+ return is_transform_valid(st->current.transform);
+}
+
+#define DEFINE_CALL_TRANSFORM(fwdrev) \
+static int call_transform_##fwdrev(struct site *st, \
+ struct transform_inst_if *transform, \
+ struct buffer_if *buf, \
+ const char **errmsg) \
+{ \
+ if (!is_transform_valid(transform)) { \
+ *errmsg="transform not set up"; \
+ return 1; \
+ } \
+ return transform->fwdrev(transform->st,buf,errmsg); \