#190 Raise an error if the imported global is already declared in the…

… NameSpaceManager

src/psyclone/psyGen.py

@@ -1937,8 +1937,16 @@ def gen_code(self, parent):
         for module_name, var_list in module_map.items():
             self._name_space_manager.add_reserved_name(module_name)
             for var_name in var_list:
-                self._name_space_manager.create_name(
-                    root_name=var_name, context="AlgArgs", label=var_name)
+                newname = self._name_space_manager.create_name(
+                    root_name=var_name,
+                    context="AlgArgs",
+                    label=var_name)
+                # There is a name clash with this variable name and we can not
+                # accept indexed names for global variables.
+                if var_name != newname:
+                    raise KeyError(
+                        "The imported variable '{0}' is already defined in the"
+                        " NameSpaceManager of the Invoke.".format(var_name))
 
         if self._opencl:
             parent.add(UseGen(parent, name="iso_c_binding"))

src/psyclone/tests/domain/gocean/transformations/globalstoargs_test.py

@@ -292,7 +292,7 @@ def set_to_real(variable):
         " by another symbol." in str(err.value)
 
 
-def test_globalstoargumentstrans_clash_namespace(monkeypatch):
+def test_globalstoargumentstrans_clash_namespace_after(monkeypatch):
     ''' Check the GlobalsToArguments transformation adds the module and global
     variable names into the NameSpaceManager to prevent clashes'''
     from psyclone.transformations import KernelGlobalsToArguments
@@ -326,3 +326,35 @@ def set_to_real(variable):
     # Created names should not clash with the imported module and globalvar
     assert newname1 == "rdt_1"
     assert newname2 == "model_mod_1"
+
+
+def test_globalstoargumentstrans_clash_namespace_before(monkeypatch):
+    ''' Check the GlobalsToArguments generation will break if the global
+    variable name has already been used in the NameSpaceManager'''
+    from psyclone.transformations import KernelGlobalsToArguments
+    from psyclone.psyir.symbols import DataSymbol
+
+    trans = KernelGlobalsToArguments()
+    # Construct a testing InvokeSchedule
+    _, invoke_info = parse(os.path.join(BASEPATH, "gocean1p0",
+                                        "single_invoke_kern_with_use.f90"),
+                           api=API)
+    psy = PSyFactory(API).create(invoke_info)
+    invoke = psy.invokes.invoke_list[0]
+    kernel = invoke.schedule.coded_kernels()[0]
+
+    # Monckeypatch resolve_deferred to avoid module searching and importing
+    # in this test. In this case we assume it is a REAL
+    def set_to_real(variable):
+        variable._datatype = DataType.REAL
+    monkeypatch.setattr(DataSymbol, "resolve_deferred", set_to_real)
+
+    # Reserve 'rdt'
+    _ = invoke._name_space_manager.add_reserved_name("rdt")
+
+    # Transform and generate the new code
+    trans.apply(kernel)
+    with pytest.raises(KeyError) as err:
+        _ = str(psy.gen)
+    assert "The imported variable 'rdt' is already defined in the NameSpace" \
+        "Manager of the Invoke." in str(err.value)