+PP(pp_anonconst)
+{
+ dSP;
+ dTOPss;
+ SETs(sv_2mortal((SV *)newCONSTSUB(SvTYPE(CopSTASH(PL_curcop))==SVt_PVHV
+ ? CopSTASH(PL_curcop)
+ : NULL,
+ NULL, SvREFCNT_inc_simple_NN(sv))));
+ RETURN;
+}
+
+
+/* process one subroutine argument - typically when the sub has a signature:
+ * introduce PL_curpad[op_targ] and assign to it the value
+ * for $: (OPf_STACKED ? *sp : $_[N])
+ * for @/%: @_[N..$#_]
+ *
+ * It's equivalent to
+ * my $foo = $_[N];
+ * or
+ * my $foo = (value-on-stack)
+ * or
+ * my @foo = @_[N..$#_]
+ * etc
+ */
+
+PP(pp_argelem)
+{
+ dTARG;
+ SV *val;
+ SV ** padentry;
+ OP *o = PL_op;
+ AV *defav = GvAV(PL_defgv); /* @_ */
+ IV ix = PTR2IV(cUNOP_AUXo->op_aux);
+ IV argc;
+
+ /* do 'my $var, @var or %var' action */
+ padentry = &(PAD_SVl(o->op_targ));
+ save_clearsv(padentry);
+ targ = *padentry;
+
+ if ((o->op_private & OPpARGELEM_MASK) == OPpARGELEM_SV) {
+ if (o->op_flags & OPf_STACKED) {
+ dSP;
+ val = POPs;
+ PUTBACK;
+ }
+ else {
+ SV **svp;
+ /* should already have been checked */
+ assert(ix >= 0);
+#if IVSIZE > PTRSIZE
+ assert(ix <= SSize_t_MAX);
+#endif
+
+ svp = av_fetch(defav, ix, FALSE);
+ val = svp ? *svp : &PL_sv_undef;
+ }
+
+ /* $var = $val */
+
+ /* cargo-culted from pp_sassign */
+ assert(TAINTING_get || !TAINT_get);
+ if (UNLIKELY(TAINT_get) && !SvTAINTED(val))
+ TAINT_NOT;
+
+ SvSetMagicSV(targ, val);
+ return o->op_next;
+ }
+
+ /* must be AV or HV */
+
+ assert(!(o->op_flags & OPf_STACKED));
+ argc = ((IV)AvFILL(defav) + 1) - ix;
+
+ /* This is a copy of the relevant parts of pp_aassign().
+ */
+ if ((o->op_private & OPpARGELEM_MASK) == OPpARGELEM_AV) {
+ IV i;
+
+ if (AvFILL((AV*)targ) > -1) {
+ /* target should usually be empty. If we get get
+ * here, someone's been doing some weird closure tricks.
+ * Make a copy of all args before clearing the array,
+ * to avoid the equivalent of @a = ($a[0]) prematurely freeing
+ * elements. See similar code in pp_aassign.
+ */
+ for (i = 0; i < argc; i++) {
+ SV **svp = av_fetch(defav, ix + i, FALSE);
+ SV *newsv = newSV(0);
+ sv_setsv_flags(newsv,
+ svp ? *svp : &PL_sv_undef,
+ (SV_DO_COW_SVSETSV|SV_NOSTEAL));
+ if (!av_store(defav, ix + i, newsv))
+ SvREFCNT_dec_NN(newsv);
+ }
+ av_clear((AV*)targ);
+ }
+
+ if (argc <= 0)
+ return o->op_next;
+
+ av_extend((AV*)targ, argc);
+
+ i = 0;
+ while (argc--) {
+ SV *tmpsv;
+ SV **svp = av_fetch(defav, ix + i, FALSE);
+ SV *val = svp ? *svp : &PL_sv_undef;
+ tmpsv = newSV(0);
+ sv_setsv(tmpsv, val);
+ av_store((AV*)targ, i++, tmpsv);
+ TAINT_NOT;
+ }
+
+ }
+ else {
+ IV i;
+
+ assert((o->op_private & OPpARGELEM_MASK) == OPpARGELEM_HV);
+
+ if (SvRMAGICAL(targ) || HvUSEDKEYS((HV*)targ)) {
+ /* see "target should usually be empty" comment above */
+ for (i = 0; i < argc; i++) {
+ SV **svp = av_fetch(defav, ix + i, FALSE);
+ SV *newsv = newSV(0);
+ sv_setsv_flags(newsv,
+ svp ? *svp : &PL_sv_undef,
+ (SV_DO_COW_SVSETSV|SV_NOSTEAL));
+ if (!av_store(defav, ix + i, newsv))
+ SvREFCNT_dec_NN(newsv);
+ }
+ hv_clear((HV*)targ);
+ }
+
+ if (argc <= 0)
+ return o->op_next;
+ assert(argc % 2 == 0);
+
+ i = 0;
+ while (argc) {
+ SV *tmpsv;
+ SV **svp;
+ SV *key;
+ SV *val;
+
+ svp = av_fetch(defav, ix + i++, FALSE);
+ key = svp ? *svp : &PL_sv_undef;
+ svp = av_fetch(defav, ix + i++, FALSE);
+ val = svp ? *svp : &PL_sv_undef;
+
+ argc -= 2;
+ if (UNLIKELY(SvGMAGICAL(key)))
+ key = sv_mortalcopy(key);
+ tmpsv = newSV(0);
+ sv_setsv(tmpsv, val);
+ hv_store_ent((HV*)targ, key, tmpsv, 0);
+ TAINT_NOT;
+ }
+ }
+
+ return o->op_next;
+}
+
+/* Handle a default value for one subroutine argument (typically as part
+ * of a subroutine signature).
+ * It's equivalent to
+ * @_ > op_targ ? $_[op_targ] : result_of(op_other)