fix includes for successors for F2C

loki/transformations/transpile/fortran_c.py

@@ -9,7 +9,7 @@
 from collections import OrderedDict
 
 from loki.backend import cgen, fgen, cudagen
-from loki.batch import Transformation, ProcedureItem
+from loki.batch import Transformation
 from loki.expression import (
     symbols as sym, Variable, InlineCall, RangeIndex, Scalar, Array,
     ProcedureSymbol, SubstituteExpressions, Dereference, Reference,
@@ -201,14 +201,8 @@ def transform_subroutine(self, routine, **kwargs):
             Sourcefile.to_file(source=fgen(module), path=self.wrapperpath)
 
             # Generate C source file from Loki IR
-            # TODO: double-check whether this is called in real life and why this is not called by the tests ...
             for successor in successors:
-                if self.language == 'c':
-                    c_kernel.spec.prepend(Import(module=f'{successor.routine.name.lower()}_c.h', c_import=True))
-                else:
-                    # TODO: should include .h file, however problem compiling/running multiple compilation units ...
-                    if not isinstance(successor, ProcedureItem):
-                        c_kernel.spec.prepend(Import(module=f'{successor.routine.name.lower()}_c.c', c_import=True))
+                c_kernel.spec.prepend(Import(module=f'{successor.ir.name.lower()}_c.h', c_import=True))
 
             if depth == 1:
                 if self.language != 'c':

loki/transformations/transpile/tests/test_transpile.py

@@ -1336,6 +1336,8 @@ def test_scc_cuda_parametrise(tmp_path, here, frontend, config, horizontal, vert
     assert '#include<cuda_runtime.h>' in c_kernel
     assert '#include"kernel_c.h"' in c_kernel
     assert '#include"kernel_c_launch.h"' in c_kernel
+    assert 'include"elemental_device_c.h"' in c_kernel
+    assert 'include"device_c.h"' in c_kernel
     assert '__global__voidkernel_c' in c_kernel
     assert 'jl=threadidx.x;' in c_kernel
     assert 'b=blockidx.x;' in c_kernel
@@ -1404,6 +1406,8 @@ def test_scc_cuda_hoist(tmp_path, here, frontend, config, horizontal, vertical,
     assert '#include<cuda_runtime.h>' in c_kernel
     assert '#include"kernel_c.h"' in c_kernel
     assert '#include"kernel_c_launch.h"' in c_kernel
+    assert '#include"elemental_device_c.h"' in c_kernel
+    assert '#include"device_c.h"' in c_kernel
     assert '__global__voidkernel_c' in c_kernel
     assert 'jl=threadidx.x;' in c_kernel
     assert 'b=blockidx.x;' in c_kernel