#3473 Consider loop control variable in Reference.is_write

Author: sergisiso

src/psyclone/psyir/nodes/reference.py

@@ -131,6 +131,7 @@ def is_write(self):
         from psyclone.psyir.nodes.assignment import Assignment
         from psyclone.psyir.nodes.call import Call
         from psyclone.psyir.nodes.intrinsic_call import IntrinsicCall
+        from psyclone.psyir.nodes.loop import Loop
         parent = self.parent
         # pure or inquiry IntrinsicCall nodes do not write to their arguments.
         if (isinstance(parent, IntrinsicCall) and (parent.is_inquiry or
@@ -144,6 +145,9 @@ def is_write(self):
         # The reference that is the LHS of an assignment is a write.
         if isinstance(parent, Assignment) and parent.lhs is self:
             return True
+        # Loop control variable is also a write
+        if isinstance(parent, Loop) and parent.variable_reference is self:
+            return True
         return False
 
     @property

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

@@ -620,6 +620,8 @@ def test_reference_is_write(fortran_reader):
        a = SIN(c)
        call somecall(a)
        a = b
+       do i=1,2
+       enddo
        end subroutine"""
     psyir = fortran_reader.psyir_from_source(code)
     references = psyir.walk(Reference)
@@ -640,6 +642,8 @@ def test_reference_is_write(fortran_reader):
     # a = b has a as write and b as not
     assert references[10].is_write
     assert not references[11].is_write
+    # Loop control variable
+    assert references[12].is_write
 
 
 def test_reference_component_indices(fortran_reader):