Fix Using "isinstance" in Loop, test=develop (#28641)

Fix a bug that used in PaddleGAN model which used `isinstance` in a for loop

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

@@ -22,6 +22,7 @@ from paddle.fluid import unique_name
 from paddle.fluid.dygraph.dygraph_to_static.static_analysis import AstNodeWrapper
 from paddle.fluid.dygraph.dygraph_to_static.static_analysis import NodeVarType
 from paddle.fluid.dygraph.dygraph_to_static.static_analysis import StaticAnalysisVisitor
+from paddle.fluid.dygraph.dygraph_to_static.utils import ast_to_source_code
 from paddle.fluid.dygraph.dygraph_to_static.utils import generate_name_node
 from paddle.fluid.dygraph.dygraph_to_static.utils import get_attribute_full_name
 from paddle.fluid.dygraph.dygraph_to_static.utils import ForNodeVisitor
@@ -84,6 +85,9 @@ class NameVisitor(gast.NodeVisitor):
         self.condition_vars = defaultdict(set)
         self.in_condition = False
 
+        # Some names are types, we shouldn't record them as loop var names.
+        self.type_vars = set()
+
         self.static_analysis_visitor = StaticAnalysisVisitor(root_node)
         self.node_to_wrapper_map = self.static_analysis_visitor.get_node_to_wrapper_map(
         )
@@ -249,6 +253,18 @@ class NameVisitor(gast.NodeVisitor):
         self.generic_visit(node)
         self.current_loop.pop()
 
+    def visit_Call(self, node):
+        # Store type var names such as "isinstance(x, some_type_names)" and
+        # Remove them later
+        if isinstance(node.func, gast.Name) and node.func.id == 'isinstance':
+            type_node = node.args[1]
+            if isinstance(type_node, gast.Tuple):
+                for element in type_node.elts:
+                    self.type_vars.add(ast_to_source_code(element))
+            else:
+                self.type_vars.add(ast_to_source_code(type_node))
+        self.generic_visit(node)
+
     def _var_nodes_to_names(self, node_set, ctx_filter_set=None):
         ret = set()
         for node in node_set:
@@ -290,6 +306,7 @@ class NameVisitor(gast.NodeVisitor):
         Remove unnecessary vars from before_loop_vars, after_loop_vars or in_loop_vars about loop_node.
             1. Remove target vars of gast.For from before_loop_vars or after_loop_vars.
             2. Remove vars only in gast.comprehension.
+            3. Remove vars that are type names, for example: "isinstance(x, var_type_name)"
         :param loop_vars: before_loop_vars, after_loop_vars or in_loop_vars of loop_node.
         :param loop_node: Current loop node.
         """
@@ -361,6 +378,12 @@ class NameVisitor(gast.NodeVisitor):
                 target_vars_of_for_node.add(var)
 
         removed_vars = target_vars_of_for_node | vars_of_list_generator
+
+        # 3. Remove var type names which are stored in self.type_vars
+        for var in loop_vars:
+            if ast_to_source_code(var) in self.type_vars:
+                removed_vars.add(var)
+
         return loop_vars - removed_vars
 
 

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

@@ -0,0 +1,112 @@
+# Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License
+
+import numpy as np
+import unittest
+
+import paddle
+import paddle.nn as nn
+
+
+class SimpleReturnLayer(nn.Layer):
+    def forward(self, x):
+        return x
+
+
+class AddAttrLayer(nn.Layer):
+    def __init__(self):
+        super(AddAttrLayer, self).__init__()
+        self.attr = None
+
+    def forward(self, x):
+        out = x + self.attr
+        return out
+
+
+class IsInstanceLayer(nn.Layer):
+    def __init__(self, layer):
+        super(IsInstanceLayer, self).__init__()
+        self.layer = layer
+
+    @paddle.jit.to_static
+    def forward(self, x):
+        if isinstance(self.layer, (AddAttrLayer, )):
+            self.layer.attr = x
+        res = self.layer(x)
+        return res
+
+
+class SequentialLayer(nn.Layer):
+    def __init__(self, layers):
+        super(SequentialLayer, self).__init__()
+        self.layers = nn.LayerList(layers)
+
+    @paddle.jit.to_static
+    def forward(self, x):
+        res = x
+        for layer in self.layers:
+            if isinstance(layer, AddAttrLayer):
+                layer.attr = x
+            res = layer(res)
+        return res
+
+
+def train(model, to_static):
+    prog_trans = paddle.jit.ProgramTranslator.get_instance()
+    prog_trans.enable(to_static)
+
+    x = paddle.ones(shape=[2, 3], dtype='int32')
+    out = model(x)
+
+    return out.numpy()
+
+
+class TestIsinstance(unittest.TestCase):
+    def test_isinstance_simple_return_layer(self):
+        model = IsInstanceLayer(SimpleReturnLayer())
+        self._test_model(model)
+
+    def test_isinstance_add_attr_layer(self):
+        model = IsInstanceLayer(AddAttrLayer())
+        self._test_model(model)
+
+    def test_sequential_layer(self):
+        layers = []
+        for i in range(5):
+            layers.append(SimpleReturnLayer())
+            layers.append(AddAttrLayer())
+        model = SequentialLayer(layers)
+        self._test_model(model)
+
+    def _test_model(self, model):
+        st_out = train(model, to_static=True)
+        dy_out = train(model, to_static=False)
+        self.assertTrue(
+            np.allclose(dy_out, st_out),
+            msg="dy_out:\n {}\n st_out:\n{}".format(dy_out, st_out))
+
+
+if __name__ == "__main__":
+    unittest.main()