extern void debug_print_ids(uschar *);
extern void debug_printf_indent(const char *, ...) PRINTF_FUNCTION(1,2);
extern void debug_print_string(uschar *);
-extern void debug_print_tree(tree_node *);
+extern void debug_print_tree(const char *, tree_node *);
extern void debug_vprintf(int, const char *, va_list);
extern void debug_print_socket(int);