Fix type of mpi_f08 MPI_ERRCODES_IGNORE

[nathanweeks]

Given following program:

program test_spawn
   use mpi_f08
   implicit none

   character(len=:), allocatable  :: command
   integer :: command_length, rank
   type(MPI_Comm) :: intercomm, parent

   call get_command_argument(number=0, length=command_length)
   allocate(character(len=command_length) :: command)
   call get_command_argument(number=0, value=command)

   call MPI_Init
   call MPI_Comm_get_parent(parent=parent)
   if (parent == MPI_COMM_NULL) then
      call MPI_Comm_spawn(command=command, argv=MPI_ARGV_NULL, maxprocs=2, info=MPI_INFO_NULL, root=0, &
                         comm=MPI_COMM_WORLD, intercomm=intercomm, array_of_errcodes=MPI_ERRCODES_IGNORE)
      write(unit=*, fmt='(*(g0))') 'parent'
   else
      call MPI_Comm_rank(comm=MPI_COMM_WORLD, rank=rank)
      write(unit=*, fmt='(*(g0))') 'child ', rank
   end if
   call MPI_Finalize
end program test_spawn

gfortran 7.1.0 emits the following error:

$ mpifort test_spawn.f90

                           comm=MPI_COMM_WORLD, intercomm=intercomm, array_of_errcodes=MPI_ERRCODES_IGNORE)
                                                                                                          1
Error: There is no specific subroutine for the generic 'mpi_comm_spawn' at (1)

Per MPI 3.1, the data type of the array_of_errcodes argument is:

INTEGER :: array_of_errcodes(*)

Changing the data type of the mpi_f08 version of MPI_ERRCODES_IGNORE from "integer" to "integer, dimension(1)" seems to resolve the issue:

$ mpifort -o test_spawn.x test_spawn.f90 
$ mpiexec -n 1 -mca btl self,tcp ./test_spawn.x
child 0
child 1
parent

[ompiteam-bot]

Can one of the admins verify this patch?

[ggouaillardet]

Thanks for the patch !

can you please sign-off your commit ?
first make sure you understand what it means (IANAL), and then you can

git commit --amend -s
git push --force issue/f08_mpi_errcodes_ignore <your remote repository>

[nathanweeks]

Done.

[rhc54]

ok to test

[artpol84]

bot:mellanox:retest

[artpol84]

bot:mellanox:retest

[jsquyres]

Good catch -- thank you!