support prune (#43250)

paddle/fluid/eager/auto_code_generator/eager_generator.cc

@@ -1206,22 +1206,37 @@ static std::string GenerateGradNodeCreationContent(
     if (!input.duplicable()) {
       compute_require_grad_args += ", " + input_autograd_name;
       size_t input_position = fwd_inputs_name_pos_map.at(input_name);
-
+      bool found_target_name = false;
+      for (const auto& iter : op_base_infos) {
+        const auto& grad_outs_slot_map = iter.GetGradOutsSlotnameMap();
+        for (auto iter : grad_outs_slot_map) {
+          if ((!found_target_name) && (input_name == iter.second)) {
             const char* SET_GRAD_OUT_META_TEMPLATE =
                 "      grad_node->SetGradOutMeta(%s, %d);\n";
-      grad_node_creation_str +=
-          paddle::string::Sprintf(SET_GRAD_OUT_META_TEMPLATE,
-                                  LegalizeVarName(input_name), input_position);
-
+            grad_node_creation_str += paddle::string::Sprintf(
+                SET_GRAD_OUT_META_TEMPLATE, LegalizeVarName(input_name),
+                input_position);
+            found_target_name = true;
+          }
+        }
+      }
     } else {
       compute_require_grad_args += ", &" + input_autograd_name;
       size_t input_position = fwd_inputs_name_pos_map.at(input_name);
-
+      bool found_target_name = false;
+      for (const auto& iter : op_base_infos) {
+        const auto& grad_outs_slot_map = iter.GetGradOutsSlotnameMap();
+        for (auto iter : grad_outs_slot_map) {
+          if ((!found_target_name) && (input_name == iter.second)) {
             const char* SET_GRAD_OUT_META_TEMPLATE =
                 "      grad_node->SetGradOutMeta(%s, %d);\n";
-      grad_node_creation_str +=
-          paddle::string::Sprintf(SET_GRAD_OUT_META_TEMPLATE,
-                                  LegalizeVarName(input_name), input_position);
+            grad_node_creation_str += paddle::string::Sprintf(
+                SET_GRAD_OUT_META_TEMPLATE, LegalizeVarName(input_name),
+                input_position);
+            found_target_name = true;
+          }
+        }
+      }
     }
   }