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/Template.py

@@ -334,7 +334,7 @@ class TemplateManager:
                 inst.set_rank_executing(rank_to_execute)
             self._instructions.append(inst)
 
-    def add_stack_variable(self, variable_type: str, name: str = "", init: str = "", arr_dim: int = 0) -> str:
+    def add_stack_variable(self, variable_type: str, name: str = "", init: str = "", arr_dim: int = 1) -> str:
         """
         Adds a new stack variable and returns its name to be used in the code.
         the variable is initialized with the initializer given by the correctParameter class
@@ -355,14 +355,19 @@ class TemplateManager:
         return name
     
     def get_stack_var(self, typename: str, name: str):
-        init = self._stack_variable_inits[name] if name in self._stack_variable_inits else CorrectParameterFactory().get_initializer(typename)
+        init = ""
+        if name in self._stack_variable_inits: init = self._stack_variable_inits[name] # Explicit init has priority
+        if not init and CorrectParameterFactory().get_initializer(typename): # If no explicit init, but implicit exists...
+            for _ in range(self._stack_variable_dims[name]): # Initialize for each element in array
+                init = init + CorrectParameterFactory().get_initializer(typename) + ", "
+            init = init[:-2] # remove last ", "
+        if init and self._stack_variable_dims[name] > 1: init = "{" + init + "}" # Add initializer braces
         if init: init = f"= {init}"
-        dims = ""
         if infvars.generator_language == "c":
-            if self._stack_variable_dims[name] > 0: dims = f"[{self._stack_variable_dims[name]}]"
+            dims = f"[{self._stack_variable_dims[name]}]" if self._stack_variable_dims[name] > 1 else "" # Set array dimension
             return f"{typename} {name}{dims} {init};\n"
         else:
-            if self._stack_variable_dims[name] > 0: dims = f"({self._stack_variable_dims[name]})"
+            dims = f"(0:{self._stack_variable_dims[name] - 1})" if self._stack_variable_dims[name] > 1 else "" # Set array dimension, including explicit starting index!
             init = init.replace("{", "(/").replace("}", "/)")
             type_prefix = f"type({typename})"
             if typename == "int": type_prefix = "integer"