3 * Copyright (C) 2002, 2003, 2004, by Larry Wall and others
5 * You may distribute under the terms of either the GNU General Public
6 * License or the Artistic License, as specified in the README file.
8 * "Anyway: there was this Mr Frodo left an orphan and stranded, as you
9 * might say, among those queer Bucklanders, being brought up anyhow in
10 * Brandy Hall. A regular warren, by all accounts. Old Master Gorbadoc
11 * never had fewer than a couple of hundred relations in the place. Mr
12 * Bilbo never did a kinder deed than when he brought the lad back to
13 * live among decent folk." --the Gaffer
17 * As of Sept 2002, this file is new and may be in a state of flux for
18 * a while. I've marked things I intent to come back and look at further
19 * with an 'XXX DAPM' comment.
23 =head1 Pad Data Structures
25 =for apidoc m|AV *|CvPADLIST|CV *cv
26 CV's can have CvPADLIST(cv) set to point to an AV.
28 For these purposes "forms" are a kind-of CV, eval""s are too (except they're
29 not callable at will and are always thrown away after the eval"" is done
30 executing). Require'd files are simply evals without any outer lexical
33 XSUBs don't have CvPADLIST set - dXSTARG fetches values from PL_curpad,
34 but that is really the callers pad (a slot of which is allocated by
37 The CvPADLIST AV has does not have AvREAL set, so REFCNT of component items
38 is managed "manual" (mostly in pad.c) rather than normal av.c rules.
39 The items in the AV are not SVs as for a normal AV, but other AVs:
41 0'th Entry of the CvPADLIST is an AV which represents the "names" or rather
42 the "static type information" for lexicals.
44 The CvDEPTH'th entry of CvPADLIST AV is an AV which is the stack frame at that
45 depth of recursion into the CV.
46 The 0'th slot of a frame AV is an AV which is @_.
47 other entries are storage for variables and op targets.
50 C<PL_comppad_name> is set to the names AV.
51 C<PL_comppad> is set to the frame AV for the frame CvDEPTH == 1.
52 C<PL_curpad> is set to the body of the frame AV (i.e. AvARRAY(PL_comppad)).
54 During execution, C<PL_comppad> and C<PL_curpad> refer to the live
55 frame of the currently executing sub.
57 Iterating over the names AV iterates over all possible pad
58 items. Pad slots that are SVs_PADTMP (targets/GVs/constants) end up having
59 &PL_sv_undef "names" (see pad_alloc()).
61 Only my/our variable (SVs_PADMY/SVs_PADOUR) slots get valid names.
62 The rest are op targets/GVs/constants which are statically allocated
63 or resolved at compile time. These don't have names by which they
64 can be looked up from Perl code at run time through eval"" like
65 my/our variables can be. Since they can't be looked up by "name"
66 but only by their index allocated at compile time (which is usually
67 in PL_op->op_targ), wasting a name SV for them doesn't make sense.
69 The SVs in the names AV have their PV being the name of the variable.
70 NV+1..IV inclusive is a range of cop_seq numbers for which the name is
71 valid. For typed lexicals name SV is SVt_PVMG and SvSTASH points at the
72 type. For C<our> lexicals, the type is SVt_PVGV, and GvSTASH points at the
73 stash of the associated global (so that duplicate C<our> delarations in the
74 same package can be detected). SvCUR is sometimes hijacked to
75 store the generation number during compilation.
77 If SvFAKE is set on the name SV, then that slot in the frame AV is
78 a REFCNT'ed reference to a lexical from "outside". In this case,
79 the name SV does not use NVX and IVX to store a cop_seq range, since it is
80 in scope throughout. Instead IVX stores some flags containing info about
81 the real lexical (is it declared in an anon, and is it capable of being
82 instantiated multiple times?), and for fake ANONs, NVX contains the index
83 within the parent's pad where the lexical's value is stored, to make
86 If the 'name' is '&' the corresponding entry in frame AV
87 is a CV representing a possible closure.
88 (SvFAKE and name of '&' is not a meaningful combination currently but could
89 become so if C<my sub foo {}> is implemented.)
91 Note that formats are treated as anon subs, and are cloned each time
92 write is called (if necessary).
94 The flag SVf_PADSTALE is cleared on lexicals each time the my() is executed,
95 and set on scope exit. This allows the 'Variable $x is not available' warning
96 to be generated in evals, such as
98 { my $x = 1; sub f { eval '$x'} } f();
105 #define PERL_IN_PAD_C
109 #define PAD_MAX 999999999
116 Create a new compiling padlist, saving and updating the various global
117 vars at the same time as creating the pad itself. The following flags
118 can be OR'ed together:
120 padnew_CLONE this pad is for a cloned CV
121 padnew_SAVE save old globals
122 padnew_SAVESUB also save extra stuff for start of sub
128 Perl_pad_new(pTHX_ int flags)
130 AV *padlist, *padname, *pad, *a0;
132 ASSERT_CURPAD_LEGAL("pad_new");
134 /* XXX DAPM really need a new SAVEt_PAD which restores all or most
135 * vars (based on flags) rather than storing vals + addresses for
136 * each individually. Also see pad_block_start.
137 * XXX DAPM Try to see whether all these conditionals are required
140 /* save existing state, ... */
142 if (flags & padnew_SAVE) {
144 SAVESPTR(PL_comppad_name);
145 if (! (flags & padnew_CLONE)) {
147 SAVEI32(PL_comppad_name_fill);
148 SAVEI32(PL_min_intro_pending);
149 SAVEI32(PL_max_intro_pending);
150 SAVEI32(PL_cv_has_eval);
151 if (flags & padnew_SAVESUB) {
152 SAVEI32(PL_pad_reset_pending);
156 /* XXX DAPM interestingly, PL_comppad_name_floor never seems to be
157 * saved - check at some pt that this is okay */
159 /* ... create new pad ... */
165 if (flags & padnew_CLONE) {
166 /* XXX DAPM I dont know why cv_clone needs it
167 * doing differently yet - perhaps this separate branch can be
168 * dispensed with eventually ???
171 a0 = newAV(); /* will be @_ */
173 av_store(pad, 0, (SV*)a0);
174 AvFLAGS(a0) = AVf_REIFY;
177 av_store(pad, 0, Nullsv);
181 av_store(padlist, 0, (SV*)padname);
182 av_store(padlist, 1, (SV*)pad);
184 /* ... then update state variables */
186 PL_comppad_name = (AV*)(*av_fetch(padlist, 0, FALSE));
187 PL_comppad = (AV*)(*av_fetch(padlist, 1, FALSE));
188 PL_curpad = AvARRAY(PL_comppad);
190 if (! (flags & padnew_CLONE)) {
191 PL_comppad_name_fill = 0;
192 PL_min_intro_pending = 0;
197 DEBUG_X(PerlIO_printf(Perl_debug_log,
198 "Pad 0x%"UVxf"[0x%"UVxf"] new: compcv=0x%"UVxf
199 " name=0x%"UVxf" flags=0x%"UVxf"\n",
200 PTR2UV(PL_comppad), PTR2UV(PL_curpad), PTR2UV(PL_compcv),
201 PTR2UV(padname), (UV)flags
205 return (PADLIST*)padlist;
209 =for apidoc pad_undef
211 Free the padlist associated with a CV.
212 If parts of it happen to be current, we null the relevant
213 PL_*pad* global vars so that we don't have any dangling references left.
214 We also repoint the CvOUTSIDE of any about-to-be-orphaned
215 inner subs to the outer of this cv.
217 (This function should really be called pad_free, but the name was already
224 Perl_pad_undef(pTHX_ CV* cv)
227 PADLIST *padlist = CvPADLIST(cv);
231 if (!SvREFCNT(CvPADLIST(cv))) /* may be during global destruction */
234 DEBUG_X(PerlIO_printf(Perl_debug_log,
235 "Pad undef: cv=0x%"UVxf" padlist=0x%"UVxf"\n",
236 PTR2UV(cv), PTR2UV(padlist))
239 /* detach any '&' anon children in the pad; if afterwards they
240 * are still live, fix up their CvOUTSIDEs to point to our outside,
242 /* XXX DAPM for efficiency, we should only do this if we know we have
243 * children, or integrate this loop with general cleanup */
245 if (!PL_dirty) { /* don't bother during global destruction */
246 CV *outercv = CvOUTSIDE(cv);
247 U32 seq = CvOUTSIDE_SEQ(cv);
248 AV *comppad_name = (AV*)AvARRAY(padlist)[0];
249 SV **namepad = AvARRAY(comppad_name);
250 AV *comppad = (AV*)AvARRAY(padlist)[1];
251 SV **curpad = AvARRAY(comppad);
252 for (ix = AvFILLp(comppad_name); ix > 0; ix--) {
253 SV *namesv = namepad[ix];
254 if (namesv && namesv != &PL_sv_undef
255 && *SvPVX(namesv) == '&')
257 CV *innercv = (CV*)curpad[ix];
258 namepad[ix] = Nullsv;
259 SvREFCNT_dec(namesv);
261 if (SvREFCNT(comppad) < 2) { /* allow for /(?{ sub{} })/ */
263 SvREFCNT_dec(innercv);
265 if (SvREFCNT(innercv) /* in use, not just a prototype */
266 && CvOUTSIDE(innercv) == cv)
268 assert(CvWEAKOUTSIDE(innercv));
269 /* don't relink to grandfather if he's being freed */
270 if (outercv && SvREFCNT(outercv)) {
271 CvWEAKOUTSIDE_off(innercv);
272 CvOUTSIDE(innercv) = outercv;
273 CvOUTSIDE_SEQ(innercv) = seq;
274 SvREFCNT_inc(outercv);
277 CvOUTSIDE(innercv) = Nullcv;
286 ix = AvFILLp(padlist);
288 SV* sv = AvARRAY(padlist)[ix--];
291 if (sv == (SV*)PL_comppad_name)
292 PL_comppad_name = Nullav;
293 else if (sv == (SV*)PL_comppad) {
294 PL_comppad = Null(PAD*);
295 PL_curpad = Null(SV**);
299 SvREFCNT_dec((SV*)CvPADLIST(cv));
300 CvPADLIST(cv) = Null(PADLIST*);
307 =for apidoc pad_add_name
309 Create a new name and associated PADMY SV in the current pad; return the
311 If C<typestash> is valid, the name is for a typed lexical; set the
312 name's stash to that value.
313 If C<ourstash> is valid, it's an our lexical, set the name's
314 GvSTASH to that value
316 If fake, it means we're cloning an existing entry
322 Perl_pad_add_name(pTHX_ char *name, HV* typestash, HV* ourstash, bool fake)
324 PADOFFSET offset = pad_alloc(OP_PADSV, SVs_PADMY);
325 SV* namesv = NEWSV(1102, 0);
327 ASSERT_CURPAD_ACTIVE("pad_add_name");
330 sv_upgrade(namesv, ourstash ? SVt_PVGV : typestash ? SVt_PVMG : SVt_PVNV);
331 sv_setpv(namesv, name);
334 SvFLAGS(namesv) |= SVpad_TYPED;
335 SvSTASH(namesv) = (HV*)SvREFCNT_inc((SV*) typestash);
338 SvFLAGS(namesv) |= SVpad_OUR;
339 GvSTASH(namesv) = (HV*)SvREFCNT_inc((SV*) ourstash);
342 av_store(PL_comppad_name, offset, namesv);
345 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
346 "Pad addname: %ld \"%s\" FAKE\n", (long)offset, name));
349 /* not yet introduced */
350 SvNVX(namesv) = (NV)PAD_MAX; /* min */
351 SvIVX(namesv) = 0; /* max */
353 if (!PL_min_intro_pending)
354 PL_min_intro_pending = offset;
355 PL_max_intro_pending = offset;
356 /* if it's not a simple scalar, replace with an AV or HV */
357 /* XXX DAPM since slot has been allocated, replace
358 * av_store with PL_curpad[offset] ? */
360 av_store(PL_comppad, offset, (SV*)newAV());
361 else if (*name == '%')
362 av_store(PL_comppad, offset, (SV*)newHV());
363 SvPADMY_on(PL_curpad[offset]);
364 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
365 "Pad addname: %ld \"%s\" new lex=0x%"UVxf"\n",
366 (long)offset, name, PTR2UV(PL_curpad[offset])));
376 =for apidoc pad_alloc
378 Allocate a new my or tmp pad entry. For a my, simply push a null SV onto
379 the end of PL_comppad, but for a tmp, scan the pad from PL_padix upwards
380 for a slot which has no name and and no active value.
385 /* XXX DAPM integrate alloc(), add_name() and add_anon(),
386 * or at least rationalise ??? */
390 Perl_pad_alloc(pTHX_ I32 optype, U32 tmptype)
395 ASSERT_CURPAD_ACTIVE("pad_alloc");
397 if (AvARRAY(PL_comppad) != PL_curpad)
398 Perl_croak(aTHX_ "panic: pad_alloc");
399 if (PL_pad_reset_pending)
401 if (tmptype & SVs_PADMY) {
402 sv = *av_fetch(PL_comppad, AvFILLp(PL_comppad) + 1, TRUE);
403 retval = AvFILLp(PL_comppad);
406 SV **names = AvARRAY(PL_comppad_name);
407 SSize_t names_fill = AvFILLp(PL_comppad_name);
410 * "foreach" index vars temporarily become aliases to non-"my"
411 * values. Thus we must skip, not just pad values that are
412 * marked as current pad values, but also those with names.
414 /* HVDS why copy to sv here? we don't seem to use it */
415 if (++PL_padix <= names_fill &&
416 (sv = names[PL_padix]) && sv != &PL_sv_undef)
418 sv = *av_fetch(PL_comppad, PL_padix, TRUE);
419 if (!(SvFLAGS(sv) & (SVs_PADTMP | SVs_PADMY)) &&
420 !IS_PADGV(sv) && !IS_PADCONST(sv))
425 SvFLAGS(sv) |= tmptype;
426 PL_curpad = AvARRAY(PL_comppad);
428 DEBUG_X(PerlIO_printf(Perl_debug_log,
429 "Pad 0x%"UVxf"[0x%"UVxf"] alloc: %ld for %s\n",
430 PTR2UV(PL_comppad), PTR2UV(PL_curpad), (long) retval,
431 PL_op_name[optype]));
432 return (PADOFFSET)retval;
436 =for apidoc pad_add_anon
438 Add an anon code entry to the current compiling pad
444 Perl_pad_add_anon(pTHX_ SV* sv, OPCODE op_type)
449 name = NEWSV(1106, 0);
450 sv_upgrade(name, SVt_PVNV);
451 sv_setpvn(name, "&", 1);
454 ix = pad_alloc(op_type, SVs_PADMY);
455 av_store(PL_comppad_name, ix, name);
456 /* XXX DAPM use PL_curpad[] ? */
457 av_store(PL_comppad, ix, sv);
460 /* to avoid ref loops, we never have parent + child referencing each
461 * other simultaneously */
462 if (CvOUTSIDE((CV*)sv)) {
463 assert(!CvWEAKOUTSIDE((CV*)sv));
464 CvWEAKOUTSIDE_on((CV*)sv);
465 SvREFCNT_dec(CvOUTSIDE((CV*)sv));
473 =for apidoc pad_check_dup
475 Check for duplicate declarations: report any of:
476 * a my in the current scope with the same name;
477 * an our (anywhere in the pad) with the same name and the same stash
479 C<is_our> indicates that the name to check is an 'our' declaration
484 /* XXX DAPM integrate this into pad_add_name ??? */
487 Perl_pad_check_dup(pTHX_ char *name, bool is_our, HV *ourstash)
492 ASSERT_CURPAD_ACTIVE("pad_check_dup");
493 if (!ckWARN(WARN_MISC) || AvFILLp(PL_comppad_name) < 0)
494 return; /* nothing to check */
496 svp = AvARRAY(PL_comppad_name);
497 top = AvFILLp(PL_comppad_name);
498 /* check the current scope */
499 /* XXX DAPM - why the (I32) cast - shouldn't we ensure they're the same
501 for (off = top; (I32)off > PL_comppad_name_floor; off--) {
503 && sv != &PL_sv_undef
505 && (SvIVX(sv) == PAD_MAX || SvIVX(sv) == 0)
507 || ((SvFLAGS(sv) & SVpad_OUR) && GvSTASH(sv) == ourstash))
508 && strEQ(name, SvPVX(sv)))
510 Perl_warner(aTHX_ packWARN(WARN_MISC),
511 "\"%s\" variable %s masks earlier declaration in same %s",
512 (is_our ? "our" : "my"),
514 (SvIVX(sv) == PAD_MAX ? "scope" : "statement"));
519 /* check the rest of the pad */
523 && sv != &PL_sv_undef
525 && (SvIVX(sv) == PAD_MAX || SvIVX(sv) == 0)
526 && ((SvFLAGS(sv) & SVpad_OUR) && GvSTASH(sv) == ourstash)
527 && strEQ(name, SvPVX(sv)))
529 Perl_warner(aTHX_ packWARN(WARN_MISC),
530 "\"our\" variable %s redeclared", name);
531 Perl_warner(aTHX_ packWARN(WARN_MISC),
532 "\t(Did you mean \"local\" instead of \"our\"?)\n");
535 } while ( off-- > 0 );
541 =for apidoc pad_findmy
543 Given a lexical name, try to find its offset, first in the current pad,
544 or failing that, in the pads of any lexically enclosing subs (including
545 the complications introduced by eval). If the name is found in an outer pad,
546 then a fake entry is added to the current pad.
547 Returns the offset in the current pad, or NOT_IN_PAD on failure.
553 Perl_pad_findmy(pTHX_ char *name)
561 offset = pad_findlex(name, PL_compcv, PL_cop_seqmax, 1,
562 Null(SV**), &out_sv, &out_flags);
563 if (offset != NOT_IN_PAD)
566 /* look for an our that's being introduced; this allows
567 * our $foo = 0 unless defined $foo;
568 * to not give a warning. (Yes, this is a hack) */
570 nameav = (AV*)AvARRAY(CvPADLIST(PL_compcv))[0];
571 name_svp = AvARRAY(nameav);
572 for (offset = AvFILLp(nameav); offset > 0; offset--) {
573 SV *namesv = name_svp[offset];
574 if (namesv && namesv != &PL_sv_undef
576 && (SvFLAGS(namesv) & SVpad_OUR)
577 && strEQ(SvPVX(namesv), name)
578 && U_32(SvNVX(namesv)) == PAD_MAX /* min */
587 =for apidoc pad_findlex
589 Find a named lexical anywhere in a chain of nested pads. Add fake entries
590 in the inner pads if it's found in an outer one.
592 Returns the offset in the bottom pad of the lex or the fake lex.
593 cv is the CV in which to start the search, and seq is the current cop_seq
594 to match against. If warn is true, print appropriate warnings. The out_*
595 vars return values, and so are pointers to where the returned values
596 should be stored. out_capture, if non-null, requests that the innermost
597 instance of the lexical is captured; out_name_sv is set to the innermost
598 matched namesv or fake namesv; out_flags returns the flags normally
599 associated with the IVX field of a fake namesv.
601 Note that pad_findlex() is recursive; it recurses up the chain of CVs,
602 then comes back down, adding fake entries as it goes. It has to be this way
603 because fake namesvs in anon protoypes have to store in NVX the index into
609 /* Flags set in the SvIVX field of FAKE namesvs */
611 #define PAD_FAKELEX_ANON 1 /* the lex is declared in an ANON, or ... */
612 #define PAD_FAKELEX_MULTI 2 /* the lex can be instantiated multiple times */
614 /* the CV has finished being compiled. This is not a sufficient test for
615 * all CVs (eg XSUBs), but suffices for the CVs found in a lexical chain */
616 #define CvCOMPILED(cv) CvROOT(cv)
618 /* the CV does late binding of its lexicals */
619 #define CvLATE(cv) (CvANON(cv) || SvTYPE(cv) == SVt_PVFM)
623 S_pad_findlex(pTHX_ char *name, CV* cv, U32 seq, int warn,
624 SV** out_capture, SV** out_name_sv, int *out_flags)
626 I32 offset, new_offset;
629 AV *padlist = CvPADLIST(cv);
633 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
634 "Pad findlex cv=0x%"UVxf" searching \"%s\" seq=%d%s\n",
635 PTR2UV(cv), name, (int)seq, out_capture ? " capturing" : "" ));
637 /* first, search this pad */
639 if (padlist) { /* not an undef CV */
641 AV *nameav = (AV*)AvARRAY(padlist)[0];
642 SV **name_svp = AvARRAY(nameav);
644 for (offset = AvFILLp(nameav); offset > 0; offset--) {
645 SV *namesv = name_svp[offset];
646 if (namesv && namesv != &PL_sv_undef
647 && strEQ(SvPVX(namesv), name))
650 fake_offset = offset; /* in case we don't find a real one */
651 else if ( seq > U_32(SvNVX(namesv)) /* min */
652 && seq <= (U32)SvIVX(namesv)) /* max */
657 if (offset > 0 || fake_offset > 0 ) { /* a match! */
658 if (offset > 0) { /* not fake */
660 *out_name_sv = name_svp[offset]; /* return the namesv */
662 /* set PAD_FAKELEX_MULTI if this lex can have multiple
663 * instances. For now, we just test !CvUNIQUE(cv), but
664 * ideally, we should detect my's declared within loops
665 * etc - this would allow a wider range of 'not stayed
666 * shared' warnings. We also treated alreadly-compiled
667 * lexes as not multi as viewed from evals. */
669 *out_flags = CvANON(cv) ?
671 (!CvUNIQUE(cv) && ! CvCOMPILED(cv))
672 ? PAD_FAKELEX_MULTI : 0;
674 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
675 "Pad findlex cv=0x%"UVxf" matched: offset=%ld (%ld,%ld)\n",
676 PTR2UV(cv), (long)offset, (long)U_32(SvNVX(*out_name_sv)),
677 (long)SvIVX(*out_name_sv)));
679 else { /* fake match */
680 offset = fake_offset;
681 *out_name_sv = name_svp[offset]; /* return the namesv */
682 *out_flags = SvIVX(*out_name_sv);
683 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
684 "Pad findlex cv=0x%"UVxf" matched: offset=%ld flags=0x%lx index=%lu\n",
685 PTR2UV(cv), (long)offset, (unsigned long)*out_flags,
686 (unsigned long)SvNVX(*out_name_sv)
690 /* return the lex? */
695 if ((SvFLAGS(*out_name_sv) & SVpad_OUR)) {
696 *out_capture = Nullsv;
700 /* trying to capture from an anon prototype? */
702 ? CvANON(cv) && CvCLONE(cv) && !CvCLONED(cv)
703 : *out_flags & PAD_FAKELEX_ANON)
705 if (warn && ckWARN(WARN_CLOSURE))
706 Perl_warner(aTHX_ packWARN(WARN_CLOSURE),
707 "Variable \"%s\" is not available", name);
708 *out_capture = Nullsv;
714 if (!CvCOMPILED(cv) && (*out_flags & PAD_FAKELEX_MULTI)
715 && warn && ckWARN(WARN_CLOSURE)) {
717 Perl_warner(aTHX_ packWARN(WARN_CLOSURE),
718 "Variable \"%s\" will not stay shared", name);
721 if (fake_offset && CvANON(cv)
722 && CvCLONE(cv) &&!CvCLONED(cv))
725 /* not yet caught - look further up */
726 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
727 "Pad findlex cv=0x%"UVxf" chasing lex in outer pad\n",
730 pad_findlex(name, CvOUTSIDE(cv), CvOUTSIDE_SEQ(cv),
731 newwarn, out_capture, out_name_sv, out_flags);
736 *out_capture = AvARRAY((AV*)AvARRAY(padlist)[
737 CvDEPTH(cv) ? CvDEPTH(cv) : 1])[offset];
738 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
739 "Pad findlex cv=0x%"UVxf" found lex=0x%"UVxf"\n",
740 PTR2UV(cv), PTR2UV(*out_capture)));
742 if (SvPADSTALE(*out_capture)) {
743 if (ckWARN(WARN_CLOSURE))
744 Perl_warner(aTHX_ packWARN(WARN_CLOSURE),
745 "Variable \"%s\" is not available", name);
746 *out_capture = Nullsv;
751 *out_capture = sv_2mortal((SV*)newAV());
752 else if (*name == '%')
753 *out_capture = sv_2mortal((SV*)newHV());
755 *out_capture = sv_newmortal();
763 /* it's not in this pad - try above */
768 /* out_capture non-null means caller wants us to capture lex; in
769 * addition we capture ourselves unless it's an ANON/format */
770 new_capturep = out_capture ? out_capture :
771 CvLATE(cv) ? Null(SV**) : &new_capture;
773 offset = pad_findlex(name, CvOUTSIDE(cv), CvOUTSIDE_SEQ(cv), 1,
774 new_capturep, out_name_sv, out_flags);
775 if (offset == NOT_IN_PAD)
778 /* found in an outer CV. Add appropriate fake entry to this pad */
780 /* don't add new fake entries (via eval) to CVs that we have already
781 * finished compiling, or to undef CVs */
782 if (CvCOMPILED(cv) || !padlist)
783 return 0; /* this dummy (and invalid) value isnt used by the caller */
787 AV *ocomppad_name = PL_comppad_name;
788 PAD *ocomppad = PL_comppad;
789 PL_comppad_name = (AV*)AvARRAY(padlist)[0];
790 PL_comppad = (AV*)AvARRAY(padlist)[1];
791 PL_curpad = AvARRAY(PL_comppad);
793 new_offset = pad_add_name(
795 (SvFLAGS(*out_name_sv) & SVpad_TYPED)
796 ? SvSTASH(*out_name_sv) : Nullhv,
797 (SvFLAGS(*out_name_sv) & SVpad_OUR)
798 ? GvSTASH(*out_name_sv) : Nullhv,
802 new_namesv = AvARRAY(PL_comppad_name)[new_offset];
803 SvIVX(new_namesv) = *out_flags;
805 SvNVX(new_namesv) = (NV)0;
806 if (SvFLAGS(new_namesv) & SVpad_OUR) {
809 else if (CvLATE(cv)) {
810 /* delayed creation - just note the offset within parent pad */
811 SvNVX(new_namesv) = (NV)offset;
815 /* immediate creation - capture outer value right now */
816 av_store(PL_comppad, new_offset, SvREFCNT_inc(*new_capturep));
817 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
818 "Pad findlex cv=0x%"UVxf" saved captured sv 0x%"UVxf" at offset %ld\n",
819 PTR2UV(cv), PTR2UV(*new_capturep), (long)new_offset));
821 *out_name_sv = new_namesv;
822 *out_flags = SvIVX(new_namesv);
824 PL_comppad_name = ocomppad_name;
825 PL_comppad = ocomppad;
826 PL_curpad = ocomppad ? AvARRAY(ocomppad) : Null(SV **);
835 Get the value at offset po in the current pad.
836 Use macro PAD_SV instead of calling this function directly.
843 Perl_pad_sv(pTHX_ PADOFFSET po)
845 ASSERT_CURPAD_ACTIVE("pad_sv");
848 Perl_croak(aTHX_ "panic: pad_sv po");
849 DEBUG_X(PerlIO_printf(Perl_debug_log,
850 "Pad 0x%"UVxf"[0x%"UVxf"] sv: %ld sv=0x%"UVxf"\n",
851 PTR2UV(PL_comppad), PTR2UV(PL_curpad), (long)po, PTR2UV(PL_curpad[po]))
853 return PL_curpad[po];
858 =for apidoc pad_setsv
860 Set the entry at offset po in the current pad to sv.
861 Use the macro PAD_SETSV() rather than calling this function directly.
868 Perl_pad_setsv(pTHX_ PADOFFSET po, SV* sv)
870 ASSERT_CURPAD_ACTIVE("pad_setsv");
872 DEBUG_X(PerlIO_printf(Perl_debug_log,
873 "Pad 0x%"UVxf"[0x%"UVxf"] setsv: %ld sv=0x%"UVxf"\n",
874 PTR2UV(PL_comppad), PTR2UV(PL_curpad), (long)po, PTR2UV(sv))
883 =for apidoc pad_block_start
885 Update the pad compilation state variables on entry to a new block
891 * - integrate this in general state-saving routine ???
892 * - combine with the state-saving going on in pad_new ???
893 * - introduce a new SAVE type that does all this in one go ?
897 Perl_pad_block_start(pTHX_ int full)
899 ASSERT_CURPAD_ACTIVE("pad_block_start");
900 SAVEI32(PL_comppad_name_floor);
901 PL_comppad_name_floor = AvFILLp(PL_comppad_name);
903 PL_comppad_name_fill = PL_comppad_name_floor;
904 if (PL_comppad_name_floor < 0)
905 PL_comppad_name_floor = 0;
906 SAVEI32(PL_min_intro_pending);
907 SAVEI32(PL_max_intro_pending);
908 PL_min_intro_pending = 0;
909 SAVEI32(PL_comppad_name_fill);
910 SAVEI32(PL_padix_floor);
911 PL_padix_floor = PL_padix;
912 PL_pad_reset_pending = FALSE;
919 "Introduce" my variables to visible status.
931 ASSERT_CURPAD_ACTIVE("intro_my");
932 if (! PL_min_intro_pending)
933 return PL_cop_seqmax;
935 svp = AvARRAY(PL_comppad_name);
936 for (i = PL_min_intro_pending; i <= PL_max_intro_pending; i++) {
937 if ((sv = svp[i]) && sv != &PL_sv_undef
938 && !SvFAKE(sv) && !SvIVX(sv))
940 SvIVX(sv) = PAD_MAX; /* Don't know scope end yet. */
941 SvNVX(sv) = (NV)PL_cop_seqmax;
942 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
943 "Pad intromy: %ld \"%s\", (%ld,%ld)\n",
945 (long)U_32(SvNVX(sv)), (long)SvIVX(sv))
949 PL_min_intro_pending = 0;
950 PL_comppad_name_fill = PL_max_intro_pending; /* Needn't search higher */
951 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
952 "Pad intromy: seq -> %ld\n", (long)(PL_cop_seqmax+1)));
954 return PL_cop_seqmax++;
958 =for apidoc pad_leavemy
960 Cleanup at end of scope during compilation: set the max seq number for
961 lexicals in this scope and warn of any lexicals that never got introduced.
967 Perl_pad_leavemy(pTHX)
970 SV **svp = AvARRAY(PL_comppad_name);
973 PL_pad_reset_pending = FALSE;
975 ASSERT_CURPAD_ACTIVE("pad_leavemy");
976 if (PL_min_intro_pending && PL_comppad_name_fill < PL_min_intro_pending) {
977 for (off = PL_max_intro_pending; off >= PL_min_intro_pending; off--) {
978 if ((sv = svp[off]) && sv != &PL_sv_undef
979 && !SvFAKE(sv) && ckWARN_d(WARN_INTERNAL))
980 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
981 "%"SVf" never introduced", sv);
984 /* "Deintroduce" my variables that are leaving with this scope. */
985 for (off = AvFILLp(PL_comppad_name); off > PL_comppad_name_fill; off--) {
986 if ((sv = svp[off]) && sv != &PL_sv_undef
987 && !SvFAKE(sv) && SvIVX(sv) == PAD_MAX)
989 SvIVX(sv) = PL_cop_seqmax;
990 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
991 "Pad leavemy: %ld \"%s\", (%ld,%ld)\n",
992 (long)off, SvPVX(sv),
993 (long)U_32(SvNVX(sv)), (long)SvIVX(sv))
998 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
999 "Pad leavemy: seq = %ld\n", (long)PL_cop_seqmax));
1004 =for apidoc pad_swipe
1006 Abandon the tmp in the current pad at offset po and replace with a
1013 Perl_pad_swipe(pTHX_ PADOFFSET po, bool refadjust)
1015 ASSERT_CURPAD_LEGAL("pad_swipe");
1018 if (AvARRAY(PL_comppad) != PL_curpad)
1019 Perl_croak(aTHX_ "panic: pad_swipe curpad");
1021 Perl_croak(aTHX_ "panic: pad_swipe po");
1023 DEBUG_X(PerlIO_printf(Perl_debug_log,
1024 "Pad 0x%"UVxf"[0x%"UVxf"] swipe: %ld\n",
1025 PTR2UV(PL_comppad), PTR2UV(PL_curpad), (long)po));
1028 SvPADTMP_off(PL_curpad[po]);
1030 SvREFCNT_dec(PL_curpad[po]);
1032 PL_curpad[po] = NEWSV(1107,0);
1033 SvPADTMP_on(PL_curpad[po]);
1034 if ((I32)po < PL_padix)
1040 =for apidoc pad_reset
1042 Mark all the current temporaries for reuse
1047 /* XXX pad_reset() is currently disabled because it results in serious bugs.
1048 * It causes pad temp TARGs to be shared between OPs. Since TARGs are pushed
1049 * on the stack by OPs that use them, there are several ways to get an alias
1050 * to a shared TARG. Such an alias will change randomly and unpredictably.
1051 * We avoid doing this until we can think of a Better Way.
1054 Perl_pad_reset(pTHX)
1056 #ifdef USE_BROKEN_PAD_RESET
1059 if (AvARRAY(PL_comppad) != PL_curpad)
1060 Perl_croak(aTHX_ "panic: pad_reset curpad");
1062 DEBUG_X(PerlIO_printf(Perl_debug_log,
1063 "Pad 0x%"UVxf"[0x%"UVxf"] reset: padix %ld -> %ld",
1064 PTR2UV(PL_comppad), PTR2UV(PL_curpad),
1065 (long)PL_padix, (long)PL_padix_floor
1069 if (!PL_tainting) { /* Can't mix tainted and non-tainted temporaries. */
1070 for (po = AvMAX(PL_comppad); po > PL_padix_floor; po--) {
1071 if (PL_curpad[po] && !SvIMMORTAL(PL_curpad[po]))
1072 SvPADTMP_off(PL_curpad[po]);
1074 PL_padix = PL_padix_floor;
1077 PL_pad_reset_pending = FALSE;
1082 =for apidoc pad_tidy
1084 Tidy up a pad after we've finished compiling it:
1085 * remove most stuff from the pads of anonsub prototypes;
1087 * mark tmps as such.
1092 /* XXX DAPM surely most of this stuff should be done properly
1093 * at the right time beforehand, rather than going around afterwards
1094 * cleaning up our mistakes ???
1098 Perl_pad_tidy(pTHX_ padtidy_type type)
1103 ASSERT_CURPAD_ACTIVE("pad_tidy");
1105 /* If this CV has had any 'eval-capable' ops planted in it
1106 * (ie it contains eval '...', //ee, /$var/ or /(?{..})/), Then any
1107 * anon prototypes in the chain of CVs should be marked as cloneable,
1108 * so that for example the eval's CV in C<< sub { eval '$x' } >> gets
1109 * the right CvOUTSIDE.
1110 * If running with -d, *any* sub may potentially have an eval
1111 * excuted within it.
1114 if (PL_cv_has_eval || PL_perldb) {
1115 for (cv = PL_compcv ;cv; cv = CvOUTSIDE(cv)) {
1116 if (cv != PL_compcv && CvCOMPILED(cv))
1117 break; /* no need to mark already-compiled code */
1119 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
1120 "Pad clone on cv=0x%"UVxf"\n", PTR2UV(cv)));
1126 /* extend curpad to match namepad */
1127 if (AvFILLp(PL_comppad_name) < AvFILLp(PL_comppad))
1128 av_store(PL_comppad_name, AvFILLp(PL_comppad), Nullsv);
1130 if (type == padtidy_SUBCLONE) {
1131 SV **namep = AvARRAY(PL_comppad_name);
1133 for (ix = AvFILLp(PL_comppad); ix > 0; ix--) {
1136 if (SvIMMORTAL(PL_curpad[ix]) || IS_PADGV(PL_curpad[ix]) || IS_PADCONST(PL_curpad[ix]))
1139 * The only things that a clonable function needs in its
1140 * pad are anonymous subs.
1141 * The rest are created anew during cloning.
1143 if (!((namesv = namep[ix]) != Nullsv &&
1144 namesv != &PL_sv_undef &&
1145 *SvPVX(namesv) == '&'))
1147 SvREFCNT_dec(PL_curpad[ix]);
1148 PL_curpad[ix] = Nullsv;
1152 else if (type == padtidy_SUB) {
1153 /* XXX DAPM this same bit of code keeps appearing !!! Rationalise? */
1154 AV *av = newAV(); /* Will be @_ */
1156 av_store(PL_comppad, 0, (SV*)av);
1157 AvFLAGS(av) = AVf_REIFY;
1160 /* XXX DAPM rationalise these two similar branches */
1162 if (type == padtidy_SUB) {
1163 for (ix = AvFILLp(PL_comppad); ix > 0; ix--) {
1164 if (SvIMMORTAL(PL_curpad[ix]) || IS_PADGV(PL_curpad[ix]) || IS_PADCONST(PL_curpad[ix]))
1166 if (!SvPADMY(PL_curpad[ix]))
1167 SvPADTMP_on(PL_curpad[ix]);
1170 else if (type == padtidy_FORMAT) {
1171 for (ix = AvFILLp(PL_comppad); ix > 0; ix--) {
1172 if (!SvPADMY(PL_curpad[ix]) && !SvIMMORTAL(PL_curpad[ix]))
1173 SvPADTMP_on(PL_curpad[ix]);
1176 PL_curpad = AvARRAY(PL_comppad);
1181 =for apidoc pad_free
1183 Free the SV at offet po in the current pad.
1188 /* XXX DAPM integrate with pad_swipe ???? */
1190 Perl_pad_free(pTHX_ PADOFFSET po)
1192 ASSERT_CURPAD_LEGAL("pad_free");
1195 if (AvARRAY(PL_comppad) != PL_curpad)
1196 Perl_croak(aTHX_ "panic: pad_free curpad");
1198 Perl_croak(aTHX_ "panic: pad_free po");
1200 DEBUG_X(PerlIO_printf(Perl_debug_log,
1201 "Pad 0x%"UVxf"[0x%"UVxf"] free: %ld\n",
1202 PTR2UV(PL_comppad), PTR2UV(PL_curpad), (long)po)
1205 if (PL_curpad[po] && PL_curpad[po] != &PL_sv_undef) {
1206 SvPADTMP_off(PL_curpad[po]);
1208 /* SV could be a shared hash key (eg bugid #19022) */
1210 #ifdef PERL_COPY_ON_WRITE
1211 !SvIsCOW(PL_curpad[po])
1213 !SvFAKE(PL_curpad[po])
1216 SvREADONLY_off(PL_curpad[po]); /* could be a freed constant */
1219 if ((I32)po < PL_padix)
1226 =for apidoc do_dump_pad
1228 Dump the contents of a padlist
1234 Perl_do_dump_pad(pTHX_ I32 level, PerlIO *file, PADLIST *padlist, int full)
1246 pad_name = (AV*)*av_fetch((AV*)padlist, 0, FALSE);
1247 pad = (AV*)*av_fetch((AV*)padlist, 1, FALSE);
1248 pname = AvARRAY(pad_name);
1249 ppad = AvARRAY(pad);
1250 Perl_dump_indent(aTHX_ level, file,
1251 "PADNAME = 0x%"UVxf"(0x%"UVxf") PAD = 0x%"UVxf"(0x%"UVxf")\n",
1252 PTR2UV(pad_name), PTR2UV(pname), PTR2UV(pad), PTR2UV(ppad)
1255 for (ix = 1; ix <= AvFILLp(pad_name); ix++) {
1257 if (namesv && namesv == &PL_sv_undef) {
1262 Perl_dump_indent(aTHX_ level+1, file,
1263 "%2d. 0x%"UVxf"<%lu> FAKE \"%s\" flags=0x%lx index=%lu\n",
1266 (unsigned long) (ppad[ix] ? SvREFCNT(ppad[ix]) : 0),
1268 (unsigned long)SvIVX(namesv),
1269 (unsigned long)SvNVX(namesv)
1273 Perl_dump_indent(aTHX_ level+1, file,
1274 "%2d. 0x%"UVxf"<%lu> (%ld,%ld) \"%s\"\n",
1277 (unsigned long) (ppad[ix] ? SvREFCNT(ppad[ix]) : 0),
1278 (long)U_32(SvNVX(namesv)),
1279 (long)SvIVX(namesv),
1284 Perl_dump_indent(aTHX_ level+1, file,
1285 "%2d. 0x%"UVxf"<%lu>\n",
1288 (unsigned long) (ppad[ix] ? SvREFCNT(ppad[ix]) : 0)
1299 dump the contents of a CV
1306 S_cv_dump(pTHX_ CV *cv, char *title)
1308 CV *outside = CvOUTSIDE(cv);
1309 AV* padlist = CvPADLIST(cv);
1311 PerlIO_printf(Perl_debug_log,
1312 " %s: CV=0x%"UVxf" (%s), OUTSIDE=0x%"UVxf" (%s)\n",
1315 (CvANON(cv) ? "ANON"
1316 : (SvTYPE(cv) == SVt_PVFM) ? "FORMAT"
1317 : (cv == PL_main_cv) ? "MAIN"
1318 : CvUNIQUE(cv) ? "UNIQUE"
1319 : CvGV(cv) ? GvNAME(CvGV(cv)) : "UNDEFINED"),
1322 : CvANON(outside) ? "ANON"
1323 : (outside == PL_main_cv) ? "MAIN"
1324 : CvUNIQUE(outside) ? "UNIQUE"
1325 : CvGV(outside) ? GvNAME(CvGV(outside)) : "UNDEFINED"));
1327 PerlIO_printf(Perl_debug_log,
1328 " PADLIST = 0x%"UVxf"\n", PTR2UV(padlist));
1329 do_dump_pad(1, Perl_debug_log, padlist, 1);
1331 #endif /* DEBUGGING */
1338 =for apidoc cv_clone
1340 Clone a CV: make a new CV which points to the same code etc, but which
1341 has a newly-created pad built by copying the prototype pad and capturing
1348 Perl_cv_clone(pTHX_ CV *proto)
1351 AV* protopadlist = CvPADLIST(proto);
1352 AV* protopad_name = (AV*)*av_fetch(protopadlist, 0, FALSE);
1353 AV* protopad = (AV*)*av_fetch(protopadlist, 1, FALSE);
1354 SV** pname = AvARRAY(protopad_name);
1355 SV** ppad = AvARRAY(protopad);
1356 I32 fname = AvFILLp(protopad_name);
1357 I32 fpad = AvFILLp(protopad);
1364 assert(!CvUNIQUE(proto));
1366 /* Since cloneable anon subs can be nested, CvOUTSIDE may point
1367 * to a prototype; we instead want the cloned parent who called us.
1368 * Note that in general for formats, CvOUTSIDE != find_runcv */
1370 outside = CvOUTSIDE(proto);
1371 if (outside && CvCLONE(outside) && ! CvCLONED(outside))
1372 outside = find_runcv(NULL);
1373 depth = CvDEPTH(outside);
1374 assert(depth || SvTYPE(proto) == SVt_PVFM);
1377 assert(CvPADLIST(outside));
1380 SAVESPTR(PL_compcv);
1382 cv = PL_compcv = (CV*)NEWSV(1104, 0);
1383 sv_upgrade((SV *)cv, SvTYPE(proto));
1384 CvFLAGS(cv) = CvFLAGS(proto) & ~(CVf_CLONE|CVf_WEAKOUTSIDE);
1388 CvFILE(cv) = CvXSUB(proto) ? CvFILE(proto)
1389 : savepv(CvFILE(proto));
1391 CvFILE(cv) = CvFILE(proto);
1393 CvGV(cv) = CvGV(proto);
1394 CvSTASH(cv) = CvSTASH(proto);
1395 CvROOT(cv) = OpREFCNT_inc(CvROOT(proto));
1396 CvSTART(cv) = CvSTART(proto);
1397 CvOUTSIDE(cv) = (CV*)SvREFCNT_inc(outside);
1398 CvOUTSIDE_SEQ(cv) = CvOUTSIDE_SEQ(proto);
1401 sv_setpvn((SV*)cv, SvPVX(proto), SvCUR(proto));
1403 CvPADLIST(cv) = comppadlist = pad_new(padnew_CLONE|padnew_SAVE);
1405 av_fill(PL_comppad, fpad);
1406 for (ix = fname; ix >= 0; ix--)
1407 av_store(PL_comppad_name, ix, SvREFCNT_inc(pname[ix]));
1409 PL_curpad = AvARRAY(PL_comppad);
1411 outpad = AvARRAY(AvARRAY(CvPADLIST(outside))[depth]);
1413 for (ix = fpad; ix > 0; ix--) {
1414 SV* namesv = (ix <= fname) ? pname[ix] : Nullsv;
1416 if (namesv && namesv != &PL_sv_undef) { /* lexical */
1417 if (SvFAKE(namesv)) { /* lexical from outside? */
1418 sv = outpad[(I32)SvNVX(namesv)];
1420 /* formats may have an inactive parent */
1421 if (SvTYPE(proto) == SVt_PVFM && SvPADSTALE(sv)) {
1422 if (ckWARN(WARN_CLOSURE))
1423 Perl_warner(aTHX_ packWARN(WARN_CLOSURE),
1424 "Variable \"%s\" is not available", SvPVX(namesv));
1428 assert(!SvPADSTALE(sv));
1429 sv = SvREFCNT_inc(sv);
1433 char *name = SvPVX(namesv);
1435 sv = SvREFCNT_inc(ppad[ix]);
1436 else if (*name == '@')
1438 else if (*name == '%')
1445 else if (IS_PADGV(ppad[ix]) || IS_PADCONST(ppad[ix])) {
1446 sv = SvREFCNT_inc(ppad[ix]);
1456 PerlIO_printf(Perl_debug_log, "\nPad CV clone\n");
1457 cv_dump(outside, "Outside");
1458 cv_dump(proto, "Proto");
1465 /* Constant sub () { $x } closing over $x - see lib/constant.pm:
1466 * The prototype was marked as a candiate for const-ization,
1467 * so try to grab the current const value, and if successful,
1468 * turn into a const sub:
1470 SV* const_sv = op_const_sv(CvSTART(cv), cv);
1473 cv = newCONSTSUB(CvSTASH(proto), 0, const_sv);
1485 =for apidoc pad_fixup_inner_anons
1487 For any anon CVs in the pad, change CvOUTSIDE of that CV from
1488 old_cv to new_cv if necessary. Needed when a newly-compiled CV has to be
1489 moved to a pre-existing CV struct.
1495 Perl_pad_fixup_inner_anons(pTHX_ PADLIST *padlist, CV *old_cv, CV *new_cv)
1498 AV *comppad_name = (AV*)AvARRAY(padlist)[0];
1499 AV *comppad = (AV*)AvARRAY(padlist)[1];
1500 SV **namepad = AvARRAY(comppad_name);
1501 SV **curpad = AvARRAY(comppad);
1502 for (ix = AvFILLp(comppad_name); ix > 0; ix--) {
1503 SV *namesv = namepad[ix];
1504 if (namesv && namesv != &PL_sv_undef
1505 && *SvPVX(namesv) == '&')
1507 CV *innercv = (CV*)curpad[ix];
1508 assert(CvWEAKOUTSIDE(innercv));
1509 assert(CvOUTSIDE(innercv) == old_cv);
1510 CvOUTSIDE(innercv) = new_cv;
1517 =for apidoc pad_push
1519 Push a new pad frame onto the padlist, unless there's already a pad at
1520 this depth, in which case don't bother creating a new one.
1521 If has_args is true, give the new pad an @_ in slot zero.
1527 Perl_pad_push(pTHX_ PADLIST *padlist, int depth, int has_args)
1529 if (depth <= AvFILLp(padlist))
1533 SV** svp = AvARRAY(padlist);
1534 AV *newpad = newAV();
1535 SV **oldpad = AvARRAY(svp[depth-1]);
1536 I32 ix = AvFILLp((AV*)svp[1]);
1537 I32 names_fill = AvFILLp((AV*)svp[0]);
1538 SV** names = AvARRAY(svp[0]);
1540 for ( ;ix > 0; ix--) {
1541 if (names_fill >= ix && names[ix] != &PL_sv_undef) {
1542 char *name = SvPVX(names[ix]);
1543 if ((SvFLAGS(names[ix]) & SVf_FAKE) || *name == '&') {
1544 /* outer lexical or anon code */
1545 av_store(newpad, ix, SvREFCNT_inc(oldpad[ix]));
1547 else { /* our own lexical */
1549 av_store(newpad, ix, sv = (SV*)newAV());
1550 else if (*name == '%')
1551 av_store(newpad, ix, sv = (SV*)newHV());
1553 av_store(newpad, ix, sv = NEWSV(0, 0));
1557 else if (IS_PADGV(oldpad[ix]) || IS_PADCONST(oldpad[ix])) {
1558 av_store(newpad, ix, sv = SvREFCNT_inc(oldpad[ix]));
1561 /* save temporaries on recursion? */
1562 av_store(newpad, ix, sv = NEWSV(0, 0));
1569 av_store(newpad, 0, (SV*)av);
1570 AvFLAGS(av) = AVf_REIFY;
1572 av_store(padlist, depth, (SV*)newpad);
1573 AvFILLp(padlist) = depth;