# coding=utf-8 # Copyright 2023 Salesforce authors, The EleutherAI, and HuggingFace Teams. All rights reserved. """ PyTorch CodeT5+ 2B 6B 16B models. The implementation is mainly based on transformers.models.codegen.modeling_codegen by adding cross-attention and transformers.models.encoder_decoder.modeling_encoder_decoder.EncoderDecoderModel. """ from typing import Optional, Tuple, Union import torch import torch.utils.checkpoint from torch import nn from torch.nn import CrossEntropyLoss from transformers.activations import ACT2FN from transformers.modeling_outputs import BaseModelOutput, Seq2SeqLMOutput, \ BaseModelOutputWithPast, CausalLMOutputWithPast, \ BaseModelOutputWithPastAndCrossAttentions, CausalLMOutputWithCrossAttentions from transformers.modeling_utils import PreTrainedModel from transformers.configuration_utils import PretrainedConfig from transformers.utils import add_code_sample_docstrings, add_start_docstrings, logging from .configuration_codet5p import CodeT5pConfig, CodeT5pModuleConfig logger = logging.get_logger(__name__) CODET5P_PRETRAINED_MODEL_ARCHIVE_LIST = [ "Salesforce/codet5p-220m", "Salesforce/codet5p-770m", "Salesforce/codet5p-2b", "Salesforce/codet5p-6b", "Salesforce/codet5p-16b", # See all CodeT5+ models at https://huggingface.co/models?filter=codet5p ] # Copied from transformers.models.gptj.modeling_gptj.fixed_pos_embedding def fixed_pos_embedding(x, seq_dim=1, seq_len=None): dim = x.shape[-1] if seq_len is None: seq_len = x.shape[seq_dim] inv_freq = 1.0 / (10000 ** (torch.arange(0, dim, 2) / dim)) sinusoid_inp = ( torch.einsum("i , j -> i j", torch.arange(seq_len, dtype=torch.float), inv_freq).to(x.device).float() ) return torch.sin(sinusoid_inp), torch.cos(sinusoid_inp) # Copied from transformers.models.gptj.modeling_gptj.rotate_every_two def rotate_every_two(x): x1 = x[:, :, :, ::2] x2 = x[:, :, :, 1::2] x = torch.stack((-x2, x1), dim=-1) return x.flatten(-2) # in einsum notation: rearrange(x, '... d j -> ... (d j)') # Copied from transformers.models.gptj.modeling_gptj.duplicate_interleave def duplicate_interleave(m): """ A simple version of `torch.repeat_interleave` for duplicating a matrix while interleaving the copy. """ dim0 = m.shape[0] m = m.view(-1, 1) # flatten the matrix m = m.repeat(1, 2) # repeat all elements into the 2nd dimension m = m.view(dim0, -1) # reshape into a matrix, interleaving the copy return m # Copied from transformers.models.gptj.modeling_gptj.apply_rotary_pos_emb def apply_rotary_pos_emb(x, sincos, offset=0): sin, cos = (duplicate_interleave(t)[None, offset: x.shape[1] + offset, None, :] for t in sincos) # einsum notation for lambda t: repeat(t[offset:x.shape[1]+offset,:], "n d -> () n () (d j)", j=2) return (x * cos) + (rotate_every_two(x) * sin) # Adapted from transformers.models.codegen.modeling_codegen.CodeGenAttention class CodeT5pAttention(nn.Module): def __init__(self, config, is_cross_attention=False, is_decoder=True): super().__init__() max_positions = config.max_position_embeddings self.register_buffer( "causal_mask", torch.tril(torch.ones((max_positions, max_positions), dtype=torch.uint8)).view( 1, 1, max_positions, max_positions ), ) self.attn_dropout = nn.Dropout(config.attn_pdrop) self.resid_dropout = nn.Dropout(config.resid_pdrop) self.embed_dim = config.hidden_size self.num_attention_heads = config.num_attention_heads self.head_dim = self.embed_dim // self.num_attention_heads if self.head_dim * self.num_attention_heads != self.embed_dim: raise ValueError( f"embed_dim must be divisible by num_attention_heads (got `embed_dim`: {self.embed_dim} and" f" `num_attention_heads`: {self.num_attention_heads})." ) self.scale_attn = torch.sqrt(torch.tensor(self.head_dim, dtype=torch.float32)).to(torch.get_default_dtype()) self.is_decoder = is_decoder self.is_cross_attention = is_cross_attention if self.is_cross_attention: self.qkv_proj = nn.Linear(self.embed_dim, self.embed_dim * 2, bias=False) self.q_attn = nn.Linear(self.embed_dim, self.embed_dim, bias=False) else: self.qkv_proj = nn.Linear(self.embed_dim, self.embed_dim * 3, bias=False) self.out_proj = nn.Linear(self.embed_dim, self.embed_dim, bias=False) self.rotary_dim = None if config.rotary_dim is not None: self.rotary_dim = config.rotary_dim def _split_heads(self, x, n_head, dim_head, mp_num): reshaped = x.reshape(x.shape[:-1] + (n_head // mp_num, dim_head)) reshaped = reshaped.reshape(x.shape[:-2] + (-1,) + reshaped.shape[-1:]) return reshaped def _merge_heads(self, tensor, num_attention_heads, attn_head_size): """ Merges attn_head_size dim and num_attn_heads dim into n_ctx """ if len(tensor.shape) == 5: tensor = tensor.permute(0, 1, 3, 2, 4).contiguous() elif len(tensor.shape) == 4: tensor = tensor.permute(0, 2, 1, 3).contiguous() else: raise ValueError(f"Input tensor rank should be one of [4, 5], but is: {len(tensor.shape)}") new_shape = tensor.size()[:-2] + (num_attention_heads * attn_head_size,) return tensor.view(new_shape) def _attn( self, query, key, value, attention_mask=None, head_mask=None, ): # Keep the attention weights computation in fp32 to avoid overflow issues query = query.to(torch.float32) key = key.to(torch.float32) attn_weights = torch.matmul(query, key.transpose(-1, -2)) attn_weights = attn_weights / self.scale_attn if not self.is_cross_attention and self.is_decoder: # compute causal mask from causal mask buffer query_length, key_length = query.size(-2), key.size(-2) causal_mask = self.causal_mask[:, :, key_length - query_length: key_length, :key_length] mask_value = torch.finfo(attn_weights.dtype).min # Need to be a tensor, otherwise we get error: `RuntimeError: expected scalar type float but found double`. # Need to be on the same device, otherwise `RuntimeError: ..., x and y to be on the same device` mask_value = torch.tensor(mask_value, dtype=attn_weights.dtype).to(attn_weights.device) attn_weights = torch.where(causal_mask.bool(), attn_weights, mask_value) if attention_mask is not None: # Apply the attention mask attn_weights = attn_weights + attention_mask attn_weights = nn.Softmax(dim=-1)(attn_weights) attn_weights = attn_weights.to(value.dtype) attn_weights = self.attn_dropout(attn_weights) # Mask heads if we want to if head_mask is not None: attn_weights = attn_weights * head_mask attn_output = torch.matmul(attn_weights, value) return attn_output, attn_weights def forward( self, hidden_states: Optional[torch.FloatTensor], attention_mask: Optional[torch.FloatTensor] = None, layer_past: Optional[Tuple[torch.Tensor]] = None, head_mask: Optional[torch.FloatTensor] = None, encoder_hidden_states: Optional[torch.Tensor] = None, encoder_attention_mask: Optional[torch.FloatTensor] = None, use_cache: Optional[bool] = False, output_attentions: Optional[bool] = False, ) -> Union[ Tuple[torch.Tensor, Tuple[torch.Tensor]], Optional[Tuple[torch.Tensor, Tuple[torch.Tensor], Tuple[torch.Tensor, ...]]], ]: if encoder_hidden_states is not None: if not hasattr(self, "q_attn"): raise ValueError( "If class is used as cross attention, the weights `q_attn` have to be defined. " "Please make sure to instantiate class with `GPT2Attention(..., is_cross_attention=True)`." ) mp_num = 4 local_dim = self.head_dim * self.num_attention_heads // mp_num q = self.q_attn(hidden_states) q_split = q.reshape(q.shape[:-1] + (mp_num, -1)) query = torch.split(q_split, local_dim, dim=-1)[0] qkv = self.qkv_proj(encoder_hidden_states) qkv_split = qkv.reshape(qkv.shape[:-1] + (mp_num, -1)) value, key = torch.split(qkv_split, local_dim, dim=-1) attention_mask = encoder_attention_mask else: qkv = self.qkv_proj(hidden_states) mp_num = 4 qkv_split = qkv.reshape(qkv.shape[:-1] + (mp_num, -1)) local_dim = self.head_dim * self.num_attention_heads // mp_num query, value, key = torch.split(qkv_split, local_dim, dim=-1) query = self._split_heads(query, self.num_attention_heads, self.head_dim, mp_num=mp_num) key = self._split_heads(key, self.num_attention_heads, self.head_dim, mp_num=mp_num) value = self._split_heads(value, self.num_attention_heads, self.head_dim, mp_num=mp_num) value = value.permute(0, 2, 1, 3) seq_len = key.shape[1] offset = 0 if layer_past is not None: offset = layer_past[0].shape[-2] seq_len += offset if self.rotary_dim is not None: k_rot = key[:, :, :, : self.rotary_dim] k_pass = key[:, :, :, self.rotary_dim:] q_rot = query[:, :, :, : self.rotary_dim] q_pass = query[:, :, :, self.rotary_dim:] sincos = fixed_pos_embedding(k_rot, 1, seq_len=seq_len) k_rot = apply_rotary_pos_emb(k_rot, sincos, offset=offset) seq_len_q = query.shape[1] sincos_q = fixed_pos_embedding(q_rot, 1, seq_len=seq_len_q) q_rot = apply_rotary_pos_emb(q_rot, sincos_q, offset=offset) key = torch.cat([k_rot, k_pass], dim=-1) query = torch.cat([q_rot, q_pass], dim=-1) else: sincos = fixed_pos_embedding(key, 1, seq_len=seq_len) key = apply_rotary_pos_emb(key, sincos, offset=offset) query = apply_rotary_pos_emb(query, sincos, offset=offset) key = key.permute(0, 2, 1, 3) query = query.permute(0, 2, 1, 3) if layer_past is not None: past_key = layer_past[0] past_value = layer_past[1] key = torch.cat((past_key, key), dim=-2) value = torch.cat((past_value, value), dim=-2) if use_cache is True: present = (key, value) else: present = None # compute self-attention: V x Softmax(QK^T) attn_output, attn_weights = self._attn(query, key, value, attention_mask, head_mask) attn_output = self._merge_heads(attn_output, self.num_attention_heads, self.head_dim) attn_output = self.out_proj(attn_output) attn_output = self.resid_dropout(attn_output) outputs = (attn_output, present) if output_attentions: outputs += (attn_weights,) return outputs # a, present, (attentions) # Adapted from transformers.models.codegen.modeling_codegen.CodeGenMLP class CodeT5pMLP(nn.Module): def __init__(self, intermediate_size, config): # in MLP: intermediate_size= 4 * embed_dim super().__init__() embed_dim = config.n_embd self.fc_in = nn.Linear(embed_dim, intermediate_size) self.fc_out = nn.Linear(intermediate_size, embed_dim) self.act = ACT2FN[config.activation_function] self.dropout = nn.Dropout(config.resid_pdrop) def forward(self, hidden_states: Optional[torch.FloatTensor]) -> torch.FloatTensor: hidden_states = self.fc_in(hidden_states) hidden_states = self.act(hidden_states) hidden_states = self.fc_out(hidden_states) hidden_states = self.dropout(hidden_states) return hidden_states # Adapted from transformers.models.codegen.modeling_codegen.CodeGenBlock class CodeT5pBlock(nn.Module): def __init__(self, config, layer_idx=None): super().__init__() inner_dim = config.n_inner if config.n_inner is not None else 4 * config.n_embd self.ln_1 = nn.LayerNorm(config.n_embd, eps=config.layer_norm_epsilon) if config.is_decoder is False: self.attn = CodeT5pAttention(config, is_cross_attention=False, is_decoder=False) else: self.attn = CodeT5pAttention(config) self.mlp = CodeT5pMLP(inner_dim, config) # Adding 1 cross-attention layer at the final decoder layer self.add_cross_attention_by_layer = True \ if config.add_cross_attention and layer_idx == config.n_layer - 1 else False if config.add_cross_attention and self.add_cross_attention_by_layer: self.crossattention = CodeT5pAttention(config, is_cross_attention=True) def forward( self, hidden_states: Optional[torch.FloatTensor], layer_past: Optional[Tuple[torch.Tensor]] = None, attention_mask: Optional[torch.FloatTensor] = None, head_mask: Optional[torch.FloatTensor] = None, encoder_hidden_states: Optional[torch.Tensor] = None, encoder_attention_mask: Optional[torch.FloatTensor] = None, use_cache: Optional[bool] = False, output_attentions: Optional[bool] = False, ) -> Union[Tuple[torch.Tensor], Optional[Tuple[torch.Tensor, Tuple[torch.FloatTensor, ...]]]]: residual = hidden_states hidden_states = self.ln_1(hidden_states) attn_outputs = self.attn( hidden_states, layer_past=layer_past, attention_mask=attention_mask, head_mask=head_mask, use_cache=use_cache, output_attentions=output_attentions, ) attn_output = attn_outputs[0] # output_attn: a, present, (attentions) outputs = attn_outputs[1:] feed_forward_hidden_states = self.mlp(hidden_states) if encoder_hidden_states is not None and self.add_cross_attention_by_layer: # add one self-attention block for cross-attention if not hasattr(self, "crossattention"): raise ValueError( f"If `encoder_hidden_states` are passed, {self} has to be instantiated with " "cross-attention layers by setting `config.add_cross_attention=True`" ) # residual = hidden_states # hidden_states = self.ln_cross_attn(residual) cross_attn_outputs = self.crossattention( hidden_states, attention_mask=attention_mask, head_mask=head_mask, encoder_hidden_states=encoder_hidden_states, encoder_attention_mask=encoder_attention_mask, output_attentions=output_attentions, ) xattn_output = cross_attn_outputs[0] attn_output = attn_output + xattn_output outputs = outputs + cross_attn_outputs[2:] # add cross attentions if we output attention weights hidden_states = attn_output + feed_forward_hidden_states + residual if use_cache: outputs = (hidden_states,) + outputs else: outputs = (hidden_states,) + outputs[1:] return outputs # hidden_states, present, (attentions) # Adapted from transformers.models.codegen.modeling_codegen.CodeGenPreTrainedModel class CodeT5pPreTrainedModel(PreTrainedModel): """ An abstract class to handle weights initialization and a simple interface for downloading and loading pretrained models. """ config_class = CodeT5pModuleConfig base_model_prefix = "transformer" supports_gradient_checkpointing = True _no_split_modules = ["CodeT5pBlock"] def __init__(self, *inputs, **kwargs): super().__init__(*inputs, **kwargs) def _init_weights(self, module): """Initialize the weights.""" if isinstance(module, (nn.Linear,)): # Slightly different from Mesh Transformer JAX 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 module.bias is not None: module.bias.data.zero_() elif isinstance(module, nn.Embedding): module.weight.data.normal_(mean=0.0, std=self.config.initializer_range) if module.padding_idx is not None: module.weight.data[module.padding_idx].zero_() elif isinstance(module, nn.LayerNorm): module.bias.data.zero_() module.weight.data.fill_(1.0) def _set_gradient_checkpointing(self, module, value=False): if isinstance(module, CodeT5pModel): module.gradient_checkpointing = value # Adapted from transformers.models.codegen.modeling_codegen.CodeGenModel class CodeT5pModel(CodeT5pPreTrainedModel): def __init__(self, config): super().__init__(config) self.embed_dim = config.n_embd self.vocab_size = config.vocab_size self.wte = nn.Embedding(config.vocab_size, self.embed_dim) self.drop = nn.Dropout(config.embd_pdrop) self.h = nn.ModuleList([CodeT5pBlock(config, idx) for idx in range(config.n_layer)]) self.ln_f = nn.LayerNorm(self.embed_dim, eps=config.layer_norm_epsilon) self.rotary_dim = min(config.rotary_dim, config.n_ctx // config.num_attention_heads) self.gradient_checkpointing = False # Initialize weights and apply final processing self.post_init() def get_input_embeddings(self): return self.wte def set_input_embeddings(self, new_embeddings): self.wte = new_embeddings def forward( self, input_ids: Optional[torch.LongTensor] = None, past_key_values: Optional[Tuple[Tuple[torch.Tensor]]] = None, attention_mask: Optional[torch.FloatTensor] = None, token_type_ids: Optional[torch.LongTensor] = None, position_ids: Optional[torch.LongTensor] = None, head_mask: Optional[torch.FloatTensor] = None, inputs_embeds: Optional[torch.FloatTensor] = None, encoder_hidden_states: Optional[torch.Tensor] = None, encoder_attention_mask: Optional[torch.FloatTensor] = None, use_cache: Optional[bool] = None, output_attentions: Optional[bool] = None, output_hidden_states: Optional[bool] = None, return_dict: Optional[bool] = None, ) -> Union[Tuple, BaseModelOutputWithPastAndCrossAttentions]: output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions output_hidden_states = ( output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states ) use_cache = use_cache if use_cache is not None else self.config.use_cache return_dict = return_dict if return_dict is not None else self.config.use_return_dict if input_ids is not None and inputs_embeds is not None: raise ValueError("You cannot specify both input_ids and inputs_embeds at the same time") elif input_ids is not None: input_shape = input_ids.size() input_ids = input_ids.view(-1, input_shape[-1]) batch_size = input_ids.shape[0] elif inputs_embeds is not None: input_shape = inputs_embeds.size()[:-1] batch_size = inputs_embeds.shape[0] else: raise ValueError("You have to specify either input_ids or inputs_embeds") device = input_ids.device if input_ids is not None else inputs_embeds.device 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_key_values is None: past_length = 0 past_key_values = tuple([None] * len(self.h)) else: past_length = past_key_values[0][0].size(-2) if position_ids is None: position_ids = torch.arange(past_length, input_shape[-1] + past_length, dtype=torch.long, device=device) position_ids = position_ids.unsqueeze(0).view(-1, input_shape[-1]) # Attention mask. if attention_mask is not None: if batch_size <= 0: raise ValueError("batch_size has to be defined and > 0") attention_mask = attention_mask.view(batch_size, -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[:, None, None, :] # 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 the dtype's smallest value 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=self.dtype) # fp16 compatibility attention_mask = (1.0 - attention_mask) * torch.finfo(self.dtype).min # If a 2D or 3D attention mask is provided for the cross-attention # we need to make broadcastable to [batch_size, num_heads, seq_length, seq_length] if self.config.add_cross_attention and encoder_hidden_states is not None: encoder_batch_size, encoder_sequence_length, _ = encoder_hidden_states.size() encoder_hidden_shape = (encoder_batch_size, encoder_sequence_length) if encoder_attention_mask is None: encoder_attention_mask = torch.ones(encoder_hidden_shape, device=device) encoder_attention_mask = self.invert_attention_mask(encoder_attention_mask) else: encoder_attention_mask = None # Prepare head mask if needed # 1.0 in head_mask indicate we keep the head # attention_probs has shape bsz x num_attention_heads x N x N # head_mask has shape n_layer x batch x num_attention_heads x N x N head_mask = self.get_head_mask(head_mask, self.config.n_layer) if inputs_embeds is None: inputs_embeds = self.wte(input_ids) hidden_states = inputs_embeds if token_type_ids is not None: token_type_embeds = self.wte(token_type_ids) hidden_states = hidden_states + token_type_embeds hidden_states = self.drop(hidden_states) output_shape = input_shape + (hidden_states.size(-1),) presents = () if use_cache else None all_self_attentions = () if output_attentions else None all_cross_attentions = () if output_attentions and self.config.add_cross_attention else None all_hidden_states = () if output_hidden_states else None for i, (block, layer_past) in enumerate(zip(self.h, past_key_values)): if output_hidden_states: all_hidden_states = all_hidden_states + (hidden_states,) if self.gradient_checkpointing and self.training: if use_cache: logger.warning( "`use_cache=True` is incompatible with `config.gradient_checkpointing=True`. Setting " "`use_cache=False`..." ) use_cache = False def create_custom_forward(module): def custom_forward(*inputs): # None for past_key_value return module(*inputs, use_cache, output_attentions) return custom_forward outputs = torch.utils.checkpoint.checkpoint( create_custom_forward(block), hidden_states, None, attention_mask, head_mask[i], encoder_hidden_states, encoder_attention_mask, ) else: outputs = block( hidden_states, layer_past=layer_past, attention_mask=attention_mask, head_mask=head_mask[i], encoder_hidden_states=encoder_hidden_states, encoder_attention_mask=encoder_attention_mask, use_cache=use_cache, output_attentions=output_attentions, ) hidden_states = outputs[0] if use_cache is True: presents = presents + (outputs[1],) if output_attentions: all_self_attentions = all_self_attentions + (outputs[2 if use_cache else 1],) if self.config.add_cross_attention and self.add_cross_attention_by_layer: all_cross_attentions = all_cross_attentions + (outputs[3 if use_cache else 2],) hidden_states = self.ln_f(hidden_states) hidden_states = hidden_states.view(output_shape) # Add last hidden state if output_hidden_states: all_hidden_states = all_hidden_states + (hidden_states,) if not return_dict: return tuple( v for v in [hidden_states, presents, all_hidden_states, all_self_attentions, all_cross_attentions] if v is not None) return BaseModelOutputWithPastAndCrossAttentions( last_hidden_state=hidden_states, past_key_values=presents, hidden_states=all_hidden_states, attentions=all_self_attentions, cross_attentions=all_cross_attentions, ) # Adapted from transformers.models.codegen.modeling_codegen.CodeGenForCausalLM class CodeT5pForCausalLM(CodeT5pPreTrainedModel): _keys_to_ignore_on_load_missing = [r"h\.\d+\.attn\.causal_mask"] def __init__(self, config): super().__init__(config) self.transformer = CodeT5pModel(config) self.lm_head = nn.Linear(config.n_embd, config.vocab_size) # Initialize weights and apply final processing self.post_init() def get_output_embeddings(self): return self.lm_head def set_output_embeddings(self, new_embeddings): self.lm_head = new_embeddings def prepare_inputs_for_generation(self, input_ids, past_key_values=None, **kwargs): token_type_ids = kwargs.get("token_type_ids", None) # only last token for inputs_ids if past is defined in kwargs if past_key_values: input_ids = input_ids[:, -1].unsqueeze(-1) if token_type_ids is not None: token_type_ids = token_type_ids[:, -1].unsqueeze(-1) attention_mask = kwargs.get("attention_mask", None) position_ids = kwargs.get("position_ids", None) if attention_mask is not None and position_ids is None: # create position_ids on the fly for batch generation position_ids = attention_mask.long().cumsum(-1) - 1 position_ids.masked_fill_(attention_mask == 0, 1) if past_key_values: position_ids = position_ids[:, -1].unsqueeze(-1) else: position_ids = None return { "input_ids": input_ids, "past_key_values": past_key_values, "use_cache": kwargs.get("use_cache"), "position_ids": position_ids, "attention_mask": attention_mask, "token_type_ids": token_type_ids, } def forward( self, input_ids: Optional[torch.LongTensor] = None, past_key_values: Optional[Tuple[Tuple[torch.Tensor]]] = None, attention_mask: Optional[torch.FloatTensor] = None, token_type_ids: Optional[torch.LongTensor] = None, position_ids: Optional[torch.LongTensor] = None, head_mask: Optional[torch.FloatTensor] = None, inputs_embeds: Optional[torch.FloatTensor] = None, encoder_hidden_states: Optional[torch.Tensor] = None, encoder_attention_mask: Optional[torch.FloatTensor] = None, labels: Optional[torch.LongTensor] = None, use_cache: Optional[bool] = None, output_attentions: Optional[bool] = None, output_hidden_states: Optional[bool] = None, return_dict: Optional[bool] = None, ) -> Union[Tuple, CausalLMOutputWithCrossAttentions]: r""" labels (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*): Labels for language modeling. Note that the labels **are shifted** inside the model, i.e. you can set `labels = input_ids` Indices are selected in `[-100, 0, ..., config.vocab_size]` All labels set to `-100` are ignored (masked), the loss is only computed for labels in `[0, ..., config.vocab_size]` """ return_dict = return_dict if return_dict is not None else self.config.use_return_dict transformer_outputs = self.transformer( input_ids, past_key_values=past_key_values, attention_mask=attention_mask, token_type_ids=token_type_ids, position_ids=position_ids, head_mask=head_mask, inputs_embeds=inputs_embeds, encoder_hidden_states=encoder_hidden_states, encoder_attention_mask=encoder_attention_mask, use_cache=use_cache, output_attentions=output_attentions, output_hidden_states=output_hidden_states, return_dict=return_dict, ) hidden_states = transformer_outputs[0] # make sure sampling in fp16 works correctly and # compute loss in fp32 to match with mesh-tf version # https://github.com/EleutherAI/gpt-neo/blob/89ce74164da2fb16179106f54e2269b5da8db333/models/gpt2/gpt2.py#L179 lm_logits = self.lm_head(hidden_states).to(torch.float32) loss = None 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() loss = loss_fct(shift_logits.view(-1, shift_logits.size(-1)), shift_labels.view(-1)) loss = loss.to(hidden_states.dtype) if not return_dict: output = (lm_logits,) + transformer_outputs[1:] return ((loss,) + output) if loss is not None else output return CausalLMOutputWithCrossAttentions( loss=loss, logits=lm_logits, past_key_values=transformer_outputs.past_key_values, hidden_states=transformer_outputs.hidden_states, attentions=transformer_outputs.attentions, cross_attentions=transformer_outputs.cross_attentions, ) @staticmethod def _reorder_cache( past_key_values: Tuple[Tuple[torch.Tensor]], beam_idx: torch.Tensor ) -> Tuple[Tuple[torch.Tensor]]: """ This function is used to re-order the `past_key_values` cache if [`~PretrainedModel.beam_search`] or [`~PretrainedModel.beam_sample`] is called. This is required to match `past_key_values` with the correct beam_idx at every generation step. """ return tuple( tuple(past_state.index_select(0, beam_idx.to(past_state.device)) for past_state in layer_past) for layer_past in past_key_values ) def shift_tokens_right(input_ids: torch.Tensor, pad_token_id: int, decoder_start_token_id: int): """ Shift input ids one token to the right. """ shifted_input_ids = input_ids.new_zeros(input_ids.shape) shifted_input_ids[:, 1:] = input_ids[:, :-1].clone() if decoder_start_token_id is None: raise ValueError("Make sure to set the decoder_start_token_id attribute of the model's configuration.") shifted_input_ids[:, 0] = decoder_start_token_id if pad_token_id is None: raise ValueError("Make sure to set the pad_token_id attribute of the model's configuration.") # replace possible -100 values in labels by `pad_token_id` shifted_input_ids.masked_fill_(shifted_input_ids == -100, pad_token_id) return shifted_input_ids # Adapted from transformers.models.encoder_decoder.modeling_encoder_decoder.EncoderDecoderModel class CodeT5pEncoderDecoderModel(PreTrainedModel): config_class = CodeT5pConfig _no_split_modules = ["CodeT5pBlock"] def __init__( self, config: Optional[PretrainedConfig] = None, encoder: Optional[PreTrainedModel] = None, decoder: Optional[PreTrainedModel] = None, ): if config is None and (encoder is None or decoder is None): raise ValueError("Either a configuration or an encoder and a decoder has to be provided.") if config is None: config = CodeT5pConfig.from_encoder_decoder_configs(encoder.config, decoder.config) else: if not isinstance(config, self.config_class): raise ValueError(f"Config: {config} has to be of type {self.config_class}") if config.decoder.cross_attention_hidden_size is not None: if config.decoder.cross_attention_hidden_size != config.encoder.hidden_size: raise ValueError( "If `cross_attention_hidden_size` is specified in the decoder's configuration, it has to be equal" f" to the encoder's `hidden_size`. Got {config.decoder.cross_attention_hidden_size} for" f" `config.decoder.cross_attention_hidden_size` and {config.encoder.hidden_size} for" " `config.encoder.hidden_size`." ) # initialize with config super().__init__(config) if encoder is None: encoder = CodeT5pModel(config.encoder) if decoder is None: decoder = CodeT5pForCausalLM(config.decoder) self.encoder = encoder self.decoder = decoder if self.encoder.config.to_dict() != self.config.encoder.to_dict(): logger.warning( f"Config of the encoder: {self.encoder.__class__} is overwritten by shared encoder config:" f" {self.config.encoder}" ) if self.decoder.config.to_dict() != self.config.decoder.to_dict(): logger.warning( f"Config of the decoder: {self.decoder.__class__} is overwritten by shared decoder config:" f" {self.config.decoder}" ) # make sure that the individual model's config refers to the shared config # so that the updates to the config will be synced self.encoder.config = self.config.encoder self.decoder.config = self.config.decoder # encoder outputs might need to be projected to different dimension for decoder if ( self.encoder.config.hidden_size != self.decoder.config.hidden_size and self.decoder.config.cross_attention_hidden_size is None ): self.enc_to_dec_proj = nn.Linear(self.encoder.config.hidden_size, self.decoder.config.hidden_size) if self.encoder.get_output_embeddings() is not None: raise ValueError( f"The encoder {self.encoder} should not have a LM Head. Please use a model without LM Head" ) # tie encoder, decoder weights if config set accordingly self.tie_weights() def tie_weights(self): # tie encoder & decoder if needed if self.config.tie_encoder_decoder: # tie encoder and decoder base model decoder_base_model_prefix = self.decoder.base_model_prefix self._tie_encoder_decoder_weights( self.encoder, self.decoder._modules[decoder_base_model_prefix], self.decoder.base_model_prefix ) def get_encoder(self): return self.encoder def get_decoder(self): return self.decoder def get_input_embeddings(self): return self.encoder.get_input_embeddings() def get_output_embeddings(self): return self.decoder.get_output_embeddings() def set_output_embeddings(self, new_embeddings): return self.decoder.set_output_embeddings(new_embeddings) @classmethod def from_pretrained(cls, *args, **kwargs): # At the moment fast initialization is not supported for composite models if kwargs.get("_fast_init", False): logger.warning( "Fast initialization is currently not supported for EncoderDecoderModel. " "Falling back to slow initialization..." ) kwargs["_fast_init"] = False return super().from_pretrained(*args, **kwargs) def forward( self, input_ids: Optional[torch.LongTensor] = None, attention_mask: Optional[torch.FloatTensor] = None, decoder_input_ids: Optional[torch.LongTensor] = None, decoder_attention_mask: Optional[torch.BoolTensor] = None, encoder_outputs: Optional[Tuple[torch.FloatTensor]] = None, past_key_values: Tuple[Tuple[torch.FloatTensor]] = None, inputs_embeds: Optional[torch.FloatTensor] = None, decoder_inputs_embeds: Optional[torch.FloatTensor] = None, labels: Optional[torch.LongTensor] = None, use_cache: Optional[bool] = None, output_attentions: Optional[bool] = None, output_hidden_states: Optional[bool] = None, return_dict: Optional[bool] = None, **kwargs, ) -> Union[Tuple, Seq2SeqLMOutput]: return_dict = return_dict if return_dict is not None else self.config.use_return_dict kwargs_encoder = {argument: value for argument, value in kwargs.items() if not argument.startswith("decoder_")} kwargs_decoder = { argument[len("decoder_"):]: value for argument, value in kwargs.items() if argument.startswith("decoder_") } if encoder_outputs is None: encoder_outputs = self.encoder( input_ids=input_ids, attention_mask=attention_mask, inputs_embeds=inputs_embeds, output_attentions=output_attentions, output_hidden_states=output_hidden_states, return_dict=return_dict, **kwargs_encoder, ) elif isinstance(encoder_outputs, tuple): encoder_outputs = BaseModelOutput(*encoder_outputs) encoder_hidden_states = encoder_outputs[0] # optionally project encoder_hidden_states if ( self.encoder.config.hidden_size != self.decoder.config.hidden_size and self.decoder.config.cross_attention_hidden_size is None ): encoder_hidden_states = self.enc_to_dec_proj(encoder_hidden_states) if (labels is not None) and (decoder_input_ids is None and decoder_inputs_embeds is None): decoder_input_ids = shift_tokens_right( labels, self.config.pad_token_id, self.config.decoder_start_token_id ) # Decode decoder_outputs = self.decoder( input_ids=decoder_input_ids, attention_mask=decoder_attention_mask, encoder_hidden_states=encoder_hidden_states, encoder_attention_mask=attention_mask, inputs_embeds=decoder_inputs_embeds, output_attentions=output_attentions, output_hidden_states=output_hidden_states, use_cache=use_cache, past_key_values=past_key_values, return_dict=return_dict, **kwargs_decoder, ) # Compute loss independent from decoder (as some shift the logits inside them) loss = None if labels is not None: # warnings.warn(DEPRECATION_WARNING, FutureWarning) logits = decoder_outputs.logits if return_dict else decoder_outputs[0] loss_fct = CrossEntropyLoss() loss = loss_fct(logits.reshape(-1, self.decoder.config.vocab_size), labels.view(-1)) if not return_dict: if loss is not None: return (loss,) + decoder_outputs + encoder_outputs else: return decoder_outputs + encoder_outputs return Seq2SeqLMOutput( loss=loss, logits=decoder_outputs.logits, past_key_values=decoder_outputs.past_key_values, decoder_hidden_states=decoder_outputs.hidden_states, decoder_attentions=decoder_outputs.attentions, cross_attentions=decoder_outputs.cross_attentions, encoder_last_hidden_state=encoder_outputs.last_hidden_state, encoder_hidden_states=encoder_outputs.hidden_states, encoder_attentions=encoder_outputs.attentions, ) def prepare_decoder_input_ids_from_labels(self, labels: torch.Tensor): return shift_tokens_right(labels, self.config.pad_token_id, self.config.decoder_start_token_id) def prepare_inputs_for_generation( self, input_ids, past=None, attention_mask=None, use_cache=None, encoder_outputs=None, **kwargs ): decoder_inputs = self.decoder.prepare_inputs_for_generation(input_ids, past=past) decoder_attention_mask = decoder_inputs["attention_mask"] if "attention_mask" in decoder_inputs else None input_dict = { "attention_mask": attention_mask, "decoder_attention_mask": decoder_attention_mask, "decoder_input_ids": decoder_inputs["input_ids"], "encoder_outputs": encoder_outputs, "past_key_values": decoder_inputs["past_key_values"], "use_cache": use_cache, } return input_dict def resize_token_embeddings(self, *args, **kwargs): raise NotImplementedError( "Resizing the embedding layers via the EncoderDecoderModel directly is not supported. Please use the" " respective methods of the wrapped objects (model.encoder.resize_token_embeddings(...) or" " model.decoder.resize_token_embeddings(...))" ) def _reorder_cache(self, past, beam_idx): # apply decoder cache reordering here return self.decoder._reorder_cache(past, beam_idx)