3 * Copyright (C) 2002,2003 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).
103 #define PAD_MAX 999999999
110 Create a new compiling padlist, saving and updating the various global
111 vars at the same time as creating the pad itself. The following flags
112 can be OR'ed together:
114 padnew_CLONE this pad is for a cloned CV
115 padnew_SAVE save old globals
116 padnew_SAVESUB also save extra stuff for start of sub
122 Perl_pad_new(pTHX_ int flags)
124 AV *padlist, *padname, *pad, *a0;
126 ASSERT_CURPAD_LEGAL("pad_new");
128 /* XXX DAPM really need a new SAVEt_PAD which restores all or most
129 * vars (based on flags) rather than storing vals + addresses for
130 * each individually. Also see pad_block_start.
131 * XXX DAPM Try to see whether all these conditionals are required
134 /* save existing state, ... */
136 if (flags & padnew_SAVE) {
138 SAVESPTR(PL_comppad_name);
139 if (! (flags & padnew_CLONE)) {
141 SAVEI32(PL_comppad_name_fill);
142 SAVEI32(PL_min_intro_pending);
143 SAVEI32(PL_max_intro_pending);
144 SAVEI32(PL_cv_has_eval);
145 if (flags & padnew_SAVESUB) {
146 SAVEI32(PL_pad_reset_pending);
150 /* XXX DAPM interestingly, PL_comppad_name_floor never seems to be
151 * saved - check at some pt that this is okay */
153 /* ... create new pad ... */
159 if (flags & padnew_CLONE) {
160 /* XXX DAPM I dont know why cv_clone needs it
161 * doing differently yet - perhaps this separate branch can be
162 * dispensed with eventually ???
165 a0 = newAV(); /* will be @_ */
167 av_store(pad, 0, (SV*)a0);
168 AvFLAGS(a0) = AVf_REIFY;
171 av_store(pad, 0, Nullsv);
175 av_store(padlist, 0, (SV*)padname);
176 av_store(padlist, 1, (SV*)pad);
178 /* ... then update state variables */
180 PL_comppad_name = (AV*)(*av_fetch(padlist, 0, FALSE));
181 PL_comppad = (AV*)(*av_fetch(padlist, 1, FALSE));
182 PL_curpad = AvARRAY(PL_comppad);
184 if (! (flags & padnew_CLONE)) {
185 PL_comppad_name_fill = 0;
186 PL_min_intro_pending = 0;
191 DEBUG_X(PerlIO_printf(Perl_debug_log,
192 "Pad 0x%"UVxf"[0x%"UVxf"] new: compcv=0x%"UVxf
193 " name=0x%"UVxf" flags=0x%"UVxf"\n",
194 PTR2UV(PL_comppad), PTR2UV(PL_curpad), PTR2UV(PL_compcv),
195 PTR2UV(padname), (UV)flags
199 return (PADLIST*)padlist;
203 =for apidoc pad_undef
205 Free the padlist associated with a CV.
206 If parts of it happen to be current, we null the relevant
207 PL_*pad* global vars so that we don't have any dangling references left.
208 We also repoint the CvOUTSIDE of any about-to-be-orphaned
209 inner subs to the outer of this cv.
211 (This function should really be called pad_free, but the name was already
218 Perl_pad_undef(pTHX_ CV* cv)
221 PADLIST *padlist = CvPADLIST(cv);
225 if (!SvREFCNT(CvPADLIST(cv))) /* may be during global destruction */
228 DEBUG_X(PerlIO_printf(Perl_debug_log,
229 "Pad undef: cv=0x%"UVxf" padlist=0x%"UVxf"\n",
230 PTR2UV(cv), PTR2UV(padlist))
233 /* detach any '&' anon children in the pad; if afterwards they
234 * are still live, fix up their CvOUTSIDEs to point to our outside,
236 /* XXX DAPM for efficiency, we should only do this if we know we have
237 * children, or integrate this loop with general cleanup */
239 if (!PL_dirty) { /* don't bother during global destruction */
240 CV *outercv = CvOUTSIDE(cv);
241 U32 seq = CvOUTSIDE_SEQ(cv);
242 AV *comppad_name = (AV*)AvARRAY(padlist)[0];
243 SV **namepad = AvARRAY(comppad_name);
244 AV *comppad = (AV*)AvARRAY(padlist)[1];
245 SV **curpad = AvARRAY(comppad);
246 for (ix = AvFILLp(comppad_name); ix > 0; ix--) {
247 SV *namesv = namepad[ix];
248 if (namesv && namesv != &PL_sv_undef
249 && *SvPVX(namesv) == '&')
251 CV *innercv = (CV*)curpad[ix];
252 namepad[ix] = Nullsv;
253 SvREFCNT_dec(namesv);
255 SvREFCNT_dec(innercv);
256 if (SvREFCNT(innercv) /* in use, not just a prototype */
257 && CvOUTSIDE(innercv) == cv)
259 assert(CvWEAKOUTSIDE(innercv));
260 CvWEAKOUTSIDE_off(innercv);
261 CvOUTSIDE_SEQ(innercv) = seq;
262 /* don't relink to grandfather if he's being freed */
263 if (SvREFCNT(outercv)) {
264 CvOUTSIDE(innercv) = outercv;
265 SvREFCNT_inc(outercv);
268 CvOUTSIDE(innercv) = Nullcv;
275 ix = AvFILLp(padlist);
277 SV* sv = AvARRAY(padlist)[ix--];
280 if (sv == (SV*)PL_comppad_name)
281 PL_comppad_name = Nullav;
282 else if (sv == (SV*)PL_comppad) {
283 PL_comppad = Null(PAD*);
284 PL_curpad = Null(SV**);
288 SvREFCNT_dec((SV*)CvPADLIST(cv));
289 CvPADLIST(cv) = Null(PADLIST*);
296 =for apidoc pad_add_name
298 Create a new name and associated PADMY SV in the current pad; return the
300 If C<typestash> is valid, the name is for a typed lexical; set the
301 name's stash to that value.
302 If C<ourstash> is valid, it's an our lexical, set the name's
303 GvSTASH to that value
305 If fake, it means we're cloning an existing entry
311 Perl_pad_add_name(pTHX_ char *name, HV* typestash, HV* ourstash, bool fake)
313 PADOFFSET offset = pad_alloc(OP_PADSV, SVs_PADMY);
314 SV* namesv = NEWSV(1102, 0);
316 ASSERT_CURPAD_ACTIVE("pad_add_name");
319 sv_upgrade(namesv, ourstash ? SVt_PVGV : typestash ? SVt_PVMG : SVt_PVNV);
320 sv_setpv(namesv, name);
323 SvFLAGS(namesv) |= SVpad_TYPED;
324 SvSTASH(namesv) = (HV*)SvREFCNT_inc((SV*) typestash);
327 SvFLAGS(namesv) |= SVpad_OUR;
328 GvSTASH(namesv) = (HV*)SvREFCNT_inc((SV*) ourstash);
331 av_store(PL_comppad_name, offset, namesv);
334 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
335 "Pad addname: %ld \"%s\" FAKE\n", (long)offset, name));
338 /* not yet introduced */
339 SvNVX(namesv) = (NV)PAD_MAX; /* min */
340 SvIVX(namesv) = 0; /* max */
342 if (!PL_min_intro_pending)
343 PL_min_intro_pending = offset;
344 PL_max_intro_pending = offset;
345 /* if it's not a simple scalar, replace with an AV or HV */
346 /* XXX DAPM since slot has been allocated, replace
347 * av_store with PL_curpad[offset] ? */
349 av_store(PL_comppad, offset, (SV*)newAV());
350 else if (*name == '%')
351 av_store(PL_comppad, offset, (SV*)newHV());
352 SvPADMY_on(PL_curpad[offset]);
353 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
354 "Pad addname: %ld \"%s\" new lex=0x%"UVxf"\n",
355 (long)offset, name, PTR2UV(PL_curpad[offset])));
365 =for apidoc pad_alloc
367 Allocate a new my or tmp pad entry. For a my, simply push a null SV onto
368 the end of PL_comppad, but for a tmp, scan the pad from PL_padix upwards
369 for a slot which has no name and and no active value.
374 /* XXX DAPM integrate alloc(), add_name() and add_anon(),
375 * or at least rationalise ??? */
379 Perl_pad_alloc(pTHX_ I32 optype, U32 tmptype)
384 ASSERT_CURPAD_ACTIVE("pad_alloc");
386 if (AvARRAY(PL_comppad) != PL_curpad)
387 Perl_croak(aTHX_ "panic: pad_alloc");
388 if (PL_pad_reset_pending)
390 if (tmptype & SVs_PADMY) {
391 sv = *av_fetch(PL_comppad, AvFILLp(PL_comppad) + 1, TRUE);
392 retval = AvFILLp(PL_comppad);
395 SV **names = AvARRAY(PL_comppad_name);
396 SSize_t names_fill = AvFILLp(PL_comppad_name);
399 * "foreach" index vars temporarily become aliases to non-"my"
400 * values. Thus we must skip, not just pad values that are
401 * marked as current pad values, but also those with names.
403 /* HVDS why copy to sv here? we don't seem to use it */
404 if (++PL_padix <= names_fill &&
405 (sv = names[PL_padix]) && sv != &PL_sv_undef)
407 sv = *av_fetch(PL_comppad, PL_padix, TRUE);
408 if (!(SvFLAGS(sv) & (SVs_PADTMP | SVs_PADMY)) &&
409 !IS_PADGV(sv) && !IS_PADCONST(sv))
414 SvFLAGS(sv) |= tmptype;
415 PL_curpad = AvARRAY(PL_comppad);
417 DEBUG_X(PerlIO_printf(Perl_debug_log,
418 "Pad 0x%"UVxf"[0x%"UVxf"] alloc: %ld for %s\n",
419 PTR2UV(PL_comppad), PTR2UV(PL_curpad), (long) retval,
420 PL_op_name[optype]));
421 return (PADOFFSET)retval;
425 =for apidoc pad_add_anon
427 Add an anon code entry to the current compiling pad
433 Perl_pad_add_anon(pTHX_ SV* sv, OPCODE op_type)
438 name = NEWSV(1106, 0);
439 sv_upgrade(name, SVt_PVNV);
440 sv_setpvn(name, "&", 1);
443 ix = pad_alloc(op_type, SVs_PADMY);
444 av_store(PL_comppad_name, ix, name);
445 /* XXX DAPM use PL_curpad[] ? */
446 av_store(PL_comppad, ix, sv);
449 /* to avoid ref loops, we never have parent + child referencing each
450 * other simultaneously */
451 if (CvOUTSIDE((CV*)sv)) {
452 assert(!CvWEAKOUTSIDE((CV*)sv));
453 CvWEAKOUTSIDE_on((CV*)sv);
454 SvREFCNT_dec(CvOUTSIDE((CV*)sv));
462 =for apidoc pad_check_dup
464 Check for duplicate declarations: report any of:
465 * a my in the current scope with the same name;
466 * an our (anywhere in the pad) with the same name and the same stash
468 C<is_our> indicates that the name to check is an 'our' declaration
473 /* XXX DAPM integrate this into pad_add_name ??? */
476 Perl_pad_check_dup(pTHX_ char *name, bool is_our, HV *ourstash)
481 ASSERT_CURPAD_ACTIVE("pad_check_dup");
482 if (!ckWARN(WARN_MISC) || AvFILLp(PL_comppad_name) < 0)
483 return; /* nothing to check */
485 svp = AvARRAY(PL_comppad_name);
486 top = AvFILLp(PL_comppad_name);
487 /* check the current scope */
488 /* XXX DAPM - why the (I32) cast - shouldn't we ensure they're the same
490 for (off = top; (I32)off > PL_comppad_name_floor; off--) {
492 && sv != &PL_sv_undef
494 && (SvIVX(sv) == PAD_MAX || SvIVX(sv) == 0)
496 || ((SvFLAGS(sv) & SVpad_OUR) && GvSTASH(sv) == ourstash))
497 && strEQ(name, SvPVX(sv)))
499 Perl_warner(aTHX_ packWARN(WARN_MISC),
500 "\"%s\" variable %s masks earlier declaration in same %s",
501 (is_our ? "our" : "my"),
503 (SvIVX(sv) == PAD_MAX ? "scope" : "statement"));
508 /* check the rest of the pad */
512 && sv != &PL_sv_undef
514 && (SvIVX(sv) == PAD_MAX || SvIVX(sv) == 0)
515 && ((SvFLAGS(sv) & SVpad_OUR) && GvSTASH(sv) == ourstash)
516 && strEQ(name, SvPVX(sv)))
518 Perl_warner(aTHX_ packWARN(WARN_MISC),
519 "\"our\" variable %s redeclared", name);
520 Perl_warner(aTHX_ packWARN(WARN_MISC),
521 "\t(Did you mean \"local\" instead of \"our\"?)\n");
524 } while ( off-- > 0 );
530 =for apidoc pad_findmy
532 Given a lexical name, try to find its offset, first in the current pad,
533 or failing that, in the pads of any lexically enclosing subs (including
534 the complications introduced by eval). If the name is found in an outer pad,
535 then a fake entry is added to the current pad.
536 Returns the offset in the current pad, or NOT_IN_PAD on failure.
542 Perl_pad_findmy(pTHX_ char *name)
550 offset = pad_findlex(name, PL_compcv, PL_cop_seqmax, 1,
551 Null(SV**), &out_sv, &out_flags);
552 if (offset != NOT_IN_PAD)
555 /* look for an our that's being introduced; this allows
556 * our $foo = 0 unless defined $foo;
557 * to not give a warning. (Yes, this is a hack) */
559 nameav = (AV*)AvARRAY(CvPADLIST(PL_compcv))[0];
560 name_svp = AvARRAY(nameav);
561 for (offset = AvFILLp(nameav); offset > 0; offset--) {
562 SV *namesv = name_svp[offset];
563 if (namesv && namesv != &PL_sv_undef
565 && (SvFLAGS(namesv) & SVpad_OUR)
566 && strEQ(SvPVX(namesv), name)
567 && U_32(SvNVX(namesv)) == PAD_MAX /* min */
576 =for apidoc pad_findlex
578 Find a named lexical anywhere in a chain of nested pads. Add fake entries
579 in the inner pads if it's found in an outer one.
581 Returns the offset in the bottom pad of the lex or the fake lex.
582 cv is the CV in which to start the search, and seq is the current cop_seq
583 to match against. If warn is true, print appropriate warnings. The out_*
584 vars return values, and so are pointers to where the returned values
585 should be stored. out_capture, if non-null, requests that the innermost
586 instance of the lexical is captured; out_name_sv is set to the innermost
587 matched namesv or fake namesv; out_flags returns the flags normally
588 associated with the IVX field of a fake namesv.
590 Note that pad_findlex() is recursive; it recurses up the chain of CVs,
591 then comes back down, adding fake entries as it goes. It has to be this way
592 because fake namesvs in anon protoypes have to store in NVX the index into
598 /* Flags set in the SvIVX field of FAKE namesvs */
600 #define PAD_FAKELEX_ANON 1 /* the lex is declared in an ANON, or ... */
601 #define PAD_FAKELEX_MULTI 2 /* the lex can be instantiated multiple times */
603 /* the CV has finished being compiled. This is not a sufficient test for
604 * all CVs (eg XSUBs), but suffices for the CVs found in a lexical chain */
605 #define CvCOMPILED(cv) CvROOT(cv)
607 /* the CV does late binding of its lexicals */
608 #define CvLATE(cv) (CvANON(cv) || SvTYPE(cv) == SVt_PVFM)
612 S_pad_findlex(pTHX_ char *name, CV* cv, U32 seq, int warn,
613 SV** out_capture, SV** out_name_sv, int *out_flags)
615 I32 offset, new_offset;
618 AV *padlist = CvPADLIST(cv);
622 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
623 "Pad findlex cv=0x%"UVxf" searching \"%s\" seq=%d%s\n",
624 PTR2UV(cv), name, (int)seq, out_capture ? " capturing" : "" ));
626 /* first, search this pad */
628 if (padlist) { /* not an undef CV */
630 AV *nameav = (AV*)AvARRAY(padlist)[0];
631 SV **name_svp = AvARRAY(nameav);
633 for (offset = AvFILLp(nameav); offset > 0; offset--) {
634 SV *namesv = name_svp[offset];
635 if (namesv && namesv != &PL_sv_undef
636 && strEQ(SvPVX(namesv), name))
639 fake_offset = offset; /* in case we don't find a real one */
640 else if ( seq > U_32(SvNVX(namesv)) /* min */
641 && seq <= (U32)SvIVX(namesv)) /* max */
646 if (offset > 0 || fake_offset > 0 ) { /* a match! */
647 if (offset > 0) { /* not fake */
649 *out_name_sv = name_svp[offset]; /* return the namesv */
651 /* set PAD_FAKELEX_MULTI if this lex can have multiple
652 * instances. For now, we just test !CvUNIQUE(cv), but
653 * ideally, we should detect my's declared within loops
654 * etc - this would allow a wider range of 'not stayed
655 * shared' warnings. We also treated alreadly-compiled
656 * lexes as not multi as viewed from evals. */
658 *out_flags = CvANON(cv) ?
660 (!CvUNIQUE(cv) && ! CvCOMPILED(cv))
661 ? PAD_FAKELEX_MULTI : 0;
663 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
664 "Pad findlex cv=0x%"UVxf" matched: offset=%ld (%ld,%ld)\n",
665 PTR2UV(cv), (long)offset, (long)U_32(SvNVX(*out_name_sv)),
666 (long)SvIVX(*out_name_sv)));
668 else { /* fake match */
669 offset = fake_offset;
670 *out_name_sv = name_svp[offset]; /* return the namesv */
671 *out_flags = SvIVX(*out_name_sv);
672 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
673 "Pad findlex cv=0x%"UVxf" matched: offset=%ld flags=0x%lx index=%lu\n",
674 PTR2UV(cv), (long)offset, (unsigned long)*out_flags,
675 (unsigned long)SvNVX(*out_name_sv)
679 /* return the lex? */
684 if ((SvFLAGS(*out_name_sv) & SVpad_OUR)) {
685 *out_capture = Nullsv;
689 /* trying to capture from an anon prototype? */
691 ? CvANON(cv) && CvCLONE(cv) && !CvCLONED(cv)
692 : *out_flags & PAD_FAKELEX_ANON)
694 if (warn && ckWARN(WARN_CLOSURE))
695 Perl_warner(aTHX_ packWARN(WARN_CLOSURE),
696 "Variable \"%s\" is not available", name);
697 *out_capture = Nullsv;
703 if (!CvCOMPILED(cv) && (*out_flags & PAD_FAKELEX_MULTI)
704 && warn && ckWARN(WARN_CLOSURE)) {
706 Perl_warner(aTHX_ packWARN(WARN_CLOSURE),
707 "Variable \"%s\" will not stay shared", name);
710 if (fake_offset && CvANON(cv)
711 && CvCLONE(cv) &&!CvCLONED(cv))
714 /* not yet caught - look further up */
715 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
716 "Pad findlex cv=0x%"UVxf" chasing lex in outer pad\n",
719 pad_findlex(name, CvOUTSIDE(cv), CvOUTSIDE_SEQ(cv),
720 newwarn, out_capture, out_name_sv, out_flags);
725 *out_capture = AvARRAY((AV*)AvARRAY(padlist)[
726 CvDEPTH(cv) ? CvDEPTH(cv) : 1])[offset];
727 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
728 "Pad findlex cv=0x%"UVxf" found lex=0x%"UVxf"\n",
729 PTR2UV(cv), PTR2UV(*out_capture)));
731 if (SvPADSTALE(*out_capture)) {
732 if (ckWARN(WARN_CLOSURE))
733 Perl_warner(aTHX_ packWARN(WARN_CLOSURE),
734 "Variable \"%s\" is not available", name);
735 *out_capture = Nullsv;
740 *out_capture = sv_2mortal((SV*)newAV());
741 else if (*name == '%')
742 *out_capture = sv_2mortal((SV*)newHV());
744 *out_capture = sv_newmortal();
752 /* it's not in this pad - try above */
757 /* out_capture non-null means caller wants us to capture lex; in
758 * addition we capture ourselves unless it's an ANON/format */
759 new_capturep = out_capture ? out_capture :
760 CvLATE(cv) ? Null(SV**) : &new_capture;
762 offset = pad_findlex(name, CvOUTSIDE(cv), CvOUTSIDE_SEQ(cv), 1,
763 new_capturep, out_name_sv, out_flags);
764 if (offset == NOT_IN_PAD)
767 /* found in an outer CV. Add appropriate fake entry to this pad */
769 /* don't add new fake entries (via eval) to CVs that we have already
770 * finished compiling, or to undef CVs */
771 if (CvCOMPILED(cv) || !padlist)
772 return 0; /* this dummy (and invalid) value isnt used by the caller */
776 AV *ocomppad_name = PL_comppad_name;
777 PAD *ocomppad = PL_comppad;
778 PL_comppad_name = (AV*)AvARRAY(padlist)[0];
779 PL_comppad = (AV*)AvARRAY(padlist)[1];
780 PL_curpad = AvARRAY(PL_comppad);
782 new_offset = pad_add_name(
784 (SvFLAGS(*out_name_sv) & SVpad_TYPED)
785 ? SvSTASH(*out_name_sv) : Nullhv,
786 (SvFLAGS(*out_name_sv) & SVpad_OUR)
787 ? GvSTASH(*out_name_sv) : Nullhv,
791 new_namesv = AvARRAY(PL_comppad_name)[new_offset];
792 SvIVX(new_namesv) = *out_flags;
794 SvNVX(new_namesv) = (NV)0;
795 if (SvFLAGS(new_namesv) & SVpad_OUR) {
798 else if (CvLATE(cv)) {
799 /* delayed creation - just note the offset within parent pad */
800 SvNVX(new_namesv) = (NV)offset;
804 /* immediate creation - capture outer value right now */
805 av_store(PL_comppad, new_offset, SvREFCNT_inc(*new_capturep));
806 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
807 "Pad findlex cv=0x%"UVxf" saved captured sv 0x%"UVxf" at offset %ld\n",
808 PTR2UV(cv), PTR2UV(*new_capturep), (long)new_offset));
810 *out_name_sv = new_namesv;
811 *out_flags = SvIVX(new_namesv);
813 PL_comppad_name = ocomppad_name;
814 PL_comppad = ocomppad;
815 PL_curpad = ocomppad ? AvARRAY(ocomppad) : Null(SV **);
824 Get the value at offset po in the current pad.
825 Use macro PAD_SV instead of calling this function directly.
832 Perl_pad_sv(pTHX_ PADOFFSET po)
834 ASSERT_CURPAD_ACTIVE("pad_sv");
837 Perl_croak(aTHX_ "panic: pad_sv po");
838 DEBUG_X(PerlIO_printf(Perl_debug_log,
839 "Pad 0x%"UVxf"[0x%"UVxf"] sv: %ld sv=0x%"UVxf"\n",
840 PTR2UV(PL_comppad), PTR2UV(PL_curpad), (long)po, PTR2UV(PL_curpad[po]))
842 return PL_curpad[po];
847 =for apidoc pad_setsv
849 Set the entry at offset po in the current pad to sv.
850 Use the macro PAD_SETSV() rather than calling this function directly.
857 Perl_pad_setsv(pTHX_ PADOFFSET po, SV* sv)
859 ASSERT_CURPAD_ACTIVE("pad_setsv");
861 DEBUG_X(PerlIO_printf(Perl_debug_log,
862 "Pad 0x%"UVxf"[0x%"UVxf"] setsv: %ld sv=0x%"UVxf"\n",
863 PTR2UV(PL_comppad), PTR2UV(PL_curpad), (long)po, PTR2UV(sv))
872 =for apidoc pad_block_start
874 Update the pad compilation state variables on entry to a new block
880 * - integrate this in general state-saving routine ???
881 * - combine with the state-saving going on in pad_new ???
882 * - introduce a new SAVE type that does all this in one go ?
886 Perl_pad_block_start(pTHX_ int full)
888 ASSERT_CURPAD_ACTIVE("pad_block_start");
889 SAVEI32(PL_comppad_name_floor);
890 PL_comppad_name_floor = AvFILLp(PL_comppad_name);
892 PL_comppad_name_fill = PL_comppad_name_floor;
893 if (PL_comppad_name_floor < 0)
894 PL_comppad_name_floor = 0;
895 SAVEI32(PL_min_intro_pending);
896 SAVEI32(PL_max_intro_pending);
897 PL_min_intro_pending = 0;
898 SAVEI32(PL_comppad_name_fill);
899 SAVEI32(PL_padix_floor);
900 PL_padix_floor = PL_padix;
901 PL_pad_reset_pending = FALSE;
908 "Introduce" my variables to visible status.
920 ASSERT_CURPAD_ACTIVE("intro_my");
921 if (! PL_min_intro_pending)
922 return PL_cop_seqmax;
924 svp = AvARRAY(PL_comppad_name);
925 for (i = PL_min_intro_pending; i <= PL_max_intro_pending; i++) {
926 if ((sv = svp[i]) && sv != &PL_sv_undef
927 && !SvFAKE(sv) && !SvIVX(sv))
929 SvIVX(sv) = PAD_MAX; /* Don't know scope end yet. */
930 SvNVX(sv) = (NV)PL_cop_seqmax;
931 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
932 "Pad intromy: %ld \"%s\", (%ld,%ld)\n",
934 (long)U_32(SvNVX(sv)), (long)SvIVX(sv))
938 PL_min_intro_pending = 0;
939 PL_comppad_name_fill = PL_max_intro_pending; /* Needn't search higher */
940 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
941 "Pad intromy: seq -> %ld\n", (long)(PL_cop_seqmax+1)));
943 return PL_cop_seqmax++;
947 =for apidoc pad_leavemy
949 Cleanup at end of scope during compilation: set the max seq number for
950 lexicals in this scope and warn of any lexicals that never got introduced.
956 Perl_pad_leavemy(pTHX)
959 SV **svp = AvARRAY(PL_comppad_name);
962 PL_pad_reset_pending = FALSE;
964 ASSERT_CURPAD_ACTIVE("pad_leavemy");
965 if (PL_min_intro_pending && PL_comppad_name_fill < PL_min_intro_pending) {
966 for (off = PL_max_intro_pending; off >= PL_min_intro_pending; off--) {
967 if ((sv = svp[off]) && sv != &PL_sv_undef
968 && !SvFAKE(sv) && ckWARN_d(WARN_INTERNAL))
969 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
970 "%"SVf" never introduced", sv);
973 /* "Deintroduce" my variables that are leaving with this scope. */
974 for (off = AvFILLp(PL_comppad_name); off > PL_comppad_name_fill; off--) {
975 if ((sv = svp[off]) && sv != &PL_sv_undef
976 && !SvFAKE(sv) && SvIVX(sv) == PAD_MAX)
978 SvIVX(sv) = PL_cop_seqmax;
979 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
980 "Pad leavemy: %ld \"%s\", (%ld,%ld)\n",
981 (long)off, SvPVX(sv),
982 (long)U_32(SvNVX(sv)), (long)SvIVX(sv))
987 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
988 "Pad leavemy: seq = %ld\n", (long)PL_cop_seqmax));
993 =for apidoc pad_swipe
995 Abandon the tmp in the current pad at offset po and replace with a
1002 Perl_pad_swipe(pTHX_ PADOFFSET po, bool refadjust)
1004 ASSERT_CURPAD_LEGAL("pad_swipe");
1007 if (AvARRAY(PL_comppad) != PL_curpad)
1008 Perl_croak(aTHX_ "panic: pad_swipe curpad");
1010 Perl_croak(aTHX_ "panic: pad_swipe po");
1012 DEBUG_X(PerlIO_printf(Perl_debug_log,
1013 "Pad 0x%"UVxf"[0x%"UVxf"] swipe: %ld\n",
1014 PTR2UV(PL_comppad), PTR2UV(PL_curpad), (long)po));
1017 SvPADTMP_off(PL_curpad[po]);
1019 SvREFCNT_dec(PL_curpad[po]);
1021 PL_curpad[po] = NEWSV(1107,0);
1022 SvPADTMP_on(PL_curpad[po]);
1023 if ((I32)po < PL_padix)
1029 =for apidoc pad_reset
1031 Mark all the current temporaries for reuse
1036 /* XXX pad_reset() is currently disabled because it results in serious bugs.
1037 * It causes pad temp TARGs to be shared between OPs. Since TARGs are pushed
1038 * on the stack by OPs that use them, there are several ways to get an alias
1039 * to a shared TARG. Such an alias will change randomly and unpredictably.
1040 * We avoid doing this until we can think of a Better Way.
1043 Perl_pad_reset(pTHX)
1045 #ifdef USE_BROKEN_PAD_RESET
1048 if (AvARRAY(PL_comppad) != PL_curpad)
1049 Perl_croak(aTHX_ "panic: pad_reset curpad");
1051 DEBUG_X(PerlIO_printf(Perl_debug_log,
1052 "Pad 0x%"UVxf"[0x%"UVxf"] reset: padix %ld -> %ld",
1053 PTR2UV(PL_comppad), PTR2UV(PL_curpad),
1054 (long)PL_padix, (long)PL_padix_floor
1058 if (!PL_tainting) { /* Can't mix tainted and non-tainted temporaries. */
1059 for (po = AvMAX(PL_comppad); po > PL_padix_floor; po--) {
1060 if (PL_curpad[po] && !SvIMMORTAL(PL_curpad[po]))
1061 SvPADTMP_off(PL_curpad[po]);
1063 PL_padix = PL_padix_floor;
1066 PL_pad_reset_pending = FALSE;
1071 =for apidoc pad_tidy
1073 Tidy up a pad after we've finished compiling it:
1074 * remove most stuff from the pads of anonsub prototypes;
1076 * mark tmps as such.
1081 /* XXX DAPM surely most of this stuff should be done properly
1082 * at the right time beforehand, rather than going around afterwards
1083 * cleaning up our mistakes ???
1087 Perl_pad_tidy(pTHX_ padtidy_type type)
1092 ASSERT_CURPAD_ACTIVE("pad_tidy");
1094 /* If this CV has had any 'eval-capable' ops planted in it
1095 * (ie it contains eval '...', //ee, /$var/ or /(?{..})/), Then any
1096 * anon prototypes in the chain of CVs should be marked as cloneable,
1097 * so that for example the eval's CV in C<< sub { eval '$x' } >> gets
1098 * the right CvOUTSIDE.
1099 * If running with -d, *any* sub may potentially have an eval
1100 * excuted within it.
1103 if (PL_cv_has_eval || PL_perldb) {
1104 for (cv = PL_compcv ;cv; cv = CvOUTSIDE(cv)) {
1105 if (cv != PL_compcv && CvCOMPILED(cv))
1106 break; /* no need to mark already-compiled code */
1108 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
1109 "Pad clone on cv=0x%"UVxf"\n", PTR2UV(cv)));
1115 /* extend curpad to match namepad */
1116 if (AvFILLp(PL_comppad_name) < AvFILLp(PL_comppad))
1117 av_store(PL_comppad_name, AvFILLp(PL_comppad), Nullsv);
1119 if (type == padtidy_SUBCLONE) {
1120 SV **namep = AvARRAY(PL_comppad_name);
1122 for (ix = AvFILLp(PL_comppad); ix > 0; ix--) {
1125 if (SvIMMORTAL(PL_curpad[ix]) || IS_PADGV(PL_curpad[ix]) || IS_PADCONST(PL_curpad[ix]))
1128 * The only things that a clonable function needs in its
1129 * pad are anonymous subs.
1130 * The rest are created anew during cloning.
1132 if (!((namesv = namep[ix]) != Nullsv &&
1133 namesv != &PL_sv_undef &&
1134 *SvPVX(namesv) == '&'))
1136 SvREFCNT_dec(PL_curpad[ix]);
1137 PL_curpad[ix] = Nullsv;
1141 else if (type == padtidy_SUB) {
1142 /* XXX DAPM this same bit of code keeps appearing !!! Rationalise? */
1143 AV *av = newAV(); /* Will be @_ */
1145 av_store(PL_comppad, 0, (SV*)av);
1146 AvFLAGS(av) = AVf_REIFY;
1149 /* XXX DAPM rationalise these two similar branches */
1151 if (type == padtidy_SUB) {
1152 for (ix = AvFILLp(PL_comppad); ix > 0; ix--) {
1153 if (SvIMMORTAL(PL_curpad[ix]) || IS_PADGV(PL_curpad[ix]) || IS_PADCONST(PL_curpad[ix]))
1155 if (!SvPADMY(PL_curpad[ix]))
1156 SvPADTMP_on(PL_curpad[ix]);
1159 else if (type == padtidy_FORMAT) {
1160 for (ix = AvFILLp(PL_comppad); ix > 0; ix--) {
1161 if (!SvPADMY(PL_curpad[ix]) && !SvIMMORTAL(PL_curpad[ix]))
1162 SvPADTMP_on(PL_curpad[ix]);
1165 PL_curpad = AvARRAY(PL_comppad);
1170 =for apidoc pad_free
1172 Free the SV at offet po in the current pad.
1177 /* XXX DAPM integrate with pad_swipe ???? */
1179 Perl_pad_free(pTHX_ PADOFFSET po)
1181 ASSERT_CURPAD_LEGAL("pad_free");
1184 if (AvARRAY(PL_comppad) != PL_curpad)
1185 Perl_croak(aTHX_ "panic: pad_free curpad");
1187 Perl_croak(aTHX_ "panic: pad_free po");
1189 DEBUG_X(PerlIO_printf(Perl_debug_log,
1190 "Pad 0x%"UVxf"[0x%"UVxf"] free: %ld\n",
1191 PTR2UV(PL_comppad), PTR2UV(PL_curpad), (long)po)
1194 if (PL_curpad[po] && PL_curpad[po] != &PL_sv_undef) {
1195 SvPADTMP_off(PL_curpad[po]);
1197 /* SV could be a shared hash key (eg bugid #19022) */
1199 #ifdef PERL_COPY_ON_WRITE
1200 !SvIsCOW(PL_curpad[po])
1202 !SvFAKE(PL_curpad[po])
1205 SvREADONLY_off(PL_curpad[po]); /* could be a freed constant */
1208 if ((I32)po < PL_padix)
1215 =for apidoc do_dump_pad
1217 Dump the contents of a padlist
1223 Perl_do_dump_pad(pTHX_ I32 level, PerlIO *file, PADLIST *padlist, int full)
1235 pad_name = (AV*)*av_fetch((AV*)padlist, 0, FALSE);
1236 pad = (AV*)*av_fetch((AV*)padlist, 1, FALSE);
1237 pname = AvARRAY(pad_name);
1238 ppad = AvARRAY(pad);
1239 Perl_dump_indent(aTHX_ level, file,
1240 "PADNAME = 0x%"UVxf"(0x%"UVxf") PAD = 0x%"UVxf"(0x%"UVxf")\n",
1241 PTR2UV(pad_name), PTR2UV(pname), PTR2UV(pad), PTR2UV(ppad)
1244 for (ix = 1; ix <= AvFILLp(pad_name); ix++) {
1246 if (namesv && namesv == &PL_sv_undef) {
1251 Perl_dump_indent(aTHX_ level+1, file,
1252 "%2d. 0x%"UVxf"<%lu> FAKE \"%s\" flags=0x%x index=%lu\n",
1255 (unsigned long) (ppad[ix] ? SvREFCNT(ppad[ix]) : 0),
1257 (unsigned long)SvIVX(namesv),
1258 (unsigned long)SvNVX(namesv)
1262 Perl_dump_indent(aTHX_ level+1, file,
1263 "%2d. 0x%"UVxf"<%lu> (%ld,%ld) \"%s\"\n",
1266 (unsigned long) (ppad[ix] ? SvREFCNT(ppad[ix]) : 0),
1267 (long)U_32(SvNVX(namesv)),
1268 (long)SvIVX(namesv),
1273 Perl_dump_indent(aTHX_ level+1, file,
1274 "%2d. 0x%"UVxf"<%lu>\n",
1277 (unsigned long) (ppad[ix] ? SvREFCNT(ppad[ix]) : 0)
1288 dump the contents of a CV
1295 S_cv_dump(pTHX_ CV *cv, char *title)
1297 CV *outside = CvOUTSIDE(cv);
1298 AV* padlist = CvPADLIST(cv);
1300 PerlIO_printf(Perl_debug_log,
1301 " %s: CV=0x%"UVxf" (%s), OUTSIDE=0x%"UVxf" (%s)\n",
1304 (CvANON(cv) ? "ANON"
1305 : (SvTYPE(cv) == SVt_PVFM) ? "FORMAT"
1306 : (cv == PL_main_cv) ? "MAIN"
1307 : CvUNIQUE(cv) ? "UNIQUE"
1308 : CvGV(cv) ? GvNAME(CvGV(cv)) : "UNDEFINED"),
1311 : CvANON(outside) ? "ANON"
1312 : (outside == PL_main_cv) ? "MAIN"
1313 : CvUNIQUE(outside) ? "UNIQUE"
1314 : CvGV(outside) ? GvNAME(CvGV(outside)) : "UNDEFINED"));
1316 PerlIO_printf(Perl_debug_log,
1317 " PADLIST = 0x%"UVxf"\n", PTR2UV(padlist));
1318 do_dump_pad(1, Perl_debug_log, padlist, 1);
1320 #endif /* DEBUGGING */
1327 =for apidoc cv_clone
1329 Clone a CV: make a new CV which points to the same code etc, but which
1330 has a newly-created pad built by copying the prototype pad and capturing
1337 Perl_cv_clone(pTHX_ CV *proto)
1340 AV* protopadlist = CvPADLIST(proto);
1341 AV* protopad_name = (AV*)*av_fetch(protopadlist, 0, FALSE);
1342 AV* protopad = (AV*)*av_fetch(protopadlist, 1, FALSE);
1343 SV** pname = AvARRAY(protopad_name);
1344 SV** ppad = AvARRAY(protopad);
1345 I32 fname = AvFILLp(protopad_name);
1346 I32 fpad = AvFILLp(protopad);
1353 assert(!CvUNIQUE(proto));
1355 /* Since cloneable anon subs can be nested, CvOUTSIDE may point
1356 * to a prototype; we instead want the cloned parent who called us.
1357 * Note that in general for formats, CvOUTSIDE != find_runcv */
1359 outside = CvOUTSIDE(proto);
1360 if (outside && CvCLONE(outside) && ! CvCLONED(outside))
1361 outside = find_runcv(NULL);
1362 depth = CvDEPTH(outside);
1363 assert(depth || SvTYPE(proto) == SVt_PVFM);
1366 assert(CvPADLIST(outside));
1369 SAVESPTR(PL_compcv);
1371 cv = PL_compcv = (CV*)NEWSV(1104, 0);
1372 sv_upgrade((SV *)cv, SvTYPE(proto));
1373 CvFLAGS(cv) = CvFLAGS(proto) & ~(CVf_CLONE|CVf_WEAKOUTSIDE);
1377 CvFILE(cv) = CvXSUB(proto) ? CvFILE(proto)
1378 : savepv(CvFILE(proto));
1380 CvFILE(cv) = CvFILE(proto);
1382 CvGV(cv) = CvGV(proto);
1383 CvSTASH(cv) = CvSTASH(proto);
1384 CvROOT(cv) = OpREFCNT_inc(CvROOT(proto));
1385 CvSTART(cv) = CvSTART(proto);
1386 CvOUTSIDE(cv) = (CV*)SvREFCNT_inc(outside);
1387 CvOUTSIDE_SEQ(cv) = CvOUTSIDE_SEQ(proto);
1390 sv_setpvn((SV*)cv, SvPVX(proto), SvCUR(proto));
1392 CvPADLIST(cv) = comppadlist = pad_new(padnew_CLONE|padnew_SAVE);
1394 av_fill(PL_comppad, fpad);
1395 for (ix = fname; ix >= 0; ix--)
1396 av_store(PL_comppad_name, ix, SvREFCNT_inc(pname[ix]));
1398 PL_curpad = AvARRAY(PL_comppad);
1400 outpad = AvARRAY(AvARRAY(CvPADLIST(outside))[depth]);
1402 for (ix = fpad; ix > 0; ix--) {
1403 SV* namesv = (ix <= fname) ? pname[ix] : Nullsv;
1405 if (namesv && namesv != &PL_sv_undef) { /* lexical */
1406 if (SvFAKE(namesv)) { /* lexical from outside? */
1407 sv = outpad[(I32)SvNVX(namesv)];
1409 /* formats may have an inactive parent */
1410 if (SvTYPE(proto) == SVt_PVFM && SvPADSTALE(sv)) {
1411 if (ckWARN(WARN_CLOSURE))
1412 Perl_warner(aTHX_ packWARN(WARN_CLOSURE),
1413 "Variable \"%s\" is not available", SvPVX(namesv));
1417 assert(!SvPADSTALE(sv));
1418 sv = SvREFCNT_inc(sv);
1422 char *name = SvPVX(namesv);
1424 sv = SvREFCNT_inc(ppad[ix]);
1425 else if (*name == '@')
1427 else if (*name == '%')
1434 else if (IS_PADGV(ppad[ix]) || IS_PADCONST(ppad[ix])) {
1435 sv = SvREFCNT_inc(ppad[ix]);
1445 PerlIO_printf(Perl_debug_log, "\nPad CV clone\n");
1446 cv_dump(outside, "Outside");
1447 cv_dump(proto, "Proto");
1454 /* Constant sub () { $x } closing over $x - see lib/constant.pm:
1455 * The prototype was marked as a candiate for const-ization,
1456 * so try to grab the current const value, and if successful,
1457 * turn into a const sub:
1459 SV* const_sv = op_const_sv(CvSTART(cv), cv);
1462 cv = newCONSTSUB(CvSTASH(proto), 0, const_sv);
1474 =for apidoc pad_fixup_inner_anons
1476 For any anon CVs in the pad, change CvOUTSIDE of that CV from
1477 old_cv to new_cv if necessary. Needed when a newly-compiled CV has to be
1478 moved to a pre-existing CV struct.
1484 Perl_pad_fixup_inner_anons(pTHX_ PADLIST *padlist, CV *old_cv, CV *new_cv)
1487 AV *comppad_name = (AV*)AvARRAY(padlist)[0];
1488 AV *comppad = (AV*)AvARRAY(padlist)[1];
1489 SV **namepad = AvARRAY(comppad_name);
1490 SV **curpad = AvARRAY(comppad);
1491 for (ix = AvFILLp(comppad_name); ix > 0; ix--) {
1492 SV *namesv = namepad[ix];
1493 if (namesv && namesv != &PL_sv_undef
1494 && *SvPVX(namesv) == '&')
1496 CV *innercv = (CV*)curpad[ix];
1497 assert(CvWEAKOUTSIDE(innercv));
1498 assert(CvOUTSIDE(innercv) == old_cv);
1499 CvOUTSIDE(innercv) = new_cv;
1506 =for apidoc pad_push
1508 Push a new pad frame onto the padlist, unless there's already a pad at
1509 this depth, in which case don't bother creating a new one.
1510 If has_args is true, give the new pad an @_ in slot zero.
1516 Perl_pad_push(pTHX_ PADLIST *padlist, int depth, int has_args)
1518 if (depth <= AvFILLp(padlist))
1522 SV** svp = AvARRAY(padlist);
1523 AV *newpad = newAV();
1524 SV **oldpad = AvARRAY(svp[depth-1]);
1525 I32 ix = AvFILLp((AV*)svp[1]);
1526 I32 names_fill = AvFILLp((AV*)svp[0]);
1527 SV** names = AvARRAY(svp[0]);
1529 for ( ;ix > 0; ix--) {
1530 if (names_fill >= ix && names[ix] != &PL_sv_undef) {
1531 char *name = SvPVX(names[ix]);
1532 if ((SvFLAGS(names[ix]) & SVf_FAKE) || *name == '&') {
1533 /* outer lexical or anon code */
1534 av_store(newpad, ix, SvREFCNT_inc(oldpad[ix]));
1536 else { /* our own lexical */
1538 av_store(newpad, ix, sv = (SV*)newAV());
1539 else if (*name == '%')
1540 av_store(newpad, ix, sv = (SV*)newHV());
1542 av_store(newpad, ix, sv = NEWSV(0, 0));
1546 else if (IS_PADGV(oldpad[ix]) || IS_PADCONST(oldpad[ix])) {
1547 av_store(newpad, ix, sv = SvREFCNT_inc(oldpad[ix]));
1550 /* save temporaries on recursion? */
1551 av_store(newpad, ix, sv = NEWSV(0, 0));
1558 av_store(newpad, 0, (SV*)av);
1559 AvFLAGS(av) = AVf_REIFY;
1561 av_store(padlist, depth, (SV*)newpad);
1562 AvFILLp(padlist) = depth;