3 * Copyright (C) 2002, 2003, 2004, 2005, 2006, 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 This file contains the functions that create and manipulate scratchpads,
26 which are array-of-array data structures attached to a CV (ie a sub)
27 and which store lexical variables and opcode temporary and per-thread
30 =for apidoc m|AV *|CvPADLIST|CV *cv
31 CV's can have CvPADLIST(cv) set to point to an AV.
33 For these purposes "forms" are a kind-of CV, eval""s are too (except they're
34 not callable at will and are always thrown away after the eval"" is done
35 executing). Require'd files are simply evals without any outer lexical
38 XSUBs don't have CvPADLIST set - dXSTARG fetches values from PL_curpad,
39 but that is really the callers pad (a slot of which is allocated by
42 The CvPADLIST AV has does not have AvREAL set, so REFCNT of component items
43 is managed "manual" (mostly in pad.c) rather than normal av.c rules.
44 The items in the AV are not SVs as for a normal AV, but other AVs:
46 0'th Entry of the CvPADLIST is an AV which represents the "names" or rather
47 the "static type information" for lexicals.
49 The CvDEPTH'th entry of CvPADLIST AV is an AV which is the stack frame at that
50 depth of recursion into the CV.
51 The 0'th slot of a frame AV is an AV which is @_.
52 other entries are storage for variables and op targets.
55 C<PL_comppad_name> is set to the names AV.
56 C<PL_comppad> is set to the frame AV for the frame CvDEPTH == 1.
57 C<PL_curpad> is set to the body of the frame AV (i.e. AvARRAY(PL_comppad)).
59 During execution, C<PL_comppad> and C<PL_curpad> refer to the live
60 frame of the currently executing sub.
62 Iterating over the names AV iterates over all possible pad
63 items. Pad slots that are SVs_PADTMP (targets/GVs/constants) end up having
64 &PL_sv_undef "names" (see pad_alloc()).
66 Only my/our variable (SVs_PADMY/SVs_PADOUR) slots get valid names.
67 The rest are op targets/GVs/constants which are statically allocated
68 or resolved at compile time. These don't have names by which they
69 can be looked up from Perl code at run time through eval"" like
70 my/our variables can be. Since they can't be looked up by "name"
71 but only by their index allocated at compile time (which is usually
72 in PL_op->op_targ), wasting a name SV for them doesn't make sense.
74 The SVs in the names AV have their PV being the name of the variable.
75 NV+1..IV inclusive is a range of cop_seq numbers for which the name is
76 valid. For typed lexicals name SV is SVt_PVMG and SvSTASH points at the
77 type. For C<our> lexicals, the type is also SVt_PVGV, with the MAGIC slot
78 pointing at the stash of the associated global (so that duplicate C<our>
79 declarations in the same package can be detected). SvCUR is sometimes
80 hijacked to store the generation number during compilation.
82 If SvFAKE is set on the name SV, then that slot in the frame AV is
83 a REFCNT'ed reference to a lexical from "outside". In this case,
84 the name SV does not use NVX and IVX to store a cop_seq range, since it is
85 in scope throughout. Instead IVX stores some flags containing info about
86 the real lexical (is it declared in an anon, and is it capable of being
87 instantiated multiple times?), and for fake ANONs, NVX contains the index
88 within the parent's pad where the lexical's value is stored, to make
91 If the 'name' is '&' the corresponding entry in frame AV
92 is a CV representing a possible closure.
93 (SvFAKE and name of '&' is not a meaningful combination currently but could
94 become so if C<my sub foo {}> is implemented.)
96 Note that formats are treated as anon subs, and are cloned each time
97 write is called (if necessary).
99 The flag SVf_PADSTALE is cleared on lexicals each time the my() is executed,
100 and set on scope exit. This allows the 'Variable $x is not available' warning
101 to be generated in evals, such as
103 { my $x = 1; sub f { eval '$x'} } f();
110 #define PERL_IN_PAD_C
114 #define PAD_MAX 999999999
117 void pad_peg(const char* s) {
126 Create a new compiling padlist, saving and updating the various global
127 vars at the same time as creating the pad itself. The following flags
128 can be OR'ed together:
130 padnew_CLONE this pad is for a cloned CV
131 padnew_SAVE save old globals
132 padnew_SAVESUB also save extra stuff for start of sub
138 Perl_pad_new(pTHX_ int flags)
141 AV *padlist, *padname, *pad;
143 ASSERT_CURPAD_LEGAL("pad_new");
145 /* XXX DAPM really need a new SAVEt_PAD which restores all or most
146 * vars (based on flags) rather than storing vals + addresses for
147 * each individually. Also see pad_block_start.
148 * XXX DAPM Try to see whether all these conditionals are required
151 /* save existing state, ... */
153 if (flags & padnew_SAVE) {
155 SAVESPTR(PL_comppad_name);
156 if (! (flags & padnew_CLONE)) {
158 SAVEI32(PL_comppad_name_fill);
159 SAVEI32(PL_min_intro_pending);
160 SAVEI32(PL_max_intro_pending);
161 SAVEI32(PL_cv_has_eval);
162 if (flags & padnew_SAVESUB) {
163 SAVEI32(PL_pad_reset_pending);
167 /* XXX DAPM interestingly, PL_comppad_name_floor never seems to be
168 * saved - check at some pt that this is okay */
170 /* ... create new pad ... */
176 if (flags & padnew_CLONE) {
177 /* XXX DAPM I dont know why cv_clone needs it
178 * doing differently yet - perhaps this separate branch can be
179 * dispensed with eventually ???
182 AV * const a0 = newAV(); /* will be @_ */
184 av_store(pad, 0, (SV*)a0);
188 av_store(pad, 0, NULL);
192 av_store(padlist, 0, (SV*)padname);
193 av_store(padlist, 1, (SV*)pad);
195 /* ... then update state variables */
197 PL_comppad_name = (AV*)(*av_fetch(padlist, 0, FALSE));
198 PL_comppad = (AV*)(*av_fetch(padlist, 1, FALSE));
199 PL_curpad = AvARRAY(PL_comppad);
201 if (! (flags & padnew_CLONE)) {
202 PL_comppad_name_fill = 0;
203 PL_min_intro_pending = 0;
208 DEBUG_X(PerlIO_printf(Perl_debug_log,
209 "Pad 0x%"UVxf"[0x%"UVxf"] new: compcv=0x%"UVxf
210 " name=0x%"UVxf" flags=0x%"UVxf"\n",
211 PTR2UV(PL_comppad), PTR2UV(PL_curpad), PTR2UV(PL_compcv),
212 PTR2UV(padname), (UV)flags
216 return (PADLIST*)padlist;
220 =for apidoc pad_undef
222 Free the padlist associated with a CV.
223 If parts of it happen to be current, we null the relevant
224 PL_*pad* global vars so that we don't have any dangling references left.
225 We also repoint the CvOUTSIDE of any about-to-be-orphaned
226 inner subs to the outer of this cv.
228 (This function should really be called pad_free, but the name was already
235 Perl_pad_undef(pTHX_ CV* cv)
239 const PADLIST * const padlist = CvPADLIST(cv);
241 pad_peg("pad_undef");
244 if (SvIS_FREED(padlist)) /* may be during global destruction */
247 DEBUG_X(PerlIO_printf(Perl_debug_log,
248 "Pad undef: cv=0x%"UVxf" padlist=0x%"UVxf"\n",
249 PTR2UV(cv), PTR2UV(padlist))
252 /* detach any '&' anon children in the pad; if afterwards they
253 * are still live, fix up their CvOUTSIDEs to point to our outside,
255 /* XXX DAPM for efficiency, we should only do this if we know we have
256 * children, or integrate this loop with general cleanup */
258 if (!PL_dirty) { /* don't bother during global destruction */
259 CV * const outercv = CvOUTSIDE(cv);
260 const U32 seq = CvOUTSIDE_SEQ(cv);
261 AV * const comppad_name = (AV*)AvARRAY(padlist)[0];
262 SV ** const namepad = AvARRAY(comppad_name);
263 AV * const comppad = (AV*)AvARRAY(padlist)[1];
264 SV ** const curpad = AvARRAY(comppad);
265 for (ix = AvFILLp(comppad_name); ix > 0; ix--) {
266 SV * const namesv = namepad[ix];
267 if (namesv && namesv != &PL_sv_undef
268 && *SvPVX_const(namesv) == '&')
270 CV * const innercv = (CV*)curpad[ix];
271 U32 inner_rc = SvREFCNT(innercv);
274 SvREFCNT_dec(namesv);
276 if (SvREFCNT(comppad) < 2) { /* allow for /(?{ sub{} })/ */
278 SvREFCNT_dec(innercv);
282 /* in use, not just a prototype */
283 if (inner_rc && (CvOUTSIDE(innercv) == cv)) {
284 assert(CvWEAKOUTSIDE(innercv));
285 /* don't relink to grandfather if he's being freed */
286 if (outercv && SvREFCNT(outercv)) {
287 CvWEAKOUTSIDE_off(innercv);
288 CvOUTSIDE(innercv) = outercv;
289 CvOUTSIDE_SEQ(innercv) = seq;
290 SvREFCNT_inc_simple_void_NN(outercv);
293 CvOUTSIDE(innercv) = NULL;
300 ix = AvFILLp(padlist);
302 const SV* const sv = AvARRAY(padlist)[ix--];
304 if (sv == (SV*)PL_comppad_name)
305 PL_comppad_name = NULL;
306 else if (sv == (SV*)PL_comppad) {
313 SvREFCNT_dec((SV*)CvPADLIST(cv));
314 CvPADLIST(cv) = NULL;
321 =for apidoc pad_add_name
323 Create a new name and associated PADMY SV in the current pad; return the
325 If C<typestash> is valid, the name is for a typed lexical; set the
326 name's stash to that value.
327 If C<ourstash> is valid, it's an our lexical, set the name's
328 OURSTASH to that value
330 If fake, it means we're cloning an existing entry
336 Perl_pad_add_name(pTHX_ const char *name, HV* typestash, HV* ourstash, bool fake)
339 const PADOFFSET offset = pad_alloc(OP_PADSV, SVs_PADMY);
340 SV* const namesv = newSV(0);
342 ASSERT_CURPAD_ACTIVE("pad_add_name");
345 sv_upgrade(namesv, (ourstash || typestash) ? SVt_PVMG : SVt_PVNV);
346 sv_setpv(namesv, name);
349 SvPAD_TYPED_on(namesv);
350 SvSTASH_set(namesv, (HV*)SvREFCNT_inc_simple_NN((SV*)typestash));
353 SvPAD_OUR_on(namesv);
354 OURSTASH_set(namesv, ourstash);
355 SvREFCNT_inc_simple_void_NN(ourstash);
358 av_store(PL_comppad_name, offset, namesv);
361 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
362 "Pad addname: %ld \"%s\" FAKE\n", (long)offset, name));
365 /* not yet introduced */
366 SvNV_set(namesv, (NV)PAD_MAX); /* min */
367 SvIV_set(namesv, 0); /* max */
369 if (!PL_min_intro_pending)
370 PL_min_intro_pending = offset;
371 PL_max_intro_pending = offset;
372 /* if it's not a simple scalar, replace with an AV or HV */
373 /* XXX DAPM since slot has been allocated, replace
374 * av_store with PL_curpad[offset] ? */
376 av_store(PL_comppad, offset, (SV*)newAV());
377 else if (*name == '%')
378 av_store(PL_comppad, offset, (SV*)newHV());
379 SvPADMY_on(PL_curpad[offset]);
380 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
381 "Pad addname: %ld \"%s\" new lex=0x%"UVxf"\n",
382 (long)offset, name, PTR2UV(PL_curpad[offset])));
392 =for apidoc pad_alloc
394 Allocate a new my or tmp pad entry. For a my, simply push a null SV onto
395 the end of PL_comppad, but for a tmp, scan the pad from PL_padix upwards
396 for a slot which has no name and no active value.
401 /* XXX DAPM integrate alloc(), add_name() and add_anon(),
402 * or at least rationalise ??? */
403 /* And flag whether the incoming name is UTF8 or 8 bit?
404 Could do this either with the +ve/-ve hack of the HV code, or expanding
405 the flag bits. Either way, this makes proper Unicode safe pad support.
406 Also could change the sv structure to make the NV a union with 2 U32s,
407 so that SvCUR() could stop being overloaded in pad SVs.
412 Perl_pad_alloc(pTHX_ I32 optype, U32 tmptype)
418 PERL_UNUSED_ARG(optype);
419 ASSERT_CURPAD_ACTIVE("pad_alloc");
421 if (AvARRAY(PL_comppad) != PL_curpad)
422 Perl_croak(aTHX_ "panic: pad_alloc");
423 if (PL_pad_reset_pending)
425 if (tmptype & SVs_PADMY) {
426 sv = *av_fetch(PL_comppad, AvFILLp(PL_comppad) + 1, TRUE);
427 retval = AvFILLp(PL_comppad);
430 SV * const * const names = AvARRAY(PL_comppad_name);
431 const SSize_t names_fill = AvFILLp(PL_comppad_name);
434 * "foreach" index vars temporarily become aliases to non-"my"
435 * values. Thus we must skip, not just pad values that are
436 * marked as current pad values, but also those with names.
438 /* HVDS why copy to sv here? we don't seem to use it */
439 if (++PL_padix <= names_fill &&
440 (sv = names[PL_padix]) && sv != &PL_sv_undef)
442 sv = *av_fetch(PL_comppad, PL_padix, TRUE);
443 if (!(SvFLAGS(sv) & (SVs_PADTMP | SVs_PADMY)) &&
444 !IS_PADGV(sv) && !IS_PADCONST(sv))
449 SvFLAGS(sv) |= tmptype;
450 PL_curpad = AvARRAY(PL_comppad);
452 DEBUG_X(PerlIO_printf(Perl_debug_log,
453 "Pad 0x%"UVxf"[0x%"UVxf"] alloc: %ld for %s\n",
454 PTR2UV(PL_comppad), PTR2UV(PL_curpad), (long) retval,
455 PL_op_name[optype]));
456 #ifdef DEBUG_LEAKING_SCALARS
457 sv->sv_debug_optype = optype;
458 sv->sv_debug_inpad = 1;
460 return (PADOFFSET)retval;
464 =for apidoc pad_add_anon
466 Add an anon code entry to the current compiling pad
472 Perl_pad_add_anon(pTHX_ SV* sv, OPCODE op_type)
476 SV* const name = newSV(0);
478 sv_upgrade(name, SVt_PVNV);
479 sv_setpvn(name, "&", 1);
482 ix = pad_alloc(op_type, SVs_PADMY);
483 av_store(PL_comppad_name, ix, name);
484 /* XXX DAPM use PL_curpad[] ? */
485 av_store(PL_comppad, ix, sv);
488 /* to avoid ref loops, we never have parent + child referencing each
489 * other simultaneously */
490 if (CvOUTSIDE((CV*)sv)) {
491 assert(!CvWEAKOUTSIDE((CV*)sv));
492 CvWEAKOUTSIDE_on((CV*)sv);
493 SvREFCNT_dec(CvOUTSIDE((CV*)sv));
501 =for apidoc pad_check_dup
503 Check for duplicate declarations: report any of:
504 * a my in the current scope with the same name;
505 * an our (anywhere in the pad) with the same name and the same stash
507 C<is_our> indicates that the name to check is an 'our' declaration
512 /* XXX DAPM integrate this into pad_add_name ??? */
515 Perl_pad_check_dup(pTHX_ const char *name, bool is_our, const HV *ourstash)
521 ASSERT_CURPAD_ACTIVE("pad_check_dup");
522 if (AvFILLp(PL_comppad_name) < 0 || !ckWARN(WARN_MISC))
523 return; /* nothing to check */
525 svp = AvARRAY(PL_comppad_name);
526 top = AvFILLp(PL_comppad_name);
527 /* check the current scope */
528 /* XXX DAPM - why the (I32) cast - shouldn't we ensure they're the same
530 for (off = top; (I32)off > PL_comppad_name_floor; off--) {
531 SV * const sv = svp[off];
533 && sv != &PL_sv_undef
535 && (SvIVX(sv) == PAD_MAX || SvIVX(sv) == 0)
536 && strEQ(name, SvPVX_const(sv)))
538 if (is_our && (SvPAD_OUR(sv)))
539 break; /* "our" masking "our" */
540 Perl_warner(aTHX_ packWARN(WARN_MISC),
541 "\"%s\" variable %s masks earlier declaration in same %s",
542 (is_our ? "our" : "my"),
544 (SvIVX(sv) == PAD_MAX ? "scope" : "statement"));
549 /* check the rest of the pad */
552 SV * const sv = svp[off];
554 && sv != &PL_sv_undef
556 && (SvIVX(sv) == PAD_MAX || SvIVX(sv) == 0)
557 && OURSTASH(sv) == ourstash
558 && strEQ(name, SvPVX_const(sv)))
560 Perl_warner(aTHX_ packWARN(WARN_MISC),
561 "\"our\" variable %s redeclared", name);
562 if ((I32)off <= PL_comppad_name_floor)
563 Perl_warner(aTHX_ packWARN(WARN_MISC),
564 "\t(Did you mean \"local\" instead of \"our\"?)\n");
567 } while ( off-- > 0 );
573 =for apidoc pad_findmy
575 Given a lexical name, try to find its offset, first in the current pad,
576 or failing that, in the pads of any lexically enclosing subs (including
577 the complications introduced by eval). If the name is found in an outer pad,
578 then a fake entry is added to the current pad.
579 Returns the offset in the current pad, or NOT_IN_PAD on failure.
585 Perl_pad_findmy(pTHX_ const char *name)
594 pad_peg("pad_findmy");
595 offset = pad_findlex(name, PL_compcv, PL_cop_seqmax, 1,
596 NULL, &out_sv, &out_flags);
597 if (offset != NOT_IN_PAD)
600 /* look for an our that's being introduced; this allows
601 * our $foo = 0 unless defined $foo;
602 * to not give a warning. (Yes, this is a hack) */
604 nameav = (AV*)AvARRAY(CvPADLIST(PL_compcv))[0];
605 name_svp = AvARRAY(nameav);
606 for (offset = AvFILLp(nameav); offset > 0; offset--) {
607 const SV * const namesv = name_svp[offset];
608 if (namesv && namesv != &PL_sv_undef
610 && (SvPAD_OUR(namesv))
611 && strEQ(SvPVX_const(namesv), name)
612 && U_32(SvNVX(namesv)) == PAD_MAX /* min */
620 * Returns the offset of a lexical $_, if there is one, at run time.
621 * Used by the UNDERBAR XS macro.
625 Perl_find_rundefsvoffset(pTHX)
630 return pad_findlex("$_", find_runcv(NULL), PL_curcop->cop_seq, 1,
631 NULL, &out_sv, &out_flags);
635 =for apidoc pad_findlex
637 Find a named lexical anywhere in a chain of nested pads. Add fake entries
638 in the inner pads if it's found in an outer one.
640 Returns the offset in the bottom pad of the lex or the fake lex.
641 cv is the CV in which to start the search, and seq is the current cop_seq
642 to match against. If warn is true, print appropriate warnings. The out_*
643 vars return values, and so are pointers to where the returned values
644 should be stored. out_capture, if non-null, requests that the innermost
645 instance of the lexical is captured; out_name_sv is set to the innermost
646 matched namesv or fake namesv; out_flags returns the flags normally
647 associated with the IVX field of a fake namesv.
649 Note that pad_findlex() is recursive; it recurses up the chain of CVs,
650 then comes back down, adding fake entries as it goes. It has to be this way
651 because fake namesvs in anon protoypes have to store in NVX the index into
657 /* Flags set in the SvIVX field of FAKE namesvs */
659 #define PAD_FAKELEX_ANON 1 /* the lex is declared in an ANON, or ... */
660 #define PAD_FAKELEX_MULTI 2 /* the lex can be instantiated multiple times */
662 /* the CV has finished being compiled. This is not a sufficient test for
663 * all CVs (eg XSUBs), but suffices for the CVs found in a lexical chain */
664 #define CvCOMPILED(cv) CvROOT(cv)
666 /* the CV does late binding of its lexicals */
667 #define CvLATE(cv) (CvANON(cv) || SvTYPE(cv) == SVt_PVFM)
671 S_pad_findlex(pTHX_ const char *name, const CV* cv, U32 seq, int warn,
672 SV** out_capture, SV** out_name_sv, int *out_flags)
675 I32 offset, new_offset;
678 const AV * const padlist = CvPADLIST(cv);
682 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
683 "Pad findlex cv=0x%"UVxf" searching \"%s\" seq=%d%s\n",
684 PTR2UV(cv), name, (int)seq, out_capture ? " capturing" : "" ));
686 /* first, search this pad */
688 if (padlist) { /* not an undef CV */
690 const AV * const nameav = (AV*)AvARRAY(padlist)[0];
691 SV * const * const name_svp = AvARRAY(nameav);
693 for (offset = AvFILLp(nameav); offset > 0; offset--) {
694 const SV * const namesv = name_svp[offset];
695 if (namesv && namesv != &PL_sv_undef
696 && strEQ(SvPVX_const(namesv), name))
699 fake_offset = offset; /* in case we don't find a real one */
700 else if ( seq > U_32(SvNVX(namesv)) /* min */
701 && seq <= (U32)SvIVX(namesv)) /* max */
706 if (offset > 0 || fake_offset > 0 ) { /* a match! */
707 if (offset > 0) { /* not fake */
709 *out_name_sv = name_svp[offset]; /* return the namesv */
711 /* set PAD_FAKELEX_MULTI if this lex can have multiple
712 * instances. For now, we just test !CvUNIQUE(cv), but
713 * ideally, we should detect my's declared within loops
714 * etc - this would allow a wider range of 'not stayed
715 * shared' warnings. We also treated alreadly-compiled
716 * lexes as not multi as viewed from evals. */
718 *out_flags = CvANON(cv) ?
720 (!CvUNIQUE(cv) && ! CvCOMPILED(cv))
721 ? PAD_FAKELEX_MULTI : 0;
723 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
724 "Pad findlex cv=0x%"UVxf" matched: offset=%ld (%ld,%ld)\n",
725 PTR2UV(cv), (long)offset, (long)U_32(SvNVX(*out_name_sv)),
726 (long)SvIVX(*out_name_sv)));
728 else { /* fake match */
729 offset = fake_offset;
730 *out_name_sv = name_svp[offset]; /* return the namesv */
731 *out_flags = SvIVX(*out_name_sv);
732 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
733 "Pad findlex cv=0x%"UVxf" matched: offset=%ld flags=0x%lx index=%lu\n",
734 PTR2UV(cv), (long)offset, (unsigned long)*out_flags,
735 (unsigned long)SvNVX(*out_name_sv)
739 /* return the lex? */
744 if (SvPAD_OUR(*out_name_sv)) {
749 /* trying to capture from an anon prototype? */
751 ? CvANON(cv) && CvCLONE(cv) && !CvCLONED(cv)
752 : *out_flags & PAD_FAKELEX_ANON)
754 if (warn && ckWARN(WARN_CLOSURE))
755 Perl_warner(aTHX_ packWARN(WARN_CLOSURE),
756 "Variable \"%s\" is not available", name);
763 if (!CvCOMPILED(cv) && (*out_flags & PAD_FAKELEX_MULTI)
764 && warn && ckWARN(WARN_CLOSURE)) {
766 Perl_warner(aTHX_ packWARN(WARN_CLOSURE),
767 "Variable \"%s\" will not stay shared", name);
770 if (fake_offset && CvANON(cv)
771 && CvCLONE(cv) &&!CvCLONED(cv))
774 /* not yet caught - look further up */
775 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
776 "Pad findlex cv=0x%"UVxf" chasing lex in outer pad\n",
779 (void) pad_findlex(name, CvOUTSIDE(cv),
781 newwarn, out_capture, out_name_sv, out_flags);
786 *out_capture = AvARRAY((AV*)AvARRAY(padlist)[
787 CvDEPTH(cv) ? CvDEPTH(cv) : 1])[offset];
788 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
789 "Pad findlex cv=0x%"UVxf" found lex=0x%"UVxf"\n",
790 PTR2UV(cv), PTR2UV(*out_capture)));
792 if (SvPADSTALE(*out_capture)) {
793 if (ckWARN(WARN_CLOSURE))
794 Perl_warner(aTHX_ packWARN(WARN_CLOSURE),
795 "Variable \"%s\" is not available", name);
801 *out_capture = sv_2mortal((SV*)newAV());
802 else if (*name == '%')
803 *out_capture = sv_2mortal((SV*)newHV());
805 *out_capture = sv_newmortal();
813 /* it's not in this pad - try above */
818 /* out_capture non-null means caller wants us to capture lex; in
819 * addition we capture ourselves unless it's an ANON/format */
820 new_capturep = out_capture ? out_capture :
821 CvLATE(cv) ? NULL : &new_capture;
823 offset = pad_findlex(name, CvOUTSIDE(cv), CvOUTSIDE_SEQ(cv), 1,
824 new_capturep, out_name_sv, out_flags);
825 if (offset == NOT_IN_PAD)
828 /* found in an outer CV. Add appropriate fake entry to this pad */
830 /* don't add new fake entries (via eval) to CVs that we have already
831 * finished compiling, or to undef CVs */
832 if (CvCOMPILED(cv) || !padlist)
833 return 0; /* this dummy (and invalid) value isnt used by the caller */
837 AV * const ocomppad_name = PL_comppad_name;
838 PAD * const ocomppad = PL_comppad;
839 PL_comppad_name = (AV*)AvARRAY(padlist)[0];
840 PL_comppad = (AV*)AvARRAY(padlist)[1];
841 PL_curpad = AvARRAY(PL_comppad);
843 new_offset = pad_add_name(
844 SvPVX_const(*out_name_sv),
845 SvPAD_TYPED(*out_name_sv)
846 ? SvSTASH(*out_name_sv) : NULL,
847 OURSTASH(*out_name_sv),
851 new_namesv = AvARRAY(PL_comppad_name)[new_offset];
852 SvIV_set(new_namesv, *out_flags);
854 SvNV_set(new_namesv, (NV)0);
855 if (SvPAD_OUR(new_namesv)) {
856 /*EMPTY*/; /* do nothing */
858 else if (CvLATE(cv)) {
859 /* delayed creation - just note the offset within parent pad */
860 SvNV_set(new_namesv, (NV)offset);
864 /* immediate creation - capture outer value right now */
865 av_store(PL_comppad, new_offset, SvREFCNT_inc(*new_capturep));
866 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
867 "Pad findlex cv=0x%"UVxf" saved captured sv 0x%"UVxf" at offset %ld\n",
868 PTR2UV(cv), PTR2UV(*new_capturep), (long)new_offset));
870 *out_name_sv = new_namesv;
871 *out_flags = SvIVX(new_namesv);
873 PL_comppad_name = ocomppad_name;
874 PL_comppad = ocomppad;
875 PL_curpad = ocomppad ? AvARRAY(ocomppad) : NULL;
885 Get the value at offset po in the current pad.
886 Use macro PAD_SV instead of calling this function directly.
893 Perl_pad_sv(pTHX_ PADOFFSET po)
896 ASSERT_CURPAD_ACTIVE("pad_sv");
899 Perl_croak(aTHX_ "panic: pad_sv po");
900 DEBUG_X(PerlIO_printf(Perl_debug_log,
901 "Pad 0x%"UVxf"[0x%"UVxf"] sv: %ld sv=0x%"UVxf"\n",
902 PTR2UV(PL_comppad), PTR2UV(PL_curpad), (long)po, PTR2UV(PL_curpad[po]))
904 return PL_curpad[po];
909 =for apidoc pad_setsv
911 Set the entry at offset po in the current pad to sv.
912 Use the macro PAD_SETSV() rather than calling this function directly.
918 Perl_pad_setsv(pTHX_ PADOFFSET po, SV* sv)
921 ASSERT_CURPAD_ACTIVE("pad_setsv");
923 DEBUG_X(PerlIO_printf(Perl_debug_log,
924 "Pad 0x%"UVxf"[0x%"UVxf"] setsv: %ld sv=0x%"UVxf"\n",
925 PTR2UV(PL_comppad), PTR2UV(PL_curpad), (long)po, PTR2UV(sv))
934 =for apidoc pad_block_start
936 Update the pad compilation state variables on entry to a new block
942 * - integrate this in general state-saving routine ???
943 * - combine with the state-saving going on in pad_new ???
944 * - introduce a new SAVE type that does all this in one go ?
948 Perl_pad_block_start(pTHX_ int full)
951 ASSERT_CURPAD_ACTIVE("pad_block_start");
952 SAVEI32(PL_comppad_name_floor);
953 PL_comppad_name_floor = AvFILLp(PL_comppad_name);
955 PL_comppad_name_fill = PL_comppad_name_floor;
956 if (PL_comppad_name_floor < 0)
957 PL_comppad_name_floor = 0;
958 SAVEI32(PL_min_intro_pending);
959 SAVEI32(PL_max_intro_pending);
960 PL_min_intro_pending = 0;
961 SAVEI32(PL_comppad_name_fill);
962 SAVEI32(PL_padix_floor);
963 PL_padix_floor = PL_padix;
964 PL_pad_reset_pending = FALSE;
971 "Introduce" my variables to visible status.
983 ASSERT_CURPAD_ACTIVE("intro_my");
984 if (! PL_min_intro_pending)
985 return PL_cop_seqmax;
987 svp = AvARRAY(PL_comppad_name);
988 for (i = PL_min_intro_pending; i <= PL_max_intro_pending; i++) {
989 SV * const sv = svp[i];
991 if (sv && sv != &PL_sv_undef && !SvFAKE(sv) && !SvIVX(sv)) {
992 SvIV_set(sv, PAD_MAX); /* Don't know scope end yet. */
993 SvNV_set(sv, (NV)PL_cop_seqmax);
994 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
995 "Pad intromy: %ld \"%s\", (%ld,%ld)\n",
996 (long)i, SvPVX_const(sv),
997 (long)U_32(SvNVX(sv)), (long)SvIVX(sv))
1001 PL_min_intro_pending = 0;
1002 PL_comppad_name_fill = PL_max_intro_pending; /* Needn't search higher */
1003 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
1004 "Pad intromy: seq -> %ld\n", (long)(PL_cop_seqmax+1)));
1006 return PL_cop_seqmax++;
1010 =for apidoc pad_leavemy
1012 Cleanup at end of scope during compilation: set the max seq number for
1013 lexicals in this scope and warn of any lexicals that never got introduced.
1019 Perl_pad_leavemy(pTHX)
1023 SV * const * const svp = AvARRAY(PL_comppad_name);
1025 PL_pad_reset_pending = FALSE;
1027 ASSERT_CURPAD_ACTIVE("pad_leavemy");
1028 if (PL_min_intro_pending && PL_comppad_name_fill < PL_min_intro_pending) {
1029 for (off = PL_max_intro_pending; off >= PL_min_intro_pending; off--) {
1030 const SV * const sv = svp[off];
1031 if (sv && sv != &PL_sv_undef
1032 && !SvFAKE(sv) && ckWARN_d(WARN_INTERNAL))
1033 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
1034 "%"SVf" never introduced", sv);
1037 /* "Deintroduce" my variables that are leaving with this scope. */
1038 for (off = AvFILLp(PL_comppad_name); off > PL_comppad_name_fill; off--) {
1039 const SV * const sv = svp[off];
1040 if (sv && sv != &PL_sv_undef && !SvFAKE(sv) && SvIVX(sv) == PAD_MAX) {
1041 SvIV_set(sv, PL_cop_seqmax);
1042 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
1043 "Pad leavemy: %ld \"%s\", (%ld,%ld)\n",
1044 (long)off, SvPVX_const(sv),
1045 (long)U_32(SvNVX(sv)), (long)SvIVX(sv))
1050 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
1051 "Pad leavemy: seq = %ld\n", (long)PL_cop_seqmax));
1056 =for apidoc pad_swipe
1058 Abandon the tmp in the current pad at offset po and replace with a
1065 Perl_pad_swipe(pTHX_ PADOFFSET po, bool refadjust)
1068 ASSERT_CURPAD_LEGAL("pad_swipe");
1071 if (AvARRAY(PL_comppad) != PL_curpad)
1072 Perl_croak(aTHX_ "panic: pad_swipe curpad");
1074 Perl_croak(aTHX_ "panic: pad_swipe po");
1076 DEBUG_X(PerlIO_printf(Perl_debug_log,
1077 "Pad 0x%"UVxf"[0x%"UVxf"] swipe: %ld\n",
1078 PTR2UV(PL_comppad), PTR2UV(PL_curpad), (long)po));
1081 SvPADTMP_off(PL_curpad[po]);
1083 SvREFCNT_dec(PL_curpad[po]);
1086 /* if pad tmps aren't shared between ops, then there's no need to
1087 * create a new tmp when an existing op is freed */
1088 #ifdef USE_BROKEN_PAD_RESET
1089 PL_curpad[po] = newSV(0);
1090 SvPADTMP_on(PL_curpad[po]);
1092 PL_curpad[po] = &PL_sv_undef;
1094 if ((I32)po < PL_padix)
1100 =for apidoc pad_reset
1102 Mark all the current temporaries for reuse
1107 /* XXX pad_reset() is currently disabled because it results in serious bugs.
1108 * It causes pad temp TARGs to be shared between OPs. Since TARGs are pushed
1109 * on the stack by OPs that use them, there are several ways to get an alias
1110 * to a shared TARG. Such an alias will change randomly and unpredictably.
1111 * We avoid doing this until we can think of a Better Way.
1114 Perl_pad_reset(pTHX)
1117 #ifdef USE_BROKEN_PAD_RESET
1118 if (AvARRAY(PL_comppad) != PL_curpad)
1119 Perl_croak(aTHX_ "panic: pad_reset curpad");
1121 DEBUG_X(PerlIO_printf(Perl_debug_log,
1122 "Pad 0x%"UVxf"[0x%"UVxf"] reset: padix %ld -> %ld",
1123 PTR2UV(PL_comppad), PTR2UV(PL_curpad),
1124 (long)PL_padix, (long)PL_padix_floor
1128 if (!PL_tainting) { /* Can't mix tainted and non-tainted temporaries. */
1130 for (po = AvMAX(PL_comppad); po > PL_padix_floor; po--) {
1131 if (PL_curpad[po] && !SvIMMORTAL(PL_curpad[po]))
1132 SvPADTMP_off(PL_curpad[po]);
1134 PL_padix = PL_padix_floor;
1137 PL_pad_reset_pending = FALSE;
1142 =for apidoc pad_tidy
1144 Tidy up a pad after we've finished compiling it:
1145 * remove most stuff from the pads of anonsub prototypes;
1147 * mark tmps as such.
1152 /* XXX DAPM surely most of this stuff should be done properly
1153 * at the right time beforehand, rather than going around afterwards
1154 * cleaning up our mistakes ???
1158 Perl_pad_tidy(pTHX_ padtidy_type type)
1162 ASSERT_CURPAD_ACTIVE("pad_tidy");
1164 /* If this CV has had any 'eval-capable' ops planted in it
1165 * (ie it contains eval '...', //ee, /$var/ or /(?{..})/), Then any
1166 * anon prototypes in the chain of CVs should be marked as cloneable,
1167 * so that for example the eval's CV in C<< sub { eval '$x' } >> gets
1168 * the right CvOUTSIDE.
1169 * If running with -d, *any* sub may potentially have an eval
1170 * excuted within it.
1173 if (PL_cv_has_eval || PL_perldb) {
1175 for (cv = PL_compcv ;cv; cv = CvOUTSIDE(cv)) {
1176 if (cv != PL_compcv && CvCOMPILED(cv))
1177 break; /* no need to mark already-compiled code */
1179 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
1180 "Pad clone on cv=0x%"UVxf"\n", PTR2UV(cv)));
1186 /* extend curpad to match namepad */
1187 if (AvFILLp(PL_comppad_name) < AvFILLp(PL_comppad))
1188 av_store(PL_comppad_name, AvFILLp(PL_comppad), NULL);
1190 if (type == padtidy_SUBCLONE) {
1191 SV * const * const namep = AvARRAY(PL_comppad_name);
1194 for (ix = AvFILLp(PL_comppad); ix > 0; ix--) {
1197 if (SvIMMORTAL(PL_curpad[ix]) || IS_PADGV(PL_curpad[ix]) || IS_PADCONST(PL_curpad[ix]))
1200 * The only things that a clonable function needs in its
1201 * pad are anonymous subs.
1202 * The rest are created anew during cloning.
1204 if (!((namesv = namep[ix]) != NULL &&
1205 namesv != &PL_sv_undef &&
1206 *SvPVX_const(namesv) == '&'))
1208 SvREFCNT_dec(PL_curpad[ix]);
1209 PL_curpad[ix] = NULL;
1213 else if (type == padtidy_SUB) {
1214 /* XXX DAPM this same bit of code keeps appearing !!! Rationalise? */
1215 AV * const av = newAV(); /* Will be @_ */
1217 av_store(PL_comppad, 0, (SV*)av);
1221 /* XXX DAPM rationalise these two similar branches */
1223 if (type == padtidy_SUB) {
1225 for (ix = AvFILLp(PL_comppad); ix > 0; ix--) {
1226 if (SvIMMORTAL(PL_curpad[ix]) || IS_PADGV(PL_curpad[ix]) || IS_PADCONST(PL_curpad[ix]))
1228 if (!SvPADMY(PL_curpad[ix]))
1229 SvPADTMP_on(PL_curpad[ix]);
1232 else if (type == padtidy_FORMAT) {
1234 for (ix = AvFILLp(PL_comppad); ix > 0; ix--) {
1235 if (!SvPADMY(PL_curpad[ix]) && !SvIMMORTAL(PL_curpad[ix]))
1236 SvPADTMP_on(PL_curpad[ix]);
1239 PL_curpad = AvARRAY(PL_comppad);
1244 =for apidoc pad_free
1246 Free the SV at offset po in the current pad.
1251 /* XXX DAPM integrate with pad_swipe ???? */
1253 Perl_pad_free(pTHX_ PADOFFSET po)
1256 ASSERT_CURPAD_LEGAL("pad_free");
1259 if (AvARRAY(PL_comppad) != PL_curpad)
1260 Perl_croak(aTHX_ "panic: pad_free curpad");
1262 Perl_croak(aTHX_ "panic: pad_free po");
1264 DEBUG_X(PerlIO_printf(Perl_debug_log,
1265 "Pad 0x%"UVxf"[0x%"UVxf"] free: %ld\n",
1266 PTR2UV(PL_comppad), PTR2UV(PL_curpad), (long)po)
1269 if (PL_curpad[po] && PL_curpad[po] != &PL_sv_undef) {
1270 SvPADTMP_off(PL_curpad[po]);
1272 /* SV could be a shared hash key (eg bugid #19022) */
1274 #ifdef PERL_OLD_COPY_ON_WRITE
1275 !SvIsCOW(PL_curpad[po])
1277 !SvFAKE(PL_curpad[po])
1280 SvREADONLY_off(PL_curpad[po]); /* could be a freed constant */
1283 if ((I32)po < PL_padix)
1290 =for apidoc do_dump_pad
1292 Dump the contents of a padlist
1298 Perl_do_dump_pad(pTHX_ I32 level, PerlIO *file, PADLIST *padlist, int full)
1310 pad_name = (AV*)*av_fetch((AV*)padlist, 0, FALSE);
1311 pad = (AV*)*av_fetch((AV*)padlist, 1, FALSE);
1312 pname = AvARRAY(pad_name);
1313 ppad = AvARRAY(pad);
1314 Perl_dump_indent(aTHX_ level, file,
1315 "PADNAME = 0x%"UVxf"(0x%"UVxf") PAD = 0x%"UVxf"(0x%"UVxf")\n",
1316 PTR2UV(pad_name), PTR2UV(pname), PTR2UV(pad), PTR2UV(ppad)
1319 for (ix = 1; ix <= AvFILLp(pad_name); ix++) {
1320 const SV *namesv = pname[ix];
1321 if (namesv && namesv == &PL_sv_undef) {
1326 Perl_dump_indent(aTHX_ level+1, file,
1327 "%2d. 0x%"UVxf"<%lu> FAKE \"%s\" flags=0x%lx index=%lu\n",
1330 (unsigned long) (ppad[ix] ? SvREFCNT(ppad[ix]) : 0),
1331 SvPVX_const(namesv),
1332 (unsigned long)SvIVX(namesv),
1333 (unsigned long)SvNVX(namesv)
1337 Perl_dump_indent(aTHX_ level+1, file,
1338 "%2d. 0x%"UVxf"<%lu> (%ld,%ld) \"%s\"\n",
1341 (unsigned long) (ppad[ix] ? SvREFCNT(ppad[ix]) : 0),
1342 (long)U_32(SvNVX(namesv)),
1343 (long)SvIVX(namesv),
1348 Perl_dump_indent(aTHX_ level+1, file,
1349 "%2d. 0x%"UVxf"<%lu>\n",
1352 (unsigned long) (ppad[ix] ? SvREFCNT(ppad[ix]) : 0)
1363 dump the contents of a CV
1370 S_cv_dump(pTHX_ const CV *cv, const char *title)
1373 const CV * const outside = CvOUTSIDE(cv);
1374 AV* const padlist = CvPADLIST(cv);
1376 PerlIO_printf(Perl_debug_log,
1377 " %s: CV=0x%"UVxf" (%s), OUTSIDE=0x%"UVxf" (%s)\n",
1380 (CvANON(cv) ? "ANON"
1381 : (SvTYPE(cv) == SVt_PVFM) ? "FORMAT"
1382 : (cv == PL_main_cv) ? "MAIN"
1383 : CvUNIQUE(cv) ? "UNIQUE"
1384 : CvGV(cv) ? GvNAME(CvGV(cv)) : "UNDEFINED"),
1387 : CvANON(outside) ? "ANON"
1388 : (outside == PL_main_cv) ? "MAIN"
1389 : CvUNIQUE(outside) ? "UNIQUE"
1390 : CvGV(outside) ? GvNAME(CvGV(outside)) : "UNDEFINED"));
1392 PerlIO_printf(Perl_debug_log,
1393 " PADLIST = 0x%"UVxf"\n", PTR2UV(padlist));
1394 do_dump_pad(1, Perl_debug_log, padlist, 1);
1396 #endif /* DEBUGGING */
1403 =for apidoc cv_clone
1405 Clone a CV: make a new CV which points to the same code etc, but which
1406 has a newly-created pad built by copying the prototype pad and capturing
1413 Perl_cv_clone(pTHX_ CV *proto)
1417 AV* const protopadlist = CvPADLIST(proto);
1418 const AV* const protopad_name = (AV*)*av_fetch(protopadlist, 0, FALSE);
1419 const AV* const protopad = (AV*)*av_fetch(protopadlist, 1, FALSE);
1420 SV** const pname = AvARRAY(protopad_name);
1421 SV** const ppad = AvARRAY(protopad);
1422 const I32 fname = AvFILLp(protopad_name);
1423 const I32 fpad = AvFILLp(protopad);
1429 assert(!CvUNIQUE(proto));
1431 /* Since cloneable anon subs can be nested, CvOUTSIDE may point
1432 * to a prototype; we instead want the cloned parent who called us.
1433 * Note that in general for formats, CvOUTSIDE != find_runcv */
1435 outside = CvOUTSIDE(proto);
1436 if (outside && CvCLONE(outside) && ! CvCLONED(outside))
1437 outside = find_runcv(NULL);
1438 depth = CvDEPTH(outside);
1439 assert(depth || SvTYPE(proto) == SVt_PVFM);
1442 assert(CvPADLIST(outside));
1445 SAVESPTR(PL_compcv);
1447 cv = PL_compcv = (CV*)newSV(0);
1448 sv_upgrade((SV *)cv, SvTYPE(proto));
1449 CvFLAGS(cv) = CvFLAGS(proto) & ~(CVf_CLONE|CVf_WEAKOUTSIDE);
1453 CvFILE(cv) = CvISXSUB(proto) ? CvFILE(proto)
1454 : savepv(CvFILE(proto));
1456 CvFILE(cv) = CvFILE(proto);
1458 CvGV(cv) = CvGV(proto);
1459 CvSTASH(cv) = CvSTASH(proto);
1461 CvROOT(cv) = OpREFCNT_inc(CvROOT(proto));
1463 CvSTART(cv) = CvSTART(proto);
1464 CvOUTSIDE(cv) = (CV*)SvREFCNT_inc_simple(outside);
1465 CvOUTSIDE_SEQ(cv) = CvOUTSIDE_SEQ(proto);
1468 sv_setpvn((SV*)cv, SvPVX_const(proto), SvCUR(proto));
1470 CvPADLIST(cv) = pad_new(padnew_CLONE|padnew_SAVE);
1472 av_fill(PL_comppad, fpad);
1473 for (ix = fname; ix >= 0; ix--)
1474 av_store(PL_comppad_name, ix, SvREFCNT_inc(pname[ix]));
1476 PL_curpad = AvARRAY(PL_comppad);
1478 outpad = AvARRAY(AvARRAY(CvPADLIST(outside))[depth]);
1480 for (ix = fpad; ix > 0; ix--) {
1481 SV* const namesv = (ix <= fname) ? pname[ix] : NULL;
1483 if (namesv && namesv != &PL_sv_undef) { /* lexical */
1484 if (SvFAKE(namesv)) { /* lexical from outside? */
1485 sv = outpad[(I32)SvNVX(namesv)];
1487 /* formats may have an inactive parent */
1488 if (SvTYPE(proto) == SVt_PVFM && SvPADSTALE(sv)) {
1489 if (ckWARN(WARN_CLOSURE))
1490 Perl_warner(aTHX_ packWARN(WARN_CLOSURE),
1491 "Variable \"%s\" is not available", SvPVX_const(namesv));
1495 assert(!SvPADSTALE(sv));
1496 SvREFCNT_inc_simple_void_NN(sv);
1500 const char sigil = SvPVX_const(namesv)[0];
1502 sv = SvREFCNT_inc(ppad[ix]);
1503 else if (sigil == '@')
1505 else if (sigil == '%')
1512 else if (IS_PADGV(ppad[ix]) || IS_PADCONST(ppad[ix])) {
1513 sv = SvREFCNT_inc_NN(ppad[ix]);
1523 PerlIO_printf(Perl_debug_log, "\nPad CV clone\n");
1524 cv_dump(outside, "Outside");
1525 cv_dump(proto, "Proto");
1532 /* Constant sub () { $x } closing over $x - see lib/constant.pm:
1533 * The prototype was marked as a candiate for const-ization,
1534 * so try to grab the current const value, and if successful,
1535 * turn into a const sub:
1537 SV* const const_sv = op_const_sv(CvSTART(cv), cv);
1540 cv = newCONSTSUB(CvSTASH(proto), NULL, const_sv);
1552 =for apidoc pad_fixup_inner_anons
1554 For any anon CVs in the pad, change CvOUTSIDE of that CV from
1555 old_cv to new_cv if necessary. Needed when a newly-compiled CV has to be
1556 moved to a pre-existing CV struct.
1562 Perl_pad_fixup_inner_anons(pTHX_ PADLIST *padlist, CV *old_cv, CV *new_cv)
1566 AV * const comppad_name = (AV*)AvARRAY(padlist)[0];
1567 AV * const comppad = (AV*)AvARRAY(padlist)[1];
1568 SV ** const namepad = AvARRAY(comppad_name);
1569 SV ** const curpad = AvARRAY(comppad);
1570 PERL_UNUSED_ARG(old_cv);
1572 for (ix = AvFILLp(comppad_name); ix > 0; ix--) {
1573 const SV * const namesv = namepad[ix];
1574 if (namesv && namesv != &PL_sv_undef
1575 && *SvPVX_const(namesv) == '&')
1577 CV * const innercv = (CV*)curpad[ix];
1578 assert(CvWEAKOUTSIDE(innercv));
1579 assert(CvOUTSIDE(innercv) == old_cv);
1580 CvOUTSIDE(innercv) = new_cv;
1587 =for apidoc pad_push
1589 Push a new pad frame onto the padlist, unless there's already a pad at
1590 this depth, in which case don't bother creating a new one. Then give
1591 the new pad an @_ in slot zero.
1597 Perl_pad_push(pTHX_ PADLIST *padlist, int depth)
1600 if (depth > AvFILLp(padlist)) {
1601 SV** const svp = AvARRAY(padlist);
1602 AV* const newpad = newAV();
1603 SV** const oldpad = AvARRAY(svp[depth-1]);
1604 I32 ix = AvFILLp((AV*)svp[1]);
1605 const I32 names_fill = AvFILLp((AV*)svp[0]);
1606 SV** const names = AvARRAY(svp[0]);
1609 for ( ;ix > 0; ix--) {
1610 if (names_fill >= ix && names[ix] != &PL_sv_undef) {
1611 const char sigil = SvPVX_const(names[ix])[0];
1612 if ((SvFLAGS(names[ix]) & SVf_FAKE) || sigil == '&') {
1613 /* outer lexical or anon code */
1614 av_store(newpad, ix, SvREFCNT_inc(oldpad[ix]));
1616 else { /* our own lexical */
1620 else if (sigil == '%')
1624 av_store(newpad, ix, sv);
1628 else if (IS_PADGV(oldpad[ix]) || IS_PADCONST(oldpad[ix])) {
1629 av_store(newpad, ix, SvREFCNT_inc_NN(oldpad[ix]));
1632 /* save temporaries on recursion? */
1633 SV * const sv = newSV(0);
1634 av_store(newpad, ix, sv);
1640 av_store(newpad, 0, (SV*)av);
1643 av_store(padlist, depth, (SV*)newpad);
1644 AvFILLp(padlist) = depth;
1650 Perl_pad_compname_type(pTHX_ const PADOFFSET po)
1653 SV* const * const av = av_fetch(PL_comppad_name, po, FALSE);
1654 if ( SvPAD_TYPED(*av) ) {
1655 return SvSTASH(*av);
1662 * c-indentation-style: bsd
1664 * indent-tabs-mode: t
1667 * ex: set ts=8 sts=4 sw=4 noet: