Explicit config_class instead of module inspection

src/transformers/configuration_auto.py

@@ -101,20 +101,6 @@ class AutoConfig:
             "using the `AutoConfig.from_pretrained(pretrained_model_name_or_path)` method."
         )
 
-    @classmethod
-    def config_class_for_model_class(cls, model_class):
-        module = import_module(model_class.__module__)
-        return next(
-            (
-                module_attribute
-                for module_attribute_name in dir(module)
-                if module_attribute_name.endswith("Config")
-                for module_attribute in (getattr(module, module_attribute_name),)
-                if issubclass(module_attribute, PretrainedConfig)
-            ),
-            None,
-        )
-
     @classmethod
     def for_model(cls, model_type, *args, **kwargs):
         for pattern, config_class in CONFIG_MAPPING.items():

src/transformers/modeling_tf_albert.py

@@ -480,6 +480,8 @@ class TFAlbertMLMHead(tf.keras.layers.Layer):
 
 @keras_serializable
 class TFAlbertMainLayer(tf.keras.layers.Layer):
+    config_class = AlbertConfig
+
     def __init__(self, config, **kwargs):
         super().__init__(**kwargs)
         self.num_hidden_layers = config.num_hidden_layers

src/transformers/modeling_tf_bert.py

@@ -473,6 +473,8 @@ class TFBertNSPHead(tf.keras.layers.Layer):
 
 @keras_serializable
 class TFBertMainLayer(tf.keras.layers.Layer):
+    config_class = BertConfig
+
     def __init__(self, config, **kwargs):
         super().__init__(**kwargs)
         self.num_hidden_layers = config.num_hidden_layers

src/transformers/modeling_tf_ctrl.py

@@ -166,6 +166,8 @@ class TFEncoderLayer(tf.keras.layers.Layer):
 
 @keras_serializable
 class TFCTRLMainLayer(tf.keras.layers.Layer):
+    config_class = CTRLConfig
+
     def __init__(self, config, **kwargs):
         super().__init__(**kwargs)
         self.output_hidden_states = config.output_hidden_states

src/transformers/modeling_tf_gpt2.py

@@ -199,6 +199,8 @@ class TFBlock(tf.keras.layers.Layer):
 
 @keras_serializable
 class TFGPT2MainLayer(tf.keras.layers.Layer):
+    config_class = GPT2Config
+
     def __init__(self, config, *inputs, **kwargs):
         super().__init__(*inputs, **kwargs)
         self.output_hidden_states = config.output_hidden_states

src/transformers/modeling_tf_transfo_xl.py

@@ -380,6 +380,8 @@ class TFAdaptiveEmbedding(tf.keras.layers.Layer):
 
 @keras_serializable
 class TFTransfoXLMainLayer(tf.keras.layers.Layer):
+    config_class = TransfoXLConfig
+
     def __init__(self, config, **kwargs):
         super().__init__(**kwargs)
         self.output_attentions = config.output_attentions

src/transformers/modeling_tf_utils.py

@@ -50,11 +50,13 @@ class TFModelUtilsMixin:
 def keras_serializable(cls):
     initializer = cls.__init__
 
+    config_class = getattr(cls, "config_class", None)
+    if config_class is None:
+        raise AttributeError("Must set `config_class` to use @keras_serializable")
+
     def wrapped_init(self, config, *args, **kwargs):
         if isinstance(config, dict):
-            from transformers import AutoConfig
-
-            config = AutoConfig.config_class_for_model_class(cls).from_dict(config)
+            config = config_class.from_dict(config)
         initializer(self, config, *args, **kwargs)
         self._transformers_config = config
 

src/transformers/modeling_tf_xlnet.py

@@ -351,6 +351,8 @@ class TFXLNetLMHead(tf.keras.layers.Layer):
 
 @keras_serializable
 class TFXLNetMainLayer(tf.keras.layers.Layer):
+    config_class = XLNetConfig
+
     def __init__(self, config, **kwargs):
         super().__init__(**kwargs)
         self.output_attentions = config.output_attentions