+ code = SvRV(code);
+ if (SvTYPE(code) < SVt_PVCV)
+ return NULL;
+
+ return SvREFCNT_inc_simple_NN(code);
+}
+
+#if REP_WORKAROUND_REQUIRE_PROPAGATION
+STATIC IV rep_require_tag(pTHX) {
+#define rep_require_tag() rep_require_tag(aTHX)
+ const PERL_SI *si;
+
+ for (si = PL_curstackinfo; si; si = si->si_prev) {
+ I32 cxix;
+
+ for (cxix = si->si_cxix; cxix >= 0; --cxix) {
+ const PERL_CONTEXT *cx = si->si_cxstack + cxix;
+
+ if (CxTYPE(cx) == CXt_EVAL && cx->blk_eval.old_op_type == OP_REQUIRE)
+ return PTR2IV(cx);
+ }
+ }
+
+ return PTR2IV(NULL);
+}
+#endif /* REP_WORKAROUND_REQUIRE_PROPAGATION */
+
+STATIC SV *rep_tag(pTHX_ SV *comp, SV *exec) {
+#define rep_tag(C, E) rep_tag(aTHX_ (C), (E))
+ rep_hint_t *h;
+ dMY_CXT;
+
+ h = PerlMemShared_malloc(sizeof *h);
+ h->comp = rep_validate_callback(comp);
+ h->exec = rep_validate_callback(exec);
+#if REP_WORKAROUND_REQUIRE_PROPAGATION
+ h->cxreq = rep_require_tag();
+#endif /* REP_WORKAROUND_REQUIRE_PROPAGATION */
+
+#if REP_THREADSAFE
+ /* We only need for the key to be an unique tag for looking up the value later.
+ * Allocated memory provides convenient unique identifiers, so that's why we
+ * use the hint as the key itself. */
+ ptable_store(MY_CXT.tbl, h, h);
+#endif /* REP_THREADSAFE */
+
+ return newSViv(PTR2IV(h));
+}
+
+STATIC const rep_hint_t *rep_detag(pTHX_ const SV *hint) {
+#define rep_detag(H) rep_detag(aTHX_ (H))
+ rep_hint_t *h;
+ dMY_CXT;
+
+ if (!(hint && SvIOK(hint)))
+ return NULL;
+
+ h = INT2PTR(rep_hint_t *, SvIVX(hint));
+#if REP_THREADSAFE
+ h = ptable_fetch(MY_CXT.tbl, h);
+#endif /* REP_THREADSAFE */
+
+#if REP_WORKAROUND_REQUIRE_PROPAGATION
+ if (rep_require_tag() != h->cxreq)
+ return NULL;
+#endif /* REP_WORKAROUND_REQUIRE_PROPAGATION */
+
+ return h;
+}
+
+STATIC U32 rep_hash = 0;
+
+STATIC const rep_hint_t *rep_hint(pTHX) {
+#define rep_hint() rep_hint(aTHX)
+ SV *hint;
+
+#ifdef cop_hints_fetch_pvn
+ hint = cop_hints_fetch_pvn(PL_curcop,
+ __PACKAGE__, __PACKAGE_LEN__, rep_hash, 0);
+#else
+ /* We already require 5.9.5 for the regexp engine API. */
+ hint = Perl_refcounted_he_fetch(aTHX_ PL_curcop->cop_hints_hash,
+ NULL,
+ __PACKAGE__, __PACKAGE_LEN__,
+ 0,
+ rep_hash);
+#endif
+
+ return rep_detag(hint);