Fix returned arguments in IfElse_fn test=develop (#23102)

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

@@ -388,20 +388,20 @@ class IfConditionVisitor(object):
 
 
 class NameVisitor(gast.NodeVisitor):
-    def __init__(self, node_black_set=None):
-        # Set of nodes that will not be visited.
-        self.node_black_set = node_black_set or set()
+    def __init__(self, end_node=None):
+        # The terminate node of the visitor.
+        self.end_node = end_node
         # Dict to store the names and ctxs of vars.
         self.name_ids = defaultdict(list)
         # List of current visited nodes
         self.ancestor_nodes = []
-        # Available only when node_black_set is set.
+        # Available only when end_node is set.
         self._is_finished = False
         self._candidate_ctxs = (gast.Store, gast.Load, gast.Param)
 
     def visit(self, node):
         """Visit a node."""
-        if node in self.node_black_set or self._is_finished:
+        if node == self.end_node or self._is_finished:
             self._is_finished = True
             return
 
@@ -433,17 +433,24 @@ class NameVisitor(gast.NodeVisitor):
         In above two cases, we should consider to manage the scope of vars to parsing
         the arguments and returned vars correctly.
         """
+        if not self.end_node:
+            self.generic_visit(node)
+        else:
             before_if_name_ids = copy.deepcopy(self.name_ids)
             body_name_ids = self._visit_child(node.body)
-        # If the traversal process stops early, just return the name_ids that have been seen.
+            # If traversal process stops early in `if.body`, return the currently seen name_ids.
             if self._is_finished:
-            for name_id, ctxs in before_if_name_ids.items():
-                self.name_ids[name_id] = ctxs + self.name_ids[name_id]
-        # Blocks the vars in `if.body` and only inserts the vars both created in 'if/else' branch
-        # into name_ids.
+                self._update_name_ids(before_if_name_ids)
             else:
                 else_name_ids = self._visit_child(node.orelse)
-            new_name_ids = self._find_new_name_ids(body_name_ids, else_name_ids)
+                # If traversal process stops early in `if.orelse`, return the currently seen name_ids.
+                if self._is_finished:
+                    self._update_name_ids(before_if_name_ids)
+                else:
+                    # Blocks the vars in `if.body` and only inserts the vars both created in 'if/else' branch
+                    # into name_ids.
+                    new_name_ids = self._find_new_name_ids(body_name_ids,
+                                                           else_name_ids)
                     for new_name_id in new_name_ids:
                         before_if_name_ids[new_name_id].append(gast.Store())
 
@@ -463,6 +470,19 @@ class NameVisitor(gast.NodeVisitor):
         node._fields = ('value', 'targets')
         self.generic_visit(node)
 
+    def visit_FunctionDef(self, node):
+        if not self.end_node:
+            self.generic_visit(node)
+        else:
+            before_name_ids = copy.deepcopy(self.name_ids)
+            self.name_ids = defaultdict(list)
+            self.generic_visit(node)
+
+            if self._is_finished:
+                self._update_name_ids(before_name_ids)
+            else:
+                self.name_ids = before_name_ids
+
     def visit_Return(self, node):
         # Ignore the vars in return
         return
@@ -505,12 +525,16 @@ class NameVisitor(gast.NodeVisitor):
                 return True
         return False
 
+    def _update_name_ids(self, new_name_ids):
+        for name_id, ctxs in new_name_ids.items():
+            self.name_ids[name_id] = ctxs + self.name_ids[name_id]
+
 
-def get_name_ids(nodes, node_black_set=None):
+def get_name_ids(nodes, end_node=None):
     """
     Return all ast.Name.id of python variable in nodes.
     """
-    name_visitor = NameVisitor(node_black_set)
+    name_visitor = NameVisitor(end_node)
     for node in nodes:
         name_visitor.visit(node)
     return name_visitor.name_ids
@@ -611,7 +635,7 @@ def transform_if_else(node, root):
     """
     Transform ast.If into control flow statement of Paddle static graph.
     """
-    parent_name_ids = get_name_ids([root], node_black_set=[node])
+    parent_name_ids = get_name_ids([root], end_node=node)
     if_name_ids = get_name_ids(node.body)
     else_name_ids = get_name_ids(node.orelse)
 

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

@@ -102,19 +102,18 @@ def test_break_continue_in_for(x):
 
 def test_for_in_else(x):
     x = fluid.dygraph.to_variable(x)
-    #
-    # TODO: Huihuang founds that if we put the for range in else body
-    # the testcase will fail. Enable this test case after fixing it.
-    # 
-    #if False:
-    #    pass
-    #else:
-    #    for i in range(0, 10):
-    #        if i > 5:
-    #            x += 1
-    #            break
-    #        x += i
-    #
+
+    # Case 1:
+    if False:
+        pass
+    else:
+        for i in range(0, 10):
+            if i > 5:
+                x += 1
+                break
+            x += i
+
+    # Case 2:
     if False:
         pass
     else:

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

@@ -65,10 +65,24 @@ class TestGetNameIds2(TestGetNameIds):
             return z
         """
         self.all_name_ids = {
-            'x': [gast.Param(), gast.Store()],
-            'a': [gast.Store(), gast.Load()],
-            'y': [gast.Param(), gast.Load()],
-            'z': [gast.Store()]
+            'x': [
+                gast.Param(), gast.Store(), gast.Load(), gast.Load(),
+                gast.Load()
+            ],
+            'a': [gast.Store(), gast.Load(), gast.Load()],
+            'y': [
+                gast.Param(),
+                gast.Load(),
+                gast.Load(),
+                gast.Load(),
+                gast.Load(),
+            ],
+            'z': [
+                gast.Store(),
+                gast.Load(),
+                gast.Store(),
+                gast.Store(),
+            ]
         }
 
 
@@ -83,9 +97,23 @@ class TestGetNameIds3(TestGetNameIds):
             return z
         """
         self.all_name_ids = {
-            'x': [gast.Param()],
-            'y': [gast.Param()],
-            'z': [gast.Store()]
+            'x': [
+                gast.Param(),
+                gast.Load(),
+                gast.Load(),
+                gast.Load(),
+            ],
+            'y': [
+                gast.Param(),
+                gast.Load(),
+                gast.Load(),
+            ],
+            'z': [
+                gast.Store(),
+                gast.Store(),
+                gast.Load(),
+                gast.Store(),
+            ]
         }