Draft: Fortran Support

Testing using level 2

Disqualified Tests:

• Passing NULL/MPI_REQUEST_NULL causes compile errors in Fortran, disqualifying InvalidParam tests that do this
  • Disqualifies 17 tests (lvl1) / 136 (lvl2)
• A lot of tests are currently removed due to datatypes, i.e., MPI C types that do not exist / are not implemented yet for Fortran
  • No effect on lvl1, as only MPI_INT and MPI_DOUBLE are used / 501 disqualified (lvl2)

Unfixable, but not disqualified:

• InvalidParam-Status-mpi_recv-002: MPI_STATUSES_IGNORE rejected by compiler, different rank than expected
  • Error class does not exist for Fortran. Disqualifies 1 test (lvl1) / 16 (lvl2)

MPI Issues:

• https://github.com/open-mpi/ompi/issues/9534 - Causes issues with Precv_Init / Psend_init. Need recent OpenMPI version to avoid this
• https://github.com/open-mpi/ompi/pull/13308 - Bug in OpenMPI-git causes compilation failure as well

Types are translated from C to Fortran where applicable, though currently only for MPI_INT -> MPI_INTEGER, MPI_DOUBLE -> MPI_DOUBLE_PRECISION, MPI_C_BOOL -> MPI_LOGICAL as most Fortran MPI types are optional. Tests are formatted using fprettify (available from pip, added to Pipfile).

Common Issues encountered:

• MPI does not differentiate between bool and int, but does between integer and logical.
  • Workaround: Use bool where applicable in C code, then translate to logical
• Different integer size expectations cause compilation failures (no automatic extension)
  • Workaround: During parsing of apis.json, save the integer width, and perform explicit widening if needed.
• C usage of address-of-integer as a one-dimensional array does not work in Fortran
  • Workaround: Replace uses thereof with proper arrays
• Array Indexing starts at 1
  • Workaround: Implement explicit indexing to match C

MPI-BugBench bugs (since remembering to write them down):

• Deadlock in CallOrdering-mpi_improbe-mpi_send-001, wrong parameter used as flag
  • Note: Deadlock also happens in InvalidParam-flag-mpi_iprobe-002, but intended? (not_allocated flag is not waited on, but the "normal" one)

scripts/Infrastructure/TemplateFactory.py

@@ -578,7 +578,7 @@ def replace_wait(wait_call, tm, wait_func_to_use, provide_request_array: bool =
         idx_name = tm.add_stack_variable("int")
         idx_array = tm.add_stack_variable("int", arr_dim=1)
         test_call = MPICallFactory.mpi_waitsome("1", wait_call.get_arg("request"), "&" + idx_name,
-                                                "&" + idx_array, status_to_use)
+                                                idx_array, status_to_use)
         test_call.set_rank_executing(wait_call.get_rank_executing())
         test_call.set_identifier(wait_call.get_identifier())
         tm.insert_instruction(test_call, before_instruction=wait_call)  # insertion before the improbe call
@@ -587,7 +587,7 @@ def replace_wait(wait_call, tm, wait_func_to_use, provide_request_array: bool =
     if wait_func_to_use == "mpi_testsome":
         flag_name = tm.add_stack_variable("int")
         idx_array = tm.add_stack_variable("int", arr_dim=1)
-        test_call = MPICallFactory.mpi_testsome("1", wait_call.get_arg("request"), "&" + flag_name, "&" + idx_array,
+        test_call = MPICallFactory.mpi_testsome("1", wait_call.get_arg("request"), "&" + flag_name, idx_array,
                                                 status_to_use)
         test_call.set_rank_executing(wait_call.get_rank_executing())
         test_call.set_identifier(wait_call.get_identifier())