xref: /openbsd/gnu/usr.bin/perl/pad.c (revision 3d61058a)
1 /*    pad.c
2  *
3  *    Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008
4  *    by Larry Wall and others
5  *
6  *    You may distribute under the terms of either the GNU General Public
7  *    License or the Artistic License, as specified in the README file.
8  */
9 
10 /*
11  *  'Anyway: there was this Mr. Frodo left an orphan and stranded, as you
12  *   might say, among those queer Bucklanders, being brought up anyhow in
13  *   Brandy Hall.  A regular warren, by all accounts.  Old Master Gorbadoc
14  *   never had fewer than a couple of hundred relations in the place.
15  *   Mr. Bilbo never did a kinder deed than when he brought the lad back
16  *   to live among decent folk.'                           --the Gaffer
17  *
18  *     [p.23 of _The Lord of the Rings_, I/i: "A Long-Expected Party"]
19  */
20 
21 /*
22 =for apidoc_section $pad
23 
24 =for apidoc Amx|PADLIST *|CvPADLIST|CV *cv
25 
26 CV's can have CvPADLIST(cv) set to point to a PADLIST.  This is the CV's
27 scratchpad, which stores lexical variables and opcode temporary and
28 per-thread values.
29 
30 For these purposes "formats" are a kind-of CV; eval""s are too (except they're
31 not callable at will and are always thrown away after the eval"" is done
32 executing).  Require'd files are simply evals without any outer lexical
33 scope.
34 
35 XSUBs do not have a C<CvPADLIST>.  C<dXSTARG> fetches values from C<PL_curpad>,
36 but that is really the callers pad (a slot of which is allocated by
37 every entersub). Do not get or set C<CvPADLIST> if a CV is an XSUB (as
38 determined by C<CvISXSUB()>), C<CvPADLIST> slot is reused for a different
39 internal purpose in XSUBs.
40 
41 The PADLIST has a C array where pads are stored.
42 
43 The 0th entry of the PADLIST is a PADNAMELIST
44 which represents the "names" or rather
45 the "static type information" for lexicals.  The individual elements of a
46 PADNAMELIST are PADNAMEs.  Future
47 refactorings might stop the PADNAMELIST from being stored in the PADLIST's
48 array, so don't rely on it.  See L</PadlistNAMES>.
49 
50 The CvDEPTH'th entry of a PADLIST is a PAD (an AV) which is the stack frame
51 at that depth of recursion into the CV.  The 0th slot of a frame AV is an
52 AV which is C<@_>.  Other entries are storage for variables and op targets.
53 
54 Iterating over the PADNAMELIST iterates over all possible pad
55 items.  Pad slots for targets (C<SVs_PADTMP>)
56 and GVs end up having &PL_padname_undef "names", while slots for constants
57 have C<&PL_padname_const> "names" (see C<L</pad_alloc>>).  That
58 C<&PL_padname_undef>
59 and C<&PL_padname_const> are used is an implementation detail subject to
60 change.  To test for them, use C<!PadnamePV(name)> and
61 S<C<PadnamePV(name) && !PadnameLEN(name)>>, respectively.
62 
63 Only C<my>/C<our> variable slots get valid names.
64 The rest are op targets/GVs/constants which are statically allocated
65 or resolved at compile time.  These don't have names by which they
66 can be looked up from Perl code at run time through eval"" the way
67 C<my>/C<our> variables can be.  Since they can't be looked up by "name"
68 but only by their index allocated at compile time (which is usually
69 in C<< PL_op->op_targ >>), wasting a name SV for them doesn't make sense.
70 
71 The pad names in the PADNAMELIST have their PV holding the name of
72 the variable.  The C<COP_SEQ_RANGE_LOW> and C<_HIGH> fields form a range
73 (low+1..high inclusive) of cop_seq numbers for which the name is
74 valid.  During compilation, these fields may hold the special value
75 PERL_PADSEQ_INTRO to indicate various stages:
76 
77  COP_SEQ_RANGE_LOW        _HIGH
78  -----------------        -----
79  PERL_PADSEQ_INTRO            0   variable not yet introduced:
80                                   { my ($x
81  valid-seq#   PERL_PADSEQ_INTRO   variable in scope:
82                                   { my ($x);
83  valid-seq#          valid-seq#   compilation of scope complete:
84                                   { my ($x); .... }
85 
86 When a lexical var hasn't yet been introduced, it already exists from the
87 perspective of duplicate declarations, but not for variable lookups, e.g.
88 
89     my ($x, $x); # '"my" variable $x masks earlier declaration'
90     my $x = $x;  # equal to my $x = $::x;
91 
92 For typed lexicals C<PadnameTYPE> points at the type stash.  For C<our>
93 lexicals, C<PadnameOURSTASH> points at the stash of the associated global (so
94 that duplicate C<our> declarations in the same package can be detected).
95 C<PadnameGEN> is sometimes used to store the generation number during
96 compilation.
97 
98 If C<PadnameOUTER> is set on the pad name, then that slot in the frame AV
99 is a REFCNT'ed reference to a lexical from "outside".  Such entries
100 are sometimes referred to as 'fake'.  In this case, the name does not
101 use 'low' and 'high' to store a cop_seq range, since it is in scope
102 throughout.  Instead 'high' stores some flags containing info about
103 the real lexical (is it declared in an anon, and is it capable of being
104 instantiated multiple times?), and for fake ANONs, 'low' contains the index
105 within the parent's pad where the lexical's value is stored, to make
106 cloning quicker.
107 
108 If the 'name' is C<&> the corresponding entry in the PAD
109 is a CV representing a possible closure.
110 
111 Note that formats are treated as anon subs, and are cloned each time
112 write is called (if necessary).
113 
114 The flag C<SVs_PADSTALE> is cleared on lexicals each time the C<my()> is executed,
115 and set on scope exit.  This allows the
116 C<"Variable $x is not available"> warning
117 to be generated in evals, such as
118 
119     { my $x = 1; sub f { eval '$x'} } f();
120 
121 For state vars, C<SVs_PADSTALE> is overloaded to mean 'not yet initialised',
122 but this internal state is stored in a separate pad entry.
123 
124 =for apidoc Amnh||SVs_PADSTALE
125 
126 =for apidoc AmnxU|PADNAMELIST *|PL_comppad_name
127 
128 During compilation, this points to the array containing the names part
129 of the pad for the currently-compiling code.
130 
131 =for apidoc AmnxU|PAD *|PL_comppad
132 
133 During compilation, this points to the array containing the values
134 part of the pad for the currently-compiling code.  (At runtime a CV may
135 have many such value arrays; at compile time just one is constructed.)
136 At runtime, this points to the array containing the currently-relevant
137 values for the pad for the currently-executing code.
138 
139 =for apidoc AmnxU|SV **|PL_curpad
140 
141 Points directly to the body of the L</PL_comppad> array.
142 (I.e., this is C<PadARRAY(PL_comppad)>.)
143 
144 =cut
145 */
146 
147 
148 #include "EXTERN.h"
149 #define PERL_IN_PAD_C
150 #include "perl.h"
151 #include "keywords.h"
152 
153 #define COP_SEQ_RANGE_LOW_set(sv,val)		\
154   STMT_START { (sv)->xpadn_low = (val); } STMT_END
155 #define COP_SEQ_RANGE_HIGH_set(sv,val)		\
156   STMT_START { (sv)->xpadn_high = (val); } STMT_END
157 
158 #define PARENT_PAD_INDEX_set		COP_SEQ_RANGE_LOW_set
159 #define PARENT_FAKELEX_FLAGS_set	COP_SEQ_RANGE_HIGH_set
160 
161 #ifdef DEBUGGING
162 void
Perl_set_padlist(CV * cv,PADLIST * padlist)163 Perl_set_padlist(CV * cv, PADLIST *padlist){
164     PERL_ARGS_ASSERT_SET_PADLIST;
165 #  if PTRSIZE == 8
166     assert((Size_t)padlist != UINT64_C(0xEFEFEFEFEFEFEFEF));
167 #  elif PTRSIZE == 4
168     assert((Size_t)padlist != 0xEFEFEFEF);
169 #  else
170 #    error unknown pointer size
171 #  endif
172     assert(!CvISXSUB(cv));
173     ((XPVCV*)MUTABLE_PTR(SvANY(cv)))->xcv_padlist_u.xcv_padlist = padlist;
174 }
175 #endif
176 
177 /*
178 =for apidoc pad_new
179 
180 Create a new padlist, updating the global variables for the
181 currently-compiling padlist to point to the new padlist.  The following
182 flags can be OR'ed together:
183 
184     padnew_CLONE	this pad is for a cloned CV
185     padnew_SAVE		save old globals on the save stack
186     padnew_SAVESUB	also save extra stuff for start of sub
187 
188 =cut
189 */
190 
191 PADLIST *
Perl_pad_new(pTHX_ int flags)192 Perl_pad_new(pTHX_ int flags)
193 {
194     PADLIST *padlist;
195     PADNAMELIST *padname;
196     PAD *pad;
197     PAD **ary;
198 
199     ASSERT_CURPAD_LEGAL("pad_new");
200 
201     /* save existing state, ... */
202 
203     if (flags & padnew_SAVE) {
204         SAVECOMPPAD();
205         if (! (flags & padnew_CLONE)) {
206             SAVESPTR(PL_comppad_name);
207             SAVESTRLEN(PL_padix);
208             SAVESTRLEN(PL_constpadix);
209             SAVESTRLEN(PL_comppad_name_fill);
210             SAVESTRLEN(PL_min_intro_pending);
211             SAVESTRLEN(PL_max_intro_pending);
212             SAVEBOOL(PL_cv_has_eval);
213             if (flags & padnew_SAVESUB) {
214                 SAVEBOOL(PL_pad_reset_pending);
215             }
216         }
217     }
218 
219     /* ... create new pad ... */
220 
221     Newxz(padlist, 1, PADLIST);
222     pad		= newAV();
223     Newxz(AvALLOC(pad), 4, SV *); /* Originally sized to
224                                      match av_extend default */
225     AvARRAY(pad) = AvALLOC(pad);
226     AvMAX(pad) = 3;
227     AvFILLp(pad) = 0; /* @_ or NULL, set below. */
228 
229     if (flags & padnew_CLONE) {
230         AV * const a0 = newAV();			/* will be @_ */
231         AvARRAY(pad)[0] = MUTABLE_SV(a0);
232 #ifndef PERL_RC_STACK
233         AvREIFY_only(a0);
234 #endif
235 
236         PadnamelistREFCNT(padname = PL_comppad_name)++;
237     }
238     else {
239         padlist->xpadl_id = PL_padlist_generation++;
240         /* Set implicitly through use of Newxz above
241             AvARRAY(pad)[0] = NULL;
242         */
243         padname = newPADNAMELIST(0);
244         padnamelist_store(padname, 0, &PL_padname_undef);
245     }
246 
247     /* Most subroutines never recurse, hence only need 2 entries in the padlist
248        array - names, and depth=1.  The default for av_store() is to allocate
249        0..3, and even an explicit call to av_extend() with <3 will be rounded
250        up, so we inline the allocation of the array here.  */
251     Newx(ary, 2, PAD *);
252     PadlistMAX(padlist) = 1;
253     PadlistARRAY(padlist) = ary;
254     ary[0] = (PAD *)padname;
255     ary[1] = pad;
256 
257     /* ... then update state variables */
258 
259     PL_comppad		= pad;
260     PL_curpad		= AvARRAY(pad);
261 
262     if (! (flags & padnew_CLONE)) {
263         PL_comppad_name	     = padname;
264         PL_comppad_name_fill = 0;
265         PL_min_intro_pending = 0;
266         PL_padix	     = 0;
267         PL_constpadix	     = 0;
268         PL_cv_has_eval	     = 0;
269     }
270 
271     DEBUG_X(PerlIO_printf(Perl_debug_log,
272           "Pad 0x%" UVxf "[0x%" UVxf "] new:       compcv=0x%" UVxf
273               " name=0x%" UVxf " flags=0x%" UVxf "\n",
274           PTR2UV(PL_comppad), PTR2UV(PL_curpad), PTR2UV(PL_compcv),
275               PTR2UV(padname), (UV)flags
276         )
277     );
278 
279     return (PADLIST*)padlist;
280 }
281 
282 
283 /*
284 =for apidoc_section $embedding
285 
286 =for apidoc cv_undef
287 
288 Clear out all the active components of a CV.  This can happen either
289 by an explicit C<undef &foo>, or by the reference count going to zero.
290 In the former case, we keep the C<CvOUTSIDE> pointer, so that any anonymous
291 children can still follow the full lexical scope chain.
292 
293 =cut
294 */
295 
296 void
Perl_cv_undef(pTHX_ CV * cv)297 Perl_cv_undef(pTHX_ CV *cv)
298 {
299     PERL_ARGS_ASSERT_CV_UNDEF;
300     cv_undef_flags(cv, 0);
301 }
302 
303 void
Perl_cv_undef_flags(pTHX_ CV * cv,U32 flags)304 Perl_cv_undef_flags(pTHX_ CV *cv, U32 flags)
305 {
306     CV cvbody;/*CV body will never be realloced inside this func,
307                so don't read it more than once, use fake CV so existing macros
308                will work, the indirection and CV head struct optimized away*/
309     SvANY(&cvbody) = SvANY(cv);
310 
311     PERL_ARGS_ASSERT_CV_UNDEF_FLAGS;
312 
313     DEBUG_X(PerlIO_printf(Perl_debug_log,
314           "CV undef: cv=0x%" UVxf " comppad=0x%" UVxf "\n",
315             PTR2UV(cv), PTR2UV(PL_comppad))
316     );
317 
318     if (CvFILE(&cvbody)) {
319         char * file = CvFILE(&cvbody);
320         CvFILE(&cvbody) = NULL;
321         if(CvDYNFILE(&cvbody))
322             Safefree(file);
323     }
324 
325     /* CvSLABBED_off(&cvbody); *//* turned off below */
326     /* release the sub's body */
327     if (!CvISXSUB(&cvbody)) {
328         if(CvROOT(&cvbody)) {
329             assert(SvTYPE(cv) == SVt_PVCV || SvTYPE(cv) == SVt_PVFM); /*unsafe is safe */
330             if (CvDEPTHunsafe(&cvbody)) {
331                 assert(SvTYPE(cv) == SVt_PVCV);
332                 Perl_croak_nocontext("Can't undef active subroutine");
333             }
334             ENTER;
335 
336             PAD_SAVE_SETNULLPAD();
337 
338             if (CvSLABBED(&cvbody)) OpslabREFCNT_dec_padok(OpSLAB(CvROOT(&cvbody)));
339             op_free(CvROOT(&cvbody));
340             CvROOT(&cvbody) = NULL;
341             CvSTART(&cvbody) = NULL;
342             LEAVE;
343         }
344         else if (CvSLABBED(&cvbody)) {
345             if( CvSTART(&cvbody)) {
346                 ENTER;
347                 PAD_SAVE_SETNULLPAD();
348 
349                 /* discard any leaked ops */
350                 if (PL_parser)
351                     parser_free_nexttoke_ops(PL_parser, (OPSLAB *)CvSTART(&cvbody));
352                 opslab_force_free((OPSLAB *)CvSTART(&cvbody));
353                 CvSTART(&cvbody) = NULL;
354 
355                 LEAVE;
356             }
357 #ifdef DEBUGGING
358             else Perl_warn(aTHX_ "Slab leaked from cv %p", (void*)cv);
359 #endif
360         }
361     }
362     else { /* don't bother checking if CvXSUB(cv) is true, less branching */
363         CvXSUB(&cvbody) = NULL;
364     }
365     SvPOK_off(MUTABLE_SV(cv));		/* forget prototype */
366     sv_unmagic((SV *)cv, PERL_MAGIC_checkcall);
367     if (!(flags & CV_UNDEF_KEEP_NAME)) {
368         if (CvNAMED(&cvbody)) {
369             CvNAME_HEK_set(&cvbody, NULL);
370             CvNAMED_off(&cvbody);
371         }
372         else CvGV_set(cv, NULL);
373     }
374 
375     /* This 'if' block used to be a separate function, pad_undef().  */
376     if (!CvISXSUB(&cvbody) && CvPADLIST(&cvbody)) {
377         PADOFFSET ix;
378         const PADLIST *padlist = CvPADLIST(&cvbody);
379 
380         /* Free the padlist associated with a CV.
381            If parts of it happen to be current, we null the relevant PL_*pad*
382            global vars so that we don't have any dangling references left.
383            We also repoint the CvOUTSIDE of any about-to-be-orphaned inner
384            subs to the outer of this cv.  */
385 
386         DEBUG_X(PerlIO_printf(Perl_debug_log,
387                               "Pad undef: cv=0x%" UVxf " padlist=0x%" UVxf " comppad=0x%" UVxf "\n",
388                               PTR2UV(cv), PTR2UV(padlist), PTR2UV(PL_comppad))
389                 );
390 
391         /* detach any '&' anon children in the pad; if afterwards they
392          * are still live, fix up their CvOUTSIDEs to point to our outside,
393          * bypassing us. */
394 
395         if (PL_phase != PERL_PHASE_DESTRUCT) { /* don't bother during global destruction */
396             CV * const outercv = CvOUTSIDE(&cvbody);
397             const U32 seq = CvOUTSIDE_SEQ(&cvbody);
398             PADNAMELIST * const comppad_name = PadlistNAMES(padlist);
399             PADNAME ** const namepad = PadnamelistARRAY(comppad_name);
400             PAD * const comppad = PadlistARRAY(padlist)[1];
401             SV ** const curpad = AvARRAY(comppad);
402             for (ix = PadnamelistMAX(comppad_name); ix > 0; ix--) {
403                 PADNAME * const name = namepad[ix];
404                 if (name && PadnamePV(name) && *PadnamePV(name) == '&') {
405                     CV * const innercv = MUTABLE_CV(curpad[ix]);
406                     if (PadnameIsOUR(name) && CvCLONED(&cvbody)) {
407                         assert(!innercv);
408                     }
409                     else {
410                         U32 inner_rc;
411                         assert(innercv);
412                         assert(SvTYPE(innercv) != SVt_PVFM);
413                         inner_rc = SvREFCNT(innercv);
414                         assert(inner_rc);
415 
416                         if (SvREFCNT(comppad) < 2) { /* allow for /(?{ sub{} })/  */
417                             curpad[ix] = NULL;
418                             SvREFCNT_dec_NN(innercv);
419                             inner_rc--;
420                         }
421 
422                         /* in use, not just a prototype */
423                         if (inner_rc && SvTYPE(innercv) == SVt_PVCV
424                          && (CvOUTSIDE(innercv) == cv))
425                         {
426                             assert(CvWEAKOUTSIDE(innercv));
427                             /* don't relink to grandfather if he's being freed */
428                             if (outercv && SvREFCNT(outercv)) {
429                                 CvWEAKOUTSIDE_off(innercv);
430                                 CvOUTSIDE(innercv) = outercv;
431                                 CvOUTSIDE_SEQ(innercv) = seq;
432                                 SvREFCNT_inc_simple_void_NN(outercv);
433                             }
434                             else {
435                                 CvOUTSIDE(innercv) = NULL;
436                             }
437                         }
438                     }
439                 }
440             }
441         }
442 
443         ix = PadlistMAX(padlist);
444         while (ix > 0) {
445             PAD * const sv = PadlistARRAY(padlist)[ix--];
446             if (sv) {
447                 if (sv == PL_comppad) {
448                     PL_comppad = NULL;
449                     PL_curpad = NULL;
450                 }
451                 SvREFCNT_dec_NN(sv);
452             }
453         }
454         {
455             PADNAMELIST * const names = PadlistNAMES(padlist);
456             if (names == PL_comppad_name && PadnamelistREFCNT(names) == 1)
457                 PL_comppad_name = NULL;
458             PadnamelistREFCNT_dec(names);
459         }
460         if (PadlistARRAY(padlist)) Safefree(PadlistARRAY(padlist));
461         Safefree(padlist);
462         CvPADLIST_set(&cvbody, NULL);
463     }
464     else if (CvISXSUB(&cvbody)) {
465         if (CvREFCOUNTED_ANYSV(&cvbody))
466             SvREFCNT_dec(CvXSUBANY(&cvbody).any_sv);
467         CvHSCXT(&cvbody) = NULL;
468     }
469     /* else is (!CvISXSUB(&cvbody) && !CvPADLIST(&cvbody)) {do nothing;} */
470 
471 
472     /* remove CvOUTSIDE unless this is an undef rather than a free */
473     if (!SvREFCNT(cv)) {
474         CV * outside = CvOUTSIDE(&cvbody);
475         if(outside) {
476             CvOUTSIDE(&cvbody) = NULL;
477             if (!CvWEAKOUTSIDE(&cvbody))
478                 SvREFCNT_dec_NN(outside);
479         }
480     }
481     if (CvCONST(&cvbody)) {
482         SvREFCNT_dec(MUTABLE_SV(CvXSUBANY(&cvbody).any_ptr));
483         /* CvCONST_off(cv); *//* turned off below */
484     }
485     /* delete all flags except WEAKOUTSIDE and CVGV_RC, which indicate the
486      * ref status of CvOUTSIDE and CvGV, and ANON, NAMED and
487      * LEXICAL, which are used to determine the sub's name.  */
488     CvFLAGS(&cvbody) &= (CVf_WEAKOUTSIDE|CVf_CVGV_RC|CVf_ANON|CVf_LEXICAL
489                    |CVf_NAMED);
490 }
491 
492 /*
493 =for apidoc cv_forget_slab
494 
495 When a CV has a reference count on its slab (C<CvSLABBED>), it is responsible
496 for making sure it is freed.  (Hence, no two CVs should ever have a
497 reference count on the same slab.)  The CV only needs to reference the slab
498 during compilation.  Once it is compiled and C<CvROOT> attached, it has
499 finished its job, so it can forget the slab.
500 
501 =cut
502 */
503 
504 void
Perl_cv_forget_slab(pTHX_ CV * cv)505 Perl_cv_forget_slab(pTHX_ CV *cv)
506 {
507     bool slabbed;
508     OPSLAB *slab = NULL;
509 
510     if (!cv)
511         return;
512     slabbed = cBOOL(CvSLABBED(cv));
513     if (!slabbed) return;
514 
515     CvSLABBED_off(cv);
516 
517     if      (CvROOT(cv))  slab = OpSLAB(CvROOT(cv));
518     else if (CvSTART(cv)) slab = (OPSLAB *)CvSTART(cv);
519 #ifdef DEBUGGING
520     else if (slabbed)     Perl_warn(aTHX_ "Slab leaked from cv %p", (void*)cv);
521 #endif
522 
523     if (slab) {
524 #ifdef PERL_DEBUG_READONLY_OPS
525         const size_t refcnt = slab->opslab_refcnt;
526 #endif
527         OpslabREFCNT_dec(slab);
528 #ifdef PERL_DEBUG_READONLY_OPS
529         if (refcnt > 1) Slab_to_ro(slab);
530 #endif
531     }
532 }
533 
534 /*
535 =for apidoc pad_alloc_name
536 
537 Allocates a place in the currently-compiling
538 pad (via L<perlapi/pad_alloc>) and
539 then stores a name for that entry.  C<name> is adopted and
540 becomes the name entry; it must already contain the name
541 string.  C<typestash> and C<ourstash> and the C<padadd_STATE>
542 flag gets added to C<name>.
543 None of the other processing of L<perlapi/pad_add_name_pvn>
544 is done.  Returns the offset of the allocated pad slot.
545 
546 =cut
547 */
548 
549 static PADOFFSET
S_pad_alloc_name(pTHX_ PADNAME * name,U32 flags,HV * typestash,HV * ourstash)550 S_pad_alloc_name(pTHX_ PADNAME *name, U32 flags, HV *typestash,
551                        HV *ourstash)
552 {
553     const PADOFFSET offset = pad_alloc(OP_PADSV, SVs_PADMY);
554 
555     PERL_ARGS_ASSERT_PAD_ALLOC_NAME;
556 
557     ASSERT_CURPAD_ACTIVE("pad_alloc_name");
558 
559     if (typestash) {
560         PadnameFLAGS(name) |= PADNAMEf_TYPED;
561         PadnameTYPE(name) =
562             MUTABLE_HV(SvREFCNT_inc_simple_NN(MUTABLE_SV(typestash)));
563     }
564     if (ourstash) {
565         PadnameFLAGS(name) |= PADNAMEf_OUR;
566         PadnameOURSTASH_set(name, ourstash);
567         SvREFCNT_inc_simple_void_NN(ourstash);
568     }
569     else if (flags & padadd_STATE) {
570         PadnameFLAGS(name) |= PADNAMEf_STATE;
571     }
572     if (flags & padadd_FIELD) {
573         assert(HvSTASH_IS_CLASS(PL_curstash));
574         class_add_field(PL_curstash, name);
575     }
576 
577     padnamelist_store(PL_comppad_name, offset, name);
578     if (PadnameLEN(name) > 1)
579         PadnamelistMAXNAMED(PL_comppad_name) = offset;
580     return offset;
581 }
582 
583 /*
584 =for apidoc pad_add_name_pvn
585 
586 Allocates a place in the currently-compiling pad for a named lexical
587 variable.  Stores the name and other metadata in the name part of the
588 pad, and makes preparations to manage the variable's lexical scoping.
589 Returns the offset of the allocated pad slot.
590 
591 C<namepv>/C<namelen> specify the variable's name in UTF-8, including
592 leading sigil.
593 If C<typestash> is non-null, the name is for a typed lexical, and this
594 identifies the type.  If C<ourstash> is non-null, it's a lexical reference
595 to a package variable, and this identifies the package.  The following
596 flags can be OR'ed together:
597 
598  padadd_OUR          redundantly specifies if it's a package var
599  padadd_STATE        variable will retain value persistently
600  padadd_NO_DUP_CHECK skip check for lexical shadowing
601  padadd_FIELD        specifies that the lexical is a field for a class
602 
603 =cut
604 */
605 
606 PADOFFSET
Perl_pad_add_name_pvn(pTHX_ const char * namepv,STRLEN namelen,U32 flags,HV * typestash,HV * ourstash)607 Perl_pad_add_name_pvn(pTHX_ const char *namepv, STRLEN namelen,
608                 U32 flags, HV *typestash, HV *ourstash)
609 {
610     PADOFFSET offset;
611     PADNAME *name;
612 
613     PERL_ARGS_ASSERT_PAD_ADD_NAME_PVN;
614 
615     if (flags & ~(padadd_OUR|padadd_STATE|padadd_NO_DUP_CHECK|padadd_FIELD))
616         Perl_croak(aTHX_ "panic: pad_add_name_pvn illegal flag bits 0x%" UVxf,
617                    (UV)flags);
618 
619     name = newPADNAMEpvn(namepv, namelen);
620 
621     if ((flags & (padadd_NO_DUP_CHECK)) == 0) {
622         ENTER;
623         SAVEFREEPADNAME(name); /* in case of fatal warnings */
624         /* check for duplicate declaration */
625         pad_check_dup(name, flags & (padadd_OUR|padadd_FIELD), ourstash);
626         PadnameREFCNT_inc(name);
627         LEAVE;
628     }
629 
630     offset = pad_alloc_name(name, flags, typestash, ourstash);
631 
632     /* not yet introduced */
633     COP_SEQ_RANGE_LOW_set(name, PERL_PADSEQ_INTRO);
634     COP_SEQ_RANGE_HIGH_set(name, 0);
635 
636     if (!PL_min_intro_pending)
637         PL_min_intro_pending = offset;
638     PL_max_intro_pending = offset;
639     /* if it's not a simple scalar, replace with an AV or HV */
640     assert(SvTYPE(PL_curpad[offset]) == SVt_NULL);
641     assert(SvREFCNT(PL_curpad[offset]) == 1);
642     if (namelen != 0 && *namepv == '@')
643         sv_upgrade(PL_curpad[offset], SVt_PVAV);
644     else if (namelen != 0 && *namepv == '%')
645         sv_upgrade(PL_curpad[offset], SVt_PVHV);
646     else if (namelen != 0 && *namepv == '&')
647         sv_upgrade(PL_curpad[offset], SVt_PVCV);
648     assert(SvPADMY(PL_curpad[offset]));
649     DEBUG_Xv(PerlIO_printf(Perl_debug_log,
650                            "Pad addname: %ld \"%s\" new lex=0x%" UVxf "\n",
651                            (long)offset, PadnamePV(name),
652                            PTR2UV(PL_curpad[offset])));
653 
654     return offset;
655 }
656 
657 /*
658 =for apidoc pad_add_name_pv
659 
660 Exactly like L</pad_add_name_pvn>, but takes a nul-terminated string
661 instead of a string/length pair.
662 
663 =cut
664 */
665 
666 PADOFFSET
Perl_pad_add_name_pv(pTHX_ const char * name,const U32 flags,HV * typestash,HV * ourstash)667 Perl_pad_add_name_pv(pTHX_ const char *name,
668                      const U32 flags, HV *typestash, HV *ourstash)
669 {
670     PERL_ARGS_ASSERT_PAD_ADD_NAME_PV;
671     return pad_add_name_pvn(name, strlen(name), flags, typestash, ourstash);
672 }
673 
674 /*
675 =for apidoc pad_add_name_sv
676 
677 Exactly like L</pad_add_name_pvn>, but takes the name string in the form
678 of an SV instead of a string/length pair.
679 
680 =cut
681 */
682 
683 PADOFFSET
Perl_pad_add_name_sv(pTHX_ SV * name,U32 flags,HV * typestash,HV * ourstash)684 Perl_pad_add_name_sv(pTHX_ SV *name, U32 flags, HV *typestash, HV *ourstash)
685 {
686     char *namepv;
687     STRLEN namelen;
688     PERL_ARGS_ASSERT_PAD_ADD_NAME_SV;
689     namepv = SvPVutf8(name, namelen);
690     return pad_add_name_pvn(namepv, namelen, flags, typestash, ourstash);
691 }
692 
693 /*
694 =for apidoc pad_alloc
695 
696 Allocates a place in the currently-compiling pad,
697 returning the offset of the allocated pad slot.
698 No name is initially attached to the pad slot.
699 C<tmptype> is a set of flags indicating the kind of pad entry required,
700 which will be set in the value SV for the allocated pad entry:
701 
702     SVs_PADMY    named lexical variable ("my", "our", "state")
703     SVs_PADTMP   unnamed temporary store
704     SVf_READONLY constant shared between recursion levels
705 
706 C<SVf_READONLY> has been supported here only since perl 5.20.  To work with
707 earlier versions as well, use C<SVf_READONLY|SVs_PADTMP>.  C<SVf_READONLY>
708 does not cause the SV in the pad slot to be marked read-only, but simply
709 tells C<pad_alloc> that it I<will> be made read-only (by the caller), or at
710 least should be treated as such.
711 
712 C<optype> should be an opcode indicating the type of operation that the
713 pad entry is to support.  This doesn't affect operational semantics,
714 but is used for debugging.
715 
716 =cut
717 */
718 
719 PADOFFSET
Perl_pad_alloc(pTHX_ I32 optype,U32 tmptype)720 Perl_pad_alloc(pTHX_ I32 optype, U32 tmptype)
721 {
722     SV *sv;
723     PADOFFSET retval;
724 
725     PERL_UNUSED_ARG(optype);
726     ASSERT_CURPAD_ACTIVE("pad_alloc");
727 
728     if (AvARRAY(PL_comppad) != PL_curpad)
729         Perl_croak(aTHX_ "panic: pad_alloc, %p!=%p",
730                    AvARRAY(PL_comppad), PL_curpad);
731     if (PL_pad_reset_pending)
732         pad_reset();
733     if (tmptype == SVs_PADMY) { /* Not & because this ‘flag’ is 0.  */
734         /* For a my, simply push a null SV onto the end of PL_comppad. */
735         sv = *av_store_simple(PL_comppad, AvFILLp(PL_comppad) + 1, newSV_type(SVt_NULL));
736         retval = (PADOFFSET)AvFILLp(PL_comppad);
737     }
738     else {
739         /* For a tmp, scan the pad from PL_padix upwards
740          * for a slot which has no name and no active value.
741          * For a constant, likewise, but use PL_constpadix.
742          */
743         PADNAME * const * const names = PadnamelistARRAY(PL_comppad_name);
744         const SSize_t names_fill = PadnamelistMAX(PL_comppad_name);
745         const bool konst = cBOOL(tmptype & SVf_READONLY);
746         retval = konst ? PL_constpadix : PL_padix;
747         for (;;) {
748             /*
749              * Entries that close over unavailable variables
750              * in outer subs contain values not marked PADMY.
751              * Thus we must skip, not just pad values that are
752              * marked as current pad values, but also those with names.
753              * If pad_reset is enabled, ‘current’ means different
754              * things depending on whether we are allocating a con-
755              * stant or a target.  For a target, things marked PADTMP
756              * can be reused; not so for constants.
757              */
758             PADNAME *pn;
759             if (++retval <= names_fill &&
760                    (pn = names[retval]) && PadnamePV(pn))
761                 continue;
762             sv = *av_fetch_simple(PL_comppad, retval, TRUE);
763             if (!(SvFLAGS(sv) &
764 #ifdef USE_PAD_RESET
765                     (konst ? SVs_PADTMP : 0)
766 #else
767                     SVs_PADTMP
768 #endif
769                  ))
770                 break;
771         }
772         if (konst) {
773             padnamelist_store(PL_comppad_name, retval, &PL_padname_const);
774             tmptype &= ~SVf_READONLY;
775             tmptype |= SVs_PADTMP;
776         }
777         *(konst ? &PL_constpadix : &PL_padix) = retval;
778     }
779     SvFLAGS(sv) |= tmptype;
780     PL_curpad = AvARRAY(PL_comppad);
781 
782     DEBUG_X(PerlIO_printf(Perl_debug_log,
783           "Pad 0x%" UVxf "[0x%" UVxf "] alloc:   %ld for %s\n",
784           PTR2UV(PL_comppad), PTR2UV(PL_curpad), (long) retval,
785           PL_op_name[optype]));
786 #ifdef DEBUG_LEAKING_SCALARS
787     sv->sv_debug_optype = optype;
788     sv->sv_debug_inpad = 1;
789 #endif
790     return retval;
791 }
792 
793 /*
794 =for apidoc pad_add_anon
795 
796 Allocates a place in the currently-compiling pad (via L</pad_alloc>)
797 for an anonymous function that is lexically scoped inside the
798 currently-compiling function.
799 The function C<func> is linked into the pad, and its C<CvOUTSIDE> link
800 to the outer scope is weakened to avoid a reference loop.
801 
802 One reference count is stolen, so you may need to do C<SvREFCNT_inc(func)>.
803 
804 C<optype> should be an opcode indicating the type of operation that the
805 pad entry is to support.  This doesn't affect operational semantics,
806 but is used for debugging.
807 
808 =cut
809 */
810 
811 PADOFFSET
Perl_pad_add_anon(pTHX_ CV * func,I32 optype)812 Perl_pad_add_anon(pTHX_ CV* func, I32 optype)
813 {
814     PADOFFSET ix;
815     PADNAME * const name = newPADNAMEpvn("&", 1);
816 
817     PERL_ARGS_ASSERT_PAD_ADD_ANON;
818     assert (SvTYPE(func) == SVt_PVCV);
819 
820     /* These two aren't used; just make sure they're not equal to
821      * PERL_PADSEQ_INTRO.  They should be 0 by default.  */
822     assert(COP_SEQ_RANGE_LOW (name) != PERL_PADSEQ_INTRO);
823     assert(COP_SEQ_RANGE_HIGH(name) != PERL_PADSEQ_INTRO);
824     ix = pad_alloc(optype, SVs_PADMY);
825     padnamelist_store(PL_comppad_name, ix, name);
826     av_store(PL_comppad, ix, (SV*)func);
827 
828     /* to avoid ref loops, we never have parent + child referencing each
829      * other simultaneously */
830     if (CvOUTSIDE(func)) {
831         assert(!CvWEAKOUTSIDE(func));
832         CvWEAKOUTSIDE_on(func);
833         SvREFCNT_dec_NN(CvOUTSIDE(func));
834     }
835     return ix;
836 }
837 
838 void
Perl_pad_add_weakref(pTHX_ CV * func)839 Perl_pad_add_weakref(pTHX_ CV* func)
840 {
841     const PADOFFSET ix = pad_alloc(OP_NULL, SVs_PADMY);
842     PADNAME * const name = newPADNAMEpvn("&", 1);
843     SV * const rv = newRV_inc((SV *)func);
844 
845     PERL_ARGS_ASSERT_PAD_ADD_WEAKREF;
846 
847     /* These two aren't used; just make sure they're not equal to
848      * PERL_PADSEQ_INTRO.  They should be 0 by default.  */
849     assert(COP_SEQ_RANGE_LOW (name) != PERL_PADSEQ_INTRO);
850     assert(COP_SEQ_RANGE_HIGH(name) != PERL_PADSEQ_INTRO);
851     padnamelist_store(PL_comppad_name, ix, name);
852     sv_rvweaken(rv);
853     av_store(PL_comppad, ix, rv);
854 }
855 
856 /*
857 =for apidoc pad_check_dup
858 
859 Check for duplicate declarations: report any of:
860 
861      * a 'my' in the current scope with the same name;
862      * an 'our' (anywhere in the pad) with the same name and the
863        same stash as 'ourstash'
864 
865 C<is_our> indicates that the name to check is an C<"our"> declaration.
866 
867 =cut
868 */
869 
870 STATIC void
S_pad_check_dup(pTHX_ PADNAME * name,U32 flags,const HV * ourstash)871 S_pad_check_dup(pTHX_ PADNAME *name, U32 flags, const HV *ourstash)
872 {
873     PADNAME	**svp;
874     PADOFFSET	top, off;
875     const U32	is_our = flags & padadd_OUR;
876     bool        is_field = flags & padadd_FIELD;
877 
878     PERL_ARGS_ASSERT_PAD_CHECK_DUP;
879 
880     ASSERT_CURPAD_ACTIVE("pad_check_dup");
881 
882     assert((flags & ~(padadd_OUR|padadd_FIELD)) == 0);
883 
884     if (PadnamelistMAX(PL_comppad_name) < 0 || !ckWARN(WARN_SHADOW))
885         return; /* nothing to check */
886 
887     svp = PadnamelistARRAY(PL_comppad_name);
888     top = PadnamelistMAX(PL_comppad_name);
889     /* check the current scope */
890     for (off = top; off > PL_comppad_name_floor; off--) {
891         PADNAME * const pn = svp[off];
892         if (pn
893             && PadnameLEN(pn) == PadnameLEN(name)
894             && !PadnameOUTER(pn)
895             && (   COP_SEQ_RANGE_LOW(pn)  == PERL_PADSEQ_INTRO
896                 || COP_SEQ_RANGE_HIGH(pn) == PERL_PADSEQ_INTRO)
897             && memEQ(PadnamePV(pn), PadnamePV(name), PadnameLEN(name)))
898         {
899             if (is_our && (PadnameIsOUR(pn)))
900                 break; /* "our" masking "our" */
901             if (is_field && PadnameIsFIELD(pn) &&
902                     PadnameFIELDINFO(pn)->fieldstash != PL_curstash)
903                 break; /* field of a different class */
904             /* diag_listed_as: "%s" variable %s masks earlier declaration in same %s */
905             Perl_warner(aTHX_ packWARN(WARN_SHADOW),
906                 "\"%s\" %s %" PNf " masks earlier declaration in same %s",
907                 (   is_our                         ? "our"   :
908                     PL_parser->in_my == KEY_my     ? "my"    :
909                     PL_parser->in_my == KEY_sigvar ? "my"    :
910                     PL_parser->in_my == KEY_field  ? "field" :
911                                                      "state" ),
912                 *PadnamePV(pn) == '&' ? "subroutine" : "variable",
913                 PNfARG(pn),
914                 (COP_SEQ_RANGE_HIGH(pn) == PERL_PADSEQ_INTRO
915                     ? "scope" : "statement"));
916             --off;
917             break;
918         }
919     }
920     /* check the rest of the pad */
921     if (is_our) {
922         while (off > 0) {
923             PADNAME * const pn = svp[off];
924             if (pn
925                 && PadnameLEN(pn) == PadnameLEN(name)
926                 && !PadnameOUTER(pn)
927                 && (   COP_SEQ_RANGE_LOW(pn)  == PERL_PADSEQ_INTRO
928                     || COP_SEQ_RANGE_HIGH(pn) == PERL_PADSEQ_INTRO)
929                 && PadnameOURSTASH(pn) == ourstash
930                 && memEQ(PadnamePV(pn), PadnamePV(name), PadnameLEN(name)))
931             {
932                 Perl_warner(aTHX_ packWARN(WARN_SHADOW),
933                     "\"our\" variable %" PNf " redeclared", PNfARG(pn));
934                 if (off <= PL_comppad_name_floor)
935                     Perl_warner(aTHX_ packWARN(WARN_SHADOW),
936                         "\t(Did you mean \"local\" instead of \"our\"?)\n");
937                 break;
938             }
939             --off;
940         }
941     }
942 }
943 
944 
945 /*
946 =for apidoc pad_findmy_pvn
947 
948 Given the name of a lexical variable, find its position in the
949 currently-compiling pad.
950 C<namepv>/C<namelen> specify the variable's name, including leading sigil.
951 C<flags> is reserved and must be zero.
952 If it is not in the current pad but appears in the pad of any lexically
953 enclosing scope, then a pseudo-entry for it is added in the current pad.
954 Returns the offset in the current pad,
955 or C<NOT_IN_PAD> if no such lexical is in scope.
956 
957 =cut
958 */
959 
960 PADOFFSET
Perl_pad_findmy_pvn(pTHX_ const char * namepv,STRLEN namelen,U32 flags)961 Perl_pad_findmy_pvn(pTHX_ const char *namepv, STRLEN namelen, U32 flags)
962 {
963     PADNAME *out_pn;
964     int out_flags;
965     PADOFFSET offset;
966     const PADNAMELIST *namelist;
967     PADNAME **name_p;
968 
969     PERL_ARGS_ASSERT_PAD_FINDMY_PVN;
970 
971     if (flags)
972         Perl_croak(aTHX_ "panic: pad_findmy_pvn illegal flag bits 0x%" UVxf,
973                    (UV)flags);
974 
975     /* compilation errors can zero PL_compcv */
976     if (!PL_compcv)
977         return NOT_IN_PAD;
978 
979     offset = pad_findlex(namepv, namelen, flags,
980                 PL_compcv, PL_cop_seqmax, 1, NULL, &out_pn, &out_flags);
981     if (offset != NOT_IN_PAD)
982         return offset;
983 
984     /* Skip the ‘our’ hack for subroutines, as the warning does not apply.
985      */
986     if (*namepv == '&') return NOT_IN_PAD;
987 
988     /* look for an our that's being introduced; this allows
989      *    our $foo = 0 unless defined $foo;
990      * to not give a warning. (Yes, this is a hack) */
991 
992     namelist = PadlistNAMES(CvPADLIST(PL_compcv));
993     name_p = PadnamelistARRAY(namelist);
994     for (offset = PadnamelistMAXNAMED(namelist); offset > 0; offset--) {
995         const PADNAME * const name = name_p[offset];
996         if (name && PadnameLEN(name) == namelen
997             && !PadnameOUTER(name)
998             && (PadnameIsOUR(name))
999             && (  PadnamePV(name) == namepv
1000                || memEQ(PadnamePV(name), namepv, namelen)  )
1001             && COP_SEQ_RANGE_LOW(name) == PERL_PADSEQ_INTRO
1002         )
1003             return offset;
1004     }
1005     return NOT_IN_PAD;
1006 }
1007 
1008 /*
1009 =for apidoc pad_findmy_pv
1010 
1011 Exactly like L</pad_findmy_pvn>, but takes a nul-terminated string
1012 instead of a string/length pair.
1013 
1014 =cut
1015 */
1016 
1017 PADOFFSET
Perl_pad_findmy_pv(pTHX_ const char * name,U32 flags)1018 Perl_pad_findmy_pv(pTHX_ const char *name, U32 flags)
1019 {
1020     PERL_ARGS_ASSERT_PAD_FINDMY_PV;
1021     return pad_findmy_pvn(name, strlen(name), flags);
1022 }
1023 
1024 /*
1025 =for apidoc pad_findmy_sv
1026 
1027 Exactly like L</pad_findmy_pvn>, but takes the name string in the form
1028 of an SV instead of a string/length pair.
1029 
1030 =cut
1031 */
1032 
1033 PADOFFSET
Perl_pad_findmy_sv(pTHX_ SV * name,U32 flags)1034 Perl_pad_findmy_sv(pTHX_ SV *name, U32 flags)
1035 {
1036     char *namepv;
1037     STRLEN namelen;
1038     PERL_ARGS_ASSERT_PAD_FINDMY_SV;
1039     namepv = SvPVutf8(name, namelen);
1040     return pad_findmy_pvn(namepv, namelen, flags);
1041 }
1042 
1043 /*
1044 =for apidoc find_rundefsv
1045 
1046 Returns the global variable C<$_>.
1047 
1048 =cut
1049 */
1050 
1051 SV *
Perl_find_rundefsv(pTHX)1052 Perl_find_rundefsv(pTHX)
1053 {
1054     return DEFSV;
1055 }
1056 
1057 /*
1058 =for apidoc pad_findlex
1059 
1060 Find a named lexical anywhere in a chain of nested pads.  Add fake entries
1061 in the inner pads if it's found in an outer one.
1062 
1063 Returns the offset in the bottom pad of the lex or the fake lex.
1064 C<cv> is the CV in which to start the search, and seq is the current C<cop_seq>
1065 to match against.  If C<warn> is true, print appropriate warnings.  The C<out_>*
1066 vars return values, and so are pointers to where the returned values
1067 should be stored.  C<out_capture>, if non-null, requests that the innermost
1068 instance of the lexical is captured; C<out_name> is set to the innermost
1069 matched pad name or fake pad name; C<out_flags> returns the flags normally
1070 associated with the C<PARENT_FAKELEX_FLAGS> field of a fake pad name.
1071 
1072 Note that C<pad_findlex()> is recursive; it recurses up the chain of CVs,
1073 then comes back down, adding fake entries
1074 as it goes.  It has to be this way
1075 because fake names in anon prototypes have to store in C<xpadn_low> the
1076 index into the parent pad.
1077 
1078 =cut
1079 */
1080 
1081 /* the CV has finished being compiled. This is not a sufficient test for
1082  * all CVs (eg XSUBs), but suffices for the CVs found in a lexical chain */
1083 #define CvCOMPILED(cv)	CvROOT(cv)
1084 
1085 /* the CV does late binding of its lexicals */
1086 #define CvLATE(cv) (CvANON(cv) || CvCLONE(cv) || SvTYPE(cv) == SVt_PVFM)
1087 
1088 static void
S_unavailable(pTHX_ PADNAME * name)1089 S_unavailable(pTHX_ PADNAME *name)
1090 {
1091     /* diag_listed_as: Variable "%s" is not available */
1092     Perl_ck_warner(aTHX_ packWARN(WARN_CLOSURE),
1093                         "%s \"%" PNf "\" is not available",
1094                          *PadnamePV(name) == '&'
1095                                          ? "Subroutine"
1096                                          : "Variable",
1097                          PNfARG(name));
1098 }
1099 
1100 STATIC PADOFFSET
S_pad_findlex(pTHX_ const char * namepv,STRLEN namelen,U32 flags,const CV * cv,U32 seq,int warn,SV ** out_capture,PADNAME ** out_name,int * out_flags)1101 S_pad_findlex(pTHX_ const char *namepv, STRLEN namelen, U32 flags, const CV* cv, U32 seq,
1102         int warn, SV** out_capture, PADNAME** out_name, int *out_flags)
1103 {
1104     PADOFFSET offset, new_offset;
1105     SV *new_capture;
1106     SV **new_capturep;
1107     const PADLIST * const padlist = CvPADLIST(cv);
1108     const bool staleok = cBOOL(flags & padadd_STALEOK);
1109     const bool fieldok = cBOOL(flags & padfind_FIELD_OK);
1110 
1111     PERL_ARGS_ASSERT_PAD_FINDLEX;
1112 
1113     flags &= ~(padadd_STALEOK|padfind_FIELD_OK); /* one-shot flags */
1114     if (flags)
1115         Perl_croak(aTHX_ "panic: pad_findlex illegal flag bits 0x%" UVxf,
1116                    (UV)flags);
1117 
1118     *out_flags = 0;
1119 
1120     DEBUG_Xv(PerlIO_printf(Perl_debug_log,
1121         "Pad findlex cv=0x%" UVxf " searching \"%.*s\" seq=%d%s\n",
1122                            PTR2UV(cv), (int)namelen, namepv, (int)seq,
1123         out_capture ? " capturing" : "" ));
1124 
1125     /* first, search this pad */
1126 
1127     if (padlist) { /* not an undef CV */
1128         PADOFFSET fake_offset = 0;
1129         const PADNAMELIST * const names = PadlistNAMES(padlist);
1130         PADNAME * const * const name_p = PadnamelistARRAY(names);
1131 
1132         for (offset = PadnamelistMAXNAMED(names); offset > 0; offset--) {
1133             const PADNAME * const name = name_p[offset];
1134             if (name && PadnameLEN(name) == namelen
1135                      && (  PadnamePV(name) == namepv
1136                         || memEQ(PadnamePV(name), namepv, namelen)  ))
1137             {
1138                 if (PadnameOUTER(name)) {
1139                     fake_offset = offset; /* in case we don't find a real one */
1140                     continue;
1141                 }
1142                 if (PadnameIN_SCOPE(name, seq))
1143                     break;
1144             }
1145         }
1146 
1147         if (offset > 0 || fake_offset > 0 ) { /* a match! */
1148             if (offset > 0) { /* not fake */
1149                 fake_offset = 0;
1150                 *out_name = name_p[offset]; /* return the name */
1151 
1152                 if (PadnameIsFIELD(*out_name) && !fieldok)
1153                     croak("Field %" SVf " is not accessible outside a method",
1154                             SVfARG(PadnameSV(*out_name)));
1155 
1156                 /* set PAD_FAKELEX_MULTI if this lex can have multiple
1157                  * instances. For now, we just test !CvUNIQUE(cv), but
1158                  * ideally, we should detect my's declared within loops
1159                  * etc - this would allow a wider range of 'not stayed
1160                  * shared' warnings. We also treated already-compiled
1161                  * lexes as not multi as viewed from evals. */
1162 
1163                 *out_flags = CvANON(cv) ?
1164                         PAD_FAKELEX_ANON :
1165                             (!CvUNIQUE(cv) && ! CvCOMPILED(cv))
1166                                 ? PAD_FAKELEX_MULTI : 0;
1167 
1168                 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
1169                     "Pad findlex cv=0x%" UVxf " matched: offset=%ld (%lu,%lu)\n",
1170                     PTR2UV(cv), (long)offset,
1171                     (unsigned long)COP_SEQ_RANGE_LOW(*out_name),
1172                     (unsigned long)COP_SEQ_RANGE_HIGH(*out_name)));
1173             }
1174             else { /* fake match */
1175                 offset = fake_offset;
1176                 *out_name = name_p[offset]; /* return the name */
1177                 *out_flags = PARENT_FAKELEX_FLAGS(*out_name);
1178                 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
1179                     "Pad findlex cv=0x%" UVxf " matched: offset=%ld flags=0x%lx index=%lu\n",
1180                     PTR2UV(cv), (long)offset, (unsigned long)*out_flags,
1181                     (unsigned long) PARENT_PAD_INDEX(*out_name)
1182                 ));
1183             }
1184 
1185             /* return the lex? */
1186 
1187             if (out_capture) {
1188 
1189                 /* our ? */
1190                 if (PadnameIsOUR(*out_name)) {
1191                     *out_capture = NULL;
1192                     return offset;
1193                 }
1194 
1195                 /* trying to capture from an anon prototype? */
1196                 if (CvCOMPILED(cv)
1197                         ? CvANON(cv) && CvCLONE(cv) && !CvCLONED(cv)
1198                         : *out_flags & PAD_FAKELEX_ANON)
1199                 {
1200                     if (warn)
1201                         S_unavailable(aTHX_
1202                                       *out_name);
1203 
1204                     *out_capture = NULL;
1205                 }
1206 
1207                 /* real value */
1208                 else {
1209                     int newwarn = warn;
1210                     if (!CvCOMPILED(cv) && (*out_flags & PAD_FAKELEX_MULTI)
1211                          && !PadnameIsSTATE(name_p[offset])
1212                          && warn && ckWARN(WARN_CLOSURE)) {
1213                         newwarn = 0;
1214                         /* diag_listed_as: Variable "%s" will not stay
1215                                            shared */
1216                         Perl_warner(aTHX_ packWARN(WARN_CLOSURE),
1217                             "%s \"%" UTF8f "\" will not stay shared",
1218                              *namepv == '&' ? "Subroutine" : "Variable",
1219                              UTF8fARG(1, namelen, namepv));
1220                     }
1221 
1222                     if (fake_offset && CvANON(cv)
1223                             && CvCLONE(cv) &&!CvCLONED(cv))
1224                     {
1225                         PADNAME *n;
1226                         /* not yet caught - look further up */
1227                         DEBUG_Xv(PerlIO_printf(Perl_debug_log,
1228                             "Pad findlex cv=0x%" UVxf " chasing lex in outer pad\n",
1229                             PTR2UV(cv)));
1230                         n = *out_name;
1231                         (void) pad_findlex(namepv, namelen, flags, CvOUTSIDE(cv),
1232                             CvOUTSIDE_SEQ(cv),
1233                             newwarn, out_capture, out_name, out_flags);
1234                         *out_name = n;
1235                         return offset;
1236                     }
1237 
1238                     *out_capture = AvARRAY(PadlistARRAY(padlist)[
1239                                     CvDEPTH(cv) ? CvDEPTH(cv) : 1])[offset];
1240                     DEBUG_Xv(PerlIO_printf(Perl_debug_log,
1241                         "Pad findlex cv=0x%" UVxf " found lex=0x%" UVxf "\n",
1242                         PTR2UV(cv), PTR2UV(*out_capture)));
1243 
1244                     if (SvPADSTALE(*out_capture)
1245                         && (!CvDEPTH(cv) || !staleok)
1246                         && !PadnameIsSTATE(name_p[offset]))
1247                     {
1248                         S_unavailable(aTHX_
1249                                       name_p[offset]);
1250                         *out_capture = NULL;
1251                     }
1252                 }
1253                 if (!*out_capture) {
1254                     if (namelen != 0 && *namepv == '@')
1255                         *out_capture = newSV_type_mortal(SVt_PVAV);
1256                     else if (namelen != 0 && *namepv == '%')
1257                         *out_capture = newSV_type_mortal(SVt_PVHV);
1258                     else if (namelen != 0 && *namepv == '&')
1259                         *out_capture = newSV_type_mortal(SVt_PVCV);
1260                     else
1261                         *out_capture = newSV_type_mortal(SVt_NULL);
1262                 }
1263             }
1264 
1265             return offset;
1266         }
1267     }
1268 
1269     /* it's not in this pad - try above */
1270 
1271     if (!CvOUTSIDE(cv))
1272         return NOT_IN_PAD;
1273 
1274     /* out_capture non-null means caller wants us to capture lex; in
1275      * addition we capture ourselves unless it's an ANON/format */
1276     new_capturep = out_capture ? out_capture :
1277                 CvLATE(cv) ? NULL : &new_capture;
1278 
1279     U32 recurse_flags = flags;
1280     if(new_capturep == &new_capture)
1281         recurse_flags |= padadd_STALEOK;
1282     if(CvIsMETHOD(cv))
1283         recurse_flags |= padfind_FIELD_OK;
1284 
1285     offset = pad_findlex(namepv, namelen, recurse_flags,
1286                 CvOUTSIDE(cv), CvOUTSIDE_SEQ(cv), 1,
1287                 new_capturep, out_name, out_flags);
1288     if (offset == NOT_IN_PAD)
1289         return NOT_IN_PAD;
1290 
1291     if (PadnameIsFIELD(*out_name)) {
1292         HV *fieldstash = PadnameFIELDINFO(*out_name)->fieldstash;
1293 
1294         /* fields are only visible to the class that declared them */
1295         if(fieldstash != PL_curstash)
1296             croak("Field %" SVf " of %" HvNAMEf_QUOTEDPREFIX " is not accessible in a method of %" HvNAMEf_QUOTEDPREFIX,
1297                 SVfARG(PadnameSV(*out_name)), HvNAMEfARG(fieldstash), HvNAMEfARG(PL_curstash));
1298     }
1299 
1300     /* found in an outer CV. Add appropriate fake entry to this pad */
1301 
1302     /* don't add new fake entries (via eval) to CVs that we have already
1303      * finished compiling, or to undef CVs */
1304     if (CvCOMPILED(cv) || !padlist)
1305         return 0; /* this dummy (and invalid) value isnt used by the caller */
1306 
1307     {
1308         PADNAME *new_name = newPADNAMEouter(*out_name);
1309         PADNAMELIST * const ocomppad_name = PL_comppad_name;
1310         PAD * const ocomppad = PL_comppad;
1311         PL_comppad_name = PadlistNAMES(padlist);
1312         PL_comppad = PadlistARRAY(padlist)[1];
1313         PL_curpad = AvARRAY(PL_comppad);
1314 
1315         new_offset
1316             = pad_alloc_name(new_name,
1317                               PadnameIsSTATE(*out_name) ? padadd_STATE : 0,
1318                               PadnameTYPE(*out_name),
1319                               PadnameOURSTASH(*out_name)
1320                               );
1321 
1322         DEBUG_Xv(PerlIO_printf(Perl_debug_log,
1323                                "Pad addname: %ld \"%.*s\" FAKE\n",
1324                                (long)new_offset,
1325                                (int) PadnameLEN(new_name),
1326                                PadnamePV(new_name)));
1327         PARENT_FAKELEX_FLAGS_set(new_name, *out_flags);
1328 
1329         PARENT_PAD_INDEX_set(new_name, 0);
1330         if (PadnameIsOUR(new_name)) {
1331             NOOP;   /* do nothing */
1332         }
1333         else if (CvLATE(cv)) {
1334             /* delayed creation - just note the offset within parent pad */
1335             PARENT_PAD_INDEX_set(new_name, offset);
1336             CvCLONE_on(cv);
1337         }
1338         else {
1339             /* immediate creation - capture outer value right now */
1340             av_store(PL_comppad, new_offset, SvREFCNT_inc(*new_capturep));
1341             /* But also note the offset, as newMYSUB needs it */
1342             PARENT_PAD_INDEX_set(new_name, offset);
1343             DEBUG_Xv(PerlIO_printf(Perl_debug_log,
1344                 "Pad findlex cv=0x%" UVxf " saved captured sv 0x%" UVxf " at offset %ld\n",
1345                 PTR2UV(cv), PTR2UV(*new_capturep), (long)new_offset));
1346         }
1347         *out_name = new_name;
1348         *out_flags = PARENT_FAKELEX_FLAGS(new_name);
1349 
1350         PL_comppad_name = ocomppad_name;
1351         PL_comppad = ocomppad;
1352         PL_curpad = ocomppad ? AvARRAY(ocomppad) : NULL;
1353     }
1354     return new_offset;
1355 }
1356 
1357 #ifdef DEBUGGING
1358 
1359 /*
1360 =for apidoc pad_sv
1361 
1362 Get the value at offset C<po> in the current (compiling or executing) pad.
1363 Use macro C<PAD_SV> instead of calling this function directly.
1364 
1365 =cut
1366 */
1367 
1368 SV *
Perl_pad_sv(pTHX_ PADOFFSET po)1369 Perl_pad_sv(pTHX_ PADOFFSET po)
1370 {
1371     ASSERT_CURPAD_ACTIVE("pad_sv");
1372 
1373     if (!po)
1374         Perl_croak(aTHX_ "panic: pad_sv po");
1375     DEBUG_X(PerlIO_printf(Perl_debug_log,
1376         "Pad 0x%" UVxf "[0x%" UVxf "] sv:      %ld sv=0x%" UVxf "\n",
1377         PTR2UV(PL_comppad), PTR2UV(PL_curpad), (long)po, PTR2UV(PL_curpad[po]))
1378     );
1379     return PL_curpad[po];
1380 }
1381 
1382 /*
1383 =for apidoc pad_setsv
1384 
1385 Set the value at offset C<po> in the current (compiling or executing) pad.
1386 Use the macro C<PAD_SETSV()> rather than calling this function directly.
1387 
1388 =cut
1389 */
1390 
1391 void
Perl_pad_setsv(pTHX_ PADOFFSET po,SV * sv)1392 Perl_pad_setsv(pTHX_ PADOFFSET po, SV* sv)
1393 {
1394     PERL_ARGS_ASSERT_PAD_SETSV;
1395 
1396     ASSERT_CURPAD_ACTIVE("pad_setsv");
1397 
1398     DEBUG_X(PerlIO_printf(Perl_debug_log,
1399         "Pad 0x%" UVxf "[0x%" UVxf "] setsv:   %ld sv=0x%" UVxf "\n",
1400         PTR2UV(PL_comppad), PTR2UV(PL_curpad), (long)po, PTR2UV(sv))
1401     );
1402     PL_curpad[po] = sv;
1403 }
1404 
1405 #endif /* DEBUGGING */
1406 
1407 /*
1408 =for apidoc pad_block_start
1409 
1410 Update the pad compilation state variables on entry to a new block.
1411 
1412 =cut
1413 */
1414 
1415 void
Perl_pad_block_start(pTHX_ int full)1416 Perl_pad_block_start(pTHX_ int full)
1417 {
1418     ASSERT_CURPAD_ACTIVE("pad_block_start");
1419     SAVESTRLEN(PL_comppad_name_floor);
1420     PL_comppad_name_floor = PadnamelistMAX(PL_comppad_name);
1421     if (full)
1422         PL_comppad_name_fill = PL_comppad_name_floor;
1423     if (PL_comppad_name_floor < 0)
1424         PL_comppad_name_floor = 0;
1425     SAVESTRLEN(PL_min_intro_pending);
1426     SAVESTRLEN(PL_max_intro_pending);
1427     PL_min_intro_pending = 0;
1428     SAVESTRLEN(PL_comppad_name_fill);
1429     SAVESTRLEN(PL_padix_floor);
1430     /* PL_padix_floor is what PL_padix is reset to at the start of each
1431        statement, by pad_reset().  We set it when entering a new scope
1432        to keep things like this working:
1433             print "$foo$bar", do { this(); that() . "foo" };
1434        We must not let "$foo$bar" and the later concatenation share the
1435        same target.  */
1436     PL_padix_floor = PL_padix;
1437     PL_pad_reset_pending = FALSE;
1438 }
1439 
1440 /*
1441 =for apidoc intro_my
1442 
1443 "Introduce" C<my> variables to visible status.  This is called during parsing
1444 at the end of each statement to make lexical variables visible to subsequent
1445 statements.
1446 
1447 =cut
1448 */
1449 
1450 U32
Perl_intro_my(pTHX)1451 Perl_intro_my(pTHX)
1452 {
1453     PADNAME **svp;
1454     PADOFFSET i;
1455     U32 seq;
1456 
1457     ASSERT_CURPAD_ACTIVE("intro_my");
1458     if (PL_compiling.cop_seq) {
1459         seq = PL_compiling.cop_seq;
1460         PL_compiling.cop_seq = 0;
1461     }
1462     else
1463         seq = PL_cop_seqmax;
1464     if (! PL_min_intro_pending)
1465         return seq;
1466 
1467     svp = PadnamelistARRAY(PL_comppad_name);
1468     for (i = PL_min_intro_pending; i <= PL_max_intro_pending; i++) {
1469         PADNAME * const sv = svp[i];
1470 
1471         if (sv && PadnameLEN(sv) && !PadnameOUTER(sv)
1472             && COP_SEQ_RANGE_LOW(sv) == PERL_PADSEQ_INTRO)
1473         {
1474             COP_SEQ_RANGE_HIGH_set(sv, PERL_PADSEQ_INTRO); /* Don't know scope end yet. */
1475             COP_SEQ_RANGE_LOW_set(sv, PL_cop_seqmax);
1476             DEBUG_Xv(PerlIO_printf(Perl_debug_log,
1477                 "Pad intromy: %ld \"%s\", (%lu,%lu)\n",
1478                 (long)i, PadnamePV(sv),
1479                 (unsigned long)COP_SEQ_RANGE_LOW(sv),
1480                 (unsigned long)COP_SEQ_RANGE_HIGH(sv))
1481             );
1482         }
1483     }
1484     COP_SEQMAX_INC;
1485     PL_min_intro_pending = 0;
1486     PL_comppad_name_fill = PL_max_intro_pending; /* Needn't search higher */
1487     DEBUG_Xv(PerlIO_printf(Perl_debug_log,
1488                 "Pad intromy: seq -> %ld\n", (long)(PL_cop_seqmax)));
1489 
1490     return seq;
1491 }
1492 
1493 /*
1494 =for apidoc pad_leavemy
1495 
1496 Cleanup at end of scope during compilation: set the max seq number for
1497 lexicals in this scope and warn of any lexicals that never got introduced.
1498 
1499 =cut
1500 */
1501 
1502 OP *
Perl_pad_leavemy(pTHX)1503 Perl_pad_leavemy(pTHX)
1504 {
1505     PADOFFSET off;
1506     OP *o = NULL;
1507     PADNAME * const * const svp = PadnamelistARRAY(PL_comppad_name);
1508 
1509     PL_pad_reset_pending = FALSE;
1510 
1511     ASSERT_CURPAD_ACTIVE("pad_leavemy");
1512     if (PL_min_intro_pending && PL_comppad_name_fill < PL_min_intro_pending) {
1513         for (off = PL_max_intro_pending; off >= PL_min_intro_pending; off--) {
1514             const PADNAME * const name = svp[off];
1515             if (name && PadnameLEN(name) && !PadnameOUTER(name))
1516                 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
1517                                       "%" PNf " never introduced",
1518                                        PNfARG(name));
1519         }
1520     }
1521     /* "Deintroduce" my variables that are leaving with this scope. */
1522     for (off = PadnamelistMAX(PL_comppad_name);
1523          off > PL_comppad_name_fill; off--) {
1524         PADNAME * const sv = svp[off];
1525         if (sv && PadnameLEN(sv) && !PadnameOUTER(sv)
1526             && COP_SEQ_RANGE_HIGH(sv) == PERL_PADSEQ_INTRO)
1527         {
1528             COP_SEQ_RANGE_HIGH_set(sv, PL_cop_seqmax);
1529             DEBUG_Xv(PerlIO_printf(Perl_debug_log,
1530                 "Pad leavemy: %ld \"%s\", (%lu,%lu)\n",
1531                 (long)off, PadnamePV(sv),
1532                 (unsigned long)COP_SEQ_RANGE_LOW(sv),
1533                 (unsigned long)COP_SEQ_RANGE_HIGH(sv))
1534             );
1535             if (!PadnameIsSTATE(sv) && !PadnameIsOUR(sv)
1536              && *PadnamePV(sv) == '&' && PadnameLEN(sv) > 1) {
1537                 OP *kid = newOP(OP_INTROCV, 0);
1538                 kid->op_targ = off;
1539                 o = op_prepend_elem(OP_LINESEQ, kid, o);
1540             }
1541         }
1542     }
1543     COP_SEQMAX_INC;
1544     DEBUG_Xv(PerlIO_printf(Perl_debug_log,
1545             "Pad leavemy: seq = %ld\n", (long)PL_cop_seqmax));
1546     return o;
1547 }
1548 
1549 /*
1550 =for apidoc pad_swipe
1551 
1552 Abandon the tmp in the current pad at offset C<po> and replace with a
1553 new one.
1554 
1555 =cut
1556 */
1557 
1558 void
Perl_pad_swipe(pTHX_ PADOFFSET po,bool refadjust)1559 Perl_pad_swipe(pTHX_ PADOFFSET po, bool refadjust)
1560 {
1561     ASSERT_CURPAD_LEGAL("pad_swipe");
1562     if (!PL_curpad)
1563         return;
1564     if (AvARRAY(PL_comppad) != PL_curpad)
1565         Perl_croak(aTHX_ "panic: pad_swipe curpad, %p!=%p",
1566                    AvARRAY(PL_comppad), PL_curpad);
1567     if (!po || ((SSize_t)po) > AvFILLp(PL_comppad))
1568         Perl_croak(aTHX_ "panic: pad_swipe po=%ld, fill=%ld",
1569                    (long)po, (long)AvFILLp(PL_comppad));
1570 
1571     DEBUG_X(PerlIO_printf(Perl_debug_log,
1572                 "Pad 0x%" UVxf "[0x%" UVxf "] swipe:   %ld\n",
1573                 PTR2UV(PL_comppad), PTR2UV(PL_curpad), (long)po));
1574 
1575     if (refadjust)
1576         SvREFCNT_dec(PL_curpad[po]);
1577 
1578 
1579     /* if pad tmps aren't shared between ops, then there's no need to
1580      * create a new tmp when an existing op is freed */
1581 #ifdef USE_PAD_RESET
1582     PL_curpad[po] = newSV_type(SVt_NULL);
1583     SvPADTMP_on(PL_curpad[po]);
1584 #else
1585     PL_curpad[po] = NULL;
1586 #endif
1587     if (PadnamelistMAX(PL_comppad_name) != -1
1588      && (PADOFFSET)PadnamelistMAX(PL_comppad_name) >= po) {
1589         if (PadnamelistARRAY(PL_comppad_name)[po]) {
1590             assert(!PadnameLEN(PadnamelistARRAY(PL_comppad_name)[po]));
1591         }
1592         PadnamelistARRAY(PL_comppad_name)[po] = &PL_padname_undef;
1593     }
1594     /* Use PL_constpadix here, not PL_padix.  The latter may have been
1595        reset by pad_reset.  We don’t want pad_alloc to have to scan the
1596        whole pad when allocating a constant. */
1597     if (po < PL_constpadix)
1598         PL_constpadix = po - 1;
1599 }
1600 
1601 /*
1602 =for apidoc pad_reset
1603 
1604 Mark all the current temporaries for reuse
1605 
1606 =cut
1607 */
1608 
1609 /* pad_reset() causes pad temp TARGs (operator targets) to be shared
1610  * between OPs from different statements.  During compilation, at the start
1611  * of each statement pad_reset resets PL_padix back to its previous value.
1612  * When allocating a target, pad_alloc begins its scan through the pad at
1613  * PL_padix+1.  */
1614 static void
S_pad_reset(pTHX)1615 S_pad_reset(pTHX)
1616 {
1617 #ifdef USE_PAD_RESET
1618     if (AvARRAY(PL_comppad) != PL_curpad)
1619         Perl_croak(aTHX_ "panic: pad_reset curpad, %p!=%p",
1620                    AvARRAY(PL_comppad), PL_curpad);
1621 
1622     DEBUG_X(PerlIO_printf(Perl_debug_log,
1623             "Pad 0x%" UVxf "[0x%" UVxf "] reset:     padix %ld -> %ld",
1624             PTR2UV(PL_comppad), PTR2UV(PL_curpad),
1625                 (long)PL_padix, (long)PL_padix_floor
1626             )
1627     );
1628 
1629     if (!TAINTING_get) {	/* Can't mix tainted and non-tainted temporaries. */
1630         PL_padix = PL_padix_floor;
1631     }
1632 #endif
1633     PL_pad_reset_pending = FALSE;
1634 }
1635 
1636 /*
1637 =for apidoc pad_tidy
1638 
1639 Tidy up a pad at the end of compilation of the code to which it belongs.
1640 Jobs performed here are: remove most stuff from the pads of anonsub
1641 prototypes; give it a C<@_>; mark temporaries as such.  C<type> indicates
1642 the kind of subroutine:
1643 
1644     padtidy_SUB        ordinary subroutine
1645     padtidy_SUBCLONE   prototype for lexical closure
1646     padtidy_FORMAT     format
1647 
1648 =cut
1649 */
1650 
1651 void
Perl_pad_tidy(pTHX_ padtidy_type type)1652 Perl_pad_tidy(pTHX_ padtidy_type type)
1653 {
1654 
1655     ASSERT_CURPAD_ACTIVE("pad_tidy");
1656 
1657     /* If this CV has had any 'eval-capable' ops planted in it:
1658      * i.e. it contains any of:
1659      *
1660      *     * eval '...',
1661      *     * //ee,
1662      *     * use re 'eval'; /$var/
1663      *     * /(?{..})/),
1664      *
1665      * Then any anon prototypes in the chain of CVs should be marked as
1666      * cloneable, so that for example the eval's CV in
1667      *
1668      *    sub { eval '$x' }
1669      *
1670      * gets the right CvOUTSIDE.  If running with -d, *any* sub may
1671      * potentially have an eval executed within it.
1672      */
1673 
1674     if (PL_cv_has_eval || PL_perldb) {
1675         const CV *cv;
1676         for (cv = PL_compcv ;cv; cv = CvOUTSIDE(cv)) {
1677             if (cv != PL_compcv && CvCOMPILED(cv))
1678                 break; /* no need to mark already-compiled code */
1679             if (CvANON(cv)) {
1680                 DEBUG_Xv(PerlIO_printf(Perl_debug_log,
1681                     "Pad clone on cv=0x%" UVxf "\n", PTR2UV(cv)));
1682                 CvCLONE_on(cv);
1683             }
1684         }
1685     }
1686 
1687     /* extend namepad to match curpad */
1688     if (PadnamelistMAX(PL_comppad_name) < AvFILLp(PL_comppad))
1689         padnamelist_store(PL_comppad_name, AvFILLp(PL_comppad), NULL);
1690 
1691     if (type == padtidy_SUBCLONE) {
1692         PADNAME ** const namep = PadnamelistARRAY(PL_comppad_name);
1693         PADOFFSET ix;
1694 
1695         for (ix = AvFILLp(PL_comppad); ix > 0; ix--) {
1696             PADNAME *namesv;
1697             if (!namep[ix]) namep[ix] = &PL_padname_undef;
1698 
1699             /*
1700              * The only things that a clonable function needs in its
1701              * pad are anonymous subs, constants and GVs.
1702              * The rest are created anew during cloning.
1703              */
1704             if (!PL_curpad[ix] || SvIMMORTAL(PL_curpad[ix]))
1705                 continue;
1706             namesv = namep[ix];
1707             if (!(PadnamePV(namesv) &&
1708                    (!PadnameLEN(namesv) || *PadnamePV(namesv) == '&')))
1709             {
1710                 SvREFCNT_dec(PL_curpad[ix]);
1711                 PL_curpad[ix] = NULL;
1712             }
1713         }
1714     }
1715     else if (type == padtidy_SUB) {
1716         AV * const av = newAV();			/* Will be @_ */
1717         av_store(PL_comppad, 0, MUTABLE_SV(av));
1718 #ifndef PERL_RC_STACK
1719         AvREIFY_only(av);
1720 #endif
1721     }
1722 
1723     if (type == padtidy_SUB || type == padtidy_FORMAT) {
1724         PADNAME ** const namep = PadnamelistARRAY(PL_comppad_name);
1725         PADOFFSET ix;
1726         for (ix = AvFILLp(PL_comppad); ix > 0; ix--) {
1727             if (!namep[ix]) namep[ix] = &PL_padname_undef;
1728             if (!PL_curpad[ix] || SvIMMORTAL(PL_curpad[ix]))
1729                 continue;
1730             if (SvPADMY(PL_curpad[ix]) && !PadnameOUTER(namep[ix])) {
1731                 /* This is a work around for how the current implementation of
1732                    ?{ } blocks in regexps interacts with lexicals.
1733 
1734                    One of our lexicals.
1735                    Can't do this on all lexicals, otherwise sub baz() won't
1736                    compile in
1737 
1738                    my $foo;
1739 
1740                    sub bar { ++$foo; }
1741 
1742                    sub baz { ++$foo; }
1743 
1744                    because completion of compiling &bar calling pad_tidy()
1745                    would cause (top level) $foo to be marked as stale, and
1746                    "no longer available".  */
1747                 SvPADSTALE_on(PL_curpad[ix]);
1748             }
1749         }
1750     }
1751     PL_curpad = AvARRAY(PL_comppad);
1752 }
1753 
1754 /*
1755 =for apidoc pad_free
1756 
1757 Free the SV at offset po in the current pad.
1758 
1759 =cut
1760 */
1761 
1762 void
Perl_pad_free(pTHX_ PADOFFSET po)1763 Perl_pad_free(pTHX_ PADOFFSET po)
1764 {
1765 #ifndef USE_PAD_RESET
1766     SV *sv;
1767 #endif
1768     ASSERT_CURPAD_LEGAL("pad_free");
1769     if (!PL_curpad)
1770         return;
1771     if (AvARRAY(PL_comppad) != PL_curpad)
1772         Perl_croak(aTHX_ "panic: pad_free curpad, %p!=%p",
1773                    AvARRAY(PL_comppad), PL_curpad);
1774     if (!po)
1775         Perl_croak(aTHX_ "panic: pad_free po");
1776 
1777     DEBUG_X(PerlIO_printf(Perl_debug_log,
1778             "Pad 0x%" UVxf "[0x%" UVxf "] free:    %ld\n",
1779             PTR2UV(PL_comppad), PTR2UV(PL_curpad), (long)po)
1780     );
1781 
1782 #ifndef USE_PAD_RESET
1783     sv = PL_curpad[po];
1784     if (sv && sv != &PL_sv_undef && !SvPADMY(sv))
1785         SvFLAGS(sv) &= ~SVs_PADTMP;
1786 
1787     if (po < PL_padix)
1788         PL_padix = po - 1;
1789 #endif
1790 }
1791 
1792 /*
1793 =for apidoc do_dump_pad
1794 
1795 Dump the contents of a padlist
1796 
1797 =cut
1798 */
1799 
1800 void
Perl_do_dump_pad(pTHX_ I32 level,PerlIO * file,PADLIST * padlist,int full)1801 Perl_do_dump_pad(pTHX_ I32 level, PerlIO *file, PADLIST *padlist, int full)
1802 {
1803     const PADNAMELIST *pad_name;
1804     const AV *pad;
1805     PADNAME **pname;
1806     SV **ppad;
1807     PADOFFSET ix;
1808 
1809     PERL_ARGS_ASSERT_DO_DUMP_PAD;
1810 
1811     if (!padlist) {
1812         return;
1813     }
1814     pad_name = PadlistNAMES(padlist);
1815     pad = PadlistARRAY(padlist)[1];
1816     pname = PadnamelistARRAY(pad_name);
1817     ppad = AvARRAY(pad);
1818     Perl_dump_indent(aTHX_ level, file,
1819             "PADNAME = 0x%" UVxf "(0x%" UVxf ") PAD = 0x%" UVxf "(0x%" UVxf ")\n",
1820             PTR2UV(pad_name), PTR2UV(pname), PTR2UV(pad), PTR2UV(ppad)
1821     );
1822 
1823     for (ix = 1; ix <= PadnamelistMAX(pad_name); ix++) {
1824         const PADNAME *namesv = pname[ix];
1825         if (namesv && !PadnameLEN(namesv)) {
1826             namesv = NULL;
1827         }
1828         if (namesv) {
1829             if (PadnameOUTER(namesv))
1830                 Perl_dump_indent(aTHX_ level+1, file,
1831                     "%2d. 0x%" UVxf "<%lu> FAKE \"%s\" flags=0x%lx index=%lu\n",
1832                     (int) ix,
1833                     PTR2UV(ppad[ix]),
1834                     (unsigned long) (ppad[ix] ? SvREFCNT(ppad[ix]) : 0),
1835                     PadnamePV(namesv),
1836                     (unsigned long)PARENT_FAKELEX_FLAGS(namesv),
1837                     (unsigned long)PARENT_PAD_INDEX(namesv)
1838 
1839                 );
1840             else
1841                 Perl_dump_indent(aTHX_ level+1, file,
1842                     "%2d. 0x%" UVxf "<%lu> (%lu,%lu) \"%s\"\n",
1843                     (int) ix,
1844                     PTR2UV(ppad[ix]),
1845                     (unsigned long) (ppad[ix] ? SvREFCNT(ppad[ix]) : 0),
1846                     (unsigned long)COP_SEQ_RANGE_LOW(namesv),
1847                     (unsigned long)COP_SEQ_RANGE_HIGH(namesv),
1848                     PadnamePV(namesv)
1849                 );
1850         }
1851         else if (full) {
1852             Perl_dump_indent(aTHX_ level+1, file,
1853                 "%2d. 0x%" UVxf "<%lu>\n",
1854                 (int) ix,
1855                 PTR2UV(ppad[ix]),
1856                 (unsigned long) (ppad[ix] ? SvREFCNT(ppad[ix]) : 0)
1857             );
1858         }
1859     }
1860 }
1861 
1862 #ifdef DEBUGGING
1863 
1864 /*
1865 =for apidoc cv_dump
1866 
1867 dump the contents of a CV
1868 
1869 =cut
1870 */
1871 
1872 STATIC void
S_cv_dump(pTHX_ const CV * cv,const char * title)1873 S_cv_dump(pTHX_ const CV *cv, const char *title)
1874 {
1875     const CV * const outside = CvOUTSIDE(cv);
1876 
1877     PERL_ARGS_ASSERT_CV_DUMP;
1878 
1879     PerlIO_printf(Perl_debug_log,
1880                   "  %s: CV=0x%" UVxf " (%s), OUTSIDE=0x%" UVxf " (%s)\n",
1881                   title,
1882                   PTR2UV(cv),
1883                   (CvANON(cv) ? "ANON"
1884                    : (SvTYPE(cv) == SVt_PVFM) ? "FORMAT"
1885                    : (cv == PL_main_cv) ? "MAIN"
1886                    : CvUNIQUE(cv) ? "UNIQUE"
1887                    : CvGV(cv) ? GvNAME(CvGV(cv)) : "UNDEFINED"),
1888                   PTR2UV(outside),
1889                   (!outside ? "null"
1890                    : CvANON(outside) ? "ANON"
1891                    : (outside == PL_main_cv) ? "MAIN"
1892                    : CvUNIQUE(outside) ? "UNIQUE"
1893                    : CvGV(outside) ? GvNAME(CvGV(outside)) : "UNDEFINED"));
1894 
1895     if (!CvISXSUB(cv)) {
1896         /* SVPADLIST(cv) will fail an assert if CvISXSUB(cv) is true,
1897          * and if the assert is removed this code will SEGV. XSUBs don't
1898          * have padlists I believe - Yves */
1899         PADLIST* const padlist = CvPADLIST(cv);
1900         PerlIO_printf(Perl_debug_log,
1901                     "    PADLIST = 0x%" UVxf "\n", PTR2UV(padlist));
1902         do_dump_pad(1, Perl_debug_log, padlist, 1);
1903     }
1904 }
1905 
1906 #endif /* DEBUGGING */
1907 
1908 /*
1909 =for apidoc cv_clone
1910 
1911 Clone a CV, making a lexical closure.  C<proto> supplies the prototype
1912 of the function: its code, pad structure, and other attributes.
1913 The prototype is combined with a capture of outer lexicals to which the
1914 code refers, which are taken from the currently-executing instance of
1915 the immediately surrounding code.
1916 
1917 =cut
1918 */
1919 
1920 static CV *S_cv_clone(pTHX_ CV *proto, CV *cv, CV *outside, HV *cloned);
1921 
1922 static CV *
S_cv_clone_pad(pTHX_ CV * proto,CV * cv,CV * outside,HV * cloned,bool newcv)1923 S_cv_clone_pad(pTHX_ CV *proto, CV *cv, CV *outside, HV *cloned,
1924                      bool newcv)
1925 {
1926     PADOFFSET ix;
1927     PADLIST* const protopadlist = CvPADLIST(proto);
1928     PADNAMELIST *const protopad_name = PadlistNAMES(protopadlist);
1929     const PAD *const protopad = PadlistARRAY(protopadlist)[1];
1930     PADNAME** const pname = PadnamelistARRAY(protopad_name);
1931     SV** const ppad = AvARRAY(protopad);
1932     const PADOFFSET fname = PadnamelistMAX(protopad_name);
1933     const PADOFFSET fpad = AvFILLp(protopad);
1934     SV** outpad;
1935     long depth;
1936     U32 subclones = 0;
1937     bool trouble = FALSE;
1938 
1939     assert(!CvUNIQUE(proto));
1940 
1941     /* Anonymous subs have a weak CvOUTSIDE pointer, so its value is not
1942      * reliable.  The currently-running sub is always the one we need to
1943      * close over.
1944      * For my subs, the currently-running sub may not be the one we want.
1945      * We have to check whether it is a clone of CvOUTSIDE.
1946      * Note that in general for formats, CvOUTSIDE != find_runcv.
1947      * Since formats may be nested inside closures, CvOUTSIDE may point
1948      * to a prototype; we instead want the cloned parent who called us.
1949      */
1950 
1951     if (!outside) {
1952       if (CvWEAKOUTSIDE(proto))
1953         outside = find_runcv(NULL);
1954       else {
1955         outside = CvOUTSIDE(proto);
1956         if ((CvCLONE(outside) && ! CvCLONED(outside))
1957             || !CvPADLIST(outside)
1958             || CvPADLIST(outside)->xpadl_id != protopadlist->xpadl_outid) {
1959             outside = find_runcv_where(
1960                 FIND_RUNCV_padid_eq, PTR2IV(protopadlist->xpadl_outid), NULL
1961             );
1962             /* outside could be null */
1963         }
1964       }
1965     }
1966     depth = outside ? CvDEPTH(outside) : 0;
1967     if (!depth)
1968         depth = 1;
1969 
1970     ENTER;
1971     SAVESPTR(PL_compcv);
1972     PL_compcv = cv;
1973     if (newcv) SAVEFREESV(cv); /* in case of fatal warnings */
1974 
1975     CvOUTSIDE(cv)	= MUTABLE_CV(SvREFCNT_inc_simple(outside));
1976 
1977     SAVESPTR(PL_comppad_name);
1978     PL_comppad_name = protopad_name;
1979     CvPADLIST_set(cv, pad_new(padnew_CLONE|padnew_SAVE));
1980     CvPADLIST(cv)->xpadl_id = protopadlist->xpadl_id;
1981 
1982     av_fill(PL_comppad, fpad);
1983 
1984     PL_curpad = AvARRAY(PL_comppad);
1985 
1986     outpad = outside && CvPADLIST(outside)
1987         ? AvARRAY(PadlistARRAY(CvPADLIST(outside))[depth])
1988         : NULL;
1989     if (outpad) CvPADLIST(cv)->xpadl_outid = CvPADLIST(outside)->xpadl_id;
1990 
1991     for (ix = fpad; ix > 0; ix--) {
1992         PADNAME* const namesv = (ix <= fname) ? pname[ix] : NULL;
1993         SV *sv = NULL;
1994         if (namesv && PadnameLEN(namesv)) { /* lexical */
1995           if (PadnameIsOUR(namesv)) { /* or maybe not so lexical */
1996                 NOOP;
1997           }
1998           else {
1999             if (PadnameOUTER(namesv)) {   /* lexical from outside? */
2000                 /* formats may have an inactive, or even undefined, parent;
2001                    but state vars are always available. */
2002                 if (!outpad || !(sv = outpad[PARENT_PAD_INDEX(namesv)])
2003                  || (  SvPADSTALE(sv) && !PadnameIsSTATE(namesv)
2004                     && (!outside || !CvDEPTH(outside)))  ) {
2005                     S_unavailable(aTHX_ namesv);
2006                     sv = NULL;
2007                 }
2008                 else
2009                     SvREFCNT_inc_simple_void_NN(sv);
2010             }
2011             if (!sv) {
2012                 const char sigil = PadnamePV(namesv)[0];
2013                 if (sigil == '&')
2014                     /* If there are state subs, we need to clone them, too.
2015                        But they may need to close over variables we have
2016                        not cloned yet.  So we will have to do a second
2017                        pass.  Furthermore, there may be state subs clos-
2018                        ing over other state subs’ entries, so we have
2019                        to put a stub here and then clone into it on the
2020                        second pass. */
2021                     if (PadnameIsSTATE(namesv) && !CvCLONED(ppad[ix])) {
2022                         assert(SvTYPE(ppad[ix]) == SVt_PVCV);
2023                         subclones ++;
2024                         if (CvOUTSIDE(ppad[ix]) != proto)
2025                              trouble = TRUE;
2026                         sv = newSV_type(SVt_PVCV);
2027                         CvLEXICAL_on(sv);
2028                     }
2029                     else if (PadnameLEN(namesv)>1 && !PadnameIsOUR(namesv))
2030                     {
2031                         /* my sub */
2032                         /* Just provide a stub, but name it.  It will be
2033                            upgraded to the real thing on scope entry. */
2034                         U32 hash;
2035                         PERL_HASH(hash, PadnamePV(namesv)+1,
2036                                   PadnameLEN(namesv) - 1);
2037                         sv = newSV_type(SVt_PVCV);
2038                         CvNAME_HEK_set(
2039                             sv,
2040                             share_hek(PadnamePV(namesv)+1,
2041                                       1 - PadnameLEN(namesv),
2042                                       hash)
2043                         );
2044                         CvLEXICAL_on(sv);
2045                     }
2046                     else sv = SvREFCNT_inc(ppad[ix]);
2047                 else if (sigil == '@')
2048                     sv = MUTABLE_SV(newAV());
2049                 else if (sigil == '%')
2050                     sv = MUTABLE_SV(newHV());
2051                 else
2052                     sv = newSV_type(SVt_NULL);
2053                 /* reset the 'assign only once' flag on each state var */
2054                 if (sigil != '&' && PadnameIsSTATE(namesv))
2055                     SvPADSTALE_on(sv);
2056             }
2057           }
2058         }
2059         else if (namesv && PadnamePV(namesv)) {
2060             sv = SvREFCNT_inc_NN(ppad[ix]);
2061         }
2062         else {
2063             sv = newSV_type(SVt_NULL);
2064             SvPADTMP_on(sv);
2065         }
2066         PL_curpad[ix] = sv;
2067     }
2068 
2069     if (subclones)
2070     {
2071         if (trouble || cloned) {
2072             /* Uh-oh, we have trouble!  At least one of the state subs here
2073                has its CvOUTSIDE pointer pointing somewhere unexpected.  It
2074                could be pointing to another state protosub that we are
2075                about to clone.  So we have to track which sub clones come
2076                from which protosubs.  If the CvOUTSIDE pointer for a parti-
2077                cular sub points to something we have not cloned yet, we
2078                delay cloning it.  We must loop through the pad entries,
2079                until we get a full pass with no cloning.  If any uncloned
2080                subs remain (probably nested inside anonymous or ‘my’ subs),
2081                then they get cloned in a final pass.
2082              */
2083             bool cloned_in_this_pass;
2084             if (!cloned)
2085                 cloned = (HV *)newSV_type_mortal(SVt_PVHV);
2086             do {
2087                 cloned_in_this_pass = FALSE;
2088                 for (ix = fpad; ix > 0; ix--) {
2089                     PADNAME * const name =
2090                         (ix <= fname) ? pname[ix] : NULL;
2091                     if (name && name != &PL_padname_undef
2092                      && !PadnameOUTER(name) && PadnamePV(name)[0] == '&'
2093                      && PadnameIsSTATE(name) && !CvCLONED(PL_curpad[ix]))
2094                     {
2095                         CV * const protokey = CvOUTSIDE(ppad[ix]);
2096                         CV ** const cvp = protokey == proto
2097                             ? &cv
2098                             : (CV **)hv_fetch(cloned, (char *)&protokey,
2099                                               sizeof(CV *), 0);
2100                         if (cvp && *cvp) {
2101                             S_cv_clone(aTHX_ (CV *)ppad[ix],
2102                                              (CV *)PL_curpad[ix],
2103                                              *cvp, cloned);
2104                             (void)hv_store(cloned, (char *)&ppad[ix],
2105                                      sizeof(CV *),
2106                                      SvREFCNT_inc_simple_NN(PL_curpad[ix]),
2107                                      0);
2108                             subclones--;
2109                             cloned_in_this_pass = TRUE;
2110                         }
2111                     }
2112                 }
2113             } while (cloned_in_this_pass);
2114             if (subclones)
2115                 for (ix = fpad; ix > 0; ix--) {
2116                     PADNAME * const name =
2117                         (ix <= fname) ? pname[ix] : NULL;
2118                     if (name && name != &PL_padname_undef
2119                      && !PadnameOUTER(name) && PadnamePV(name)[0] == '&'
2120                      && PadnameIsSTATE(name) && !CvCLONED(PL_curpad[ix]))
2121                         S_cv_clone(aTHX_ (CV *)ppad[ix],
2122                                          (CV *)PL_curpad[ix],
2123                                          CvOUTSIDE(ppad[ix]), cloned);
2124                 }
2125         }
2126         else for (ix = fpad; ix > 0; ix--) {
2127             PADNAME * const name = (ix <= fname) ? pname[ix] : NULL;
2128             if (name && name != &PL_padname_undef && !PadnameOUTER(name)
2129              && PadnamePV(name)[0] == '&' && PadnameIsSTATE(name))
2130                 S_cv_clone(aTHX_ (CV *)ppad[ix], (CV *)PL_curpad[ix], cv,
2131                                  NULL);
2132         }
2133     }
2134 
2135     if (newcv) SvREFCNT_inc_simple_void_NN(cv);
2136     LEAVE;
2137 
2138     if (CvCONST(cv)) {
2139         /* Constant sub () { $x } closing over $x:
2140          * The prototype was marked as a candidate for const-ization,
2141          * so try to grab the current const value, and if successful,
2142          * turn into a const sub:
2143          */
2144         SV* const_sv;
2145         OP *o = CvSTART(cv);
2146         assert(newcv);
2147         for (; o; o = o->op_next)
2148             if (o->op_type == OP_PADSV)
2149                 break;
2150         ASSUME(o->op_type == OP_PADSV);
2151         const_sv = PAD_BASE_SV(CvPADLIST(cv), o->op_targ);
2152         /* the candidate should have 1 ref from this pad and 1 ref
2153          * from the parent */
2154         if (const_sv && SvREFCNT(const_sv) == 2) {
2155             const bool was_method = cBOOL(CvNOWARN_AMBIGUOUS(cv));
2156             if (outside) {
2157                 PADNAME * const pn =
2158                     PadlistNAMESARRAY(CvPADLIST(outside))
2159                         [PARENT_PAD_INDEX(PadlistNAMESARRAY(
2160                             CvPADLIST(cv))[o->op_targ])];
2161                 assert(PadnameOUTER(PadlistNAMESARRAY(CvPADLIST(cv))
2162                                         [o->op_targ]));
2163                 if (PadnameLVALUE(pn)) {
2164                     /* We have a lexical that is potentially modifiable
2165                        elsewhere, so making a constant will break clo-
2166                        sure behaviour.  If this is a ‘simple lexical
2167                        op tree’, i.e., sub(){$x}, emit a deprecation
2168                        warning, but continue to exhibit the old behav-
2169                        iour of making it a constant based on the ref-
2170                        count of the candidate variable.
2171 
2172                        A simple lexical op tree looks like this:
2173 
2174                          leavesub
2175                            lineseq
2176                              nextstate
2177                              padsv
2178                      */
2179                     if (OpSIBLING(
2180                          cUNOPx(cUNOPx(CvROOT(cv))->op_first)->op_first
2181                         ) == o
2182                      && !OpSIBLING(o))
2183                     {
2184                         Perl_croak(aTHX_
2185                             "Constants from lexical variables potentially modified "
2186                             "elsewhere are no longer permitted");
2187                     }
2188                     else
2189                         goto constoff;
2190                 }
2191             }
2192             SvREFCNT_inc_simple_void_NN(const_sv);
2193             /* If the lexical is not used elsewhere, it is safe to turn on
2194                SvPADTMP, since it is only when it is used in lvalue con-
2195                text that the difference is observable.  */
2196             SvREADONLY_on(const_sv);
2197             SvPADTMP_on(const_sv);
2198             SvREFCNT_dec_NN(cv);
2199             cv = newCONSTSUB(CvSTASH(proto), NULL, const_sv);
2200             if (was_method)
2201                 CvNOWARN_AMBIGUOUS_on(cv);
2202         }
2203         else {
2204           constoff:
2205             CvCONST_off(cv);
2206         }
2207     }
2208 
2209     return cv;
2210 }
2211 
2212 static CV *
S_cv_clone(pTHX_ CV * proto,CV * cv,CV * outside,HV * cloned)2213 S_cv_clone(pTHX_ CV *proto, CV *cv, CV *outside, HV *cloned)
2214 {
2215     const bool newcv = !cv;
2216 
2217     assert(!CvUNIQUE(proto));
2218 
2219     if (!cv) cv = MUTABLE_CV(newSV_type(SvTYPE(proto)));
2220     CvFLAGS(cv) = CvFLAGS(proto) & ~(CVf_CLONE|CVf_WEAKOUTSIDE|CVf_CVGV_RC
2221                                     |CVf_SLABBED);
2222     CvCLONED_on(cv);
2223 
2224     CvFILE(cv)		= CvDYNFILE(proto) ? savepv(CvFILE(proto))
2225                                            : CvFILE(proto);
2226     if (CvNAMED(proto))
2227          CvNAME_HEK_set(cv, share_hek_hek(CvNAME_HEK(proto)));
2228     else CvGV_set(cv,CvGV(proto));
2229     CvSTASH_set(cv, CvSTASH(proto));
2230 
2231     /* It is unlikely that proto is an xsub, but it could happen; e.g. if a
2232      * module has performed a lexical sub import trick on an xsub. This
2233      * happens with builtin::import, for example
2234      */
2235     if (UNLIKELY(CvISXSUB(proto))) {
2236         CvXSUB(cv)    = CvXSUB(proto);
2237         CvXSUBANY(cv) = CvXSUBANY(proto);
2238         if (CvREFCOUNTED_ANYSV(cv) || CvCONST(cv))
2239             SvREFCNT_inc(CvXSUBANY(cv).any_sv);
2240     }
2241     else {
2242         OP_REFCNT_LOCK;
2243         CvROOT(cv) = OpREFCNT_inc(CvROOT(proto));
2244         OP_REFCNT_UNLOCK;
2245         CvSTART(cv) = CvSTART(proto);
2246         CvOUTSIDE_SEQ(cv) = CvOUTSIDE_SEQ(proto);
2247     }
2248 
2249     if (SvPOK(proto)) {
2250         sv_setpvn(MUTABLE_SV(cv), SvPVX_const(proto), SvCUR(proto));
2251         if (SvUTF8(proto))
2252            SvUTF8_on(MUTABLE_SV(cv));
2253     }
2254     if (SvMAGIC(proto))
2255         mg_copy((SV *)proto, (SV *)cv, 0, 0);
2256 
2257     if (!CvISXSUB(proto) && CvPADLIST(proto))
2258         cv = S_cv_clone_pad(aTHX_ proto, cv, outside, cloned, newcv);
2259 
2260     DEBUG_Xv(
2261         PerlIO_printf(Perl_debug_log, "\nPad CV clone\n");
2262         if (CvOUTSIDE(cv)) cv_dump(CvOUTSIDE(cv), "Outside");
2263         cv_dump(proto,	 "Proto");
2264         cv_dump(cv,	 "To");
2265     );
2266 
2267     return cv;
2268 }
2269 
2270 CV *
Perl_cv_clone(pTHX_ CV * proto)2271 Perl_cv_clone(pTHX_ CV *proto)
2272 {
2273     PERL_ARGS_ASSERT_CV_CLONE;
2274 
2275     if (!CvPADLIST(proto)) Perl_croak(aTHX_ "panic: no pad in cv_clone");
2276     return S_cv_clone(aTHX_ proto, NULL, NULL, NULL);
2277 }
2278 
2279 /* Called only by pp_clonecv */
2280 CV *
Perl_cv_clone_into(pTHX_ CV * proto,CV * target)2281 Perl_cv_clone_into(pTHX_ CV *proto, CV *target)
2282 {
2283     PERL_ARGS_ASSERT_CV_CLONE_INTO;
2284     cv_undef(target);
2285     return S_cv_clone(aTHX_ proto, target, NULL, NULL);
2286 }
2287 
2288 /*
2289 =for apidoc cv_name
2290 
2291 Returns an SV containing the name of the CV, mainly for use in error
2292 reporting.  The CV may actually be a GV instead, in which case the returned
2293 SV holds the GV's name.  Anything other than a GV or CV is treated as a
2294 string already holding the sub name, but this could change in the future.
2295 
2296 An SV may be passed as a second argument.  If so, the name will be assigned
2297 to it and it will be returned.  Otherwise the returned SV will be a new
2298 mortal.
2299 
2300 If C<flags> has the C<CV_NAME_NOTQUAL> bit set, then the package name will not be
2301 included.  If the first argument is neither a CV nor a GV, this flag is
2302 ignored (subject to change).
2303 
2304 =for apidoc Amnh||CV_NAME_NOTQUAL
2305 
2306 =cut
2307 */
2308 
2309 SV *
Perl_cv_name(pTHX_ CV * cv,SV * sv,U32 flags)2310 Perl_cv_name(pTHX_ CV *cv, SV *sv, U32 flags)
2311 {
2312     PERL_ARGS_ASSERT_CV_NAME;
2313     if (!isGV_with_GP(cv) && SvTYPE(cv) != SVt_PVCV) {
2314         if (sv) sv_setsv(sv,(SV *)cv);
2315         return sv ? (sv) : (SV *)cv;
2316     }
2317     {
2318         SV * const retsv = sv ? (sv) : sv_newmortal();
2319         if (SvTYPE(cv) == SVt_PVCV) {
2320             if (CvNAMED(cv)) {
2321                 if (CvLEXICAL(cv) || flags & CV_NAME_NOTQUAL)
2322                     sv_sethek(retsv, CvNAME_HEK(cv));
2323                 else {
2324                     if (CvSTASH(cv) && HvNAME_HEK(CvSTASH(cv)))
2325                         sv_sethek(retsv, HvNAME_HEK(CvSTASH(cv)));
2326                     else
2327                         sv_setpvs(retsv, "__ANON__");
2328                     sv_catpvs(retsv, "::");
2329                     sv_cathek(retsv, CvNAME_HEK(cv));
2330                 }
2331             }
2332             else if (CvLEXICAL(cv) || flags & CV_NAME_NOTQUAL)
2333                 sv_sethek(retsv, GvNAME_HEK(GvEGV(CvGV(cv))));
2334             else gv_efullname3(retsv, CvGV(cv), NULL);
2335         }
2336         else if (flags & CV_NAME_NOTQUAL) sv_sethek(retsv, GvNAME_HEK(cv));
2337         else gv_efullname3(retsv,(GV *)cv,NULL);
2338         return retsv;
2339     }
2340 }
2341 
2342 /*
2343 =for apidoc pad_fixup_inner_anons
2344 
2345 For any anon CVs in the pad, change C<CvOUTSIDE> of that CV from
2346 C<old_cv> to C<new_cv> if necessary.  Needed when a newly-compiled CV has to be
2347 moved to a pre-existing CV struct.
2348 
2349 =cut
2350 */
2351 
2352 void
Perl_pad_fixup_inner_anons(pTHX_ PADLIST * padlist,CV * old_cv,CV * new_cv)2353 Perl_pad_fixup_inner_anons(pTHX_ PADLIST *padlist, CV *old_cv, CV *new_cv)
2354 {
2355     PADOFFSET ix;
2356     PADNAMELIST * const comppad_name = PadlistNAMES(padlist);
2357     AV * const comppad = PadlistARRAY(padlist)[1];
2358     PADNAME ** const namepad = PadnamelistARRAY(comppad_name);
2359     SV ** const curpad = AvARRAY(comppad);
2360 
2361     PERL_ARGS_ASSERT_PAD_FIXUP_INNER_ANONS;
2362     PERL_UNUSED_ARG(old_cv);
2363 
2364     for (ix = PadnamelistMAX(comppad_name); ix > 0; ix--) {
2365         const PADNAME *name = namepad[ix];
2366         if (name && name != &PL_padname_undef && !PadnameIsOUR(name)
2367             && *PadnamePV(name) == '&')
2368         {
2369           CV *innercv = MUTABLE_CV(curpad[ix]);
2370           if (UNLIKELY(PadnameOUTER(name))) {
2371             CV *cv = new_cv;
2372             PADNAME **names = namepad;
2373             PADOFFSET i = ix;
2374             while (PadnameOUTER(name)) {
2375                 assert(SvTYPE(cv) == SVt_PVCV);
2376                 cv = CvOUTSIDE(cv);
2377                 names = PadlistNAMESARRAY(CvPADLIST(cv));
2378                 i = PARENT_PAD_INDEX(name);
2379                 name = names[i];
2380             }
2381             innercv = (CV *)PadARRAY(PadlistARRAY(CvPADLIST(cv))[1])[i];
2382           }
2383           if (SvTYPE(innercv) == SVt_PVCV) {
2384             /* XXX 0afba48f added code here to check for a proto CV
2385                    attached to the pad entry by magic.  But shortly there-
2386                    after 81df9f6f95 moved the magic to the pad name.  The
2387                    code here was never updated, so it wasn’t doing anything
2388                    and got deleted when PADNAME became a distinct type.  Is
2389                    there any bug as a result?  */
2390             if (CvOUTSIDE(innercv) == old_cv) {
2391                 if (!CvWEAKOUTSIDE(innercv)) {
2392                     SvREFCNT_dec(old_cv);
2393                     SvREFCNT_inc_simple_void_NN(new_cv);
2394                 }
2395                 CvOUTSIDE(innercv) = new_cv;
2396             }
2397           }
2398           else { /* format reference */
2399             SV * const rv = curpad[ix];
2400             CV *innercv;
2401             if (!SvOK(rv)) continue;
2402             assert(SvROK(rv));
2403             assert(SvWEAKREF(rv));
2404             innercv = (CV *)SvRV(rv);
2405             assert(!CvWEAKOUTSIDE(innercv));
2406             assert(CvOUTSIDE(innercv) == old_cv);
2407             SvREFCNT_dec(CvOUTSIDE(innercv));
2408             CvOUTSIDE(innercv) = (CV *)SvREFCNT_inc_simple_NN(new_cv);
2409           }
2410         }
2411     }
2412 }
2413 
2414 /*
2415 =for apidoc pad_push
2416 
2417 Push a new pad frame onto the padlist, unless there's already a pad at
2418 this depth, in which case don't bother creating a new one.  Then give
2419 the new pad an C<@_> in slot zero.
2420 
2421 =cut
2422 */
2423 
2424 void
Perl_pad_push(pTHX_ PADLIST * padlist,int depth)2425 Perl_pad_push(pTHX_ PADLIST *padlist, int depth)
2426 {
2427     PERL_ARGS_ASSERT_PAD_PUSH;
2428 
2429     if (depth > PadlistMAX(padlist) || !PadlistARRAY(padlist)[depth]) {
2430         PAD** const svp = PadlistARRAY(padlist);
2431         AV* const newpad = newAV();
2432         SV** const oldpad = AvARRAY(svp[depth-1]);
2433         PADOFFSET ix = AvFILLp((const AV *)svp[1]);
2434         const PADOFFSET names_fill = PadnamelistMAX((PADNAMELIST *)svp[0]);
2435         PADNAME ** const names = PadnamelistARRAY((PADNAMELIST *)svp[0]);
2436         AV *av;
2437 
2438         Newxz( AvALLOC(newpad), ix + 1, SV *);
2439         AvARRAY(newpad) = AvALLOC(newpad);
2440         AvMAX(newpad) = AvFILLp(newpad) = ix;
2441 
2442         for ( ;ix > 0; ix--) {
2443             SV *sv;
2444             if (names_fill >= ix && PadnameLEN(names[ix])) {
2445                 const char sigil = PadnamePV(names[ix])[0];
2446                 if (PadnameOUTER(names[ix])
2447                         || PadnameIsSTATE(names[ix])
2448                         || sigil == '&')
2449                 {
2450                     SV *tmp = oldpad[ix];
2451                     if (sigil == '&' && SvTYPE(tmp) == SVt_PVCV
2452                         && !PadnameOUTER(names[ix])
2453                         && CvLEXICAL(tmp) && CvCLONED(tmp)
2454                         && !PadnameIsOUR(names[ix])
2455                         && !PadnameIsSTATE(names[ix])) {
2456                         /* lexical sub that needs cloning */
2457                         sv = newSV_type(SVt_PVCV);
2458                     }
2459                     else {
2460                         /* outer non-cloning lexical or anon code */
2461                         sv = SvREFCNT_inc(tmp);
2462                     }
2463                 }
2464                 else {		/* our own lexical */
2465                     if (sigil == '@')
2466                         sv = MUTABLE_SV(newAV());
2467                     else if (sigil == '%')
2468                         sv = MUTABLE_SV(newHV());
2469                     else
2470                         sv = newSV_type(SVt_NULL);
2471                 }
2472             }
2473             else if (PadnamePV(names[ix])) {
2474                 sv = SvREFCNT_inc_NN(oldpad[ix]);
2475             }
2476             else {
2477                 /* save temporaries on recursion? */
2478                 sv = newSV_type(SVt_NULL);
2479                 SvPADTMP_on(sv);
2480             }
2481             AvARRAY(newpad)[ix] = sv;
2482         }
2483         av = newAV();
2484         AvARRAY(newpad)[0] = MUTABLE_SV(av);
2485 #ifndef PERL_RC_STACK
2486         AvREIFY_only(av);
2487 #endif
2488 
2489         padlist_store(padlist, depth, newpad);
2490     }
2491 }
2492 
2493 #if defined(USE_ITHREADS)
2494 
2495 /*
2496 =for apidoc padlist_dup
2497 
2498 Duplicates a pad.
2499 
2500 =cut
2501 */
2502 
2503 PADLIST *
Perl_padlist_dup(pTHX_ PADLIST * srcpad,CLONE_PARAMS * param)2504 Perl_padlist_dup(pTHX_ PADLIST *srcpad, CLONE_PARAMS *param)
2505 {
2506     PADLIST *dstpad;
2507     bool cloneall;
2508     PADOFFSET max;
2509 
2510     PERL_ARGS_ASSERT_PADLIST_DUP;
2511 
2512     cloneall = cBOOL(param->flags & CLONEf_COPY_STACKS);
2513     assert (SvREFCNT(PadlistARRAY(srcpad)[1]) == 1);
2514 
2515     max = cloneall ? PadlistMAX(srcpad) : 1;
2516 
2517     Newx(dstpad, 1, PADLIST);
2518     ptr_table_store(PL_ptr_table, srcpad, dstpad);
2519     PadlistMAX(dstpad) = max;
2520     Newx(PadlistARRAY(dstpad), max + 1, PAD *);
2521 
2522     PadlistARRAY(dstpad)[0] = (PAD *)padnamelist_dup_inc(PadlistNAMES(srcpad), param);
2523     if (cloneall) {
2524         PADOFFSET depth;
2525         for (depth = 1; depth <= max; ++depth)
2526             PadlistARRAY(dstpad)[depth] =
2527                 av_dup_inc(PadlistARRAY(srcpad)[depth], param);
2528     } else {
2529         /* CvDEPTH() on our subroutine will be set to 0, so there's no need
2530            to build anything other than the first level of pads.  */
2531         PADOFFSET ix = AvFILLp(PadlistARRAY(srcpad)[1]);
2532         AV *pad1;
2533         const PADOFFSET names_fill = PadnamelistMAX(PadlistNAMES(srcpad));
2534         const PAD *const srcpad1 = PadlistARRAY(srcpad)[1];
2535         SV **oldpad = AvARRAY(srcpad1);
2536         PADNAME ** const names = PadnamelistARRAY(PadlistNAMES(dstpad));
2537         SV **pad1a;
2538         AV *args;
2539 
2540         pad1 = newAV();
2541 
2542         av_extend(pad1, ix);
2543         PadlistARRAY(dstpad)[1] = pad1;
2544         pad1a = AvARRAY(pad1);
2545 
2546         if (ix > -1) {
2547             AvFILLp(pad1) = ix;
2548 
2549             for ( ;ix > 0; ix--) {
2550                 if (!oldpad[ix]) {
2551                     pad1a[ix] = NULL;
2552                 } else if (names_fill >= ix && names[ix] &&
2553                            PadnameLEN(names[ix])) {
2554                     const char sigil = PadnamePV(names[ix])[0];
2555                     if (PadnameOUTER(names[ix])
2556                         || PadnameIsSTATE(names[ix])
2557                         || sigil == '&')
2558                         {
2559                             /* outer lexical or anon code */
2560                             pad1a[ix] = sv_dup_inc(oldpad[ix], param);
2561                         }
2562                     else {		/* our own lexical */
2563                         if(SvPADSTALE(oldpad[ix]) && SvREFCNT(oldpad[ix]) > 1) {
2564                             /* This is a work around for how the current
2565                                implementation of ?{ } blocks in regexps
2566                                interacts with lexicals.  */
2567                             pad1a[ix] = sv_dup_inc(oldpad[ix], param);
2568                         } else {
2569                             SV *sv;
2570 
2571                             if (sigil == '@')
2572                                 sv = MUTABLE_SV(newAV());
2573                             else if (sigil == '%')
2574                                 sv = MUTABLE_SV(newHV());
2575                             else
2576                                 sv = newSV_type(SVt_NULL);
2577                             pad1a[ix] = sv;
2578                         }
2579                     }
2580                 }
2581                 else if ((  names_fill >= ix && names[ix]
2582                          && PadnamePV(names[ix])  )) {
2583                     pad1a[ix] = sv_dup_inc(oldpad[ix], param);
2584                 }
2585                 else {
2586                     /* save temporaries on recursion? */
2587                     SV * const sv = newSV_type(SVt_NULL);
2588                     pad1a[ix] = sv;
2589 
2590                     /* SvREFCNT(oldpad[ix]) != 1 for some code in threads.xs
2591                        FIXTHAT before merging this branch.
2592                        (And I know how to) */
2593                     if (SvPADTMP(oldpad[ix]))
2594                         SvPADTMP_on(sv);
2595                 }
2596             }
2597 
2598             if (oldpad[0]) {
2599                 args = newAV();			/* Will be @_ */
2600 #ifndef PERL_RC_STACK
2601                 AvREIFY_only(args);
2602 #endif
2603                 pad1a[0] = (SV *)args;
2604             }
2605         }
2606     }
2607 
2608     return dstpad;
2609 }
2610 
2611 #endif /* USE_ITHREADS */
2612 
2613 PAD **
Perl_padlist_store(pTHX_ PADLIST * padlist,I32 key,PAD * val)2614 Perl_padlist_store(pTHX_ PADLIST *padlist, I32 key, PAD *val)
2615 {
2616     PAD **ary;
2617     SSize_t const oldmax = PadlistMAX(padlist);
2618 
2619     PERL_ARGS_ASSERT_PADLIST_STORE;
2620 
2621     assert(key >= 0);
2622 
2623     if (key > PadlistMAX(padlist)) {
2624         av_extend_guts(NULL,key,&PadlistMAX(padlist),
2625                        (SV ***)&PadlistARRAY(padlist),
2626                        (SV ***)&PadlistARRAY(padlist));
2627         Zero(PadlistARRAY(padlist)+oldmax+1, PadlistMAX(padlist)-oldmax,
2628              PAD *);
2629     }
2630     ary = PadlistARRAY(padlist);
2631     SvREFCNT_dec(ary[key]);
2632     ary[key] = val;
2633     return &ary[key];
2634 }
2635 
2636 /*
2637 =for apidoc newPADNAMELIST
2638 
2639 Creates a new pad name list.  C<max> is the highest index for which space
2640 is allocated.
2641 
2642 =cut
2643 */
2644 
2645 PADNAMELIST *
Perl_newPADNAMELIST(size_t max)2646 Perl_newPADNAMELIST(size_t max)
2647 {
2648     PADNAMELIST *pnl;
2649     Newx(pnl, 1, PADNAMELIST);
2650     Newxz(PadnamelistARRAY(pnl), max+1, PADNAME *);
2651     PadnamelistMAX(pnl) = -1;
2652     PadnamelistREFCNT(pnl) = 1;
2653     PadnamelistMAXNAMED(pnl) = 0;
2654     pnl->xpadnl_max = max;
2655     return pnl;
2656 }
2657 
2658 /*
2659 =for apidoc padnamelist_store
2660 
2661 Stores the pad name (which may be null) at the given index, freeing any
2662 existing pad name in that slot.
2663 
2664 =cut
2665 */
2666 
2667 PADNAME **
Perl_padnamelist_store(pTHX_ PADNAMELIST * pnl,SSize_t key,PADNAME * val)2668 Perl_padnamelist_store(pTHX_ PADNAMELIST *pnl, SSize_t key, PADNAME *val)
2669 {
2670     PADNAME **ary;
2671 
2672     PERL_ARGS_ASSERT_PADNAMELIST_STORE;
2673 
2674     assert(key >= 0);
2675 
2676     if (key > pnl->xpadnl_max)
2677         av_extend_guts(NULL,key,&pnl->xpadnl_max,
2678                        (SV ***)&PadnamelistARRAY(pnl),
2679                        (SV ***)&PadnamelistARRAY(pnl));
2680     if (PadnamelistMAX(pnl) < key) {
2681         Zero(PadnamelistARRAY(pnl)+PadnamelistMAX(pnl)+1,
2682              key-PadnamelistMAX(pnl), PADNAME *);
2683         PadnamelistMAX(pnl) = key;
2684     }
2685     ary = PadnamelistARRAY(pnl);
2686     if (ary[key])
2687         PadnameREFCNT_dec(ary[key]);
2688     ary[key] = val;
2689     return &ary[key];
2690 }
2691 
2692 /*
2693 =for apidoc padnamelist_fetch
2694 
2695 Fetches the pad name from the given index.
2696 
2697 =cut
2698 */
2699 
2700 PADNAME *
Perl_padnamelist_fetch(PADNAMELIST * pnl,SSize_t key)2701 Perl_padnamelist_fetch(PADNAMELIST *pnl, SSize_t key)
2702 {
2703     PERL_ARGS_ASSERT_PADNAMELIST_FETCH;
2704     ASSUME(key >= 0);
2705 
2706     return key > PadnamelistMAX(pnl) ? NULL : PadnamelistARRAY(pnl)[key];
2707 }
2708 
2709 void
Perl_padnamelist_free(pTHX_ PADNAMELIST * pnl)2710 Perl_padnamelist_free(pTHX_ PADNAMELIST *pnl)
2711 {
2712     PERL_ARGS_ASSERT_PADNAMELIST_FREE;
2713     if (!--PadnamelistREFCNT(pnl)) {
2714         while(PadnamelistMAX(pnl) >= 0)
2715         {
2716             PADNAME * const pn =
2717                 PadnamelistARRAY(pnl)[PadnamelistMAX(pnl)--];
2718             if (pn)
2719                 PadnameREFCNT_dec(pn);
2720         }
2721         Safefree(PadnamelistARRAY(pnl));
2722         Safefree(pnl);
2723     }
2724 }
2725 
2726 #if defined(USE_ITHREADS)
2727 
2728 /*
2729 =for apidoc padnamelist_dup
2730 
2731 Duplicates a pad name list.
2732 
2733 =cut
2734 */
2735 
2736 PADNAMELIST *
Perl_padnamelist_dup(pTHX_ PADNAMELIST * srcpad,CLONE_PARAMS * param)2737 Perl_padnamelist_dup(pTHX_ PADNAMELIST *srcpad, CLONE_PARAMS *param)
2738 {
2739     PADNAMELIST *dstpad;
2740     SSize_t max = PadnamelistMAX(srcpad);
2741 
2742     PERL_ARGS_ASSERT_PADNAMELIST_DUP;
2743 
2744     /* look for it in the table first */
2745     dstpad = (PADNAMELIST *)ptr_table_fetch(PL_ptr_table, srcpad);
2746     if (dstpad)
2747         return dstpad;
2748 
2749     dstpad = newPADNAMELIST(max);
2750     PadnamelistREFCNT(dstpad) = 0; /* The caller will increment it.  */
2751     PadnamelistMAXNAMED(dstpad) = PadnamelistMAXNAMED(srcpad);
2752     PadnamelistMAX(dstpad) = max;
2753 
2754     ptr_table_store(PL_ptr_table, srcpad, dstpad);
2755     for (; max >= 0; max--)
2756       if (PadnamelistARRAY(srcpad)[max]) {
2757         PadnamelistARRAY(dstpad)[max] =
2758             padname_dup_inc(PadnamelistARRAY(srcpad)[max], param);
2759       }
2760 
2761     return dstpad;
2762 }
2763 
2764 #endif /* USE_ITHREADS */
2765 
2766 /*
2767 =for apidoc newPADNAMEpvn
2768 
2769 Constructs and returns a new pad name.  C<s> must be a UTF-8 string.  Do not
2770 use this for pad names that point to outer lexicals.  See
2771 C<L</newPADNAMEouter>>.
2772 
2773 =cut
2774 */
2775 
2776 PADNAME *
Perl_newPADNAMEpvn(const char * s,STRLEN len)2777 Perl_newPADNAMEpvn(const char *s, STRLEN len)
2778 {
2779     struct padname_with_str *alloc;
2780     char *alloc2; /* for Newxz */
2781     PADNAME *pn;
2782     PERL_ARGS_ASSERT_NEWPADNAMEPVN;
2783     Newxz(alloc2,
2784           STRUCT_OFFSET(struct padname_with_str, xpadn_str[0]) + len + 1,
2785           char);
2786     alloc = (struct padname_with_str *)alloc2;
2787     pn = (PADNAME *)alloc;
2788     PadnameREFCNT(pn) = 1;
2789     PadnamePV(pn) = alloc->xpadn_str;
2790     Copy(s, PadnamePV(pn), len, char);
2791     *(PadnamePV(pn) + len) = '\0';
2792     PadnameLEN(pn) = len;
2793     return pn;
2794 }
2795 
2796 /*
2797 =for apidoc newPADNAMEouter
2798 
2799 Constructs and returns a new pad name.  Only use this function for names
2800 that refer to outer lexicals.  (See also L</newPADNAMEpvn>.)  C<outer> is
2801 the outer pad name that this one mirrors.  The returned pad name has the
2802 C<PADNAMEf_OUTER> flag already set.
2803 
2804 =for apidoc Amnh||PADNAMEf_OUTER
2805 
2806 =cut
2807 */
2808 
2809 PADNAME *
Perl_newPADNAMEouter(PADNAME * outer)2810 Perl_newPADNAMEouter(PADNAME *outer)
2811 {
2812     PADNAME *pn;
2813     PERL_ARGS_ASSERT_NEWPADNAMEOUTER;
2814     Newxz(pn, 1, PADNAME);
2815     PadnameREFCNT(pn) = 1;
2816     PadnamePV(pn) = PadnamePV(outer);
2817     /* Not PadnameREFCNT(outer), because ‘outer’ may itself close over
2818        another entry.  The original pad name owns the buffer.  */
2819     PadnameREFCNT_inc(PADNAME_FROM_PV(PadnamePV(outer)));
2820     PadnameFLAGS(pn) = PADNAMEf_OUTER;
2821     if(PadnameIsFIELD(outer)) {
2822         PadnameFIELDINFO(pn) = PadnameFIELDINFO(outer);
2823         PadnameFIELDINFO(pn)->refcount++;
2824         PadnameFLAGS(pn) |= PADNAMEf_FIELD;
2825     }
2826     PadnameLEN(pn) = PadnameLEN(outer);
2827     return pn;
2828 }
2829 
2830 void
Perl_padname_free(pTHX_ PADNAME * pn)2831 Perl_padname_free(pTHX_ PADNAME *pn)
2832 {
2833     PERL_ARGS_ASSERT_PADNAME_FREE;
2834     if (!--PadnameREFCNT(pn)) {
2835         if (UNLIKELY(pn == &PL_padname_undef || pn == &PL_padname_const)) {
2836             PadnameREFCNT(pn) = SvREFCNT_IMMORTAL;
2837             return;
2838         }
2839         SvREFCNT_dec(PadnameTYPE(pn)); /* Takes care of protocv, too.  */
2840         SvREFCNT_dec(PadnameOURSTASH(pn));
2841         if (PadnameOUTER(pn))
2842             PadnameREFCNT_dec(PADNAME_FROM_PV(PadnamePV(pn)));
2843         if (PadnameIsFIELD(pn)) {
2844             struct padname_fieldinfo *info = PadnameFIELDINFO(pn);
2845             if(!--info->refcount) {
2846                 SvREFCNT_dec(info->fieldstash);
2847                 /* todo: something about defop */
2848                 SvREFCNT_dec(info->paramname);
2849 
2850                 Safefree(info);
2851             }
2852         }
2853         Safefree(pn);
2854     }
2855 }
2856 
2857 #if defined(USE_ITHREADS)
2858 
2859 /*
2860 =for apidoc padname_dup
2861 
2862 Duplicates a pad name.
2863 
2864 =cut
2865 */
2866 
2867 PADNAME *
Perl_padname_dup(pTHX_ PADNAME * src,CLONE_PARAMS * param)2868 Perl_padname_dup(pTHX_ PADNAME *src, CLONE_PARAMS *param)
2869 {
2870     PADNAME *dst;
2871 
2872     PERL_ARGS_ASSERT_PADNAME_DUP;
2873 
2874     /* look for it in the table first */
2875     dst = (PADNAME *)ptr_table_fetch(PL_ptr_table, src);
2876     if (dst)
2877         return dst;
2878 
2879     if (!PadnamePV(src)) {
2880         dst = &PL_padname_undef;
2881         ptr_table_store(PL_ptr_table, src, dst);
2882         return dst;
2883     }
2884 
2885     dst = PadnameOUTER(src)
2886      ? newPADNAMEouter(padname_dup(PADNAME_FROM_PV(PadnamePV(src)), param))
2887      : newPADNAMEpvn(PadnamePV(src), PadnameLEN(src));
2888     ptr_table_store(PL_ptr_table, src, dst);
2889     PadnameLEN(dst) = PadnameLEN(src);
2890     PadnameFLAGS(dst) = PadnameFLAGS(src);
2891     PadnameREFCNT(dst) = 0; /* The caller will increment it.  */
2892     PadnameTYPE   (dst) = (HV *)sv_dup_inc((SV *)PadnameTYPE(src), param);
2893     PadnameOURSTASH(dst) = (HV *)sv_dup_inc((SV *)PadnameOURSTASH(src),
2894                                             param);
2895     if(PadnameIsFIELD(src) && !PadnameOUTER(src)) {
2896         struct padname_fieldinfo *sinfo = PadnameFIELDINFO(src);
2897         struct padname_fieldinfo *dinfo;
2898         Newxz(dinfo, 1, struct padname_fieldinfo);
2899 
2900         dinfo->refcount   = 1;
2901         dinfo->fieldix    = sinfo->fieldix;
2902         dinfo->fieldstash = hv_dup_inc(sinfo->fieldstash, param);
2903         dinfo->paramname  = sv_dup_inc(sinfo->paramname, param);
2904 
2905         PadnameFIELDINFO(dst) = dinfo;
2906     }
2907     dst->xpadn_low  = src->xpadn_low;
2908     dst->xpadn_high = src->xpadn_high;
2909     dst->xpadn_gen  = src->xpadn_gen;
2910     return dst;
2911 }
2912 
2913 #endif /* USE_ITHREADS */
2914 
2915 /*
2916 =for apidoc_section $lexer
2917 =for apidoc suspend_compcv
2918 
2919 Implements part of the concept of a "suspended compilation CV", which can be
2920 used to pause the parser and compiler during parsing a CV in order to come
2921 back to it later on.
2922 
2923 This function saves the current state of the subroutine under compilation
2924 (C<PL_compcv>) into the supplied buffer.  This should be used initially to
2925 create the state in the buffer, as the final thing before a C<LEAVE> within a
2926 block.
2927 
2928     ENTER;
2929     start_subparse(0);
2930     ...
2931 
2932     suspend_compcv(&buffer);
2933     LEAVE;
2934 
2935 Once suspended, the C<resume_compcv_final> or C<resume_compcv_and_save>
2936 function can later be used to continue the parsing from the point this stopped.
2937 
2938 =cut
2939 */
2940 
2941 void
Perl_suspend_compcv(pTHX_ struct suspended_compcv * buffer)2942 Perl_suspend_compcv(pTHX_ struct suspended_compcv *buffer)
2943 {
2944     PERL_ARGS_ASSERT_SUSPEND_COMPCV;
2945 
2946     buffer->compcv = PL_compcv;
2947 
2948     buffer->padix             = PL_padix;
2949     buffer->constpadix        = PL_constpadix;
2950 
2951     buffer->comppad_name_fill = PL_comppad_name_fill;
2952     buffer->min_intro_pending = PL_min_intro_pending;
2953     buffer->max_intro_pending = PL_max_intro_pending;
2954 
2955     buffer->cv_has_eval       = PL_cv_has_eval;
2956     buffer->pad_reset_pending = PL_pad_reset_pending;
2957 }
2958 
2959 /*
2960 =for apidoc resume_compcv_final
2961 
2962 Resumes the parser state previously saved using the C<suspend_compcv> function
2963 for a final time before being compiled into a full CV.  This should be used
2964 within an C<ENTER>/C<LEAVE> scoped pair.
2965 
2966 =for apidoc resume_compcv_and_save
2967 
2968 Resumes a buffer previously suspended by the C<suspend_compcv> function, in a
2969 way that will be re-suspended at the end of the scope so it can be used again
2970 later.  This should be used within an C<ENTER>/C<LEAVE> scoped pair.
2971 
2972 =cut
2973 */
2974 
2975 void
Perl_resume_compcv(pTHX_ struct suspended_compcv * buffer,bool save)2976 Perl_resume_compcv(pTHX_ struct suspended_compcv *buffer, bool save)
2977 {
2978     PERL_ARGS_ASSERT_RESUME_COMPCV;
2979 
2980     SAVESPTR(PL_compcv);
2981     PL_compcv = buffer->compcv;
2982     PAD_SET_CUR(CvPADLIST(PL_compcv), 1);
2983 
2984     SAVESPTR(PL_comppad_name);
2985     PL_comppad_name = PadlistNAMES(CvPADLIST(PL_compcv));
2986 
2987     SAVESTRLEN(PL_padix);             PL_padix             = buffer->padix;
2988     SAVESTRLEN(PL_constpadix);        PL_constpadix        = buffer->constpadix;
2989     SAVESTRLEN(PL_comppad_name_fill); PL_comppad_name_fill = buffer->comppad_name_fill;
2990     SAVESTRLEN(PL_min_intro_pending); PL_min_intro_pending = buffer->min_intro_pending;
2991     SAVESTRLEN(PL_max_intro_pending); PL_max_intro_pending = buffer->max_intro_pending;
2992 
2993     SAVEBOOL(PL_cv_has_eval);       PL_cv_has_eval       = buffer->cv_has_eval;
2994     SAVEBOOL(PL_pad_reset_pending); PL_pad_reset_pending = buffer->pad_reset_pending;
2995 
2996     if(save)
2997         SAVEDESTRUCTOR_X(&Perl_suspend_compcv, buffer);
2998 }
2999 
3000 /*
3001  * ex: set ts=8 sts=4 sw=4 et:
3002  */
3003