3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
4 * 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others
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.
12 * '...for the Entwives desired order, and plenty, and peace (by which they
13 * meant that things should remain where they had set them).' --Treebeard
15 * [p.476 of _The Lord of the Rings_, III/iv: "Treebeard"]
23 Perl_av_reify(pTHX_ AV *av)
27 PERL_ARGS_ASSERT_AV_REIFY;
28 assert(SvTYPE(av) == SVt_PVAV);
33 if (SvTIED_mg((const SV *)av, PERL_MAGIC_tied))
34 Perl_ck_warner_d(aTHX_ packWARN(WARN_DEBUGGING), "av_reify called on tied array");
37 while (key > AvFILLp(av) + 1)
38 AvARRAY(av)[--key] = NULL;
40 SV * const sv = AvARRAY(av)[--key];
41 if (sv != &PL_sv_undef)
42 SvREFCNT_inc_simple_void(sv);
44 key = AvARRAY(av) - AvALLOC(av);
46 AvALLOC(av)[--key] = NULL;
54 Pre-extend an array so that it is capable of storing values at indexes
55 C<0..key>. Thus C<av_extend(av,99)> guarantees that the array can store 100
56 elements, i.e. that C<av_store(av, 0, sv)> through C<av_store(av, 99, sv)>
57 on a plain array will work without any further memory allocation.
59 If the av argument is a tied array then will call the C<EXTEND> tied
60 array method with an argument of C<(key+1)>.
66 Perl_av_extend(pTHX_ AV *av, SSize_t key)
70 PERL_ARGS_ASSERT_AV_EXTEND;
71 assert(SvTYPE(av) == SVt_PVAV);
73 mg = SvTIED_mg((const SV *)av, PERL_MAGIC_tied);
75 SV *arg1 = sv_newmortal();
76 /* NOTE: the API for av_extend() is NOT the same as the tie method EXTEND.
78 * The C function takes an *index* (assumes 0 indexed arrays) and ensures
79 * that the array is at least as large as the index provided.
81 * The tied array method EXTEND takes a *count* and ensures that the array
82 * is at least that many elements large. Thus we have to +1 the key when
83 * we call the tied method.
85 sv_setiv(arg1, (IV)(key + 1));
86 Perl_magic_methcall(aTHX_ MUTABLE_SV(av), mg, SV_CONST(EXTEND), G_DISCARD, 1,
90 av_extend_guts(av,key,&AvMAX(av),&AvALLOC(av),&AvARRAY(av));
93 /* The guts of av_extend. *Not* for general use! */
94 /* Also called directly from pp_assign, padlist_store, padnamelist_store */
96 Perl_av_extend_guts(pTHX_ AV *av, SSize_t key, SSize_t *maxp, SV ***allocp,
99 PERL_ARGS_ASSERT_AV_EXTEND_GUTS;
101 if (key < -1) /* -1 is legal */
103 "panic: av_extend_guts() negative count (%" IVdf ")", (IV)key);
106 SSize_t ary_offset = *maxp + 1;
110 if (av && *allocp != *arrayp) { /* a shifted SV* array exists */
111 to_null = *arrayp - *allocp;
113 ary_offset = AvFILLp(av) + 1;
115 Move(*arrayp, *allocp, AvFILLp(av)+1, SV*);
117 if (key > *maxp - 10) {
118 newmax = key + *maxp;
121 } else if (*allocp) { /* a full SV* array exists */
123 #ifdef Perl_safesysmalloc_size
124 /* Whilst it would be quite possible to move this logic around
125 (as I did in the SV code), so as to set AvMAX(av) early,
126 based on calling Perl_safesysmalloc_size() immediately after
127 allocation, I'm not convinced that it is a great idea here.
128 In an array we have to loop round setting everything to
129 NULL, which means writing to memory, potentially lots
130 of it, whereas for the SV buffer case we don't touch the
131 "bonus" memory. So there there is no cost in telling the
132 world about it, whereas here we have to do work before we can
133 tell the world about it, and that work involves writing to
134 memory that might never be read. So, I feel, better to keep
135 the current lazy system of only writing to it if our caller
136 has a need for more space. NWC */
137 newmax = Perl_safesysmalloc_size((void*)*allocp) /
138 sizeof(const SV *) - 1;
143 /* overflow-safe version of newmax = key + *maxp/5 */
145 newmax = (key > SSize_t_MAX - newmax)
146 ? SSize_t_MAX : key + newmax;
149 /* it should really be newmax+1 here, but if newmax
150 * happens to equal SSize_t_MAX, then newmax+1 is
151 * undefined. This means technically we croak one
152 * index lower than we should in theory; in practice
153 * its unlikely the system has SSize_t_MAX/sizeof(SV*)
155 MEM_WRAP_CHECK_s(newmax, SV*, "Out of memory during array extend");
157 #ifdef STRESS_REALLOC
159 SV ** const old_alloc = *allocp;
160 Newx(*allocp, newmax+1, SV*);
161 Copy(old_alloc, *allocp, *maxp + 1, SV*);
165 Renew(*allocp,newmax+1, SV*);
167 #ifdef Perl_safesysmalloc_size
170 to_null += newmax - *maxp;
173 /* See GH#18014 for discussion of when this might be needed: */
174 if (av == PL_curstack) { /* Oops, grew stack (via av_store()?) */
175 PL_stack_sp = *allocp + (PL_stack_sp - PL_stack_base);
176 PL_stack_base = *allocp;
177 PL_stack_max = PL_stack_base + newmax;
179 } else { /* there is no SV* array yet */
180 *maxp = key < 3 ? 3 : key;
182 /* see comment above about newmax+1*/
183 MEM_WRAP_CHECK_s(*maxp, SV*,
184 "Out of memory during array extend");
186 /* Newxz isn't used below because testing showed it to be slower
187 * than Newx+Zero (also slower than Newx + the previous while
188 * loop) for small arrays, which are very common in perl. */
189 Newx(*allocp, *maxp+1, SV*);
190 /* Stacks require only the first element to be &PL_sv_undef
191 * (set elsewhere). However, since non-stack AVs are likely
192 * to dominate in modern production applications, stacks
193 * don't get any special treatment here.
194 * See https://github.com/Perl/perl5/pull/18690 for more detail */
200 if (av && AvREAL(av)) {
202 Zero(*allocp + ary_offset,to_null,SV*);
212 Returns the SV at the specified index in the array. The C<key> is the
213 index. If lval is true, you are guaranteed to get a real SV back (in case
214 it wasn't real before), which you can then modify. Check that the return
215 value is non-null before dereferencing it to a C<SV*>.
217 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for
218 more information on how to use this function on tied arrays.
220 The rough perl equivalent is C<$myarray[$key]>.
226 S_adjust_index(pTHX_ AV *av, const MAGIC *mg, SSize_t *keyp)
228 bool adjust_index = 1;
230 /* Handle negative array indices 20020222 MJD */
231 SV * const ref = SvTIED_obj(MUTABLE_SV(av), mg);
233 if (SvROK(ref) && SvOBJECT(SvRV(ref))) {
234 SV * const * const negative_indices_glob =
235 hv_fetchs(SvSTASH(SvRV(ref)), NEGATIVE_INDICES_VAR, 0);
237 if (negative_indices_glob && isGV(*negative_indices_glob)
238 && SvTRUE(GvSV(*negative_indices_glob)))
244 *keyp += AvFILL(av) + 1;
252 Perl_av_fetch(pTHX_ AV *av, SSize_t key, I32 lval)
257 PERL_ARGS_ASSERT_AV_FETCH;
258 assert(SvTYPE(av) == SVt_PVAV);
260 if (UNLIKELY(SvRMAGICAL(av))) {
261 const MAGIC * const tied_magic
262 = mg_find((const SV *)av, PERL_MAGIC_tied);
263 if (tied_magic || mg_find((const SV *)av, PERL_MAGIC_regdata)) {
266 if (!S_adjust_index(aTHX_ av, tied_magic, &key))
271 sv_upgrade(sv, SVt_PVLV);
272 mg_copy(MUTABLE_SV(av), sv, 0, key);
273 if (!tied_magic) /* for regdata, force leavesub to make copies */
276 LvTARG(sv) = sv; /* fake (SV**) */
277 return &(LvTARG(sv));
282 size = AvFILLp(av) + 1;
283 key += neg * size; /* handle negative index without using branch */
285 /* the cast from SSize_t to Size_t allows both (key < 0) and (key >= size)
286 * to be tested as a single condition */
287 if ((Size_t)key >= (Size_t)size) {
293 if (!AvARRAY(av)[key]) {
295 return lval ? av_store(av,key,newSV(0)) : NULL;
298 return &AvARRAY(av)[key];
304 Stores an SV in an array. The array index is specified as C<key>. The
305 return value will be C<NULL> if the operation failed or if the value did not
306 need to be actually stored within the array (as in the case of tied
307 arrays). Otherwise, it can be dereferenced
308 to get the C<SV*> that was stored
311 Note that the caller is responsible for suitably incrementing the reference
312 count of C<val> before the call, and decrementing it if the function
315 Approximate Perl equivalent: C<splice(@myarray, $key, 1, $val)>.
317 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for
318 more information on how to use this function on tied arrays.
324 Perl_av_store(pTHX_ AV *av, SSize_t key, SV *val)
328 PERL_ARGS_ASSERT_AV_STORE;
329 assert(SvTYPE(av) == SVt_PVAV);
331 /* S_regclass relies on being able to pass in a NULL sv
332 (unicode_alternate may be NULL).
335 if (SvRMAGICAL(av)) {
336 const MAGIC * const tied_magic = mg_find((const SV *)av, PERL_MAGIC_tied);
339 if (!S_adjust_index(aTHX_ av, tied_magic, &key))
343 mg_copy(MUTABLE_SV(av), val, 0, key);
351 key += AvFILL(av) + 1;
356 if (SvREADONLY(av) && key >= AvFILL(av))
357 Perl_croak_no_modify();
359 if (!AvREAL(av) && AvREIFY(av))
364 if (AvFILLp(av) < key) {
366 if (av == PL_curstack && key > PL_stack_sp - PL_stack_base)
367 PL_stack_sp = PL_stack_base + key; /* XPUSH in disguise */
369 ary[++AvFILLp(av)] = NULL;
370 } while (AvFILLp(av) < key);
375 SvREFCNT_dec(ary[key]);
377 if (SvSMAGICAL(av)) {
378 const MAGIC *mg = SvMAGIC(av);
380 for (; mg; mg = mg->mg_moremagic) {
381 if (!isUPPER(mg->mg_type)) continue;
383 sv_magic(val, MUTABLE_SV(av), toLOWER(mg->mg_type), 0, key);
385 if (PL_delaymagic && mg->mg_type == PERL_MAGIC_isa) {
386 PL_delaymagic |= DM_ARRAY_ISA;
391 mg_set(MUTABLE_SV(av));
397 =for apidoc av_new_alloc
399 Creates a new AV and allocates its SV* array.
401 This is similar to but more efficient than doing:
406 The size parameter is used to pre-allocate a SV* array large enough to
407 hold at least elements 0..(size-1). size must be at least 1.
409 The zeroflag parameter controls whether the array is NULL initialized.
415 Perl_av_new_alloc(pTHX_ SSize_t size, bool zeroflag)
417 AV * const av = newAV();
419 PERL_ARGS_ASSERT_AV_NEW_ALLOC;
422 Newx(ary, size, SV*); /* Newx performs the memwrap check */
425 AvMAX(av) = size - 1;
428 Zero(ary, size, SV*);
436 Creates a new AV and populates it with a list of SVs. The SVs are copied
437 into the array, so they may be freed after the call to C<av_make>. The new AV
438 will have a reference count of 1.
440 Perl equivalent: C<my @new_array = ($scalar1, $scalar2, $scalar3...);>
446 Perl_av_make(pTHX_ SSize_t size, SV **strp)
448 AV * const av = newAV();
449 /* sv_upgrade does AvREAL_only() */
450 PERL_ARGS_ASSERT_AV_MAKE;
451 assert(SvTYPE(av) == SVt_PVAV);
453 if (size) { /* "defined" was returning undef for size==0 anyway. */
461 AvMAX(av) = size - 1;
462 /* avoid av being leaked if croak when calling magic below */
464 PL_tmps_stack[++PL_tmps_ix] = (SV*)av;
465 orig_ix = PL_tmps_ix;
467 for (i = 0; i < size; i++) {
470 /* Don't let sv_setsv swipe, since our source array might
471 have multiple references to the same temp scalar (e.g.
472 from a list slice) */
474 SvGETMAGIC(*strp); /* before newSV, in case it dies */
477 sv_setsv_flags(ary[i], *strp,
478 SV_DO_COW_SVSETSV|SV_NOSTEAL);
481 /* disarm av's leak guard */
482 if (LIKELY(PL_tmps_ix == orig_ix))
485 PL_tmps_stack[orig_ix] = &PL_sv_undef;
493 Frees all the elements of an array, leaving it empty.
494 The XS equivalent of C<@array = ()>. See also L</av_undef>.
496 Note that it is possible that the actions of a destructor called directly
497 or indirectly by freeing an element of the array could cause the reference
498 count of the array itself to be reduced (e.g. by deleting an entry in the
499 symbol table). So it is a possibility that the AV could have been freed
500 (or even reallocated) on return from the call unless you hold a reference
507 Perl_av_clear(pTHX_ AV *av)
513 PERL_ARGS_ASSERT_AV_CLEAR;
514 assert(SvTYPE(av) == SVt_PVAV);
517 if (SvREFCNT(av) == 0) {
518 Perl_ck_warner_d(aTHX_ packWARN(WARN_DEBUGGING), "Attempt to clear deleted array");
523 Perl_croak_no_modify();
525 /* Give any tie a chance to cleanup first */
526 if (SvRMAGICAL(av)) {
527 const MAGIC* const mg = SvMAGIC(av);
528 if (PL_delaymagic && mg && mg->mg_type == PERL_MAGIC_isa)
529 PL_delaymagic |= DM_ARRAY_ISA;
531 mg_clear(MUTABLE_SV(av));
537 if ((real = cBOOL(AvREAL(av)))) {
538 SV** const ary = AvARRAY(av);
539 SSize_t index = AvFILLp(av) + 1;
541 /* avoid av being freed when calling destructors below */
543 PL_tmps_stack[++PL_tmps_ix] = SvREFCNT_inc_simple_NN(av);
544 orig_ix = PL_tmps_ix;
547 SV * const sv = ary[--index];
548 /* undef the slot before freeing the value, because a
549 * destructor might try to modify this array */
554 extra = AvARRAY(av) - AvALLOC(av);
557 AvARRAY(av) = AvALLOC(av);
561 /* disarm av's premature free guard */
562 if (LIKELY(PL_tmps_ix == orig_ix))
565 PL_tmps_stack[orig_ix] = &PL_sv_undef;
573 Undefines the array. The XS equivalent of C<undef(@array)>.
575 As well as freeing all the elements of the array (like C<av_clear()>), this
576 also frees the memory used by the av to store its list of scalars.
578 See L</av_clear> for a note about the array possibly being invalid on
585 Perl_av_undef(pTHX_ AV *av)
588 SSize_t orig_ix = PL_tmps_ix; /* silence bogus warning about possible unitialized use */
590 PERL_ARGS_ASSERT_AV_UNDEF;
591 assert(SvTYPE(av) == SVt_PVAV);
593 /* Give any tie a chance to cleanup first */
594 if (SvTIED_mg((const SV *)av, PERL_MAGIC_tied))
597 real = cBOOL(AvREAL(av));
599 SSize_t key = AvFILLp(av) + 1;
601 /* avoid av being freed when calling destructors below */
603 PL_tmps_stack[++PL_tmps_ix] = SvREFCNT_inc_simple_NN(av);
604 orig_ix = PL_tmps_ix;
607 SvREFCNT_dec(AvARRAY(av)[--key]);
610 Safefree(AvALLOC(av));
613 AvMAX(av) = AvFILLp(av) = -1;
615 if(SvRMAGICAL(av)) mg_clear(MUTABLE_SV(av));
617 /* disarm av's premature free guard */
618 if (LIKELY(PL_tmps_ix == orig_ix))
621 PL_tmps_stack[orig_ix] = &PL_sv_undef;
628 =for apidoc av_create_and_push
630 Push an SV onto the end of the array, creating the array if necessary.
631 A small internal helper function to remove a commonly duplicated idiom.
637 Perl_av_create_and_push(pTHX_ AV **const avp, SV *const val)
639 PERL_ARGS_ASSERT_AV_CREATE_AND_PUSH;
649 Pushes an SV (transferring control of one reference count) onto the end of the
650 array. The array will grow automatically to accommodate the addition.
652 Perl equivalent: C<push @myarray, $val;>.
658 Perl_av_push(pTHX_ AV *av, SV *val)
662 PERL_ARGS_ASSERT_AV_PUSH;
663 assert(SvTYPE(av) == SVt_PVAV);
666 Perl_croak_no_modify();
668 if ((mg = SvTIED_mg((const SV *)av, PERL_MAGIC_tied))) {
669 Perl_magic_methcall(aTHX_ MUTABLE_SV(av), mg, SV_CONST(PUSH), G_DISCARD, 1,
673 av_store(av,AvFILLp(av)+1,val);
679 Removes one SV from the end of the array, reducing its size by one and
680 returning the SV (transferring control of one reference count) to the
681 caller. Returns C<&PL_sv_undef> if the array is empty.
683 Perl equivalent: C<pop(@myarray);>
689 Perl_av_pop(pTHX_ AV *av)
694 PERL_ARGS_ASSERT_AV_POP;
695 assert(SvTYPE(av) == SVt_PVAV);
698 Perl_croak_no_modify();
699 if ((mg = SvTIED_mg((const SV *)av, PERL_MAGIC_tied))) {
700 retval = Perl_magic_methcall(aTHX_ MUTABLE_SV(av), mg, SV_CONST(POP), 0, 0);
702 retval = newSVsv(retval);
707 retval = AvARRAY(av)[AvFILLp(av)];
708 AvARRAY(av)[AvFILLp(av)--] = NULL;
710 mg_set(MUTABLE_SV(av));
711 return retval ? retval : &PL_sv_undef;
716 =for apidoc av_create_and_unshift_one
718 Unshifts an SV onto the beginning of the array, creating the array if
720 A small internal helper function to remove a commonly duplicated idiom.
726 Perl_av_create_and_unshift_one(pTHX_ AV **const avp, SV *const val)
728 PERL_ARGS_ASSERT_AV_CREATE_AND_UNSHIFT_ONE;
733 return av_store(*avp, 0, val);
737 =for apidoc av_unshift
739 Unshift the given number of C<undef> values onto the beginning of the
740 array. The array will grow automatically to accommodate the addition.
742 Perl equivalent: S<C<unshift @myarray, ((undef) x $num);>>
748 Perl_av_unshift(pTHX_ AV *av, SSize_t num)
753 PERL_ARGS_ASSERT_AV_UNSHIFT;
754 assert(SvTYPE(av) == SVt_PVAV);
757 Perl_croak_no_modify();
759 if ((mg = SvTIED_mg((const SV *)av, PERL_MAGIC_tied))) {
760 Perl_magic_methcall(aTHX_ MUTABLE_SV(av), mg, SV_CONST(UNSHIFT),
761 G_DISCARD | G_UNDEF_FILL, num);
767 if (!AvREAL(av) && AvREIFY(av))
769 i = AvARRAY(av) - AvALLOC(av);
777 AvARRAY(av) = AvARRAY(av) - i;
781 const SSize_t i = AvFILLp(av);
782 /* Create extra elements */
783 const SSize_t slide = i > 0 ? i : 0;
785 av_extend(av, i + num);
788 Move(ary, ary + num, i + 1, SV*);
792 /* Make extra elements into a buffer */
794 AvFILLp(av) -= slide;
795 AvARRAY(av) = AvARRAY(av) + slide;
802 Removes one SV from the start of the array, reducing its size by one and
803 returning the SV (transferring control of one reference count) to the
804 caller. Returns C<&PL_sv_undef> if the array is empty.
806 Perl equivalent: C<shift(@myarray);>
812 Perl_av_shift(pTHX_ AV *av)
817 PERL_ARGS_ASSERT_AV_SHIFT;
818 assert(SvTYPE(av) == SVt_PVAV);
821 Perl_croak_no_modify();
822 if ((mg = SvTIED_mg((const SV *)av, PERL_MAGIC_tied))) {
823 retval = Perl_magic_methcall(aTHX_ MUTABLE_SV(av), mg, SV_CONST(SHIFT), 0, 0);
825 retval = newSVsv(retval);
830 retval = *AvARRAY(av);
833 AvARRAY(av) = AvARRAY(av) + 1;
837 mg_set(MUTABLE_SV(av));
838 return retval ? retval : &PL_sv_undef;
842 =for apidoc av_tindex
843 =for apidoc_item av_top_index
845 These behave identically.
846 If the array C<av> is empty, these return -1; otherwise they return the maximum
847 value of the indices of all the array elements which are currently defined in
850 They process 'get' magic.
852 The Perl equivalent for these is C<$#av>.
854 Use C<L</av_count>> to get the number of elements in an array.
858 Same as L</av_top_index>. Note that, unlike what the name implies, it returns
859 the maximum index in the array. This is unlike L</sv_len>, which returns what
862 B<To get the true number of elements in the array, instead use C<L</av_count>>>.
868 Perl_av_len(pTHX_ AV *av)
870 PERL_ARGS_ASSERT_AV_LEN;
872 return av_top_index(av);
878 Set the highest index in the array to the given number, equivalent to
879 Perl's S<C<$#array = $fill;>>.
881 The number of elements in the array will be S<C<fill + 1>> after
882 C<av_fill()> returns. If the array was previously shorter, then the
883 additional elements appended are set to NULL. If the array
884 was longer, then the excess elements are freed. S<C<av_fill(av, -1)>> is
885 the same as C<av_clear(av)>.
890 Perl_av_fill(pTHX_ AV *av, SSize_t fill)
894 PERL_ARGS_ASSERT_AV_FILL;
895 assert(SvTYPE(av) == SVt_PVAV);
899 if ((mg = SvTIED_mg((const SV *)av, PERL_MAGIC_tied))) {
900 SV *arg1 = sv_newmortal();
901 sv_setiv(arg1, (IV)(fill + 1));
902 Perl_magic_methcall(aTHX_ MUTABLE_SV(av), mg, SV_CONST(STORESIZE), G_DISCARD,
906 if (fill <= AvMAX(av)) {
907 SSize_t key = AvFILLp(av);
908 SV** const ary = AvARRAY(av);
912 SvREFCNT_dec(ary[key]);
923 mg_set(MUTABLE_SV(av));
926 (void)av_store(av,fill,NULL);
930 =for apidoc av_delete
932 Deletes the element indexed by C<key> from the array, makes the element
933 mortal, and returns it. If C<flags> equals C<G_DISCARD>, the element is
934 freed and NULL is returned. NULL is also returned if C<key> is out of
937 Perl equivalent: S<C<splice(@myarray, $key, 1, undef)>> (with the
938 C<splice> in void context if C<G_DISCARD> is present).
943 Perl_av_delete(pTHX_ AV *av, SSize_t key, I32 flags)
947 PERL_ARGS_ASSERT_AV_DELETE;
948 assert(SvTYPE(av) == SVt_PVAV);
951 Perl_croak_no_modify();
953 if (SvRMAGICAL(av)) {
954 const MAGIC * const tied_magic
955 = mg_find((const SV *)av, PERL_MAGIC_tied);
956 if ((tied_magic || mg_find((const SV *)av, PERL_MAGIC_regdata))) {
959 if (!S_adjust_index(aTHX_ av, tied_magic, &key))
962 svp = av_fetch(av, key, TRUE);
966 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
967 sv_unmagic(sv, PERL_MAGIC_tiedelem); /* No longer an element */
976 key += AvFILL(av) + 1;
981 if (key > AvFILLp(av))
984 if (!AvREAL(av) && AvREIFY(av))
986 sv = AvARRAY(av)[key];
987 AvARRAY(av)[key] = NULL;
988 if (key == AvFILLp(av)) {
991 } while (--key >= 0 && !AvARRAY(av)[key]);
994 mg_set(MUTABLE_SV(av));
997 if (flags & G_DISCARD) {
1001 else if (AvREAL(av))
1008 =for apidoc av_exists
1010 Returns true if the element indexed by C<key> has been initialized.
1012 This relies on the fact that uninitialized array elements are set to
1015 Perl equivalent: C<exists($myarray[$key])>.
1020 Perl_av_exists(pTHX_ AV *av, SSize_t key)
1022 PERL_ARGS_ASSERT_AV_EXISTS;
1023 assert(SvTYPE(av) == SVt_PVAV);
1025 if (SvRMAGICAL(av)) {
1026 const MAGIC * const tied_magic
1027 = mg_find((const SV *)av, PERL_MAGIC_tied);
1028 const MAGIC * const regdata_magic
1029 = mg_find((const SV *)av, PERL_MAGIC_regdata);
1030 if (tied_magic || regdata_magic) {
1032 /* Handle negative array indices 20020222 MJD */
1034 if (!S_adjust_index(aTHX_ av, tied_magic, &key))
1038 if(key >= 0 && regdata_magic) {
1039 if (key <= AvFILL(av))
1045 SV * const sv = sv_newmortal();
1046 mg_copy(MUTABLE_SV(av), sv, 0, key);
1047 mg = mg_find(sv, PERL_MAGIC_tiedelem);
1049 magic_existspack(sv, mg);
1051 I32 retbool = SvTRUE_nomg_NN(sv);
1052 return cBOOL(retbool);
1060 key += AvFILL(av) + 1;
1065 if (key <= AvFILLp(av) && AvARRAY(av)[key])
1067 if (SvSMAGICAL(AvARRAY(av)[key])
1068 && mg_find(AvARRAY(av)[key], PERL_MAGIC_nonelem))
1077 S_get_aux_mg(pTHX_ AV *av) {
1080 PERL_ARGS_ASSERT_GET_AUX_MG;
1081 assert(SvTYPE(av) == SVt_PVAV);
1083 mg = mg_find((const SV *)av, PERL_MAGIC_arylen_p);
1086 mg = sv_magicext(MUTABLE_SV(av), 0, PERL_MAGIC_arylen_p,
1087 &PL_vtbl_arylen_p, 0, 0);
1089 /* sv_magicext won't set this for us because we pass in a NULL obj */
1090 mg->mg_flags |= MGf_REFCOUNTED;
1096 Perl_av_arylen_p(pTHX_ AV *av) {
1097 MAGIC *const mg = get_aux_mg(av);
1099 PERL_ARGS_ASSERT_AV_ARYLEN_P;
1100 assert(SvTYPE(av) == SVt_PVAV);
1102 return &(mg->mg_obj);
1106 Perl_av_iter_p(pTHX_ AV *av) {
1107 MAGIC *const mg = get_aux_mg(av);
1109 PERL_ARGS_ASSERT_AV_ITER_P;
1110 assert(SvTYPE(av) == SVt_PVAV);
1112 if (sizeof(IV) == sizeof(SSize_t)) {
1113 return (IV *)&(mg->mg_len);
1117 mg->mg_len = IVSIZE;
1119 mg->mg_ptr = (char *) temp;
1121 return (IV *)mg->mg_ptr;
1126 Perl_av_nonelem(pTHX_ AV *av, SSize_t ix) {
1127 SV * const sv = newSV(0);
1128 PERL_ARGS_ASSERT_AV_NONELEM;
1129 if (!av_store(av,ix,sv))
1130 return sv_2mortal(sv); /* has tie magic */
1131 sv_magic(sv, NULL, PERL_MAGIC_nonelem, NULL, 0);
1136 * ex: set ts=8 sts=4 sw=4 et: