Merge pull request #3456 from stfc/3446_fix_routine_update_symtab

(Closes #3446) Update to fix issues with codeblocks and routine names when comments exist.

Author: arporter

changelog

@@ -1,3 +1,6 @@
+   3) PR #3456 for #3446. Fix issues with CodeBlocks and routine names
+   in the presence of comments.
+
    2) PR #3450 for #3262. Updates the LFRic GPU scripts and aggregates
    the transformation statistics.
 

src/psyclone/psyir/nodes/routine.py

@@ -354,7 +354,12 @@ def update_parent_symbol_table(self, new_parent):
                                     (Fortran2003.Subroutine_Subprogram,
                                      Fortran2003.Function_Subprogram))
                     for routine in routines:
-                        name = str(routine.children[0].children[1])
+                        # Have to walk to find the subroutine_stmt as
+                        # comments can appear before the subroutine stmt.
+                        subroutine_stmt = walk(routine,
+                                               (Fortran2003.Subroutine_Stmt,
+                                                Fortran2003.Function_Stmt))
+                        name = str(subroutine_stmt[0].children[1])
                         if name == self.name:
                             raise GenerationError(
                                     f"Can't add routine '{self.name}' into"

src/psyclone/tests/psyir/nodes/routine_test.py

@@ -43,6 +43,7 @@
 
 from psyclone.errors import GenerationError
 from psyclone.psyGen import CodedKern
+from psyclone.psyir.frontend.fortran import FortranReader
 from psyclone.psyir.nodes import (Assignment, Call, CodeBlock, Container,
                                   Literal, Reference, Routine, ScopingNode)
 from psyclone.psyir.symbols import (
@@ -400,6 +401,47 @@ def test_routine_update_parent_symbol_table_illegal_parent(fortran_reader):
             in str(excinfo.value))
 
 
+@pytest.mark.parametrize("routine_type", ["function", "subroutine"])
+def test_routine_update_parent_symbol_table_with_comments(routine_type):
+    ''' Test when we have a CodeBlock representing a routine that
+    if there are also comments before it in the tree we can still
+    check the name of the subroutine without failing inside
+    update_parent_symbol_table. '''
+
+    code = f"""module test
+
+    contains
+
+        ! This routine will be a codeblock.
+        {routine_type} routine()
+            procedure (halo_exchange_routine) :: exchange_halo_group
+        end {routine_type}
+
+        subroutine routine1(a, b, c)
+            integer, intent(inout) :: a, b, c
+
+            call routine2()
+        end subroutine
+
+        subroutine routine2()
+
+        end subroutine
+
+end module"""
+
+    fortran_reader = FortranReader(ignore_comments=False)
+    psyir = fortran_reader.psyir_from_source(code)
+    alt_routine = Routine.create("routine")
+
+    module = psyir.walk(Container)[1]
+    assert isinstance(module.children[0], CodeBlock)
+    with pytest.raises(GenerationError) as excinfo:
+        module.addchild(alt_routine)
+    assert ("Can't add routine 'routine' into a scope that already contains "
+            "a resolved symbol with the same name."
+            in str(excinfo.value))
+
+
 def test_routine_update_parent_symbol_table():
     ''' Test the update_parent_symbol_table function of the Routine class.
     Some of the tests here are accessed through addchild of a container. '''