[Eager] Remove enable_legacy_dygraph setting (#42363)

* [Eager] Remove enable_legacy_dygraph setting

* Add more tests

python/paddle/fluid/tests/unittests/dygraph_to_static/test_simnet_v2.py

@@ -20,9 +20,6 @@ import unittest
 
 from simnet_dygraph_model_v2 import BOW, HingeLoss
 
-from paddle.fluid.framework import _enable_legacy_dygraph
-_enable_legacy_dygraph()
-
 SEED = 102
 random.seed(SEED)
 

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

@@ -23,7 +23,6 @@ import paddle.static as static
 import paddle.fluid as fluid
 from paddle.fluid import Program, program_guard
 from paddle.fluid.framework import _test_eager_guard, _enable_legacy_dygraph
-_enable_legacy_dygraph()
 import os
 
 from paddle import _C_ops
@@ -979,6 +978,7 @@ class TestDropoutBackward(unittest.TestCase):
                         ), self.cal_grad_downscale_in_infer(mask.numpy())))
 
     def test_backward_upscale_train(self):
+        _enable_legacy_dygraph()
         for place in self.places:
             with fluid.dygraph.guard(place):
 
@@ -1010,6 +1010,7 @@ class TestDropoutBackward(unittest.TestCase):
                         ), self.cal_grad_upscale_train(mask.numpy(), prob)))
 
     def test_backward_upscale_train_2(self):
+        _enable_legacy_dygraph()
         for place in self.places:
             with fluid.dygraph.guard(place):
 
@@ -1025,6 +1026,23 @@ class TestDropoutBackward(unittest.TestCase):
                     np.allclose(input.gradient(
                     ), self.cal_grad_upscale_train(mask.numpy(), prob)))
 
+    def test_backward_upscale_train_2_eager(self):
+        for place in self.places:
+            with fluid.dygraph.guard(place):
+                with _test_eager_guard():
+
+                    prob = 0.3
+                    input = paddle.uniform([40, 40], dtype="float32")
+                    input.stop_gradient = False
+                    out, mask = _C_ops.final_state_dropout(
+                        input, None, 0.3, False, "upscale_in_train", 0, False)
+
+                    out.backward()
+
+                    self.assertTrue(
+                        np.allclose(input.gradient(
+                        ), self.cal_grad_upscale_train(mask.numpy(), prob)))
+
 
 class TestRandomValue(unittest.TestCase):
     def test_fixed_random_number(self):

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

@@ -21,9 +21,6 @@ import paddle.nn.functional as F
 
 from paddle.incubate.optimizer.functional.lbfgs import minimize_lbfgs
 
-from paddle.fluid.framework import _enable_legacy_dygraph
-_enable_legacy_dygraph()
-
 np.random.seed(123)
 
 

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

@@ -20,8 +20,6 @@ import os
 import sys
 import subprocess
 import paddle
-from paddle.fluid.framework import _enable_legacy_dygraph
-_enable_legacy_dygraph()
 
 paddle.enable_static()