support pp accuracy calculation

paddlenlp/trainer/trainer.py

@@ -3190,7 +3190,13 @@
 
         # Metrics!
         if self.compute_metrics is not None and all_preds is not None and all_labels is not None:
-            metrics = self.compute_metrics(EvalPrediction(predictions=all_preds, label_ids=all_labels))
+            # all_labels maybe is a tuple when prediction_steps output label_mask
+            if isinstance(all_labels, (list, tuple)):
+                # compute_metrics in train.py
+                metrics = self.compute_metrics(EvalPrediction(predictions=all_preds, label_ids=all_labels[0]))
+            else:
+                # compute_metrics in modeling.py
+                metrics = self.compute_metrics(EvalPrediction(predictions=all_preds, label_ids=all_labels))
         else:
             metrics = {}