ABI: MPI_Abi_set_fortran_booleans() is broken, boolean values may not fit in C int

[dalcinl]

The current C prototype of MPI_Abi_set_fortran_booleans is

int MPI_Abi_set_fortran_booleans(int logical_size, int logical_true, int logical_false);

However, for logical size={8|16}, the values of logical_{true|false} may not fit in a C int.

Jeff has proposed the following quick fix in private communication with me:

int MPI_Abi_set_fortran_booleans(int logical_size, const void *logical_true, const void *logical_false);

PS: If the main intention of this API is to be called from Fortran, maybe we can take one small step further and use the Fortran-default pass-by-address for all arguments, that is, use const int *logical_size, --- --- this way saving about one second to type the extra VALUE attribute that would be required otherwise in the Fortran side to declare the Fortran interface to this BIND(C) routine.

[dalcinl]

@jeffhammond Please remember/consider my additional proposition. Calls to MPI_Abi_set_fortran_booleans for each logical size are optional, and if not called, MPI assumes int<N>_t TRUE=1 and int<N>_t FALSE=0.

[jeffhammond]

Fixing the binding is a smaller change than making it optional. I guess we will have to wait until 5.1 to make it optional.

[jeffhammond]

fixed by https://github.com/mpi-forum/mpi-standard/pull/1046

[jeffhammond]

superceded by #902