fix: local variable sin referenced before assignment

paddlenlp/transformers/llama/modeling.py

@@ -1023,7 +1023,7 @@ def forward(
                     "with a layer index."
                 )
             kv_seq_len += past_key_value.get_seq_length(self.layer_idx)
-
+        sin = cos = None
         if self.config.rope:
             if self.reshard_layer is not None:
                 batch_size, seq_length, _, _ = query_states.shape
@@ -1066,11 +1066,12 @@ def forward(
                     cos, sin = self.rotary_emb(value_states, seq_len=kv_seq_len)
 
                 query_states, key_states = apply_rotary_pos_emb(query_states, key_states, cos, sin, position_ids)
-
+        cache_kwargs = {}
         # [bs, seq_len, num_head, head_dim]
         if past_key_value is not None:
             # reuse k, v, self_attention
-            cache_kwargs = {"sin": sin, "cos": cos}  # Specific to RoPE models
+            if sin is not None and cos is not None:
+                cache_kwargs = {"sin": sin, "cos": cos}  # Specific to RoPE models
             key_states, value_states = past_key_value.update(key_states, value_states, self.layer_idx, cache_kwargs)
 
         if self.kv_indices is not None: