[Dy2stat] Fix function lookup bug in convert_call (#24567) (#24571)

* fix convert call globals_funcs test=develop

* add import statement test=develop

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

@@ -102,7 +102,10 @@ def convert_call(func):
         if func.__name__ == '<lambda>':
             return func
         try:
-            if func in func.__globals__.values():
+            global_funcs = set([
+                fn for fn in func.__globals__.values() if inspect.isfunction(fn)
+            ])
+            if func in global_funcs:
                 converted_call = to_static_func(func)
                 func_self = getattr(func, '__self__', None)
         except AttributeError:

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

@@ -368,6 +368,7 @@ class ProgramTranslator(object):
 
                 prog_trans = fluid.dygraph.ProgramTranslator()
 
+                with fluid.dygraph.guard():
                     x = np.ones([1, 2])
                     x_v = prog_trans.get_output(func, x)
                     print(x_v.numpy()) # [[0. 0.]]
@@ -472,7 +473,7 @@ class ProgramTranslator(object):
                 x = np.ones([1, 2])
                 main_prog, start_prog, inputs, outputs = prog_trans.get_program(func, x)
                 print([i.name for i in inputs])
-                # ['x_0'] the feed input variable name representing x
+                # ['feed_0'] the feed input variable name representing x
                 print([o.name for o in outputs])
                 # ['_generated_var_4'] the fetch output variable name representing x_v