adding TF 2.0 model

transformers/configuration_ctrl.py

@@ -53,8 +53,8 @@ class CTRLConfig(PretrainedConfig):
     def __init__(
         self,
         vocab_size_or_config_json_file=246534,
-        n_positions=50000,
-        n_ctx=512,
+        n_positions=256,
+        n_ctx=256,
         n_embd=1280,
         dff=8192,
         n_layer=48,

transformers/modeling_ctrl.py

@@ -351,7 +351,7 @@ class CTRLModel(CTRLPreTrainedModel):
 
         x = self.w(input_ids)
         # x = embedded.unsqueeze(0) if len(input_ids.shape)<2 else embedded
-        seq_len = input_ids.shape[1]
+        seq_len = input_ids.shape[-1]
         mask = torch.triu(torch.ones(seq_len, seq_len), 1).to(x.device)
 
         x *= np.sqrt(self.d_model_size)

transformers/modeling_roberta.py

@@ -172,7 +172,8 @@ class RobertaModel(BertModel):
         if input_ids[:, 0].sum().item() != 0:
             logger.warning("A sequence with no special tokens has been passed to the RoBERTa model. "
                            "This model requires special tokens in order to work. "
-                           "Please specify add_special_tokens=True in your encoding.")
+                           "Please specify add_special_tokens=True in your tokenize.encode()"
+                           "or tokenizer.convert_tokens_to_ids().")
         return super(RobertaModel, self).forward(input_ids,
                                                  attention_mask=attention_mask,
                                                  token_type_ids=token_type_ids,

transformers/modeling_tf_ctrl.py

@@ -25,7 +25,7 @@ import numpy as np
 import tensorflow as tf
 
 from .configuration_ctrl import CTRLConfig
-from .modeling_tf_utils import TFPreTrainedModel, get_initializer
+from .modeling_tf_utils import TFPreTrainedModel, get_initializer, shape_list, TFSharedEmbeddings
 from .file_utils import add_start_docstrings
 from .modeling_tf_pytorch_utils import load_pytorch_checkpoint_in_tf2_model
 
@@ -33,12 +33,19 @@ logger = logging.getLogger(__name__)
 
 TF_CTRL_PRETRAINED_MODEL_ARCHIVE_MAP = {"ctrl": "https://s3.amazonaws.com/models.huggingface.co/bert/ctrl-tf_model.h5"}
 
+def load_ctrl_pt_weights_in_tf2(tf_model, pytorch_checkpoint_path):
+    # build the network
+    inputs_list = [[7, 6, 0, 0, 1], [1, 2, 3, 0, 0], [0, 0, 0, 4, 5]]
+    tf_inputs = tf.constant(inputs_list)
+    tfo = tf_model(tf_inputs, training=False)
+    return load_pytorch_checkpoint_in_tf2_model(tf_model, pytorch_checkpoint_path, tf_inputs=tf_inputs)
+
 
 def angle_defn(pos, i, d_model_size):
     angle_rates = 1 / np.power(10000, (2 * (i//2)) / np.float32(d_model_size))
     return pos * angle_rates
 
-def positional_encoding(position, d_model_size, dtype):
+def positional_encoding(position, d_model_size):
     # create the sinusoidal pattern for the positional encoding
     angle_rads = angle_defn(np.arange(position)[:, np.newaxis],
                             np.arange(d_model_size)[np.newaxis, :],
@@ -47,14 +54,15 @@ def positional_encoding(position, d_model_size, dtype):
     sines = np.sin(angle_rads[:, 0::2])
     cosines = np.cos(angle_rads[:, 1::2])
 
-    pos_encoding = tf.cast(np.concatenate([sines, cosines], axis=-1)[np.newaxis, ...], dtype=tf.float32)
+    # pos_encoding = tf.cast(np.concatenate([sines, cosines], axis=-1)[np.newaxis, ...], dtype=tf.float32)
+    pos_encoding = tf.cast(np.concatenate([sines, cosines], axis=-1), dtype=tf.float32)
     return pos_encoding
 
 def scaled_dot_product_attention(q, k, v, mask, attention_mask=None, head_mask=None):
     # calculate attention
     matmul_qk = tf.matmul(q, k, transpose_b=True)
     
-    dk = tf.cast(tf.shape(k)[-1], tf.float32)
+    dk = tf.cast(shape_list(k)[-1], tf.float32)
     scaled_attention_logits = matmul_qk / tf.math.sqrt(dk)
 
     if mask is not None:
@@ -94,7 +102,7 @@ class TFMultiHeadAttention(tf.keras.layers.Layer):
         x = tf.reshape(x, (batch_size, -1, self.num_heads, self.depth))
         return tf.transpose(x, perm=[0, 2, 1, 3])
 
-    def call(self, inputs, training=False)
+    def call(self, inputs, training=False):
         v, k, q, mask, layer_past, attention_mask, head_mask = inputs
         batch_size = q.shape[0]
 
@@ -124,31 +132,34 @@ class TFMultiHeadAttention(tf.keras.layers.Layer):
 
 
 
-def point_wise_feed_forward_network(d_model_size, dff):
-    return tf.keras.Sequential([tf.keras.layers.Dense(dff, activation='relu'), 
-                                tf.keras.layers.Dense(d_model_size)])
+def point_wise_feed_forward_network(d_model_size, dff, name=""):
+    return tf.keras.Sequential([
+            tf.keras.layers.Dense(dff, activation='relu', name="0"), 
+            tf.keras.layers.Dense(d_model_size, name="2")
+        ], name="ffn")
 
 
 class TFEncoderLayer(tf.keras.layers.Layer):
-    def __init__(self, d_model_size, num_heads, dff, rate=0.1, output_attentions=False, **kwargs):
+    def __init__(self, d_model_size, num_heads, dff, rate=0.1, layer_norm_epsilon=1e-6, output_attentions=False, **kwargs):
         super(TFEncoderLayer, self).__init__(**kwargs)
 
-        self.multi_head_attention = MultiHeadAttention(d_model_size, num_heads, output_attentions)
-        self.ffn = point_wise_feed_forward_network(d_model_size, dff)
+        self.multi_head_attention = TFMultiHeadAttention(d_model_size,
+                                                         num_heads,
+                                                         output_attentions,
+                                                         name="multi_head_attention")
+        self.ffn = point_wise_feed_forward_network(d_model_size, dff, name="ffn")
 
-        self.layernorm1 = torch.nn.LayerNorm(d_model_size, eps=1e-6)
-        self.layernorm2 = torch.nn.LayerNorm(d_model_size, eps=1e-6)
+        self.layernorm1 = tf.keras.layers.LayerNormalization(epsilon=layer_norm_epsilon, name="layernorm1")
+        self.layernorm2 = tf.keras.layers.LayerNormalization(epsilon=layer_norm_epsilon, name="layernorm2")
 
-        self.dropout1 = torch.nn.Dropout(rate)
-        self.dropout2 = torch.nn.Dropout(rate)
+        self.dropout1 = tf.keras.layers.Dropout(rate)
+        self.dropout2 = tf.keras.layers.Dropout(rate)
 
     def call(self, inputs, training=False):
         x, mask, layer_past, attention_mask, head_mask = inputs
         normed = self.layernorm1(x)
-        attn_outputs = self.multi_head_attention(normed, normed, normed, mask,
-                                                      layer_past=layer_past,
-                                                      attention_mask=attention_mask,
-                                                      head_mask=head_mask)
+        attn_outputs = self.multi_head_attention([normed, normed, normed, mask, layer_past,
+                                                  attention_mask, head_mask], training=training)
         attn_output = attn_outputs[0]
         attn_output = self.dropout1(attn_output, training=training)
         out1 = x + attn_output
@@ -162,6 +173,152 @@ class TFEncoderLayer(tf.keras.layers.Layer):
         return outputs
 
 
+class TFCTRLMainLayer(tf.keras.layers.Layer):
+    def __init__(self, config, **kwargs):
+        super(TFCTRLMainLayer, self).__init__(**kwargs)
+        self.output_hidden_states = config.output_hidden_states
+        self.d_model_size = config.n_embd
+        self.num_layers = config.n_layer
+
+        self.pos_encoding = positional_encoding(config.n_positions, self.d_model_size)
+
+        self.output_attentions = config.output_attentions
+
+        self.w = TFSharedEmbeddings(config.vocab_size,
+                                    config.n_embd,
+                                    initializer_range=config.initializer_range,
+                                    name="w")
+
+        self.dropout = tf.keras.layers.Dropout(config.embd_pdrop)
+        self.h = [TFEncoderLayer(config.n_embd,
+                                 config.n_head,
+                                 config.dff,
+                                 config.resid_pdrop,
+                                 config.layer_norm_epsilon,
+                                 config.output_attentions,
+                                 name='h_._{}'.format(i)) for i in range(config.n_layer)]
+        self.layernorm = tf.keras.layers.LayerNormalization(epsilon=config.layer_norm_epsilon, name="layernorm")
+
+    def _resize_token_embeddings(self, new_num_tokens):
+        raise NotImplementedError
+
+    def _prune_heads(self, heads_to_prune):
+        """ Prunes heads of the model.
+                heads_to_prune: dict of {layer_num: list of heads to prune in this layer}
+        """
+        raise NotImplementedError
+
+    def call(self, inputs, past=None, attention_mask=None, token_type_ids=None, position_ids=None, head_mask=None, training=False):
+        if isinstance(inputs, (tuple, list)):
+            input_ids = inputs[0]
+            past = inputs[1] if len(inputs) > 1 else past
+            attention_mask = inputs[2] if len(inputs) > 2 else attention_mask
+            token_type_ids = inputs[3] if len(inputs) > 3 else token_type_ids
+            position_ids = inputs[4] if len(inputs) > 4 else position_ids
+            head_mask = inputs[5] if len(inputs) > 5 else head_mask
+            assert len(inputs) <= 6, "Too many inputs."
+        elif isinstance(inputs, dict):
+            input_ids = inputs.get('input_ids')
+            past = inputs.get('past', past)
+            attention_mask = inputs.get('attention_mask', attention_mask)
+            token_type_ids = inputs.get('token_type_ids', token_type_ids)
+            position_ids = inputs.get('position_ids', position_ids)
+            head_mask = inputs.get('head_mask', head_mask)
+            assert len(inputs) <= 6, "Too many inputs."
+        else:
+            input_ids = inputs
+
+        input_shape = shape_list(input_ids)
+        input_ids = tf.reshape(input_ids, [-1, input_shape[-1]])
+
+        if past is None:
+            past_length = 0
+            past = [None] * len(self.h)
+        else:
+            past_length = shape_list(past[0][0])[-2]
+        if position_ids is None:
+            position_ids = tf.range(past_length, shape_list(input_ids)[-1] + past_length, dtype=tf.int32)[tf.newaxis, :]
+
+        # Attention mask.
+        if attention_mask is not None:
+            # We create a 3D attention mask from a 2D tensor mask.
+            # Sizes are [batch_size, 1, 1, to_seq_length]
+            # So we can broadcast to [batch_size, num_heads, from_seq_length, to_seq_length]
+            # this attention mask is more simple than the triangular masking of causal attention
+            # used in OpenAI GPT, we just need to prepare the broadcast dimension here.
+            attention_mask = attention_mask[:, tf.newaxis, tf.newaxis, :]
+
+            # Since attention_mask is 1.0 for positions we want to attend and 0.0 for
+            # masked positions, this operation will create a tensor which is 0.0 for
+            # positions we want to attend and -10000.0 for masked positions.
+            # Since we are adding it to the raw scores before the softmax, this is
+            # effectively the same as removing these entirely.
+
+            attention_mask = tf.cast(attention_mask, tf.float32)
+            attention_mask = (1.0 - attention_mask) * -10000.0
+        else:
+            attention_mask = None
+
+        # Prepare head mask if needed
+        # 1.0 in head_mask indicate we keep the head
+        # attention_probs has shape bsz x n_heads x N x N
+        # head_mask has shape n_layer x batch x n_heads x N x N
+        if head_mask is not None:
+            raise NotImplementedError
+        else:
+            head_mask = [None] * self.num_layers
+
+        if token_type_ids is not None:
+            token_type_ids = tf.reshape(token_type_ids, [-1, shape_list(token_type_ids)[-1]])
+            token_type_embeds = self.w(token_type_ids, mode='embedding')
+            token_type_embeds *= tf.math.sqrt(tf.cast(self.d_model_size, tf.float32))
+        else:
+            token_type_embeds = 0
+        position_ids = tf.reshape(position_ids, [-1, shape_list(position_ids)[-1]])
+
+        inputs_embeds = self.w(input_ids)
+        # x = embedded.unsqueeze(0) if len(input_ids.shape)<2 else embedded
+        seq_len = input_shape[-1]
+        mask = 1 - tf.linalg.band_part(tf.ones((seq_len, seq_len)), -1, 0)
+
+        inputs_embeds *= tf.math.sqrt(tf.cast(self.d_model_size, tf.float32))
+
+        pos_embeds = tf.gather(self.pos_encoding, position_ids)
+
+        hidden_states = inputs_embeds + pos_embeds + token_type_embeds
+
+        hidden_states = self.dropout(hidden_states, training=training)
+
+        output_shape = input_shape + [shape_list(hidden_states)[-1]]
+        presents = ()
+        all_hidden_states = ()
+        all_attentions = []
+        for i, (h, layer_past) in enumerate(zip(self.h, past)):
+            if self.output_hidden_states:
+                all_hidden_states = all_hidden_states + (tf.reshape(hidden_states, output_shape),)
+            outputs = h([hidden_states, mask, layer_past, attention_mask, head_mask[i]], training=training)
+            hidden_states, present = outputs[:2]
+            presents = presents + (present,)
+
+            if self.output_attentions:
+                all_attentions.append(outputs[2])
+
+        hidden_states = self.layernorm(hidden_states)
+        hidden_states = tf.reshape(hidden_states, output_shape)
+        if self.output_hidden_states:
+            all_hidden_states = all_hidden_states + (hidden_states,)
+
+        outputs = (hidden_states, presents)
+        if self.output_hidden_states:
+            outputs = outputs + (all_hidden_states,)
+        if self.output_attentions:
+            # let the number of heads free (-1) so we can extract attention even after head pruning
+            attention_output_shape = input_shape[:-1] + [-1] + shape_list(all_attentions[0])[-2:]
+            all_attentions = tuple(tf.reshape(t, attention_output_shape) for t in all_attentions)
+            outputs = outputs + (all_attentions,)
+        return outputs
+
+
 class TFCTRLPreTrainedModel(TFPreTrainedModel):
     """ An abstract class to handle weights initialization and
         a simple interface for dowloading and loading pretrained models.
@@ -169,20 +326,7 @@ class TFCTRLPreTrainedModel(TFPreTrainedModel):
     config_class = CTRLConfig
     pretrained_model_archive_map = TF_CTRL_PRETRAINED_MODEL_ARCHIVE_MAP
     base_model_prefix = "transformer"
-    load_pt_weights = load_bert_pt_weights_in_tf2
-
-    def _init_weights(self, module):
-        """ Initialize the weights.
-        """
-        if isinstance(module, (nn.Linear, nn.Embedding, Conv1D)):
-            # Slightly different from the TF version which uses truncated_normal for initialization
-            # cf https://github.com/pytorch/pytorch/pull/5617
-            module.weight.data.normal_(mean=0.0, std=self.config.initializer_range)
-            if isinstance(module, (nn.Linear, Conv1D)) and module.bias is not None:
-                module.bias.data.zero_()
-        elif isinstance(module, nn.LayerNorm):
-            module.bias.data.zero_()
-            module.weight.data.fill_(1.0)
+    load_pt_weights = load_ctrl_pt_weights_in_tf2
 
 
 CTRL_START_DOCSTRING = r"""    CTRL model was proposed in 
@@ -240,172 +384,68 @@ CTRL_INPUTS_DOCSTRING = r"""    Inputs:
 class TFCTRLModel(TFCTRLPreTrainedModel):
     r"""
     Outputs: `Tuple` comprising various elements depending on the configuration (config) and inputs:
-        **last_hidden_state**: ``torch.FloatTensor`` of shape ``(batch_size, sequence_length, hidden_size)``
+        **last_hidden_state**: ``tf.Tensor`` of shape ``(batch_size, sequence_length, hidden_size)``
             Sequence of hidden-states at the last layer of the model.
         **past**:
-            list of ``torch.FloatTensor`` (one for each layer) of shape ``(batch_size, num_heads, sequence_length, sequence_length)``:
+            list of ``tf.Tensor`` (one for each layer) of shape ``(batch_size, num_heads, sequence_length, sequence_length)``:
             that contains pre-computed hidden-states (key and values in the attention blocks).
             Can be used (see `past` input) to speed up sequential decoding.
         **hidden_states**: (`optional`, returned when ``config.output_hidden_states=True``)
-            list of ``torch.FloatTensor`` (one for the output of each layer + the output of the embeddings)
+            list of ``tf.Tensor`` (one for the output of each layer + the output of the embeddings)
             of shape ``(batch_size, sequence_length, hidden_size)``:
             Hidden-states of the model at the output of each layer plus the initial embedding outputs.
         **attentions**: (`optional`, returned when ``config.output_attentions=True``)
-            list of ``torch.FloatTensor`` (one for each layer) of shape ``(batch_size, num_heads, sequence_length, sequence_length)``:
+            list of ``tf.Tensor`` (one for each layer) of shape ``(batch_size, num_heads, sequence_length, sequence_length)``:
             Attentions weights after the attention softmax, used to compute the weighted average in the self-attention heads.
 
     Examples::
 
+        import tensorflow as tf
+        from transformers import CTRLTokenizer, TFCTRLModel
+
         tokenizer = CTRLTokenizer.from_pretrained('ctrl')
-        model = CTRLModel.from_pretrained('ctrl')
-        input_ids = torch.tensor(tokenizer.encode("Links Hello, my dog is cute")).unsqueeze(0)  # Batch size 1
+        model = TFCTRLModel.from_pretrained('ctrl')
+        input_ids = tf.constant(tokenizer.encode("Hello, my dog is cute"))[None, :]  # Batch size 1
         outputs = model(input_ids)
         last_hidden_states = outputs[0]  # The last hidden-state is the first element of the output tuple
 
     """
-    def __init__(self, config, **kwargs):
-        super(TFCTRLModel, self).__init__(**kwargs)
-        self.output_hidden_states = config.output_hidden_states
-        self.d_model_size = config.n_embd
-        self.num_layers = config.n_layer
-        
-        self.pos_encoding = positional_encoding(config.n_positions, self.d_model_size, torch.float)
-            
-        self.output_attentions = config.output_attentions
-
-        self.w = nn.Embedding(config.vocab_size, config.n_embd)
+    def __init__(self, config, *inputs, **kwargs):
+        super(TFCTRLModel, self).__init__(config, *inputs, **kwargs)
+        self.transformer = TFCTRLMainLayer(config, name='transformer')
 
-        
-        self.dropout = nn.Dropout(config.embd_pdrop)
-        self.h = nn.ModuleList([EncoderLayer(config.n_embd,
-                                             config.n_head,
-                                             config.dff,
-                                             config.resid_pdrop,
-                                             config.output_attentions) for _ in range(config.n_layer)])
-        self.layernorm = nn.LayerNorm(config.n_embd, eps=config.layer_norm_epsilon)
-
-        self.init_weights()
-
-    def _resize_token_embeddings(self, new_num_tokens):
-        self.w = self._get_resized_embeddings(self.w, new_num_tokens)
-        return self.w
-
-    def _prune_heads(self, heads_to_prune):
-        """ Prunes heads of the model.
-                heads_to_prune: dict of {layer_num: list of heads to prune in this layer}
-        """
-        for layer, heads in heads_to_prune.items():
-            self.h[layer].attn.prune_heads(heads)
-
-    def forward(self, input_ids, past=None, attention_mask=None, token_type_ids=None, position_ids=None, head_mask=None):
-        input_shape = input_ids.size()
-        input_ids = input_ids.view(-1, input_shape[-1])
-        if token_type_ids is not None:
-            token_type_ids = token_type_ids.view(-1, input_shape[-1])
-        if position_ids is not None:
-            position_ids = position_ids.view(-1, input_shape[-1])
-
-        if past is None:
-            past_length = 0
-            past = [None] * len(self.h)
-        else:
-            past_length = past[0][0].size(-2)
-        if position_ids is None:
-            position_ids = torch.arange(past_length, input_ids.size(-1) + past_length, dtype=torch.long, device=input_ids.device)
-            position_ids = position_ids.unsqueeze(0).expand_as(input_ids)
-
-        # Attention mask.
-        if attention_mask is not None:
-            attention_mask = attention_mask.view(-1, input_shape[-1])
-            # We create a 3D attention mask from a 2D tensor mask.
-            # Sizes are [batch_size, 1, 1, to_seq_length]
-            # So we can broadcast to [batch_size, num_heads, from_seq_length, to_seq_length]
-            # this attention mask is more simple than the triangular masking of causal attention
-            # used in OpenAI GPT, we just need to prepare the broadcast dimension here.
-            attention_mask = attention_mask.unsqueeze(1).unsqueeze(2)
-
-            # Since attention_mask is 1.0 for positions we want to attend and 0.0 for
-            # masked positions, this operation will create a tensor which is 0.0 for
-            # positions we want to attend and -10000.0 for masked positions.
-            # Since we are adding it to the raw scores before the softmax, this is
-            # effectively the same as removing these entirely.
-            attention_mask = attention_mask.to(dtype=next(self.parameters()).dtype) # fp16 compatibility
-            attention_mask = (1.0 - attention_mask) * -10000.0
-
-        # Prepare head mask if needed
-        # 1.0 in head_mask indicate we keep the head
-        # attention_probs has shape bsz x n_heads x N x N
-        # head_mask has shape n_layer x batch x n_heads x N x N
-        if head_mask is not None:
-            if head_mask.dim() == 1:
-                head_mask = head_mask.unsqueeze(0).unsqueeze(0).unsqueeze(-1).unsqueeze(-1)
-                head_mask = head_mask.expand(self.config.n_layer, -1, -1, -1, -1)
-            elif head_mask.dim() == 2:
-                head_mask = head_mask.unsqueeze(1).unsqueeze(-1).unsqueeze(-1)  # We can specify head_mask for each layer
-            head_mask = head_mask.to(dtype=next(self.parameters()).dtype) # switch to fload if need + fp16 compatibility
-        else:
-            head_mask = [None] * self.config.n_layer
-
-        x = self.w(input_ids)
-        # x = embedded.unsqueeze(0) if len(input_ids.shape)<2 else embedded
-        seq_len = input_ids.shape[1]
-        mask = torch.triu(torch.ones(seq_len, seq_len), 1).to(x.device)
-
-        x *= np.sqrt(self.d_model_size)
-
-        pos_x = self.pos_encoding[position_ids, :].to(x.device)
-        x += pos_x
+    def call(self, inputs, **kwargs):
+        outputs = self.transformer(inputs, **kwargs)
+        return outputs
 
-        x = self.dropout(x)
 
-        output_shape = input_shape + (x.size(-1),)
-        presents = ()
-        all_hidden_states = ()
-        all_attentions = []
-        for i, (h, layer_past) in enumerate(zip(self.h, past)):
-            if self.output_hidden_states:
-                all_hidden_states = all_hidden_states + (x.view(*output_shape),)
-            outputs = h(x,
-                        mask,
-                        layer_past=layer_past,
-                        attention_mask=attention_mask,
-                        head_mask=head_mask[i])
-            x, present = outputs[:2]
-            presents = presents + (present,)
+class TFCTRLLMHead(tf.keras.layers.Layer):
+    def __init__(self, config, input_embeddings, **kwargs):
+        super(TFCTRLLMHead, self).__init__(**kwargs)
+        self.vocab_size = config.vocab_size
 
-            if self.output_attentions:
-                all_attentions.append(outputs[2])
+        # The output weights are the same as the input embeddings, but there is
+        # an output-only bias for each token.
+        self.input_embeddings = input_embeddings
 
-        x = self.layernorm(x)
-        x = x.view(*output_shape)
-        if self.output_hidden_states:
-            all_hidden_states = all_hidden_states + (x,)
+    def build(self, input_shape):
+        self.bias = self.add_weight(shape=(self.vocab_size,),
+                                    initializer='zeros',
+                                    trainable=True,
+                                    name='bias')
+        super(TFCTRLLMHead, self).build(input_shape)
 
-        outputs = (x, presents)
-        if self.output_hidden_states:
-            outputs = outputs + (all_hidden_states,)
-        if self.output_attentions:
-            # let the number of heads free (-1) so we can extract attention even after head pruning
-            attention_output_shape = input_shape[:-1] + (-1,) + all_attentions[0].shape[-2:]
-            all_attentions = tuple(t.view(*attention_output_shape) for t in all_attentions)
-            outputs = outputs + (all_attentions,)
-        return outputs
+    def call(self, hidden_states):
+        hidden_states = self.input_embeddings(hidden_states, mode="linear")
+        hidden_states = hidden_states + self.bias
+        return hidden_states
 
 
 @add_start_docstrings("""The CTRL Model transformer with a language modeling head on top
 (linear layer with weights tied to the input embeddings). """, CTRL_START_DOCSTRING, CTRL_INPUTS_DOCSTRING)
-class CTRLLMHeadModel(CTRLPreTrainedModel):
+class TFCTRLLMHeadModel(TFCTRLPreTrainedModel):
     r"""
-        **labels**: (`optional`) ``torch.LongTensor`` of shape ``(batch_size, sequence_length)``:
-            Labels for language modeling.
-            Note that the labels **are shifted** inside the model, i.e. you can set ``lm_labels = input_ids``
-            Indices are selected in ``[-1, 0, ..., config.vocab_size]``
-            All labels set to ``-1`` are ignored (masked), the loss is only
-            computed for labels in ``[0, ..., config.vocab_size]``
-
     Outputs: `Tuple` comprising various elements depending on the configuration (config) and inputs:
-        **loss**: (`optional`, returned when ``labels`` is provided) ``torch.FloatTensor`` of shape ``(1,)``:
-            Language modeling loss.
         **prediction_scores**: ``torch.FloatTensor`` of shape ``(batch_size, sequence_length, config.vocab_size)``
             Prediction scores of the language modeling head (scores for each vocabulary token before SoftMax).
         **past**:
@@ -423,53 +463,28 @@ class CTRLLMHeadModel(CTRLPreTrainedModel):
     Examples::
 
         import torch
-        from transformers import CTRLTokenizer, CTRLLMHeadModel
+        from transformers import CTRLTokenizer, TFCTRLLMHeadModel
 
         tokenizer = CTRLTokenizer.from_pretrained('ctrl')
-        model = CTRLLMHeadModel.from_pretrained('ctrl')
+        model = TFCTRLLMHeadModel.from_pretrained('ctrl')
 
         input_ids = torch.tensor(tokenizer.encode("Links Hello, my dog is cute")).unsqueeze(0)  # Batch size 1
         outputs = model(input_ids, labels=input_ids)
         loss, logits = outputs[:2]
 
     """
-    def __init__(self, config):
-        super(CTRLLMHeadModel, self).__init__(config)
-        self.transformer = CTRLModel(config)
-        self.lm_head = nn.Linear(config.n_embd, config.vocab_size, bias=True)
-
-        self.init_weights()
-        self.tie_weights()
-
-    def tie_weights(self):
-        """ Make sure we are sharing the input and output embeddings.
-                Export to TorchScript can't handle parameter sharing so we are cloning them instead.
-        """
-        self._tie_or_clone_weights(self.lm_head, self.transformer.w)
+    def __init__(self, config, *inputs, **kwargs):
+        super(TFCTRLLMHeadModel, self).__init__(config, *inputs, **kwargs)
+        self.transformer = TFCTRLMainLayer(config, name='transformer')
 
-    def forward(self, input_ids, past=None, attention_mask=None, token_type_ids=None, position_ids=None, head_mask=None,
-                labels=None):
-        transformer_outputs = self.transformer(input_ids,
-                                               past=past,
-                                               attention_mask=attention_mask,
-                                               token_type_ids=token_type_ids,
-                                               position_ids=position_ids,
-                                               head_mask=head_mask)
+        self.lm_head = TFCTRLLMHead(config, self.transformer.w, name="lm_head")
 
+    def call(self, inputs, **kwargs):
+        transformer_outputs = self.transformer(inputs, **kwargs)
         hidden_states = transformer_outputs[0]
 
         lm_logits = self.lm_head(hidden_states)
 
         outputs = (lm_logits,) + transformer_outputs[1:]
 
-        if labels is not None:
-            # Shift so that tokens < n predict n
-            shift_logits = lm_logits[..., :-1, :].contiguous()
-            shift_labels = labels[..., 1:].contiguous()
-            # Flatten the tokens
-            loss_fct = CrossEntropyLoss(ignore_index=-1)
-            loss = loss_fct(shift_logits.view(-1, shift_logits.size(-1)),
-                            shift_labels.view(-1))
-            outputs = (loss,) + outputs
-
-        return outputs  # (loss), lm_logits, presents, (all hidden_states), (attentions)
+        return outputs  # lm_logits, presents, (all hidden_states), (attentions)

transformers/tests/modeling_tf_ctrl_test.py

+# coding=utf-8
+# Copyright 2018 The Google AI Language Team Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+import unittest
+import shutil
+import pytest
+import sys
+
+from .modeling_tf_common_test import (TFCommonTestCases, ids_tensor)
+from .configuration_common_test import ConfigTester
+
+from transformers import CTRLConfig, is_tf_available
+
+if is_tf_available():
+    import tensorflow as tf
+    from transformers.modeling_tf_ctrl import (TFCTRLModel, TFCTRLLMHeadModel,
+                                                TF_CTRL_PRETRAINED_MODEL_ARCHIVE_MAP)
+else:
+    pytestmark = pytest.mark.skip("Require TensorFlow")
+
+
+class TFCTRLModelTest(TFCommonTestCases.TFCommonModelTester):
+
+    all_model_classes = (TFCTRLModel, TFCTRLLMHeadModel) if is_tf_available() else ()
+
+    class TFCTRLModelTester(object):
+
+        def __init__(self,
+                     parent,
+                     batch_size=13,
+                     seq_length=7,
+                     is_training=True,
+                     use_token_type_ids=True,
+                     use_input_mask=True,
+                     use_labels=True,
+                     use_mc_token_ids=True,
+                     vocab_size=99,
+                     hidden_size=32,
+                     num_hidden_layers=5,
+                     num_attention_heads=4,
+                     intermediate_size=37,
+                     hidden_act="gelu",
+                     hidden_dropout_prob=0.1,
+                     attention_probs_dropout_prob=0.1,
+                     max_position_embeddings=512,
+                     type_vocab_size=16,
+                     type_sequence_label_size=2,
+                     initializer_range=0.02,
+                     num_labels=3,
+                     num_choices=4,
+                     scope=None,
+                     ):
+            self.parent = parent
+            self.batch_size = batch_size
+            self.seq_length = seq_length
+            self.is_training = is_training
+            self.use_token_type_ids = use_token_type_ids
+            self.use_input_mask = use_input_mask
+            self.use_labels = use_labels
+            self.use_mc_token_ids = use_mc_token_ids
+            self.vocab_size = vocab_size
+            self.hidden_size = hidden_size
+            self.num_hidden_layers = num_hidden_layers
+            self.num_attention_heads = num_attention_heads
+            self.intermediate_size = intermediate_size
+            self.hidden_act = hidden_act
+            self.hidden_dropout_prob = hidden_dropout_prob
+            self.attention_probs_dropout_prob = attention_probs_dropout_prob
+            self.max_position_embeddings = max_position_embeddings
+            self.type_vocab_size = type_vocab_size
+            self.type_sequence_label_size = type_sequence_label_size
+            self.initializer_range = initializer_range
+            self.num_labels = num_labels
+            self.num_choices = num_choices
+            self.scope = scope
+
+        def prepare_config_and_inputs(self):
+            input_ids = ids_tensor([self.batch_size, self.seq_length], self.vocab_size)
+
+            input_mask = None
+            if self.use_input_mask:
+                input_mask = ids_tensor([self.batch_size, self.seq_length], vocab_size=2)
+
+            token_type_ids = None
+            if self.use_token_type_ids:
+                token_type_ids = ids_tensor([self.batch_size, self.seq_length], self.type_vocab_size)
+
+            mc_token_ids = None
+            if self.use_mc_token_ids:
+                mc_token_ids = ids_tensor([self.batch_size, self.num_choices], self.seq_length)
+
+            sequence_labels = None
+            token_labels = None
+            choice_labels = None
+            if self.use_labels:
+                sequence_labels = ids_tensor([self.batch_size], self.type_sequence_label_size)
+                token_labels = ids_tensor([self.batch_size, self.seq_length], self.num_labels)
+                choice_labels = ids_tensor([self.batch_size], self.num_choices)
+
+            config = CTRLConfig(
+                vocab_size_or_config_json_file=self.vocab_size,
+                n_embd=self.hidden_size,
+                n_layer=self.num_hidden_layers,
+                n_head=self.num_attention_heads,
+                # intermediate_size=self.intermediate_size,
+                # hidden_act=self.hidden_act,
+                # hidden_dropout_prob=self.hidden_dropout_prob,
+                # attention_probs_dropout_prob=self.attention_probs_dropout_prob,
+                n_positions=self.max_position_embeddings,
+                n_ctx=self.max_position_embeddings
+                # type_vocab_size=self.type_vocab_size,
+                # initializer_range=self.initializer_range
+            )
+
+            head_mask = ids_tensor([self.num_hidden_layers, self.num_attention_heads], 2)
+
+            return config, input_ids, input_mask, head_mask, token_type_ids, mc_token_ids, sequence_labels, token_labels, choice_labels
+
+        def create_and_check_ctrl_model(self, config, input_ids, input_mask, head_mask, token_type_ids, *args):
+            model = TFCTRLModel(config=config)
+            inputs = {'input_ids': input_ids,
+                      'attention_mask': input_mask,
+                      'token_type_ids': token_type_ids}
+            sequence_output = model(inputs)[0]
+
+            inputs = [input_ids, None, input_mask]  # None is the input for 'past'
+            sequence_output = model(inputs)[0]
+
+            sequence_output = model(input_ids)[0]
+
+            result = {
+                "sequence_output": sequence_output.numpy(),
+            }
+            self.parent.assertListEqual(
+                list(result["sequence_output"].shape),
+                [self.batch_size, self.seq_length, self.hidden_size])
+
+
+        def create_and_check_ctrl_lm_head(self, config, input_ids, input_mask, head_mask, token_type_ids, *args):
+            model = TFCTRLLMHeadModel(config=config)
+            inputs = {'input_ids': input_ids,
+                      'attention_mask': input_mask,
+                      'token_type_ids': token_type_ids}
+            prediction_scores = model(inputs)[0]
+            result = {
+                "prediction_scores": prediction_scores.numpy(),
+            }
+            self.parent.assertListEqual(
+                list(result["prediction_scores"].shape),
+                [self.batch_size, self.seq_length, self.vocab_size])
+
+        def prepare_config_and_inputs_for_common(self):
+            config_and_inputs = self.prepare_config_and_inputs()
+
+            (config, input_ids, input_mask, head_mask, token_type_ids,
+             mc_token_ids, sequence_labels, token_labels, choice_labels) = config_and_inputs
+
+            inputs_dict = {'input_ids': input_ids, 'token_type_ids': token_type_ids, 'attention_mask': input_mask}
+            return config, inputs_dict
+
+    def setUp(self):
+        self.model_tester = TFCTRLModelTest.TFCTRLModelTester(self)
+        self.config_tester = ConfigTester(self, config_class=CTRLConfig, n_embd=37)
+
+    def test_config(self):
+        self.config_tester.run_common_tests()
+
+    def test_ctrl_model(self):
+        config_and_inputs = self.model_tester.prepare_config_and_inputs()
+        self.model_tester.create_and_check_ctrl_model(*config_and_inputs)
+
+    def test_ctrl_lm_head(self):
+        config_and_inputs = self.model_tester.prepare_config_and_inputs()
+        self.model_tester.create_and_check_ctrl_lm_head(*config_and_inputs)
+
+    @pytest.mark.slow
+    def test_model_from_pretrained(self):
+        cache_dir = "/tmp/transformers_test/"
+        for model_name in list(TF_CTRL_PRETRAINED_MODEL_ARCHIVE_MAP.keys())[:1]:
+            model = TFCTRLModel.from_pretrained(model_name, cache_dir=cache_dir)
+            shutil.rmtree(cache_dir)
+            self.assertIsNotNone(model)
+
+if __name__ == "__main__":
+    unittest.main()
+

transformers/tests/modeling_tf_gpt2_test.py

@@ -222,7 +222,7 @@ class TFGPT2ModelTest(TFCommonTestCases.TFCommonModelTester):
     @pytest.mark.slow
     def test_model_from_pretrained(self):
         cache_dir = "/tmp/transformers_test/"
-        for model_name in list(TF_gpt2_PRETRAINED_MODEL_ARCHIVE_MAP.keys())[:1]:
+        for model_name in list(TF_GPT2_PRETRAINED_MODEL_ARCHIVE_MAP.keys())[:1]:
             model = TFGPT2Model.from_pretrained(model_name, cache_dir=cache_dir)
             shutil.rmtree(cache_dir)
             self.assertIsNotNone(model)