test=release/1.5, cherry-pick hide not_support for dygraph (#18528)

* test=release/1.5, cherry-pick hide not_support for dygraph

* test=release/1.5, cherry-pick hide not_support for dygraph

Author: JiabinYang

python/paddle/fluid/clip.py

@@ -21,7 +21,7 @@
 from . import layers
 from . import framework
 from . import core
-from .dygraph import not_support
+from .dygraph.base import _not_support
 
 __all__ = [
     'ErrorClipByValue',
@@ -336,7 +336,7 @@ def _create_operators(self, param, grad):
         return param, new_grad
 
 
-@not_support
+@_not_support
 def set_gradient_clip(clip, param_list=None, program=None):
     """
     To specify parameters that require gradient clip.

python/paddle/fluid/dygraph/base.py

@@ -24,7 +24,6 @@
 __all__ = [
     'enabled',
     'no_grad',
-    'not_support',
     'guard',
     'to_variable',
 ]
@@ -91,7 +90,7 @@ def __impl__(*args, **kwargs):
 
 
 no_grad = wrap_decorator(_no_grad_)
-not_support = wrap_decorator(_dygraph_not_support_)
+_not_support = wrap_decorator(_dygraph_not_support_)
 
 
 @signature_safe_contextmanager

python/paddle/fluid/tests/unittests/test_imperative_decorator.py

@@ -15,6 +15,7 @@
 import paddle.fluid as fluid
 import paddle.fluid.framework as framework
 import unittest
+from test_imperative_base import new_program_scope
 
 
 class TestTracerMode(unittest.TestCase):
@@ -29,6 +30,18 @@ def no_grad_func(self, a):
         self.assertEqual(self.tracer._train_mode, False)
         return a
 
+    @fluid.dygraph.base._not_support
+    def not_support_func(self):
+        return True
+
+    def check_not_support_rlt(self, ans):
+        try:
+            rlt = self.not_support_func()
+        except AssertionError:
+            rlt = False
+        finally:
+            self.assertEqual(rlt, ans)
+
     def test_main(self):
         with fluid.dygraph.guard():
             self.tracer = framework._dygraph_tracer()
@@ -38,6 +51,12 @@ def test_main(self):
 
             self.assertEqual(self.tracer._train_mode, self.init_mode)
 
+        with fluid.dygraph.guard():
+            self.check_not_support_rlt(False)
+
+        with new_program_scope():
+            self.check_not_support_rlt(True)
+
 
 class TestTracerMode2(TestTracerMode):
     def setUp(self):