Fix activations being all the same module (#19728)

src/transformers/activations.py

@@ -13,6 +13,7 @@
 # limitations under the License.
 
 import math
+from collections import OrderedDict
 
 import torch
 from packaging import version
@@ -141,21 +142,29 @@ class LinearActivation(nn.Module):
         return input
 
 
-ACT2FN = {
-    "gelu": GELUActivation(),
-    "gelu_10": ClippedGELUActivation(-10, 10),
-    "gelu_fast": FastGELUActivation(),
-    "gelu_new": NewGELUActivation(),
-    "gelu_python": GELUActivation(use_gelu_python=True),
-    "linear": LinearActivation(),
-    "mish": MishActivation(),
-    "quick_gelu": QuickGELUActivation(),
-    "relu": nn.ReLU(),
-    "sigmoid": nn.Sigmoid(),
-    "silu": SiLUActivation(),
-    "swish": SiLUActivation(),
-    "tanh": nn.Tanh(),
+class ClassInstantier(OrderedDict):
+    def __getitem__(self, key):
+        content = super().__getitem__(key)
+        cls, kwargs = content if isinstance(content, tuple) else (content, {})
+        return cls(**kwargs)
+
+
+ACT2CLS = {
+    "gelu": GELUActivation,
+    "gelu_10": (ClippedGELUActivation, {"min": -10, "max": 10}),
+    "gelu_fast": FastGELUActivation,
+    "gelu_new": NewGELUActivation,
+    "gelu_python": (GELUActivation, {"use_gelu_python": True}),
+    "linear": LinearActivation,
+    "mish": MishActivation,
+    "quick_gelu": QuickGELUActivation,
+    "relu": nn.ReLU,
+    "sigmoid": nn.Sigmoid,
+    "silu": SiLUActivation,
+    "swish": SiLUActivation,
+    "tanh": nn.Tanh,
 }
+ACT2FN = ClassInstantier(ACT2CLS)
 
 
 def get_activation(activation_string):

tests/utils/test_activations.py

@@ -63,3 +63,11 @@ class TestActivations(unittest.TestCase):
             get_activation("bogus")
         with self.assertRaises(KeyError):
             get_activation(None)
+
+    def test_activations_are_distinct_objects(self):
+        act1 = get_activation("gelu")
+        act1.a = 1
+        act2 = get_activation("gelu")
+        self.assertEqual(act1.a, 1)
+        with self.assertRaises(AttributeError):
+            _ = act2.a