Enable MPI_F08 (#687)

* Promote MPI_F08 to an error if requested and not present

* Remove unsed parameter

* Test F08 with latest GCC

.github/workflows/testing-gcc.yml

@@ -27,6 +27,7 @@ jobs:
           -DUSE_MPI=OFF \
           -DUSE_OPENMP=ON \
           -DUSE_SMM=blas \
+          -DUSE_MPI_F08=ON \
           ..
 
     - name: Build

CMakeLists.txt

@@ -201,10 +201,9 @@ Intel MPI compiler wrappers. Check the INSTALL.md for more information.")
   if (USE_MPI_F08)
     if (NOT MPI_Fortran_HAVE_F08_MODULE)
       message(
-        WARNING
-          "The listed MPI implementation does not provide the required mpi_f08.mod interface. \
-The Fortran 90 bindings will be used instead.")
-      set(USE_MPI_F08 OFF)
+        FATAL_ERROR
+          "The listed MPI implementation does not provide the required mpi_f08.mod interface."
+      )
     endif ()
   endif ()
   if ("${MPI_Fortran_LIBRARY_VERSION_STRING}" MATCHES "Open MPI v2.1"

src/mpi/dbcsr_mpiwrap.F

@@ -110,7 +110,6 @@ MODULE dbcsr_mpiwrap
    MPI_WIN_TYPE, PARAMETER :: mp_win_null_handle = MPI_WIN_NULL
    MPI_FILE_TYPE, PARAMETER :: mp_file_null_handle = MPI_FILE_NULL
    MPI_INFO_TYPE, PARAMETER :: mp_info_null_handle = MPI_INFO_NULL
-   MPI_DATA_TYPE, PARAMETER :: mp_datatype_null_handle = MPI_DATATYPE_NULL
    INTEGER, PARAMETER, PUBLIC :: mp_status_size = MPI_STATUS_SIZE
    INTEGER, PARAMETER, PUBLIC :: mp_proc_null = MPI_PROC_NULL
    ! Set max allocatable memory by MPI to 2 GiByte
@@ -137,7 +136,6 @@ MODULE dbcsr_mpiwrap
    MPI_WIN_TYPE, PARAMETER :: mp_win_null_handle = -5
    MPI_FILE_TYPE, PARAMETER :: mp_file_null_handle = -6
    MPI_INFO_TYPE, PARAMETER :: mp_info_null_handle = -7
-   MPI_DATA_TYPE, PARAMETER :: mp_datatype_null_handle = -8
    INTEGER, PARAMETER, PUBLIC :: mp_status_size = -7
    INTEGER, PARAMETER, PUBLIC :: mp_proc_null = -8
    INTEGER, PARAMETER, PUBLIC :: mp_max_library_version_string = 1