MPI apps work when using (int*) instead of (MPI_Fint*) -- indeed, most compilers have the default sizeof(INTEGER) == sizeof(int). But that does not have to be the case; MPI_Fint is technically more correct.

Also per the last point, why are we specifying that predefined attributes behave as if they were set by deprecated functions? That seems strange.

-- Ticket URL: <https://svn.mpi-forum.org/trac/mpi-forum-web/ticket/55#comment:21

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