#define LINKLIST(o) ((o)->op_next ? (o)->op_next : linklist((OP*)o))
+#ifndef linklist
+# define linklist(o) THX_linklist(aTHX_ o)
+STATIC OP *THX_linklist(pTHX_ OP *o) {
+ OP *first;
+ if(o->op_next)
+ return o->op_next;
+ first = cUNOPo->op_first;
+ if (first) {
+ OP *kid;
+ o->op_next = LINKLIST(first);
+ kid = first;
+ for (;;) {
+ if (kid->op_sibling) {
+ kid->op_next = LINKLIST(kid->op_sibling);
+ kid = kid->op_sibling;
+ } else {
+ kid->op_next = o;
+ break;
+ }
+ }
+ } else {
+ o->op_next = o;
+ }
+ return o->op_next;
+}
+#endif /* !linklist */
+
STATIC OP *lift_cb(pTHX_ OP *o, CV *cv, void *user_data) {
dSP;
SV *sv;