fix bug of loop_vars in loop_transformer.test=develop (#23180)

python/paddle/fluid/dygraph/dygraph_to_static/loop_transformer.py

@@ -169,7 +169,7 @@ class NameVisitor(gast.NodeVisitor):
         if self._is_call_func_name_node(node):
             self.generic_visit(node)
             return
-        if node.id == "False" or node.id == "True":
+        if node.id == "False" or node.id == "True" or node.id == "None":
             self.generic_visit(node)
             return
 
@@ -187,7 +187,6 @@ class NameVisitor(gast.NodeVisitor):
     def visit_Attribute(self, node):
         if self._is_call_func_name_node(node):
             return
-
         attr_full_name = get_attribute_full_name(node)
         self.current_seen_vars.add(node)
         for loop_node in self.current_loop:

python/paddle/fluid/tests/unittests/dygraph_to_static/test_loop.py

@@ -35,6 +35,17 @@ def while_loop_dyfunc(x):
     return i
 
 
+def while_loop_dyfunc_with_none(x):
+    i = fluid.dygraph.to_variable(x)\
+        if x is not None \
+        else fluid.dygraph.to_variable(x+1)
+    flag = 1
+    while x < 10:
+        i = i + x if flag is not None else x + i
+        x = x + 1
+    return i
+
+
 def for_loop_dyfunc(max_len):
     for i in range(max_len):
         ret = fluid.layers.zeros(shape=[1], dtype='float32')
@@ -58,9 +69,14 @@ def var_create_in_for_loop(max_len):
 
 class TestNameVisitor(unittest.TestCase):
     def setUp(self):
-        self.loop_funcs = [while_loop_dyfunc, for_loop_dyfunc]
-        self.loop_var_names = [set(["i", "x"]), set(["i", "ret", "max_len"])]
-        self.create_var_names = [set(), set(["ret"])]
+        self.loop_funcs = [
+            while_loop_dyfunc, for_loop_dyfunc, while_loop_dyfunc_with_none
+        ]
+        self.loop_var_names = [
+            set(["i", "x"]), set(["i", "ret", "max_len"]),
+            set(["i", "x", "flag"])
+        ]
+        self.create_var_names = [set(), set(["ret"]), set()]
 
     def test_loop_vars(self):
         for i in range(len(self.loop_funcs)):
@@ -115,6 +131,11 @@ class TestTransformWhileLoop(unittest.TestCase):
         # self.assertTrue(np.allclose(self._run_dygraph(), self._run_static()))
 
 
+class TestTransformWhileLoopWithNone(TestTransformWhileLoop):
+    def _init_dyfunc(self):
+        self.dyfunc = while_loop_dyfunc_with_none
+
+
 class TestWhileLoopBoolOp(TestTransformWhileLoop):
     def _init_dyfunc(self):
         self.dyfunc = while_loop_bool_op