From 31c68e3d062def638f35f54ff5c533f0085b2aa1 Mon Sep 17 00:00:00 2001
From: zhhsplendid <zhhsplendid@163.com>
Date: Fri, 30 Apr 2021 06:24:37 +0000
Subject: [PATCH 1/3] Fix to_tensor Bug Reported from QA

---
 .../basic_api_transformer.py                  | 33 +++++++++++++++----
 1 file changed, 26 insertions(+), 7 deletions(-)

diff --git a/python/paddle/fluid/dygraph/dygraph_to_static/basic_api_transformer.py b/python/paddle/fluid/dygraph/dygraph_to_static/basic_api_transformer.py
index 198c2920eec7f..953def62191dd 100644
--- a/python/paddle/fluid/dygraph/dygraph_to_static/basic_api_transformer.py
+++ b/python/paddle/fluid/dygraph/dygraph_to_static/basic_api_transformer.py
@@ -33,10 +33,11 @@ def __init__(self, wrapper_root):
         self.root = wrapper_root.node
         self.class_node_dict = {}
 
-        self.name_to_tensor_shape = {}
-
     def transform(self):
+        to_tensor_transformer = ToTensorTransformer(self.root)
+        to_tensor_transformer.transform()
         self.visit(self.root)
+
         return self.wrapper_root
 
     def visit_Assign(self, node):
@@ -62,11 +63,6 @@ def visit_Expr(self, node):
 
     def _visit_Call(self, node):
         assert isinstance(node, gast.Call)
-        # Replace API `to_variable` with `fluid.layers.assign`
-        if is_to_variable(node):
-            node = to_assign_node(node)
-            return node
-
         func_name = astor.to_source(gast.gast_to_ast(node.func))
 
         if self._is_dygraph_forward(func_name):
@@ -102,6 +98,29 @@ def _update_class_node_dict(self, node):
         return False
 
 
+class ToTensorTransformer(gast.NodeTransformer):
+    """
+    Class to transform paddle.to_tensor and paddle.to_variable to paddle.assign
+    """
+
+    def __init__(self, node):
+        assert isinstance(
+            node, gast.AST
+        ), "Input non-gast.AST node for the initialization of ToTensorTransformer."
+        self.root = node
+
+    def transform(self):
+        self.visit(self.root)
+        return self.root
+
+    def visit_Call(node):
+        assert isinstance(node, gast.Call)
+        if is_to_variable(node):
+            node = to_assign_node(node)
+        generic_visit(node)
+        return node
+
+
 def is_to_variable(node):
     assert isinstance(node, gast.Call)
     api_name = utils.ast_to_source_code(node.func).strip()

From 7b9239ed32dbcb0351e56695ba315c74ec7b66f9 Mon Sep 17 00:00:00 2001
From: zhhsplendid <zhhsplendid@163.com>
Date: Fri, 30 Apr 2021 06:34:05 +0000
Subject: [PATCH 2/3] Add test

---
 .../dygraph_to_static/test_basic_api_transformation.py      | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/python/paddle/fluid/tests/unittests/dygraph_to_static/test_basic_api_transformation.py b/python/paddle/fluid/tests/unittests/dygraph_to_static/test_basic_api_transformation.py
index 630b804f9a2fb..ea745ad661425 100644
--- a/python/paddle/fluid/tests/unittests/dygraph_to_static/test_basic_api_transformation.py
+++ b/python/paddle/fluid/tests/unittests/dygraph_to_static/test_basic_api_transformation.py
@@ -64,13 +64,11 @@ def dyfunc_int_to_tensor(x):
 
 
 def dyfunc_float_to_tensor(x):
-    res = paddle.to_tensor(2.0)
-    return res
+    return paddle.to_tensor(2.0)
 
 
 def dyfunc_bool_to_tensor(x):
-    res = paddle.to_tensor(True)
-    return res
+    return paddle.to_tensor(True)
 
 
 class TestDygraphBasicApi_ToVariable(unittest.TestCase):

From 127f85d292035b368606c7239206db5fa67b9f5b Mon Sep 17 00:00:00 2001
From: zhhsplendid <zhhsplendid@163.com>
Date: Fri, 30 Apr 2021 06:58:03 +0000
Subject: [PATCH 3/3] Add test and fix bug during test

---
 .../fluid/dygraph/dygraph_to_static/basic_api_transformer.py  | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/python/paddle/fluid/dygraph/dygraph_to_static/basic_api_transformer.py b/python/paddle/fluid/dygraph/dygraph_to_static/basic_api_transformer.py
index 953def62191dd..5ea1fdfac0928 100644
--- a/python/paddle/fluid/dygraph/dygraph_to_static/basic_api_transformer.py
+++ b/python/paddle/fluid/dygraph/dygraph_to_static/basic_api_transformer.py
@@ -113,11 +113,11 @@ def transform(self):
         self.visit(self.root)
         return self.root
 
-    def visit_Call(node):
+    def visit_Call(self, node):
         assert isinstance(node, gast.Call)
         if is_to_variable(node):
             node = to_assign_node(node)
-        generic_visit(node)
+        self.generic_visit(node)
         return node