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/Branches.py

@@ -8,7 +8,7 @@ from Infrastructure.Instruction import Instruction
 from Infrastructure.Variables import ERROR_MARKER_COMMENT_BEGIN, ERROR_MARKER_COMMENT_END, ERROR_MARKER_COMMENT_BEGIN_FORT, ERROR_MARKER_COMMENT_END_FORT, adjust_var_language
 import Infrastructure.Variables as infvars
 
-for_template_c = "for (int i = @START@; i < @END@; ++i)"
+for_template_c = "for (int i = @START@; i < @END@; ++i) {"
 for_template_fort = "do i=@START@, @END@"
 
 if_template_c = "if (@COND@) {"
@@ -46,9 +46,11 @@ class IfBranch(Branch):
     def header(self):
         if infvars.generator_language == "c":
             res = if_template_c.replace("@COND@", self._cond)
+            elseif_str = "} else"
         else:
             res = if_template_fort.replace("@COND@", adjust_var_language(self._cond)).replace("!=", "/=")
-        return res if not self._elseif else f"else {res}"
+            elseif_str = "else"
+        return res if not self._elseif else f"{elseif_str} {res}"
 
     @override
     @staticmethod