+void dbg_init(merge_pair_func *dbg_info_merge_pair, merge_sets_func *dbg_info_merge_sets, snprint_dbg_func *snprint_dbg);
+
+/**
+ * The default merge_pair_func implementation, simply copies the debug info
+ * from the old Firm node to the new one if the new one does not have debug info yet.
+ *
+ * @param nw The new Firm node.
+ * @param old The old Firm node.
+ * @param info The action that cause old node to be replaced by new one.
+ */
+void default_dbg_info_merge_pair(ir_node *nw, ir_node *old, dbg_action info);
+
+/**
+ * The default merge_sets_func implementation. If n_old_nodes is equal 1, copies
+ * the debug info from the old node to all new ones (if they do not have one), else does nothing.
+ *
+ * @param new_nodes An array of new Firm nodes.
+ * @param n_new_nodes The length of the new_nodes array.
+ * @param old_nodes An array of old (replaced) Firm nodes.
+ * @param n_old_nodes The length of the old_nodes array.
+ * @param info The action that cause old node to be replaced by new one.
+ */
+void default_dbg_info_merge_sets(ir_node **new_nodes, int n_new_nodes,
+ ir_node **old_nodes, int n_old_nodes,
+ dbg_action info);