3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
4 * 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 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.
9 * "I wonder what the Entish is for 'yes' and 'no'," he thought.
12 * This file contains the code that creates, manipulates and destroys
13 * scalar values (SVs). The other types (AV, HV, GV, etc.) reuse the
14 * structure of an SV, so their creation and destruction is handled
15 * here; higher-level functions are in av.c, hv.c, and so on. Opcode
16 * level functions (eg. substr, split, join) for each of the types are
28 /* Missing proto on LynxOS */
29 char *gconvert(double, int, int, char *);
32 #ifdef PERL_UTF8_CACHE_ASSERT
33 /* if adding more checks watch out for the following tests:
34 * t/op/index.t t/op/length.t t/op/pat.t t/op/substr.t
35 * lib/utf8.t lib/Unicode/Collate/t/index.t
38 # define ASSERT_UTF8_CACHE(cache) \
39 STMT_START { if (cache) { assert((cache)[0] <= (cache)[1]); \
40 assert((cache)[2] <= (cache)[3]); \
41 assert((cache)[3] <= (cache)[1]);} \
44 # define ASSERT_UTF8_CACHE(cache) NOOP
47 #ifdef PERL_OLD_COPY_ON_WRITE
48 #define SV_COW_NEXT_SV(sv) INT2PTR(SV *,SvUVX(sv))
49 #define SV_COW_NEXT_SV_SET(current,next) SvUV_set(current, PTR2UV(next))
50 /* This is a pessimistic view. Scalar must be purely a read-write PV to copy-
54 /* ============================================================================
56 =head1 Allocation and deallocation of SVs.
58 An SV (or AV, HV, etc.) is allocated in two parts: the head (struct
59 sv, av, hv...) contains type and reference count information, and for
60 many types, a pointer to the body (struct xrv, xpv, xpviv...), which
61 contains fields specific to each type. Some types store all they need
62 in the head, so don't have a body.
64 In all but the most memory-paranoid configuations (ex: PURIFY), heads
65 and bodies are allocated out of arenas, which by default are
66 approximately 4K chunks of memory parcelled up into N heads or bodies.
67 Sv-bodies are allocated by their sv-type, guaranteeing size
68 consistency needed to allocate safely from arrays.
70 For SV-heads, the first slot in each arena is reserved, and holds a
71 link to the next arena, some flags, and a note of the number of slots.
72 Snaked through each arena chain is a linked list of free items; when
73 this becomes empty, an extra arena is allocated and divided up into N
74 items which are threaded into the free list.
76 SV-bodies are similar, but they use arena-sets by default, which
77 separate the link and info from the arena itself, and reclaim the 1st
78 slot in the arena. SV-bodies are further described later.
80 The following global variables are associated with arenas:
82 PL_sv_arenaroot pointer to list of SV arenas
83 PL_sv_root pointer to list of free SV structures
85 PL_body_arenas head of linked-list of body arenas
86 PL_body_roots[] array of pointers to list of free bodies of svtype
87 arrays are indexed by the svtype needed
89 A few special SV heads are not allocated from an arena, but are
90 instead directly created in the interpreter structure, eg PL_sv_undef.
91 The size of arenas can be changed from the default by setting
92 PERL_ARENA_SIZE appropriately at compile time.
94 The SV arena serves the secondary purpose of allowing still-live SVs
95 to be located and destroyed during final cleanup.
97 At the lowest level, the macros new_SV() and del_SV() grab and free
98 an SV head. (If debugging with -DD, del_SV() calls the function S_del_sv()
99 to return the SV to the free list with error checking.) new_SV() calls
100 more_sv() / sv_add_arena() to add an extra arena if the free list is empty.
101 SVs in the free list have their SvTYPE field set to all ones.
103 At the time of very final cleanup, sv_free_arenas() is called from
104 perl_destruct() to physically free all the arenas allocated since the
105 start of the interpreter.
107 The function visit() scans the SV arenas list, and calls a specified
108 function for each SV it finds which is still live - ie which has an SvTYPE
109 other than all 1's, and a non-zero SvREFCNT. visit() is used by the
110 following functions (specified as [function that calls visit()] / [function
111 called by visit() for each SV]):
113 sv_report_used() / do_report_used()
114 dump all remaining SVs (debugging aid)
116 sv_clean_objs() / do_clean_objs(),do_clean_named_objs()
117 Attempt to free all objects pointed to by RVs,
118 and, unless DISABLE_DESTRUCTOR_KLUDGE is defined,
119 try to do the same for all objects indirectly
120 referenced by typeglobs too. Called once from
121 perl_destruct(), prior to calling sv_clean_all()
124 sv_clean_all() / do_clean_all()
125 SvREFCNT_dec(sv) each remaining SV, possibly
126 triggering an sv_free(). It also sets the
127 SVf_BREAK flag on the SV to indicate that the
128 refcnt has been artificially lowered, and thus
129 stopping sv_free() from giving spurious warnings
130 about SVs which unexpectedly have a refcnt
131 of zero. called repeatedly from perl_destruct()
132 until there are no SVs left.
134 =head2 Arena allocator API Summary
136 Private API to rest of sv.c
140 new_XIV(), del_XIV(),
141 new_XNV(), del_XNV(),
146 sv_report_used(), sv_clean_objs(), sv_clean_all(), sv_free_arenas()
150 ============================================================================ */
153 * "A time to plant, and a time to uproot what was planted..."
157 Perl_offer_nice_chunk(pTHX_ void *const chunk, const U32 chunk_size)
163 PERL_ARGS_ASSERT_OFFER_NICE_CHUNK;
165 new_chunk = (void *)(chunk);
166 new_chunk_size = (chunk_size);
167 if (new_chunk_size > PL_nice_chunk_size) {
168 Safefree(PL_nice_chunk);
169 PL_nice_chunk = (char *) new_chunk;
170 PL_nice_chunk_size = new_chunk_size;
176 #ifdef DEBUG_LEAKING_SCALARS
177 # define FREE_SV_DEBUG_FILE(sv) Safefree((sv)->sv_debug_file)
179 # define FREE_SV_DEBUG_FILE(sv)
183 # define SvARENA_CHAIN(sv) ((sv)->sv_u.svu_rv)
184 /* Whilst I'd love to do this, it seems that things like to check on
186 # define POSION_SV_HEAD(sv) PoisonNew(sv, 1, struct STRUCT_SV)
188 # define POSION_SV_HEAD(sv) PoisonNew(&SvANY(sv), 1, void *), \
189 PoisonNew(&SvREFCNT(sv), 1, U32)
191 # define SvARENA_CHAIN(sv) SvANY(sv)
192 # define POSION_SV_HEAD(sv)
195 #define plant_SV(p) \
197 FREE_SV_DEBUG_FILE(p); \
199 SvARENA_CHAIN(p) = (void *)PL_sv_root; \
200 SvFLAGS(p) = SVTYPEMASK; \
205 #define uproot_SV(p) \
208 PL_sv_root = (SV*)SvARENA_CHAIN(p); \
213 /* make some more SVs by adding another arena */
222 sv_add_arena(PL_nice_chunk, PL_nice_chunk_size, 0);
223 PL_nice_chunk = NULL;
224 PL_nice_chunk_size = 0;
227 char *chunk; /* must use New here to match call to */
228 Newx(chunk,PERL_ARENA_SIZE,char); /* Safefree() in sv_free_arenas() */
229 sv_add_arena(chunk, PERL_ARENA_SIZE, 0);
235 /* new_SV(): return a new, empty SV head */
237 #ifdef DEBUG_LEAKING_SCALARS
238 /* provide a real function for a debugger to play with */
247 sv = S_more_sv(aTHX);
251 sv->sv_debug_optype = PL_op ? PL_op->op_type : 0;
252 sv->sv_debug_line = (U16) (PL_parser && PL_parser->copline != NOLINE
258 sv->sv_debug_inpad = 0;
259 sv->sv_debug_cloned = 0;
260 sv->sv_debug_file = PL_curcop ? savepv(CopFILE(PL_curcop)): NULL;
264 # define new_SV(p) (p)=S_new_SV(aTHX)
272 (p) = S_more_sv(aTHX); \
280 /* del_SV(): return an empty SV head to the free list */
293 S_del_sv(pTHX_ SV *p)
297 PERL_ARGS_ASSERT_DEL_SV;
302 for (sva = PL_sv_arenaroot; sva; sva = (SV *) SvANY(sva)) {
303 const SV * const sv = sva + 1;
304 const SV * const svend = &sva[SvREFCNT(sva)];
305 if (p >= sv && p < svend) {
311 if (ckWARN_d(WARN_INTERNAL))
312 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
313 "Attempt to free non-arena SV: 0x%"UVxf
314 pTHX__FORMAT, PTR2UV(p) pTHX__VALUE);
321 #else /* ! DEBUGGING */
323 #define del_SV(p) plant_SV(p)
325 #endif /* DEBUGGING */
329 =head1 SV Manipulation Functions
331 =for apidoc sv_add_arena
333 Given a chunk of memory, link it to the head of the list of arenas,
334 and split it into a list of free SVs.
340 Perl_sv_add_arena(pTHX_ char *const ptr, const U32 size, const U32 flags)
343 SV* const sva = (SV*)ptr;
347 PERL_ARGS_ASSERT_SV_ADD_ARENA;
349 /* The first SV in an arena isn't an SV. */
350 SvANY(sva) = (void *) PL_sv_arenaroot; /* ptr to next arena */
351 SvREFCNT(sva) = size / sizeof(SV); /* number of SV slots */
352 SvFLAGS(sva) = flags; /* FAKE if not to be freed */
354 PL_sv_arenaroot = sva;
355 PL_sv_root = sva + 1;
357 svend = &sva[SvREFCNT(sva) - 1];
360 SvARENA_CHAIN(sv) = (void *)(SV*)(sv + 1);
364 /* Must always set typemask because it's always checked in on cleanup
365 when the arenas are walked looking for objects. */
366 SvFLAGS(sv) = SVTYPEMASK;
369 SvARENA_CHAIN(sv) = 0;
373 SvFLAGS(sv) = SVTYPEMASK;
376 /* visit(): call the named function for each non-free SV in the arenas
377 * whose flags field matches the flags/mask args. */
380 S_visit(pTHX_ SVFUNC_t f, const U32 flags, const U32 mask)
386 PERL_ARGS_ASSERT_VISIT;
388 for (sva = PL_sv_arenaroot; sva; sva = (SV*)SvANY(sva)) {
389 register const SV * const svend = &sva[SvREFCNT(sva)];
391 for (sv = sva + 1; sv < svend; ++sv) {
392 if (SvTYPE(sv) != SVTYPEMASK
393 && (sv->sv_flags & mask) == flags
406 /* called by sv_report_used() for each live SV */
409 do_report_used(pTHX_ SV *const sv)
411 if (SvTYPE(sv) != SVTYPEMASK) {
412 PerlIO_printf(Perl_debug_log, "****\n");
419 =for apidoc sv_report_used
421 Dump the contents of all SVs not yet freed. (Debugging aid).
427 Perl_sv_report_used(pTHX)
430 visit(do_report_used, 0, 0);
436 /* called by sv_clean_objs() for each live SV */
439 do_clean_objs(pTHX_ SV *const ref)
444 SV * const target = SvRV(ref);
445 if (SvOBJECT(target)) {
446 DEBUG_D((PerlIO_printf(Perl_debug_log, "Cleaning object ref:\n "), sv_dump(ref)));
447 if (SvWEAKREF(ref)) {
448 sv_del_backref(target, ref);
454 SvREFCNT_dec(target);
459 /* XXX Might want to check arrays, etc. */
462 /* called by sv_clean_objs() for each live SV */
464 #ifndef DISABLE_DESTRUCTOR_KLUDGE
466 do_clean_named_objs(pTHX_ SV *const sv)
469 assert(SvTYPE(sv) == SVt_PVGV);
470 assert(isGV_with_GP(sv));
473 #ifdef PERL_DONT_CREATE_GVSV
476 SvOBJECT(GvSV(sv))) ||
477 (GvAV(sv) && SvOBJECT(GvAV(sv))) ||
478 (GvHV(sv) && SvOBJECT(GvHV(sv))) ||
479 /* In certain rare cases GvIOp(sv) can be NULL, which would make SvOBJECT(GvIO(sv)) dereference NULL. */
480 (GvIO(sv) ? (SvFLAGS(GvIOp(sv)) & SVs_OBJECT) : 0) ||
481 (GvCV(sv) && SvOBJECT(GvCV(sv))) )
483 DEBUG_D((PerlIO_printf(Perl_debug_log, "Cleaning named glob object:\n "), sv_dump(sv)));
484 SvFLAGS(sv) |= SVf_BREAK;
492 =for apidoc sv_clean_objs
494 Attempt to destroy all objects not yet freed
500 Perl_sv_clean_objs(pTHX)
503 PL_in_clean_objs = TRUE;
504 visit(do_clean_objs, SVf_ROK, SVf_ROK);
505 #ifndef DISABLE_DESTRUCTOR_KLUDGE
506 /* some barnacles may yet remain, clinging to typeglobs */
507 visit(do_clean_named_objs, SVt_PVGV|SVpgv_GP, SVTYPEMASK|SVp_POK|SVpgv_GP);
509 PL_in_clean_objs = FALSE;
512 /* called by sv_clean_all() for each live SV */
515 do_clean_all(pTHX_ SV *const sv)
518 if (sv == (SV*) PL_fdpid || sv == (SV *)PL_strtab) {
519 /* don't clean pid table and strtab */
522 DEBUG_D((PerlIO_printf(Perl_debug_log, "Cleaning loops: SV at 0x%"UVxf"\n", PTR2UV(sv)) ));
523 SvFLAGS(sv) |= SVf_BREAK;
528 =for apidoc sv_clean_all
530 Decrement the refcnt of each remaining SV, possibly triggering a
531 cleanup. This function may have to be called multiple times to free
532 SVs which are in complex self-referential hierarchies.
538 Perl_sv_clean_all(pTHX)
542 PL_in_clean_all = TRUE;
543 cleaned = visit(do_clean_all, 0,0);
544 PL_in_clean_all = FALSE;
549 ARENASETS: a meta-arena implementation which separates arena-info
550 into struct arena_set, which contains an array of struct
551 arena_descs, each holding info for a single arena. By separating
552 the meta-info from the arena, we recover the 1st slot, formerly
553 borrowed for list management. The arena_set is about the size of an
554 arena, avoiding the needless malloc overhead of a naive linked-list.
556 The cost is 1 arena-set malloc per ~320 arena-mallocs, + the unused
557 memory in the last arena-set (1/2 on average). In trade, we get
558 back the 1st slot in each arena (ie 1.7% of a CV-arena, less for
559 smaller types). The recovery of the wasted space allows use of
560 small arenas for large, rare body types, by changing array* fields
561 in body_details_by_type[] below.
564 char *arena; /* the raw storage, allocated aligned */
565 size_t size; /* its size ~4k typ */
566 U32 misc; /* type, and in future other things. */
571 /* Get the maximum number of elements in set[] such that struct arena_set
572 will fit within PERL_ARENA_SIZE, which is probably just under 4K, and
573 therefore likely to be 1 aligned memory page. */
575 #define ARENAS_PER_SET ((PERL_ARENA_SIZE - sizeof(struct arena_set*) \
576 - 2 * sizeof(int)) / sizeof (struct arena_desc))
579 struct arena_set* next;
580 unsigned int set_size; /* ie ARENAS_PER_SET */
581 unsigned int curr; /* index of next available arena-desc */
582 struct arena_desc set[ARENAS_PER_SET];
586 =for apidoc sv_free_arenas
588 Deallocate the memory used by all arenas. Note that all the individual SV
589 heads and bodies within the arenas must already have been freed.
594 Perl_sv_free_arenas(pTHX)
601 /* Free arenas here, but be careful about fake ones. (We assume
602 contiguity of the fake ones with the corresponding real ones.) */
604 for (sva = PL_sv_arenaroot; sva; sva = svanext) {
605 svanext = (SV*) SvANY(sva);
606 while (svanext && SvFAKE(svanext))
607 svanext = (SV*) SvANY(svanext);
614 struct arena_set *aroot = (struct arena_set*) PL_body_arenas;
617 struct arena_set *current = aroot;
620 assert(aroot->set[i].arena);
621 Safefree(aroot->set[i].arena);
629 i = PERL_ARENA_ROOTS_SIZE;
631 PL_body_roots[i] = 0;
633 Safefree(PL_nice_chunk);
634 PL_nice_chunk = NULL;
635 PL_nice_chunk_size = 0;
641 Here are mid-level routines that manage the allocation of bodies out
642 of the various arenas. There are 5 kinds of arenas:
644 1. SV-head arenas, which are discussed and handled above
645 2. regular body arenas
646 3. arenas for reduced-size bodies
648 5. pte arenas (thread related)
650 Arena types 2 & 3 are chained by body-type off an array of
651 arena-root pointers, which is indexed by svtype. Some of the
652 larger/less used body types are malloced singly, since a large
653 unused block of them is wasteful. Also, several svtypes dont have
654 bodies; the data fits into the sv-head itself. The arena-root
655 pointer thus has a few unused root-pointers (which may be hijacked
656 later for arena types 4,5)
658 3 differs from 2 as an optimization; some body types have several
659 unused fields in the front of the structure (which are kept in-place
660 for consistency). These bodies can be allocated in smaller chunks,
661 because the leading fields arent accessed. Pointers to such bodies
662 are decremented to point at the unused 'ghost' memory, knowing that
663 the pointers are used with offsets to the real memory.
665 HE, HEK arenas are managed separately, with separate code, but may
666 be merge-able later..
668 PTE arenas are not sv-bodies, but they share these mid-level
669 mechanics, so are considered here. The new mid-level mechanics rely
670 on the sv_type of the body being allocated, so we just reserve one
671 of the unused body-slots for PTEs, then use it in those (2) PTE
672 contexts below (line ~10k)
675 /* get_arena(size): this creates custom-sized arenas
676 TBD: export properly for hv.c: S_more_he().
679 Perl_get_arena(pTHX_ const size_t arena_size, const U32 misc)
682 struct arena_desc* adesc;
683 struct arena_set *aroot = (struct arena_set*) PL_body_arenas;
686 /* shouldnt need this
687 if (!arena_size) arena_size = PERL_ARENA_SIZE;
690 /* may need new arena-set to hold new arena */
691 if (!aroot || aroot->curr >= aroot->set_size) {
692 struct arena_set *newroot;
693 Newxz(newroot, 1, struct arena_set);
694 newroot->set_size = ARENAS_PER_SET;
695 newroot->next = aroot;
697 PL_body_arenas = (void *) newroot;
698 DEBUG_m(PerlIO_printf(Perl_debug_log, "new arenaset %p\n", (void*)aroot));
701 /* ok, now have arena-set with at least 1 empty/available arena-desc */
702 curr = aroot->curr++;
703 adesc = &(aroot->set[curr]);
704 assert(!adesc->arena);
706 Newx(adesc->arena, arena_size, char);
707 adesc->size = arena_size;
709 DEBUG_m(PerlIO_printf(Perl_debug_log, "arena %d added: %p size %"UVuf"\n",
710 curr, (void*)adesc->arena, (UV)arena_size));
716 /* return a thing to the free list */
718 #define del_body(thing, root) \
720 void ** const thing_copy = (void **)thing;\
721 *thing_copy = *root; \
722 *root = (void*)thing_copy; \
727 =head1 SV-Body Allocation
729 Allocation of SV-bodies is similar to SV-heads, differing as follows;
730 the allocation mechanism is used for many body types, so is somewhat
731 more complicated, it uses arena-sets, and has no need for still-live
734 At the outermost level, (new|del)_X*V macros return bodies of the
735 appropriate type. These macros call either (new|del)_body_type or
736 (new|del)_body_allocated macro pairs, depending on specifics of the
737 type. Most body types use the former pair, the latter pair is used to
738 allocate body types with "ghost fields".
740 "ghost fields" are fields that are unused in certain types, and
741 consequently dont need to actually exist. They are declared because
742 they're part of a "base type", which allows use of functions as
743 methods. The simplest examples are AVs and HVs, 2 aggregate types
744 which don't use the fields which support SCALAR semantics.
746 For these types, the arenas are carved up into *_allocated size
747 chunks, we thus avoid wasted memory for those unaccessed members.
748 When bodies are allocated, we adjust the pointer back in memory by the
749 size of the bit not allocated, so it's as if we allocated the full
750 structure. (But things will all go boom if you write to the part that
751 is "not there", because you'll be overwriting the last members of the
752 preceding structure in memory.)
754 We calculate the correction using the STRUCT_OFFSET macro. For
755 example, if xpv_allocated is the same structure as XPV then the two
756 OFFSETs sum to zero, and the pointer is unchanged. If the allocated
757 structure is smaller (no initial NV actually allocated) then the net
758 effect is to subtract the size of the NV from the pointer, to return a
759 new pointer as if an initial NV were actually allocated.
761 This is the same trick as was used for NV and IV bodies. Ironically it
762 doesn't need to be used for NV bodies any more, because NV is now at
763 the start of the structure. IV bodies don't need it either, because
764 they are no longer allocated.
766 In turn, the new_body_* allocators call S_new_body(), which invokes
767 new_body_inline macro, which takes a lock, and takes a body off the
768 linked list at PL_body_roots[sv_type], calling S_more_bodies() if
769 necessary to refresh an empty list. Then the lock is released, and
770 the body is returned.
772 S_more_bodies calls get_arena(), and carves it up into an array of N
773 bodies, which it strings into a linked list. It looks up arena-size
774 and body-size from the body_details table described below, thus
775 supporting the multiple body-types.
777 If PURIFY is defined, or PERL_ARENA_SIZE=0, arenas are not used, and
778 the (new|del)_X*V macros are mapped directly to malloc/free.
784 For each sv-type, struct body_details bodies_by_type[] carries
785 parameters which control these aspects of SV handling:
787 Arena_size determines whether arenas are used for this body type, and if
788 so, how big they are. PURIFY or PERL_ARENA_SIZE=0 set this field to
789 zero, forcing individual mallocs and frees.
791 Body_size determines how big a body is, and therefore how many fit into
792 each arena. Offset carries the body-pointer adjustment needed for
793 *_allocated body types, and is used in *_allocated macros.
795 But its main purpose is to parameterize info needed in
796 Perl_sv_upgrade(). The info here dramatically simplifies the function
797 vs the implementation in 5.8.7, making it table-driven. All fields
798 are used for this, except for arena_size.
800 For the sv-types that have no bodies, arenas are not used, so those
801 PL_body_roots[sv_type] are unused, and can be overloaded. In
802 something of a special case, SVt_NULL is borrowed for HE arenas;
803 PL_body_roots[HE_SVSLOT=SVt_NULL] is filled by S_more_he, but the
804 bodies_by_type[SVt_NULL] slot is not used, as the table is not
807 PTEs also use arenas, but are never seen in Perl_sv_upgrade. Nonetheless,
808 they get their own slot in bodies_by_type[PTE_SVSLOT =SVt_IV], so they can
809 just use the same allocation semantics. At first, PTEs were also
810 overloaded to a non-body sv-type, but this yielded hard-to-find malloc
811 bugs, so was simplified by claiming a new slot. This choice has no
812 consequence at this time.
816 struct body_details {
817 U8 body_size; /* Size to allocate */
818 U8 copy; /* Size of structure to copy (may be shorter) */
820 unsigned int type : 4; /* We have space for a sanity check. */
821 unsigned int cant_upgrade : 1; /* Cannot upgrade this type */
822 unsigned int zero_nv : 1; /* zero the NV when upgrading from this */
823 unsigned int arena : 1; /* Allocated from an arena */
824 size_t arena_size; /* Size of arena to allocate */
832 /* With -DPURFIY we allocate everything directly, and don't use arenas.
833 This seems a rather elegant way to simplify some of the code below. */
834 #define HASARENA FALSE
836 #define HASARENA TRUE
838 #define NOARENA FALSE
840 /* Size the arenas to exactly fit a given number of bodies. A count
841 of 0 fits the max number bodies into a PERL_ARENA_SIZE.block,
842 simplifying the default. If count > 0, the arena is sized to fit
843 only that many bodies, allowing arenas to be used for large, rare
844 bodies (XPVFM, XPVIO) without undue waste. The arena size is
845 limited by PERL_ARENA_SIZE, so we can safely oversize the
848 #define FIT_ARENA0(body_size) \
849 ((size_t)(PERL_ARENA_SIZE / body_size) * body_size)
850 #define FIT_ARENAn(count,body_size) \
851 ( count * body_size <= PERL_ARENA_SIZE) \
852 ? count * body_size \
853 : FIT_ARENA0 (body_size)
854 #define FIT_ARENA(count,body_size) \
856 ? FIT_ARENAn (count, body_size) \
857 : FIT_ARENA0 (body_size)
859 /* A macro to work out the offset needed to subtract from a pointer to (say)
866 to make its members accessible via a pointer to (say)
876 #define relative_STRUCT_OFFSET(longer, shorter, member) \
877 (STRUCT_OFFSET(shorter, member) - STRUCT_OFFSET(longer, member))
879 /* Calculate the length to copy. Specifically work out the length less any
880 final padding the compiler needed to add. See the comment in sv_upgrade
881 for why copying the padding proved to be a bug. */
883 #define copy_length(type, last_member) \
884 STRUCT_OFFSET(type, last_member) \
885 + sizeof (((type*)SvANY((SV*)0))->last_member)
887 static const struct body_details bodies_by_type[] = {
888 { sizeof(HE), 0, 0, SVt_NULL,
889 FALSE, NONV, NOARENA, FIT_ARENA(0, sizeof(HE)) },
891 /* The bind placeholder pretends to be an RV for now.
892 Also it's marked as "can't upgrade" to stop anyone using it before it's
894 { 0, 0, 0, SVt_BIND, TRUE, NONV, NOARENA, 0 },
896 /* IVs are in the head, so the allocation size is 0.
897 However, the slot is overloaded for PTEs. */
898 { sizeof(struct ptr_tbl_ent), /* This is used for PTEs. */
899 sizeof(IV), /* This is used to copy out the IV body. */
900 STRUCT_OFFSET(XPVIV, xiv_iv), SVt_IV, FALSE, NONV,
901 NOARENA /* IVS don't need an arena */,
902 /* But PTEs need to know the size of their arena */
903 FIT_ARENA(0, sizeof(struct ptr_tbl_ent))
906 /* 8 bytes on most ILP32 with IEEE doubles */
907 { sizeof(NV), sizeof(NV), 0, SVt_NV, FALSE, HADNV, HASARENA,
908 FIT_ARENA(0, sizeof(NV)) },
910 /* 8 bytes on most ILP32 with IEEE doubles */
911 { sizeof(xpv_allocated),
912 copy_length(XPV, xpv_len)
913 - relative_STRUCT_OFFSET(xpv_allocated, XPV, xpv_cur),
914 + relative_STRUCT_OFFSET(xpv_allocated, XPV, xpv_cur),
915 SVt_PV, FALSE, NONV, HASARENA, FIT_ARENA(0, sizeof(xpv_allocated)) },
918 { sizeof(xpviv_allocated),
919 copy_length(XPVIV, xiv_u)
920 - relative_STRUCT_OFFSET(xpviv_allocated, XPVIV, xpv_cur),
921 + relative_STRUCT_OFFSET(xpviv_allocated, XPVIV, xpv_cur),
922 SVt_PVIV, FALSE, NONV, HASARENA, FIT_ARENA(0, sizeof(xpviv_allocated)) },
925 { sizeof(XPVNV), copy_length(XPVNV, xiv_u), 0, SVt_PVNV, FALSE, HADNV,
926 HASARENA, FIT_ARENA(0, sizeof(XPVNV)) },
929 { sizeof(XPVMG), copy_length(XPVMG, xmg_stash), 0, SVt_PVMG, FALSE, HADNV,
930 HASARENA, FIT_ARENA(0, sizeof(XPVMG)) },
933 { sizeof(struct regexp_allocated), sizeof(struct regexp_allocated),
934 + relative_STRUCT_OFFSET(struct regexp_allocated, regexp, xpv_cur),
935 SVt_REGEXP, FALSE, NONV, HASARENA,
936 FIT_ARENA(0, sizeof(struct regexp_allocated))
940 { sizeof(XPVGV), sizeof(XPVGV), 0, SVt_PVGV, TRUE, HADNV,
941 HASARENA, FIT_ARENA(0, sizeof(XPVGV)) },
944 { sizeof(XPVLV), sizeof(XPVLV), 0, SVt_PVLV, TRUE, HADNV,
945 HASARENA, FIT_ARENA(0, sizeof(XPVLV)) },
947 { sizeof(xpvav_allocated),
948 copy_length(XPVAV, xmg_stash)
949 - relative_STRUCT_OFFSET(xpvav_allocated, XPVAV, xav_fill),
950 + relative_STRUCT_OFFSET(xpvav_allocated, XPVAV, xav_fill),
951 SVt_PVAV, TRUE, NONV, HASARENA, FIT_ARENA(0, sizeof(xpvav_allocated)) },
953 { sizeof(xpvhv_allocated),
954 copy_length(XPVHV, xmg_stash)
955 - relative_STRUCT_OFFSET(xpvhv_allocated, XPVHV, xhv_fill),
956 + relative_STRUCT_OFFSET(xpvhv_allocated, XPVHV, xhv_fill),
957 SVt_PVHV, TRUE, NONV, HASARENA, FIT_ARENA(0, sizeof(xpvhv_allocated)) },
960 { sizeof(xpvcv_allocated), sizeof(xpvcv_allocated),
961 + relative_STRUCT_OFFSET(xpvcv_allocated, XPVCV, xpv_cur),
962 SVt_PVCV, TRUE, NONV, HASARENA, FIT_ARENA(0, sizeof(xpvcv_allocated)) },
964 { sizeof(xpvfm_allocated), sizeof(xpvfm_allocated),
965 + relative_STRUCT_OFFSET(xpvfm_allocated, XPVFM, xpv_cur),
966 SVt_PVFM, TRUE, NONV, NOARENA, FIT_ARENA(20, sizeof(xpvfm_allocated)) },
968 /* XPVIO is 84 bytes, fits 48x */
969 { sizeof(xpvio_allocated), sizeof(xpvio_allocated),
970 + relative_STRUCT_OFFSET(xpvio_allocated, XPVIO, xpv_cur),
971 SVt_PVIO, TRUE, NONV, HASARENA, FIT_ARENA(24, sizeof(xpvio_allocated)) },
974 #define new_body_type(sv_type) \
975 (void *)((char *)S_new_body(aTHX_ sv_type))
977 #define del_body_type(p, sv_type) \
978 del_body(p, &PL_body_roots[sv_type])
981 #define new_body_allocated(sv_type) \
982 (void *)((char *)S_new_body(aTHX_ sv_type) \
983 - bodies_by_type[sv_type].offset)
985 #define del_body_allocated(p, sv_type) \
986 del_body(p + bodies_by_type[sv_type].offset, &PL_body_roots[sv_type])
989 #define my_safemalloc(s) (void*)safemalloc(s)
990 #define my_safecalloc(s) (void*)safecalloc(s, 1)
991 #define my_safefree(p) safefree((char*)p)
995 #define new_XNV() my_safemalloc(sizeof(XPVNV))
996 #define del_XNV(p) my_safefree(p)
998 #define new_XPVNV() my_safemalloc(sizeof(XPVNV))
999 #define del_XPVNV(p) my_safefree(p)
1001 #define new_XPVAV() my_safemalloc(sizeof(XPVAV))
1002 #define del_XPVAV(p) my_safefree(p)
1004 #define new_XPVHV() my_safemalloc(sizeof(XPVHV))
1005 #define del_XPVHV(p) my_safefree(p)
1007 #define new_XPVMG() my_safemalloc(sizeof(XPVMG))
1008 #define del_XPVMG(p) my_safefree(p)
1010 #define new_XPVGV() my_safemalloc(sizeof(XPVGV))
1011 #define del_XPVGV(p) my_safefree(p)
1015 #define new_XNV() new_body_type(SVt_NV)
1016 #define del_XNV(p) del_body_type(p, SVt_NV)
1018 #define new_XPVNV() new_body_type(SVt_PVNV)
1019 #define del_XPVNV(p) del_body_type(p, SVt_PVNV)
1021 #define new_XPVAV() new_body_allocated(SVt_PVAV)
1022 #define del_XPVAV(p) del_body_allocated(p, SVt_PVAV)
1024 #define new_XPVHV() new_body_allocated(SVt_PVHV)
1025 #define del_XPVHV(p) del_body_allocated(p, SVt_PVHV)
1027 #define new_XPVMG() new_body_type(SVt_PVMG)
1028 #define del_XPVMG(p) del_body_type(p, SVt_PVMG)
1030 #define new_XPVGV() new_body_type(SVt_PVGV)
1031 #define del_XPVGV(p) del_body_type(p, SVt_PVGV)
1035 /* no arena for you! */
1037 #define new_NOARENA(details) \
1038 my_safemalloc((details)->body_size + (details)->offset)
1039 #define new_NOARENAZ(details) \
1040 my_safecalloc((details)->body_size + (details)->offset)
1043 S_more_bodies (pTHX_ const svtype sv_type)
1046 void ** const root = &PL_body_roots[sv_type];
1047 const struct body_details * const bdp = &bodies_by_type[sv_type];
1048 const size_t body_size = bdp->body_size;
1051 const size_t arena_size = Perl_malloc_good_size(bdp->arena_size);
1052 #if defined(DEBUGGING) && !defined(PERL_GLOBAL_STRUCT_PRIVATE)
1053 static bool done_sanity_check;
1055 /* PERL_GLOBAL_STRUCT_PRIVATE cannot coexist with global
1056 * variables like done_sanity_check. */
1057 if (!done_sanity_check) {
1058 unsigned int i = SVt_LAST;
1060 done_sanity_check = TRUE;
1063 assert (bodies_by_type[i].type == i);
1067 assert(bdp->arena_size);
1069 start = (char*) Perl_get_arena(aTHX_ arena_size, sv_type);
1071 end = start + arena_size - 2 * body_size;
1073 /* computed count doesnt reflect the 1st slot reservation */
1074 #if defined(MYMALLOC) || defined(HAS_MALLOC_GOOD_SIZE)
1075 DEBUG_m(PerlIO_printf(Perl_debug_log,
1076 "arena %p end %p arena-size %d (from %d) type %d "
1078 (void*)start, (void*)end, (int)arena_size,
1079 (int)bdp->arena_size, sv_type, (int)body_size,
1080 (int)arena_size / (int)body_size));
1082 DEBUG_m(PerlIO_printf(Perl_debug_log,
1083 "arena %p end %p arena-size %d type %d size %d ct %d\n",
1084 (void*)start, (void*)end,
1085 (int)bdp->arena_size, sv_type, (int)body_size,
1086 (int)bdp->arena_size / (int)body_size));
1088 *root = (void *)start;
1090 while (start <= end) {
1091 char * const next = start + body_size;
1092 *(void**) start = (void *)next;
1095 *(void **)start = 0;
1100 /* grab a new thing from the free list, allocating more if necessary.
1101 The inline version is used for speed in hot routines, and the
1102 function using it serves the rest (unless PURIFY).
1104 #define new_body_inline(xpv, sv_type) \
1106 void ** const r3wt = &PL_body_roots[sv_type]; \
1107 xpv = (PTR_TBL_ENT_t*) (*((void **)(r3wt)) \
1108 ? *((void **)(r3wt)) : more_bodies(sv_type)); \
1109 *(r3wt) = *(void**)(xpv); \
1115 S_new_body(pTHX_ const svtype sv_type)
1119 new_body_inline(xpv, sv_type);
1125 static const struct body_details fake_rv =
1126 { 0, 0, 0, SVt_IV, FALSE, NONV, NOARENA, 0 };
1129 =for apidoc sv_upgrade
1131 Upgrade an SV to a more complex form. Generally adds a new body type to the
1132 SV, then copies across as much information as possible from the old body.
1133 You generally want to use the C<SvUPGRADE> macro wrapper. See also C<svtype>.
1139 Perl_sv_upgrade(pTHX_ register SV *const sv, svtype new_type)
1144 const svtype old_type = SvTYPE(sv);
1145 const struct body_details *new_type_details;
1146 const struct body_details *old_type_details
1147 = bodies_by_type + old_type;
1148 SV *referant = NULL;
1150 PERL_ARGS_ASSERT_SV_UPGRADE;
1152 if (new_type != SVt_PV && SvIsCOW(sv)) {
1153 sv_force_normal_flags(sv, 0);
1156 if (old_type == new_type)
1159 old_body = SvANY(sv);
1161 /* Copying structures onto other structures that have been neatly zeroed
1162 has a subtle gotcha. Consider XPVMG
1164 +------+------+------+------+------+-------+-------+
1165 | NV | CUR | LEN | IV | MAGIC | STASH |
1166 +------+------+------+------+------+-------+-------+
1167 0 4 8 12 16 20 24 28
1169 where NVs are aligned to 8 bytes, so that sizeof that structure is
1170 actually 32 bytes long, with 4 bytes of padding at the end:
1172 +------+------+------+------+------+-------+-------+------+
1173 | NV | CUR | LEN | IV | MAGIC | STASH | ??? |
1174 +------+------+------+------+------+-------+-------+------+
1175 0 4 8 12 16 20 24 28 32
1177 so what happens if you allocate memory for this structure:
1179 +------+------+------+------+------+-------+-------+------+------+...
1180 | NV | CUR | LEN | IV | MAGIC | STASH | GP | NAME |
1181 +------+------+------+------+------+-------+-------+------+------+...
1182 0 4 8 12 16 20 24 28 32 36
1184 zero it, then copy sizeof(XPVMG) bytes on top of it? Not quite what you
1185 expect, because you copy the area marked ??? onto GP. Now, ??? may have
1186 started out as zero once, but it's quite possible that it isn't. So now,
1187 rather than a nicely zeroed GP, you have it pointing somewhere random.
1190 (In fact, GP ends up pointing at a previous GP structure, because the
1191 principle cause of the padding in XPVMG getting garbage is a copy of
1192 sizeof(XPVMG) bytes from a XPVGV structure in sv_unglob. Right now
1193 this happens to be moot because XPVGV has been re-ordered, with GP
1194 no longer after STASH)
1196 So we are careful and work out the size of used parts of all the
1204 referant = SvRV(sv);
1205 old_type_details = &fake_rv;
1206 if (new_type == SVt_NV)
1207 new_type = SVt_PVNV;
1209 if (new_type < SVt_PVIV) {
1210 new_type = (new_type == SVt_NV)
1211 ? SVt_PVNV : SVt_PVIV;
1216 if (new_type < SVt_PVNV) {
1217 new_type = SVt_PVNV;
1221 assert(new_type > SVt_PV);
1222 assert(SVt_IV < SVt_PV);
1223 assert(SVt_NV < SVt_PV);
1230 /* Because the XPVMG of PL_mess_sv isn't allocated from the arena,
1231 there's no way that it can be safely upgraded, because perl.c
1232 expects to Safefree(SvANY(PL_mess_sv)) */
1233 assert(sv != PL_mess_sv);
1234 /* This flag bit is used to mean other things in other scalar types.
1235 Given that it only has meaning inside the pad, it shouldn't be set
1236 on anything that can get upgraded. */
1237 assert(!SvPAD_TYPED(sv));
1240 if (old_type_details->cant_upgrade)
1241 Perl_croak(aTHX_ "Can't upgrade %s (%" UVuf ") to %" UVuf,
1242 sv_reftype(sv, 0), (UV) old_type, (UV) new_type);
1245 if (old_type > new_type)
1246 Perl_croak(aTHX_ "sv_upgrade from type %d down to type %d",
1247 (int)old_type, (int)new_type);
1249 new_type_details = bodies_by_type + new_type;
1251 SvFLAGS(sv) &= ~SVTYPEMASK;
1252 SvFLAGS(sv) |= new_type;
1254 /* This can't happen, as SVt_NULL is <= all values of new_type, so one of
1255 the return statements above will have triggered. */
1256 assert (new_type != SVt_NULL);
1259 assert(old_type == SVt_NULL);
1260 SvANY(sv) = (XPVIV*)((char*)&(sv->sv_u.svu_iv) - STRUCT_OFFSET(XPVIV, xiv_iv));
1264 assert(old_type == SVt_NULL);
1265 SvANY(sv) = new_XNV();
1270 assert(new_type_details->body_size);
1273 assert(new_type_details->arena);
1274 assert(new_type_details->arena_size);
1275 /* This points to the start of the allocated area. */
1276 new_body_inline(new_body, new_type);
1277 Zero(new_body, new_type_details->body_size, char);
1278 new_body = ((char *)new_body) - new_type_details->offset;
1280 /* We always allocated the full length item with PURIFY. To do this
1281 we fake things so that arena is false for all 16 types.. */
1282 new_body = new_NOARENAZ(new_type_details);
1284 SvANY(sv) = new_body;
1285 if (new_type == SVt_PVAV) {
1289 if (old_type_details->body_size) {
1292 /* It will have been zeroed when the new body was allocated.
1293 Lets not write to it, in case it confuses a write-back
1299 #ifndef NODEFAULT_SHAREKEYS
1300 HvSHAREKEYS_on(sv); /* key-sharing on by default */
1302 HvMAX(sv) = 7; /* (start with 8 buckets) */
1303 if (old_type_details->body_size) {
1306 /* It will have been zeroed when the new body was allocated.
1307 Lets not write to it, in case it confuses a write-back
1312 /* SVt_NULL isn't the only thing upgraded to AV or HV.
1313 The target created by newSVrv also is, and it can have magic.
1314 However, it never has SvPVX set.
1316 if (old_type == SVt_IV) {
1318 } else if (old_type >= SVt_PV) {
1319 assert(SvPVX_const(sv) == 0);
1322 if (old_type >= SVt_PVMG) {
1323 SvMAGIC_set(sv, ((XPVMG*)old_body)->xmg_u.xmg_magic);
1324 SvSTASH_set(sv, ((XPVMG*)old_body)->xmg_stash);
1326 sv->sv_u.svu_array = NULL; /* or svu_hash */
1332 /* XXX Is this still needed? Was it ever needed? Surely as there is
1333 no route from NV to PVIV, NOK can never be true */
1334 assert(!SvNOKp(sv));
1346 assert(new_type_details->body_size);
1347 /* We always allocated the full length item with PURIFY. To do this
1348 we fake things so that arena is false for all 16 types.. */
1349 if(new_type_details->arena) {
1350 /* This points to the start of the allocated area. */
1351 new_body_inline(new_body, new_type);
1352 Zero(new_body, new_type_details->body_size, char);
1353 new_body = ((char *)new_body) - new_type_details->offset;
1355 new_body = new_NOARENAZ(new_type_details);
1357 SvANY(sv) = new_body;
1359 if (old_type_details->copy) {
1360 /* There is now the potential for an upgrade from something without
1361 an offset (PVNV or PVMG) to something with one (PVCV, PVFM) */
1362 int offset = old_type_details->offset;
1363 int length = old_type_details->copy;
1365 if (new_type_details->offset > old_type_details->offset) {
1366 const int difference
1367 = new_type_details->offset - old_type_details->offset;
1368 offset += difference;
1369 length -= difference;
1371 assert (length >= 0);
1373 Copy((char *)old_body + offset, (char *)new_body + offset, length,
1377 #ifndef NV_ZERO_IS_ALLBITS_ZERO
1378 /* If NV 0.0 is stores as all bits 0 then Zero() already creates a
1379 * correct 0.0 for us. Otherwise, if the old body didn't have an
1380 * NV slot, but the new one does, then we need to initialise the
1381 * freshly created NV slot with whatever the correct bit pattern is
1383 if (old_type_details->zero_nv && !new_type_details->zero_nv
1384 && !isGV_with_GP(sv))
1388 if (new_type == SVt_PVIO)
1389 IoPAGE_LEN(sv) = 60;
1390 if (old_type < SVt_PV) {
1391 /* referant will be NULL unless the old type was SVt_IV emulating
1393 sv->sv_u.svu_rv = referant;
1397 Perl_croak(aTHX_ "panic: sv_upgrade to unknown type %lu",
1398 (unsigned long)new_type);
1401 if (old_type_details->arena) {
1402 /* If there was an old body, then we need to free it.
1403 Note that there is an assumption that all bodies of types that
1404 can be upgraded came from arenas. Only the more complex non-
1405 upgradable types are allowed to be directly malloc()ed. */
1407 my_safefree(old_body);
1409 del_body((void*)((char*)old_body + old_type_details->offset),
1410 &PL_body_roots[old_type]);
1416 =for apidoc sv_backoff
1418 Remove any string offset. You should normally use the C<SvOOK_off> macro
1425 Perl_sv_backoff(pTHX_ register SV *const sv)
1428 const char * const s = SvPVX_const(sv);
1430 PERL_ARGS_ASSERT_SV_BACKOFF;
1431 PERL_UNUSED_CONTEXT;
1434 assert(SvTYPE(sv) != SVt_PVHV);
1435 assert(SvTYPE(sv) != SVt_PVAV);
1437 SvOOK_offset(sv, delta);
1439 SvLEN_set(sv, SvLEN(sv) + delta);
1440 SvPV_set(sv, SvPVX(sv) - delta);
1441 Move(s, SvPVX(sv), SvCUR(sv)+1, char);
1442 SvFLAGS(sv) &= ~SVf_OOK;
1449 Expands the character buffer in the SV. If necessary, uses C<sv_unref> and
1450 upgrades the SV to C<SVt_PV>. Returns a pointer to the character buffer.
1451 Use the C<SvGROW> wrapper instead.
1457 Perl_sv_grow(pTHX_ register SV *const sv, register STRLEN newlen)
1461 PERL_ARGS_ASSERT_SV_GROW;
1463 if (PL_madskills && newlen >= 0x100000) {
1464 PerlIO_printf(Perl_debug_log,
1465 "Allocation too large: %"UVxf"\n", (UV)newlen);
1467 #ifdef HAS_64K_LIMIT
1468 if (newlen >= 0x10000) {
1469 PerlIO_printf(Perl_debug_log,
1470 "Allocation too large: %"UVxf"\n", (UV)newlen);
1473 #endif /* HAS_64K_LIMIT */
1476 if (SvTYPE(sv) < SVt_PV) {
1477 sv_upgrade(sv, SVt_PV);
1478 s = SvPVX_mutable(sv);
1480 else if (SvOOK(sv)) { /* pv is offset? */
1482 s = SvPVX_mutable(sv);
1483 if (newlen > SvLEN(sv))
1484 newlen += 10 * (newlen - SvCUR(sv)); /* avoid copy each time */
1485 #ifdef HAS_64K_LIMIT
1486 if (newlen >= 0x10000)
1491 s = SvPVX_mutable(sv);
1493 if (newlen > SvLEN(sv)) { /* need more room? */
1494 #ifndef Perl_safesysmalloc_size
1495 newlen = PERL_STRLEN_ROUNDUP(newlen);
1497 if (SvLEN(sv) && s) {
1498 s = (char*)saferealloc(s, newlen);
1501 s = (char*)safemalloc(newlen);
1502 if (SvPVX_const(sv) && SvCUR(sv)) {
1503 Move(SvPVX_const(sv), s, (newlen < SvCUR(sv)) ? newlen : SvCUR(sv), char);
1507 #ifdef Perl_safesysmalloc_size
1508 /* Do this here, do it once, do it right, and then we will never get
1509 called back into sv_grow() unless there really is some growing
1511 SvLEN_set(sv, Perl_safesysmalloc_size(s));
1513 SvLEN_set(sv, newlen);
1520 =for apidoc sv_setiv
1522 Copies an integer into the given SV, upgrading first if necessary.
1523 Does not handle 'set' magic. See also C<sv_setiv_mg>.
1529 Perl_sv_setiv(pTHX_ register SV *const sv, const IV i)
1533 PERL_ARGS_ASSERT_SV_SETIV;
1535 SV_CHECK_THINKFIRST_COW_DROP(sv);
1536 switch (SvTYPE(sv)) {
1539 sv_upgrade(sv, SVt_IV);
1542 sv_upgrade(sv, SVt_PVIV);
1551 Perl_croak(aTHX_ "Can't coerce %s to integer in %s", sv_reftype(sv,0),
1555 (void)SvIOK_only(sv); /* validate number */
1561 =for apidoc sv_setiv_mg
1563 Like C<sv_setiv>, but also handles 'set' magic.
1569 Perl_sv_setiv_mg(pTHX_ register SV *const sv, const IV i)
1571 PERL_ARGS_ASSERT_SV_SETIV_MG;
1578 =for apidoc sv_setuv
1580 Copies an unsigned integer into the given SV, upgrading first if necessary.
1581 Does not handle 'set' magic. See also C<sv_setuv_mg>.
1587 Perl_sv_setuv(pTHX_ register SV *const sv, const UV u)
1589 PERL_ARGS_ASSERT_SV_SETUV;
1591 /* With these two if statements:
1592 u=1.49 s=0.52 cu=72.49 cs=10.64 scripts=270 tests=20865
1595 u=1.35 s=0.47 cu=73.45 cs=11.43 scripts=270 tests=20865
1597 If you wish to remove them, please benchmark to see what the effect is
1599 if (u <= (UV)IV_MAX) {
1600 sv_setiv(sv, (IV)u);
1609 =for apidoc sv_setuv_mg
1611 Like C<sv_setuv>, but also handles 'set' magic.
1617 Perl_sv_setuv_mg(pTHX_ register SV *const sv, const UV u)
1619 PERL_ARGS_ASSERT_SV_SETUV_MG;
1626 =for apidoc sv_setnv
1628 Copies a double into the given SV, upgrading first if necessary.
1629 Does not handle 'set' magic. See also C<sv_setnv_mg>.
1635 Perl_sv_setnv(pTHX_ register SV *const sv, const NV num)
1639 PERL_ARGS_ASSERT_SV_SETNV;
1641 SV_CHECK_THINKFIRST_COW_DROP(sv);
1642 switch (SvTYPE(sv)) {
1645 sv_upgrade(sv, SVt_NV);
1649 sv_upgrade(sv, SVt_PVNV);
1658 Perl_croak(aTHX_ "Can't coerce %s to number in %s", sv_reftype(sv,0),
1663 (void)SvNOK_only(sv); /* validate number */
1668 =for apidoc sv_setnv_mg
1670 Like C<sv_setnv>, but also handles 'set' magic.
1676 Perl_sv_setnv_mg(pTHX_ register SV *const sv, const NV num)
1678 PERL_ARGS_ASSERT_SV_SETNV_MG;
1684 /* Print an "isn't numeric" warning, using a cleaned-up,
1685 * printable version of the offending string
1689 S_not_a_number(pTHX_ SV *const sv)
1696 PERL_ARGS_ASSERT_NOT_A_NUMBER;
1699 dsv = newSVpvs_flags("", SVs_TEMP);
1700 pv = sv_uni_display(dsv, sv, 10, 0);
1703 const char * const limit = tmpbuf + sizeof(tmpbuf) - 8;
1704 /* each *s can expand to 4 chars + "...\0",
1705 i.e. need room for 8 chars */
1707 const char *s = SvPVX_const(sv);
1708 const char * const end = s + SvCUR(sv);
1709 for ( ; s < end && d < limit; s++ ) {
1711 if (ch & 128 && !isPRINT_LC(ch)) {
1720 else if (ch == '\r') {
1724 else if (ch == '\f') {
1728 else if (ch == '\\') {
1732 else if (ch == '\0') {
1736 else if (isPRINT_LC(ch))
1753 Perl_warner(aTHX_ packWARN(WARN_NUMERIC),
1754 "Argument \"%s\" isn't numeric in %s", pv,
1757 Perl_warner(aTHX_ packWARN(WARN_NUMERIC),
1758 "Argument \"%s\" isn't numeric", pv);
1762 =for apidoc looks_like_number
1764 Test if the content of an SV looks like a number (or is a number).
1765 C<Inf> and C<Infinity> are treated as numbers (so will not issue a
1766 non-numeric warning), even if your atof() doesn't grok them.
1772 Perl_looks_like_number(pTHX_ SV *const sv)
1774 register const char *sbegin;
1777 PERL_ARGS_ASSERT_LOOKS_LIKE_NUMBER;
1780 sbegin = SvPVX_const(sv);
1783 else if (SvPOKp(sv))
1784 sbegin = SvPV_const(sv, len);
1786 return SvFLAGS(sv) & (SVf_NOK|SVp_NOK|SVf_IOK|SVp_IOK);
1787 return grok_number(sbegin, len, NULL);
1791 S_glob_2number(pTHX_ GV * const gv)
1793 const U32 wasfake = SvFLAGS(gv) & SVf_FAKE;
1794 SV *const buffer = sv_newmortal();
1796 PERL_ARGS_ASSERT_GLOB_2NUMBER;
1798 /* FAKE globs can get coerced, so need to turn this off temporarily if it
1801 gv_efullname3(buffer, gv, "*");
1802 SvFLAGS(gv) |= wasfake;
1804 /* We know that all GVs stringify to something that is not-a-number,
1805 so no need to test that. */
1806 if (ckWARN(WARN_NUMERIC))
1807 not_a_number(buffer);
1808 /* We just want something true to return, so that S_sv_2iuv_common
1809 can tail call us and return true. */
1814 S_glob_2pv(pTHX_ GV * const gv, STRLEN * const len)
1816 const U32 wasfake = SvFLAGS(gv) & SVf_FAKE;
1817 SV *const buffer = sv_newmortal();
1819 PERL_ARGS_ASSERT_GLOB_2PV;
1821 /* FAKE globs can get coerced, so need to turn this off temporarily if it
1824 gv_efullname3(buffer, gv, "*");
1825 SvFLAGS(gv) |= wasfake;
1827 assert(SvPOK(buffer));
1829 *len = SvCUR(buffer);
1831 return SvPVX(buffer);
1834 /* Actually, ISO C leaves conversion of UV to IV undefined, but
1835 until proven guilty, assume that things are not that bad... */
1840 As 64 bit platforms often have an NV that doesn't preserve all bits of
1841 an IV (an assumption perl has been based on to date) it becomes necessary
1842 to remove the assumption that the NV always carries enough precision to
1843 recreate the IV whenever needed, and that the NV is the canonical form.
1844 Instead, IV/UV and NV need to be given equal rights. So as to not lose
1845 precision as a side effect of conversion (which would lead to insanity
1846 and the dragon(s) in t/op/numconvert.t getting very angry) the intent is
1847 1) to distinguish between IV/UV/NV slots that have cached a valid
1848 conversion where precision was lost and IV/UV/NV slots that have a
1849 valid conversion which has lost no precision
1850 2) to ensure that if a numeric conversion to one form is requested that
1851 would lose precision, the precise conversion (or differently
1852 imprecise conversion) is also performed and cached, to prevent
1853 requests for different numeric formats on the same SV causing
1854 lossy conversion chains. (lossless conversion chains are perfectly
1859 SvIOKp is true if the IV slot contains a valid value
1860 SvIOK is true only if the IV value is accurate (UV if SvIOK_UV true)
1861 SvNOKp is true if the NV slot contains a valid value
1862 SvNOK is true only if the NV value is accurate
1865 while converting from PV to NV, check to see if converting that NV to an
1866 IV(or UV) would lose accuracy over a direct conversion from PV to
1867 IV(or UV). If it would, cache both conversions, return NV, but mark
1868 SV as IOK NOKp (ie not NOK).
1870 While converting from PV to IV, check to see if converting that IV to an
1871 NV would lose accuracy over a direct conversion from PV to NV. If it
1872 would, cache both conversions, flag similarly.
1874 Before, the SV value "3.2" could become NV=3.2 IV=3 NOK, IOK quite
1875 correctly because if IV & NV were set NV *always* overruled.
1876 Now, "3.2" will become NV=3.2 IV=3 NOK, IOKp, because the flag's meaning
1877 changes - now IV and NV together means that the two are interchangeable:
1878 SvIVX == (IV) SvNVX && SvNVX == (NV) SvIVX;
1880 The benefit of this is that operations such as pp_add know that if
1881 SvIOK is true for both left and right operands, then integer addition
1882 can be used instead of floating point (for cases where the result won't
1883 overflow). Before, floating point was always used, which could lead to
1884 loss of precision compared with integer addition.
1886 * making IV and NV equal status should make maths accurate on 64 bit
1888 * may speed up maths somewhat if pp_add and friends start to use
1889 integers when possible instead of fp. (Hopefully the overhead in
1890 looking for SvIOK and checking for overflow will not outweigh the
1891 fp to integer speedup)
1892 * will slow down integer operations (callers of SvIV) on "inaccurate"
1893 values, as the change from SvIOK to SvIOKp will cause a call into
1894 sv_2iv each time rather than a macro access direct to the IV slot
1895 * should speed up number->string conversion on integers as IV is
1896 favoured when IV and NV are equally accurate
1898 ####################################################################
1899 You had better be using SvIOK_notUV if you want an IV for arithmetic:
1900 SvIOK is true if (IV or UV), so you might be getting (IV)SvUV.
1901 On the other hand, SvUOK is true iff UV.
1902 ####################################################################
1904 Your mileage will vary depending your CPU's relative fp to integer
1908 #ifndef NV_PRESERVES_UV
1909 # define IS_NUMBER_UNDERFLOW_IV 1
1910 # define IS_NUMBER_UNDERFLOW_UV 2
1911 # define IS_NUMBER_IV_AND_UV 2
1912 # define IS_NUMBER_OVERFLOW_IV 4
1913 # define IS_NUMBER_OVERFLOW_UV 5
1915 /* sv_2iuv_non_preserve(): private routine for use by sv_2iv() and sv_2uv() */
1917 /* For sv_2nv these three cases are "SvNOK and don't bother casting" */
1919 S_sv_2iuv_non_preserve(pTHX_ register SV *const sv
1927 PERL_ARGS_ASSERT_SV_2IUV_NON_PRESERVE;
1929 DEBUG_c(PerlIO_printf(Perl_debug_log,"sv_2iuv_non '%s', IV=0x%"UVxf" NV=%"NVgf" inttype=%"UVXf"\n", SvPVX_const(sv), SvIVX(sv), SvNVX(sv), (UV)numtype));
1930 if (SvNVX(sv) < (NV)IV_MIN) {
1931 (void)SvIOKp_on(sv);
1933 SvIV_set(sv, IV_MIN);
1934 return IS_NUMBER_UNDERFLOW_IV;
1936 if (SvNVX(sv) > (NV)UV_MAX) {
1937 (void)SvIOKp_on(sv);
1940 SvUV_set(sv, UV_MAX);
1941 return IS_NUMBER_OVERFLOW_UV;
1943 (void)SvIOKp_on(sv);
1945 /* Can't use strtol etc to convert this string. (See truth table in
1947 if (SvNVX(sv) <= (UV)IV_MAX) {
1948 SvIV_set(sv, I_V(SvNVX(sv)));
1949 if ((NV)(SvIVX(sv)) == SvNVX(sv)) {
1950 SvIOK_on(sv); /* Integer is precise. NOK, IOK */
1952 /* Integer is imprecise. NOK, IOKp */
1954 return SvNVX(sv) < 0 ? IS_NUMBER_UNDERFLOW_UV : IS_NUMBER_IV_AND_UV;
1957 SvUV_set(sv, U_V(SvNVX(sv)));
1958 if ((NV)(SvUVX(sv)) == SvNVX(sv)) {
1959 if (SvUVX(sv) == UV_MAX) {
1960 /* As we know that NVs don't preserve UVs, UV_MAX cannot
1961 possibly be preserved by NV. Hence, it must be overflow.
1963 return IS_NUMBER_OVERFLOW_UV;
1965 SvIOK_on(sv); /* Integer is precise. NOK, UOK */
1967 /* Integer is imprecise. NOK, IOKp */
1969 return IS_NUMBER_OVERFLOW_IV;
1971 #endif /* !NV_PRESERVES_UV*/
1974 S_sv_2iuv_common(pTHX_ SV *const sv)
1978 PERL_ARGS_ASSERT_SV_2IUV_COMMON;
1981 /* erm. not sure. *should* never get NOKp (without NOK) from sv_2nv
1982 * without also getting a cached IV/UV from it at the same time
1983 * (ie PV->NV conversion should detect loss of accuracy and cache
1984 * IV or UV at same time to avoid this. */
1985 /* IV-over-UV optimisation - choose to cache IV if possible */
1987 if (SvTYPE(sv) == SVt_NV)
1988 sv_upgrade(sv, SVt_PVNV);
1990 (void)SvIOKp_on(sv); /* Must do this first, to clear any SvOOK */
1991 /* < not <= as for NV doesn't preserve UV, ((NV)IV_MAX+1) will almost
1992 certainly cast into the IV range at IV_MAX, whereas the correct
1993 answer is the UV IV_MAX +1. Hence < ensures that dodgy boundary
1995 #if defined(NAN_COMPARE_BROKEN) && defined(Perl_isnan)
1996 if (Perl_isnan(SvNVX(sv))) {
2002 if (SvNVX(sv) < (NV)IV_MAX + 0.5) {
2003 SvIV_set(sv, I_V(SvNVX(sv)));
2004 if (SvNVX(sv) == (NV) SvIVX(sv)
2005 #ifndef NV_PRESERVES_UV
2006 && (((UV)1 << NV_PRESERVES_UV_BITS) >
2007 (UV)(SvIVX(sv) > 0 ? SvIVX(sv) : -SvIVX(sv)))
2008 /* Don't flag it as "accurately an integer" if the number
2009 came from a (by definition imprecise) NV operation, and
2010 we're outside the range of NV integer precision */
2014 SvIOK_on(sv); /* Can this go wrong with rounding? NWC */
2016 /* scalar has trailing garbage, eg "42a" */
2018 DEBUG_c(PerlIO_printf(Perl_debug_log,
2019 "0x%"UVxf" iv(%"NVgf" => %"IVdf") (precise)\n",
2025 /* IV not precise. No need to convert from PV, as NV
2026 conversion would already have cached IV if it detected
2027 that PV->IV would be better than PV->NV->IV
2028 flags already correct - don't set public IOK. */
2029 DEBUG_c(PerlIO_printf(Perl_debug_log,
2030 "0x%"UVxf" iv(%"NVgf" => %"IVdf") (imprecise)\n",
2035 /* Can the above go wrong if SvIVX == IV_MIN and SvNVX < IV_MIN,
2036 but the cast (NV)IV_MIN rounds to a the value less (more
2037 negative) than IV_MIN which happens to be equal to SvNVX ??
2038 Analogous to 0xFFFFFFFFFFFFFFFF rounding up to NV (2**64) and
2039 NV rounding back to 0xFFFFFFFFFFFFFFFF, so UVX == UV(NVX) and
2040 (NV)UVX == NVX are both true, but the values differ. :-(
2041 Hopefully for 2s complement IV_MIN is something like
2042 0x8000000000000000 which will be exact. NWC */
2045 SvUV_set(sv, U_V(SvNVX(sv)));
2047 (SvNVX(sv) == (NV) SvUVX(sv))
2048 #ifndef NV_PRESERVES_UV
2049 /* Make sure it's not 0xFFFFFFFFFFFFFFFF */
2050 /*&& (SvUVX(sv) != UV_MAX) irrelevant with code below */
2051 && (((UV)1 << NV_PRESERVES_UV_BITS) > SvUVX(sv))
2052 /* Don't flag it as "accurately an integer" if the number
2053 came from a (by definition imprecise) NV operation, and
2054 we're outside the range of NV integer precision */
2060 DEBUG_c(PerlIO_printf(Perl_debug_log,
2061 "0x%"UVxf" 2iv(%"UVuf" => %"IVdf") (as unsigned)\n",
2067 else if (SvPOKp(sv) && SvLEN(sv)) {
2069 const int numtype = grok_number(SvPVX_const(sv), SvCUR(sv), &value);
2070 /* We want to avoid a possible problem when we cache an IV/ a UV which
2071 may be later translated to an NV, and the resulting NV is not
2072 the same as the direct translation of the initial string
2073 (eg 123.456 can shortcut to the IV 123 with atol(), but we must
2074 be careful to ensure that the value with the .456 is around if the
2075 NV value is requested in the future).
2077 This means that if we cache such an IV/a UV, we need to cache the
2078 NV as well. Moreover, we trade speed for space, and do not
2079 cache the NV if we are sure it's not needed.
2082 /* SVt_PVNV is one higher than SVt_PVIV, hence this order */
2083 if ((numtype & (IS_NUMBER_IN_UV | IS_NUMBER_NOT_INT))
2084 == IS_NUMBER_IN_UV) {
2085 /* It's definitely an integer, only upgrade to PVIV */
2086 if (SvTYPE(sv) < SVt_PVIV)
2087 sv_upgrade(sv, SVt_PVIV);
2089 } else if (SvTYPE(sv) < SVt_PVNV)
2090 sv_upgrade(sv, SVt_PVNV);
2092 /* If NVs preserve UVs then we only use the UV value if we know that
2093 we aren't going to call atof() below. If NVs don't preserve UVs
2094 then the value returned may have more precision than atof() will
2095 return, even though value isn't perfectly accurate. */
2096 if ((numtype & (IS_NUMBER_IN_UV
2097 #ifdef NV_PRESERVES_UV
2100 )) == IS_NUMBER_IN_UV) {
2101 /* This won't turn off the public IOK flag if it was set above */
2102 (void)SvIOKp_on(sv);
2104 if (!(numtype & IS_NUMBER_NEG)) {
2106 if (value <= (UV)IV_MAX) {
2107 SvIV_set(sv, (IV)value);
2109 /* it didn't overflow, and it was positive. */
2110 SvUV_set(sv, value);
2114 /* 2s complement assumption */
2115 if (value <= (UV)IV_MIN) {
2116 SvIV_set(sv, -(IV)value);
2118 /* Too negative for an IV. This is a double upgrade, but
2119 I'm assuming it will be rare. */
2120 if (SvTYPE(sv) < SVt_PVNV)
2121 sv_upgrade(sv, SVt_PVNV);
2125 SvNV_set(sv, -(NV)value);
2126 SvIV_set(sv, IV_MIN);
2130 /* For !NV_PRESERVES_UV and IS_NUMBER_IN_UV and IS_NUMBER_NOT_INT we
2131 will be in the previous block to set the IV slot, and the next
2132 block to set the NV slot. So no else here. */
2134 if ((numtype & (IS_NUMBER_IN_UV | IS_NUMBER_NOT_INT))
2135 != IS_NUMBER_IN_UV) {
2136 /* It wasn't an (integer that doesn't overflow the UV). */
2137 SvNV_set(sv, Atof(SvPVX_const(sv)));
2139 if (! numtype && ckWARN(WARN_NUMERIC))
2142 #if defined(USE_LONG_DOUBLE)
2143 DEBUG_c(PerlIO_printf(Perl_debug_log, "0x%"UVxf" 2iv(%" PERL_PRIgldbl ")\n",
2144 PTR2UV(sv), SvNVX(sv)));
2146 DEBUG_c(PerlIO_printf(Perl_debug_log, "0x%"UVxf" 2iv(%"NVgf")\n",
2147 PTR2UV(sv), SvNVX(sv)));
2150 #ifdef NV_PRESERVES_UV
2151 (void)SvIOKp_on(sv);
2153 if (SvNVX(sv) < (NV)IV_MAX + 0.5) {
2154 SvIV_set(sv, I_V(SvNVX(sv)));
2155 if ((NV)(SvIVX(sv)) == SvNVX(sv)) {
2158 NOOP; /* Integer is imprecise. NOK, IOKp */
2160 /* UV will not work better than IV */
2162 if (SvNVX(sv) > (NV)UV_MAX) {
2164 /* Integer is inaccurate. NOK, IOKp, is UV */
2165 SvUV_set(sv, UV_MAX);
2167 SvUV_set(sv, U_V(SvNVX(sv)));
2168 /* 0xFFFFFFFFFFFFFFFF not an issue in here, NVs
2169 NV preservse UV so can do correct comparison. */
2170 if ((NV)(SvUVX(sv)) == SvNVX(sv)) {
2173 NOOP; /* Integer is imprecise. NOK, IOKp, is UV */
2178 #else /* NV_PRESERVES_UV */
2179 if ((numtype & (IS_NUMBER_IN_UV | IS_NUMBER_NOT_INT))
2180 == (IS_NUMBER_IN_UV | IS_NUMBER_NOT_INT)) {
2181 /* The IV/UV slot will have been set from value returned by
2182 grok_number above. The NV slot has just been set using
2185 assert (SvIOKp(sv));
2187 if (((UV)1 << NV_PRESERVES_UV_BITS) >
2188 U_V(SvNVX(sv) > 0 ? SvNVX(sv) : -SvNVX(sv))) {
2189 /* Small enough to preserve all bits. */
2190 (void)SvIOKp_on(sv);
2192 SvIV_set(sv, I_V(SvNVX(sv)));
2193 if ((NV)(SvIVX(sv)) == SvNVX(sv))
2195 /* Assumption: first non-preserved integer is < IV_MAX,
2196 this NV is in the preserved range, therefore: */
2197 if (!(U_V(SvNVX(sv) > 0 ? SvNVX(sv) : -SvNVX(sv))
2199 Perl_croak(aTHX_ "sv_2iv assumed (U_V(fabs((double)SvNVX(sv))) < (UV)IV_MAX) but SvNVX(sv)=%"NVgf" U_V is 0x%"UVxf", IV_MAX is 0x%"UVxf"\n", SvNVX(sv), U_V(SvNVX(sv)), (UV)IV_MAX);
2203 0 0 already failed to read UV.
2204 0 1 already failed to read UV.
2205 1 0 you won't get here in this case. IV/UV
2206 slot set, public IOK, Atof() unneeded.
2207 1 1 already read UV.
2208 so there's no point in sv_2iuv_non_preserve() attempting
2209 to use atol, strtol, strtoul etc. */
2211 sv_2iuv_non_preserve (sv, numtype);
2213 sv_2iuv_non_preserve (sv);
2217 #endif /* NV_PRESERVES_UV */
2218 /* It might be more code efficient to go through the entire logic above
2219 and conditionally set with SvIOKp_on() rather than SvIOK(), but it
2220 gets complex and potentially buggy, so more programmer efficient
2221 to do it this way, by turning off the public flags: */
2223 SvFLAGS(sv) &= ~(SVf_IOK|SVf_NOK);
2227 if (isGV_with_GP(sv))
2228 return glob_2number((GV *)sv);
2230 if (!(SvFLAGS(sv) & SVs_PADTMP)) {
2231 if (!PL_localizing && ckWARN(WARN_UNINITIALIZED))
2234 if (SvTYPE(sv) < SVt_IV)
2235 /* Typically the caller expects that sv_any is not NULL now. */
2236 sv_upgrade(sv, SVt_IV);
2237 /* Return 0 from the caller. */
2244 =for apidoc sv_2iv_flags
2246 Return the integer value of an SV, doing any necessary string
2247 conversion. If flags includes SV_GMAGIC, does an mg_get() first.
2248 Normally used via the C<SvIV(sv)> and C<SvIVx(sv)> macros.
2254 Perl_sv_2iv_flags(pTHX_ register SV *const sv, const I32 flags)
2259 if (SvGMAGICAL(sv) || (SvTYPE(sv) == SVt_PVGV && SvVALID(sv))) {
2260 /* FBMs use the same flag bit as SVf_IVisUV, so must let them
2261 cache IVs just in case. In practice it seems that they never
2262 actually anywhere accessible by user Perl code, let alone get used
2263 in anything other than a string context. */
2264 if (flags & SV_GMAGIC)
2269 return I_V(SvNVX(sv));
2271 if (SvPOKp(sv) && SvLEN(sv)) {
2274 = grok_number(SvPVX_const(sv), SvCUR(sv), &value);
2276 if ((numtype & (IS_NUMBER_IN_UV | IS_NUMBER_NOT_INT))
2277 == IS_NUMBER_IN_UV) {
2278 /* It's definitely an integer */
2279 if (numtype & IS_NUMBER_NEG) {
2280 if (value < (UV)IV_MIN)
2283 if (value < (UV)IV_MAX)
2288 if (ckWARN(WARN_NUMERIC))
2291 return I_V(Atof(SvPVX_const(sv)));
2296 assert(SvTYPE(sv) >= SVt_PVMG);
2297 /* This falls through to the report_uninit inside S_sv_2iuv_common. */
2298 } else if (SvTHINKFIRST(sv)) {
2302 SV * const tmpstr=AMG_CALLun(sv,numer);
2303 if (tmpstr && (!SvROK(tmpstr) || (SvRV(tmpstr) != SvRV(sv)))) {
2304 return SvIV(tmpstr);
2307 return PTR2IV(SvRV(sv));
2310 sv_force_normal_flags(sv, 0);
2312 if (SvREADONLY(sv) && !SvOK(sv)) {
2313 if (ckWARN(WARN_UNINITIALIZED))
2319 if (S_sv_2iuv_common(aTHX_ sv))
2322 DEBUG_c(PerlIO_printf(Perl_debug_log, "0x%"UVxf" 2iv(%"IVdf")\n",
2323 PTR2UV(sv),SvIVX(sv)));
2324 return SvIsUV(sv) ? (IV)SvUVX(sv) : SvIVX(sv);
2328 =for apidoc sv_2uv_flags
2330 Return the unsigned integer value of an SV, doing any necessary string
2331 conversion. If flags includes SV_GMAGIC, does an mg_get() first.
2332 Normally used via the C<SvUV(sv)> and C<SvUVx(sv)> macros.
2338 Perl_sv_2uv_flags(pTHX_ register SV *const sv, const I32 flags)
2343 if (SvGMAGICAL(sv) || (SvTYPE(sv) == SVt_PVGV && SvVALID(sv))) {
2344 /* FBMs use the same flag bit as SVf_IVisUV, so must let them
2345 cache IVs just in case. */
2346 if (flags & SV_GMAGIC)
2351 return U_V(SvNVX(sv));
2352 if (SvPOKp(sv) && SvLEN(sv)) {
2355 = grok_number(SvPVX_const(sv), SvCUR(sv), &value);
2357 if ((numtype & (IS_NUMBER_IN_UV | IS_NUMBER_NOT_INT))
2358 == IS_NUMBER_IN_UV) {
2359 /* It's definitely an integer */
2360 if (!(numtype & IS_NUMBER_NEG))
2364 if (ckWARN(WARN_NUMERIC))
2367 return U_V(Atof(SvPVX_const(sv)));
2372 assert(SvTYPE(sv) >= SVt_PVMG);
2373 /* This falls through to the report_uninit inside S_sv_2iuv_common. */
2374 } else if (SvTHINKFIRST(sv)) {
2378 SV *const tmpstr = AMG_CALLun(sv,numer);
2379 if (tmpstr && (!SvROK(tmpstr) || (SvRV(tmpstr) != SvRV(sv)))) {
2380 return SvUV(tmpstr);
2383 return PTR2UV(SvRV(sv));
2386 sv_force_normal_flags(sv, 0);
2388 if (SvREADONLY(sv) && !SvOK(sv)) {
2389 if (ckWARN(WARN_UNINITIALIZED))
2395 if (S_sv_2iuv_common(aTHX_ sv))
2399 DEBUG_c(PerlIO_printf(Perl_debug_log, "0x%"UVxf" 2uv(%"UVuf")\n",
2400 PTR2UV(sv),SvUVX(sv)));
2401 return SvIsUV(sv) ? SvUVX(sv) : (UV)SvIVX(sv);
2407 Return the num value of an SV, doing any necessary string or integer
2408 conversion, magic etc. Normally used via the C<SvNV(sv)> and C<SvNVx(sv)>
2415 Perl_sv_2nv(pTHX_ register SV *const sv)
2420 if (SvGMAGICAL(sv) || (SvTYPE(sv) == SVt_PVGV && SvVALID(sv))) {
2421 /* FBMs use the same flag bit as SVf_IVisUV, so must let them
2422 cache IVs just in case. */
2426 if ((SvPOKp(sv) && SvLEN(sv)) && !SvIOKp(sv)) {
2427 if (!SvIOKp(sv) && ckWARN(WARN_NUMERIC) &&
2428 !grok_number(SvPVX_const(sv), SvCUR(sv), NULL))
2430 return Atof(SvPVX_const(sv));
2434 return (NV)SvUVX(sv);
2436 return (NV)SvIVX(sv);
2441 assert(SvTYPE(sv) >= SVt_PVMG);
2442 /* This falls through to the report_uninit near the end of the
2444 } else if (SvTHINKFIRST(sv)) {
2448 SV *const tmpstr = AMG_CALLun(sv,numer);
2449 if (tmpstr && (!SvROK(tmpstr) || (SvRV(tmpstr) != SvRV(sv)))) {
2450 return SvNV(tmpstr);
2453 return PTR2NV(SvRV(sv));
2456 sv_force_normal_flags(sv, 0);
2458 if (SvREADONLY(sv) && !SvOK(sv)) {
2459 if (ckWARN(WARN_UNINITIALIZED))
2464 if (SvTYPE(sv) < SVt_NV) {
2465 /* The logic to use SVt_PVNV if necessary is in sv_upgrade. */
2466 sv_upgrade(sv, SVt_NV);
2467 #ifdef USE_LONG_DOUBLE
2469 STORE_NUMERIC_LOCAL_SET_STANDARD();
2470 PerlIO_printf(Perl_debug_log,
2471 "0x%"UVxf" num(%" PERL_PRIgldbl ")\n",
2472 PTR2UV(sv), SvNVX(sv));
2473 RESTORE_NUMERIC_LOCAL();
2477 STORE_NUMERIC_LOCAL_SET_STANDARD();
2478 PerlIO_printf(Perl_debug_log, "0x%"UVxf" num(%"NVgf")\n",
2479 PTR2UV(sv), SvNVX(sv));
2480 RESTORE_NUMERIC_LOCAL();
2484 else if (SvTYPE(sv) < SVt_PVNV)
2485 sv_upgrade(sv, SVt_PVNV);
2490 SvNV_set(sv, SvIsUV(sv) ? (NV)SvUVX(sv) : (NV)SvIVX(sv));
2491 #ifdef NV_PRESERVES_UV
2497 /* Only set the public NV OK flag if this NV preserves the IV */
2498 /* Check it's not 0xFFFFFFFFFFFFFFFF */
2500 SvIsUV(sv) ? ((SvUVX(sv) != UV_MAX)&&(SvUVX(sv) == U_V(SvNVX(sv))))
2501 : (SvIVX(sv) == I_V(SvNVX(sv))))
2507 else if (SvPOKp(sv) && SvLEN(sv)) {
2509 const int numtype = grok_number(SvPVX_const(sv), SvCUR(sv), &value);
2510 if (!SvIOKp(sv) && !numtype && ckWARN(WARN_NUMERIC))
2512 #ifdef NV_PRESERVES_UV
2513 if ((numtype & (IS_NUMBER_IN_UV | IS_NUMBER_NOT_INT))
2514 == IS_NUMBER_IN_UV) {
2515 /* It's definitely an integer */
2516 SvNV_set(sv, (numtype & IS_NUMBER_NEG) ? -(NV)value : (NV)value);
2518 SvNV_set(sv, Atof(SvPVX_const(sv)));
2524 SvNV_set(sv, Atof(SvPVX_const(sv)));
2525 /* Only set the public NV OK flag if this NV preserves the value in
2526 the PV at least as well as an IV/UV would.
2527 Not sure how to do this 100% reliably. */
2528 /* if that shift count is out of range then Configure's test is
2529 wonky. We shouldn't be in here with NV_PRESERVES_UV_BITS ==
2531 if (((UV)1 << NV_PRESERVES_UV_BITS) >
2532 U_V(SvNVX(sv) > 0 ? SvNVX(sv) : -SvNVX(sv))) {
2533 SvNOK_on(sv); /* Definitely small enough to preserve all bits */
2534 } else if (!(numtype & IS_NUMBER_IN_UV)) {
2535 /* Can't use strtol etc to convert this string, so don't try.
2536 sv_2iv and sv_2uv will use the NV to convert, not the PV. */
2539 /* value has been set. It may not be precise. */
2540 if ((numtype & IS_NUMBER_NEG) && (value > (UV)IV_MIN)) {
2541 /* 2s complement assumption for (UV)IV_MIN */
2542 SvNOK_on(sv); /* Integer is too negative. */
2547 if (numtype & IS_NUMBER_NEG) {
2548 SvIV_set(sv, -(IV)value);
2549 } else if (value <= (UV)IV_MAX) {
2550 SvIV_set(sv, (IV)value);
2552 SvUV_set(sv, value);
2556 if (numtype & IS_NUMBER_NOT_INT) {
2557 /* I believe that even if the original PV had decimals,
2558 they are lost beyond the limit of the FP precision.
2559 However, neither is canonical, so both only get p
2560 flags. NWC, 2000/11/25 */
2561 /* Both already have p flags, so do nothing */
2563 const NV nv = SvNVX(sv);
2564 if (SvNVX(sv) < (NV)IV_MAX + 0.5) {
2565 if (SvIVX(sv) == I_V(nv)) {
2568 /* It had no "." so it must be integer. */
2572 /* between IV_MAX and NV(UV_MAX).
2573 Could be slightly > UV_MAX */
2575 if (numtype & IS_NUMBER_NOT_INT) {
2576 /* UV and NV both imprecise. */
2578 const UV nv_as_uv = U_V(nv);
2580 if (value == nv_as_uv && SvUVX(sv) != UV_MAX) {
2589 /* It might be more code efficient to go through the entire logic above
2590 and conditionally set with SvNOKp_on() rather than SvNOK(), but it
2591 gets complex and potentially buggy, so more programmer efficient
2592 to do it this way, by turning off the public flags: */
2594 SvFLAGS(sv) &= ~(SVf_IOK|SVf_NOK);
2595 #endif /* NV_PRESERVES_UV */
2598 if (isGV_with_GP(sv)) {
2599 glob_2number((GV *)sv);
2603 if (!PL_localizing && !(SvFLAGS(sv) & SVs_PADTMP) && ckWARN(WARN_UNINITIALIZED))
2605 assert (SvTYPE(sv) >= SVt_NV);
2606 /* Typically the caller expects that sv_any is not NULL now. */
2607 /* XXX Ilya implies that this is a bug in callers that assume this
2608 and ideally should be fixed. */
2611 #if defined(USE_LONG_DOUBLE)
2613 STORE_NUMERIC_LOCAL_SET_STANDARD();
2614 PerlIO_printf(Perl_debug_log, "0x%"UVxf" 2nv(%" PERL_PRIgldbl ")\n",
2615 PTR2UV(sv), SvNVX(sv));
2616 RESTORE_NUMERIC_LOCAL();
2620 STORE_NUMERIC_LOCAL_SET_STANDARD();
2621 PerlIO_printf(Perl_debug_log, "0x%"UVxf" 1nv(%"NVgf")\n",
2622 PTR2UV(sv), SvNVX(sv));
2623 RESTORE_NUMERIC_LOCAL();
2632 Return an SV with the numeric value of the source SV, doing any necessary
2633 reference or overload conversion. You must use the C<SvNUM(sv)> macro to
2634 access this function.
2640 Perl_sv_2num(pTHX_ register SV *const sv)
2642 PERL_ARGS_ASSERT_SV_2NUM;
2647 SV * const tmpsv = AMG_CALLun(sv,numer);
2648 if (tmpsv && (!SvROK(tmpsv) || (SvRV(tmpsv) != SvRV(sv))))
2649 return sv_2num(tmpsv);
2651 return sv_2mortal(newSVuv(PTR2UV(SvRV(sv))));
2654 /* uiv_2buf(): private routine for use by sv_2pv_flags(): print an IV or
2655 * UV as a string towards the end of buf, and return pointers to start and
2658 * We assume that buf is at least TYPE_CHARS(UV) long.
2662 S_uiv_2buf(char *const buf, const IV iv, UV uv, const int is_uv, char **const peob)
2664 char *ptr = buf + TYPE_CHARS(UV);
2665 char * const ebuf = ptr;
2668 PERL_ARGS_ASSERT_UIV_2BUF;
2680 *--ptr = '0' + (char)(uv % 10);
2689 =for apidoc sv_2pv_flags
2691 Returns a pointer to the string value of an SV, and sets *lp to its length.
2692 If flags includes SV_GMAGIC, does an mg_get() first. Coerces sv to a string
2694 Normally invoked via the C<SvPV_flags> macro. C<sv_2pv()> and C<sv_2pv_nomg>
2695 usually end up here too.
2701 Perl_sv_2pv_flags(pTHX_ register SV *const sv, STRLEN *const lp, const I32 flags)
2711 if (SvGMAGICAL(sv)) {
2712 if (flags & SV_GMAGIC)
2717 if (flags & SV_MUTABLE_RETURN)
2718 return SvPVX_mutable(sv);
2719 if (flags & SV_CONST_RETURN)
2720 return (char *)SvPVX_const(sv);
2723 if (SvIOKp(sv) || SvNOKp(sv)) {
2724 char tbuf[64]; /* Must fit sprintf/Gconvert of longest IV/NV */
2729 ? my_snprintf(tbuf, sizeof(tbuf), "%"UVuf, (UV)SvUVX(sv))
2730 : my_snprintf(tbuf, sizeof(tbuf), "%"IVdf, (IV)SvIVX(sv));
2732 Gconvert(SvNVX(sv), NV_DIG, 0, tbuf);
2739 #ifdef FIXNEGATIVEZERO
2740 if (len == 2 && tbuf[0] == '-' && tbuf[1] == '0') {
2746 SvUPGRADE(sv, SVt_PV);
2749 s = SvGROW_mutable(sv, len + 1);
2752 return (char*)memcpy(s, tbuf, len + 1);
2758 assert(SvTYPE(sv) >= SVt_PVMG);
2759 /* This falls through to the report_uninit near the end of the
2761 } else if (SvTHINKFIRST(sv)) {
2765 SV *const tmpstr = AMG_CALLun(sv,string);
2766 if (tmpstr && (!SvROK(tmpstr) || (SvRV(tmpstr) != SvRV(sv)))) {
2768 /* char *pv = lp ? SvPV(tmpstr, *lp) : SvPV_nolen(tmpstr);
2772 if ((SvFLAGS(tmpstr) & (SVf_POK)) == SVf_POK) {
2773 if (flags & SV_CONST_RETURN) {
2774 pv = (char *) SvPVX_const(tmpstr);
2776 pv = (flags & SV_MUTABLE_RETURN)
2777 ? SvPVX_mutable(tmpstr) : SvPVX(tmpstr);
2780 *lp = SvCUR(tmpstr);
2782 pv = sv_2pv_flags(tmpstr, lp, flags);
2795 const SV *const referent = (SV*)SvRV(sv);
2799 retval = buffer = savepvn("NULLREF", len);
2800 } else if (SvTYPE(referent) == SVt_REGEXP) {
2801 const REGEXP * const re = (REGEXP *)referent;
2806 /* If the regex is UTF-8 we want the containing scalar to
2807 have an UTF-8 flag too */
2813 if ((seen_evals = RX_SEEN_EVALS(re)))
2814 PL_reginterp_cnt += seen_evals;
2817 *lp = RX_WRAPLEN(re);
2819 return RX_WRAPPED(re);
2821 const char *const typestr = sv_reftype(referent, 0);
2822 const STRLEN typelen = strlen(typestr);
2823 UV addr = PTR2UV(referent);
2824 const char *stashname = NULL;
2825 STRLEN stashnamelen = 0; /* hush, gcc */
2826 const char *buffer_end;
2828 if (SvOBJECT(referent)) {
2829 const HEK *const name = HvNAME_HEK(SvSTASH(referent));
2832 stashname = HEK_KEY(name);
2833 stashnamelen = HEK_LEN(name);
2835 if (HEK_UTF8(name)) {
2841 stashname = "__ANON__";
2844 len = stashnamelen + 1 /* = */ + typelen + 3 /* (0x */
2845 + 2 * sizeof(UV) + 2 /* )\0 */;
2847 len = typelen + 3 /* (0x */
2848 + 2 * sizeof(UV) + 2 /* )\0 */;
2851 Newx(buffer, len, char);
2852 buffer_end = retval = buffer + len;
2854 /* Working backwards */
2858 *--retval = PL_hexdigit[addr & 15];
2859 } while (addr >>= 4);
2865 memcpy(retval, typestr, typelen);
2869 retval -= stashnamelen;
2870 memcpy(retval, stashname, stashnamelen);
2872 /* retval may not neccesarily have reached the start of the
2874 assert (retval >= buffer);
2876 len = buffer_end - retval - 1; /* -1 for that \0 */
2884 if (SvREADONLY(sv) && !SvOK(sv)) {
2887 if (flags & SV_UNDEF_RETURNS_NULL)
2889 if (ckWARN(WARN_UNINITIALIZED))
2894 if (SvIOK(sv) || ((SvIOKp(sv) && !SvNOKp(sv)))) {
2895 /* I'm assuming that if both IV and NV are equally valid then
2896 converting the IV is going to be more efficient */
2897 const U32 isUIOK = SvIsUV(sv);
2898 char buf[TYPE_CHARS(UV)];
2902 if (SvTYPE(sv) < SVt_PVIV)
2903 sv_upgrade(sv, SVt_PVIV);
2904 ptr = uiv_2buf(buf, SvIVX(sv), SvUVX(sv), isUIOK, &ebuf);
2906 /* inlined from sv_setpvn */
2907 s = SvGROW_mutable(sv, len + 1);
2908 Move(ptr, s, len, char);
2912 else if (SvNOKp(sv)) {
2913 const int olderrno = errno;
2914 if (SvTYPE(sv) < SVt_PVNV)
2915 sv_upgrade(sv, SVt_PVNV);
2916 /* The +20 is pure guesswork. Configure test needed. --jhi */
2917 s = SvGROW_mutable(sv, NV_DIG + 20);
2918 /* some Xenix systems wipe out errno here */
2920 if (SvNVX(sv) == 0.0)
2921 my_strlcpy(s, "0", SvLEN(sv));
2925 Gconvert(SvNVX(sv), NV_DIG, 0, s);
2928 #ifdef FIXNEGATIVEZERO
2929 if (*s == '-' && s[1] == '0' && !s[2]) {
2941 if (isGV_with_GP(sv))
2942 return glob_2pv((GV *)sv, lp);
2946 if (flags & SV_UNDEF_RETURNS_NULL)
2948 if (!PL_localizing && !(SvFLAGS(sv) & SVs_PADTMP) && ckWARN(WARN_UNINITIALIZED))
2950 if (SvTYPE(sv) < SVt_PV)
2951 /* Typically the caller expects that sv_any is not NULL now. */
2952 sv_upgrade(sv, SVt_PV);
2956 const STRLEN len = s - SvPVX_const(sv);
2962 DEBUG_c(PerlIO_printf(Perl_debug_log, "0x%"UVxf" 2pv(%s)\n",
2963 PTR2UV(sv),SvPVX_const(sv)));
2964 if (flags & SV_CONST_RETURN)
2965 return (char *)SvPVX_const(sv);
2966 if (flags & SV_MUTABLE_RETURN)
2967 return SvPVX_mutable(sv);
2972 =for apidoc sv_copypv
2974 Copies a stringified representation of the source SV into the
2975 destination SV. Automatically performs any necessary mg_get and
2976 coercion of numeric values into strings. Guaranteed to preserve
2977 UTF8 flag even from overloaded objects. Similar in nature to
2978 sv_2pv[_flags] but operates directly on an SV instead of just the
2979 string. Mostly uses sv_2pv_flags to do its work, except when that
2980 would lose the UTF-8'ness of the PV.
2986 Perl_sv_copypv(pTHX_ SV *const dsv, register SV *const ssv)
2989 const char * const s = SvPV_const(ssv,len);
2991 PERL_ARGS_ASSERT_SV_COPYPV;
2993 sv_setpvn(dsv,s,len);
3001 =for apidoc sv_2pvbyte
3003 Return a pointer to the byte-encoded representation of the SV, and set *lp
3004 to its length. May cause the SV to be downgraded from UTF-8 as a
3007 Usually accessed via the C<SvPVbyte> macro.
3013 Perl_sv_2pvbyte(pTHX_ register SV *const sv, STRLEN *const lp)
3015 PERL_ARGS_ASSERT_SV_2PVBYTE;
3017 sv_utf8_downgrade(sv,0);
3018 return lp ? SvPV(sv,*lp) : SvPV_nolen(sv);
3022 =for apidoc sv_2pvutf8
3024 Return a pointer to the UTF-8-encoded representation of the SV, and set *lp
3025 to its length. May cause the SV to be upgraded to UTF-8 as a side-effect.
3027 Usually accessed via the C<SvPVutf8> macro.
3033 Perl_sv_2pvutf8(pTHX_ register SV *const sv, STRLEN *const lp)
3035 PERL_ARGS_ASSERT_SV_2PVUTF8;
3037 sv_utf8_upgrade(sv);
3038 return lp ? SvPV(sv,*lp) : SvPV_nolen(sv);
3043 =for apidoc sv_2bool
3045 This function is only called on magical items, and is only used by
3046 sv_true() or its macro equivalent.
3052 Perl_sv_2bool(pTHX_ register SV *const sv)
3056 PERL_ARGS_ASSERT_SV_2BOOL;
3064 SV * const tmpsv = AMG_CALLun(sv,bool_);
3065 if (tmpsv && (!SvROK(tmpsv) || (SvRV(tmpsv) != SvRV(sv))))
3066 return (bool)SvTRUE(tmpsv);
3068 return SvRV(sv) != 0;
3071 register XPV* const Xpvtmp = (XPV*)SvANY(sv);
3073 (*sv->sv_u.svu_pv > '0' ||
3074 Xpvtmp->xpv_cur > 1 ||
3075 (Xpvtmp->xpv_cur && *sv->sv_u.svu_pv != '0')))
3082 return SvIVX(sv) != 0;
3085 return SvNVX(sv) != 0.0;
3087 if (isGV_with_GP(sv))
3097 =for apidoc sv_utf8_upgrade
3099 Converts the PV of an SV to its UTF-8-encoded form.
3100 Forces the SV to string form if it is not already.
3101 Always sets the SvUTF8 flag to avoid future validity checks even
3102 if all the bytes have hibit clear.
3104 This is not as a general purpose byte encoding to Unicode interface:
3105 use the Encode extension for that.
3107 =for apidoc sv_utf8_upgrade_flags
3109 Converts the PV of an SV to its UTF-8-encoded form.
3110 Forces the SV to string form if it is not already.
3111 Always sets the SvUTF8 flag to avoid future validity checks even
3112 if all the bytes have hibit clear. If C<flags> has C<SV_GMAGIC> bit set,
3113 will C<mg_get> on C<sv> if appropriate, else not. C<sv_utf8_upgrade> and
3114 C<sv_utf8_upgrade_nomg> are implemented in terms of this function.
3116 This is not as a general purpose byte encoding to Unicode interface:
3117 use the Encode extension for that.
3123 Perl_sv_utf8_upgrade_flags(pTHX_ register SV *const sv, const I32 flags)
3127 PERL_ARGS_ASSERT_SV_UTF8_UPGRADE_FLAGS;
3129 if (sv == &PL_sv_undef)
3133 if (SvREADONLY(sv) && (SvPOKp(sv) || SvIOKp(sv) || SvNOKp(sv))) {
3134 (void) sv_2pv_flags(sv,&len, flags);
3138 (void) SvPV_force(sv,len);
3147 sv_force_normal_flags(sv, 0);
3150 if (PL_encoding && !(flags & SV_UTF8_NO_ENCODING))
3151 sv_recode_to_utf8(sv, PL_encoding);
3152 else { /* Assume Latin-1/EBCDIC */
3153 /* This function could be much more efficient if we
3154 * had a FLAG in SVs to signal if there are any hibit
3155 * chars in the PV. Given that there isn't such a flag
3156 * make the loop as fast as possible. */
3157 const U8 * const s = (U8 *) SvPVX_const(sv);
3158 const U8 * const e = (U8 *) SvEND(sv);
3163 /* Check for hi bit */
3164 if (!NATIVE_IS_INVARIANT(ch)) {
3165 STRLEN len = SvCUR(sv) + 1; /* Plus the \0 */
3166 U8 * const recoded = bytes_to_utf8((U8*)s, &len);
3168 SvPV_free(sv); /* No longer using what was there before. */
3169 SvPV_set(sv, (char*)recoded);
3170 SvCUR_set(sv, len - 1);
3171 SvLEN_set(sv, len); /* No longer know the real size. */
3175 /* Mark as UTF-8 even if no hibit - saves scanning loop */
3182 =for apidoc sv_utf8_downgrade
3184 Attempts to convert the PV of an SV from characters to bytes.
3185 If the PV contains a character beyond byte, this conversion will fail;
3186 in this case, either returns false or, if C<fail_ok> is not
3189 This is not as a general purpose Unicode to byte encoding interface:
3190 use the Encode extension for that.
3196 Perl_sv_utf8_downgrade(pTHX_ register SV *const sv, const bool fail_ok)
3200 PERL_ARGS_ASSERT_SV_UTF8_DOWNGRADE;
3202 if (SvPOKp(sv) && SvUTF8(sv)) {
3208 sv_force_normal_flags(sv, 0);
3210 s = (U8 *) SvPV(sv, len);
3211 if (!utf8_to_bytes(s, &len)) {
3216 Perl_croak(aTHX_ "Wide character in %s",
3219 Perl_croak(aTHX_ "Wide character");
3230 =for apidoc sv_utf8_encode
3232 Converts the PV of an SV to UTF-8, but then turns the C<SvUTF8>
3233 flag off so that it looks like octets again.
3239 Perl_sv_utf8_encode(pTHX_ register SV *const sv)
3241 PERL_ARGS_ASSERT_SV_UTF8_ENCODE;
3244 sv_force_normal_flags(sv, 0);
3246 if (SvREADONLY(sv)) {
3247 Perl_croak(aTHX_ PL_no_modify);
3249 (void) sv_utf8_upgrade(sv);
3254 =for apidoc sv_utf8_decode
3256 If the PV of the SV is an octet sequence in UTF-8
3257 and contains a multiple-byte character, the C<SvUTF8> flag is turned on
3258 so that it looks like a character. If the PV contains only single-byte
3259 characters, the C<SvUTF8> flag stays being off.
3260 Scans PV for validity and returns false if the PV is invalid UTF-8.
3266 Perl_sv_utf8_decode(pTHX_ register SV *const sv)
3268 PERL_ARGS_ASSERT_SV_UTF8_DECODE;
3274 /* The octets may have got themselves encoded - get them back as
3277 if (!sv_utf8_downgrade(sv, TRUE))
3280 /* it is actually just a matter of turning the utf8 flag on, but
3281 * we want to make sure everything inside is valid utf8 first.
3283 c = (const U8 *) SvPVX_const(sv);
3284 if (!is_utf8_string(c, SvCUR(sv)+1))
3286 e = (const U8 *) SvEND(sv);
3289 if (!UTF8_IS_INVARIANT(ch)) {
3299 =for apidoc sv_setsv
3301 Copies the contents of the source SV C<ssv> into the destination SV
3302 C<dsv>. The source SV may be destroyed if it is mortal, so don't use this
3303 function if the source SV needs to be reused. Does not handle 'set' magic.
3304 Loosely speaking, it performs a copy-by-value, obliterating any previous
3305 content of the destination.
3307 You probably want to use one of the assortment of wrappers, such as
3308 C<SvSetSV>, C<SvSetSV_nosteal>, C<SvSetMagicSV> and
3309 C<SvSetMagicSV_nosteal>.
3311 =for apidoc sv_setsv_flags
3313 Copies the contents of the source SV C<ssv> into the destination SV
3314 C<dsv>. The source SV may be destroyed if it is mortal, so don't use this
3315 function if the source SV needs to be reused. Does not handle 'set' magic.
3316 Loosely speaking, it performs a copy-by-value, obliterating any previous
3317 content of the destination.
3318 If the C<flags> parameter has the C<SV_GMAGIC> bit set, will C<mg_get> on
3319 C<ssv> if appropriate, else not. If the C<flags> parameter has the
3320 C<NOSTEAL> bit set then the buffers of temps will not be stolen. <sv_setsv>
3321 and C<sv_setsv_nomg> are implemented in terms of this function.
3323 You probably want to use one of the assortment of wrappers, such as
3324 C<SvSetSV>, C<SvSetSV_nosteal>, C<SvSetMagicSV> and
3325 C<SvSetMagicSV_nosteal>.
3327 This is the primary function for copying scalars, and most other
3328 copy-ish functions and macros use this underneath.
3334 S_glob_assign_glob(pTHX_ SV *const dstr, SV *const sstr, const int dtype)
3336 I32 mro_changes = 0; /* 1 = method, 2 = isa */
3338 PERL_ARGS_ASSERT_GLOB_ASSIGN_GLOB;
3340 if (dtype != SVt_PVGV) {
3341 const char * const name = GvNAME(sstr);
3342 const STRLEN len = GvNAMELEN(sstr);
3344 if (dtype >= SVt_PV) {
3350 SvUPGRADE(dstr, SVt_PVGV);
3351 (void)SvOK_off(dstr);
3352 /* FIXME - why are we doing this, then turning it off and on again
3354 isGV_with_GP_on(dstr);
3356 GvSTASH(dstr) = GvSTASH(sstr);
3358 Perl_sv_add_backref(aTHX_ (SV*)GvSTASH(dstr), dstr);
3359 gv_name_set((GV *)dstr, name, len, GV_ADD);
3360 SvFAKE_on(dstr); /* can coerce to non-glob */
3363 #ifdef GV_UNIQUE_CHECK
3364 if (GvUNIQUE((GV*)dstr)) {
3365 Perl_croak(aTHX_ PL_no_modify);
3369 if(GvGP((GV*)sstr)) {
3370 /* If source has method cache entry, clear it */
3372 SvREFCNT_dec(GvCV(sstr));
3376 /* If source has a real method, then a method is
3378 else if(GvCV((GV*)sstr)) {
3383 /* If dest already had a real method, that's a change as well */
3384 if(!mro_changes && GvGP((GV*)dstr) && GvCVu((GV*)dstr)) {
3388 if(strEQ(GvNAME((GV*)dstr),"ISA"))
3392 isGV_with_GP_off(dstr);
3393 (void)SvOK_off(dstr);
3394 isGV_with_GP_on(dstr);
3395 GvINTRO_off(dstr); /* one-shot flag */
3396 GvGP(dstr) = gp_ref(GvGP(sstr));
3397 if (SvTAINTED(sstr))
3399 if (GvIMPORTED(dstr) != GVf_IMPORTED
3400 && CopSTASH_ne(PL_curcop, GvSTASH(dstr)))
3402 GvIMPORTED_on(dstr);
3405 if(mro_changes == 2) mro_isa_changed_in(GvSTASH(dstr));
3406 else if(mro_changes) mro_method_changed_in(GvSTASH(dstr));
3411 S_glob_assign_ref(pTHX_ SV *const dstr, SV *const sstr)
3413 SV * const sref = SvREFCNT_inc(SvRV(sstr));
3415 const int intro = GvINTRO(dstr);
3418 const U32 stype = SvTYPE(sref);
3420 PERL_ARGS_ASSERT_GLOB_ASSIGN_REF;
3422 #ifdef GV_UNIQUE_CHECK
3423 if (GvUNIQUE((GV*)dstr)) {
3424 Perl_croak(aTHX_ PL_no_modify);
3429 GvINTRO_off(dstr); /* one-shot flag */
3430 GvLINE(dstr) = CopLINE(PL_curcop);
3431 GvEGV(dstr) = (GV*)dstr;
3436 location = (SV **) &GvCV(dstr);
3437 import_flag = GVf_IMPORTED_CV;
3440 location = (SV **) &GvHV(dstr);
3441 import_flag = GVf_IMPORTED_HV;
3444 location = (SV **) &GvAV(dstr);
3445 import_flag = GVf_IMPORTED_AV;
3448 location = (SV **) &GvIOp(dstr);
3451 location = (SV **) &GvFORM(dstr);
3453 location = &GvSV(dstr);
3454 import_flag = GVf_IMPORTED_SV;
3457 if (stype == SVt_PVCV) {
3458 /*if (GvCVGEN(dstr) && (GvCV(dstr) != (CV*)sref || GvCVGEN(dstr))) {*/
3459 if (GvCVGEN(dstr)) {
3460 SvREFCNT_dec(GvCV(dstr));
3462 GvCVGEN(dstr) = 0; /* Switch off cacheness. */
3465 SAVEGENERICSV(*location);
3469 if (stype == SVt_PVCV && (*location != sref || GvCVGEN(dstr))) {
3470 CV* const cv = (CV*)*location;
3472 if (!GvCVGEN((GV*)dstr) &&
3473 (CvROOT(cv) || CvXSUB(cv)))
3475 /* Redefining a sub - warning is mandatory if
3476 it was a const and its value changed. */
3477 if (CvCONST(cv) && CvCONST((CV*)sref)
3478 && cv_const_sv(cv) == cv_const_sv((CV*)sref)) {
3480 /* They are 2 constant subroutines generated from
3481 the same constant. This probably means that
3482 they are really the "same" proxy subroutine
3483 instantiated in 2 places. Most likely this is
3484 when a constant is exported twice. Don't warn.
3487 else if (ckWARN(WARN_REDEFINE)
3489 && (!CvCONST((CV*)sref)
3490 || sv_cmp(cv_const_sv(cv),
3491 cv_const_sv((CV*)sref))))) {
3492 Perl_warner(aTHX_ packWARN(WARN_REDEFINE),
3495 ? "Constant subroutine %s::%s redefined"
3496 : "Subroutine %s::%s redefined"),
3497 HvNAME_get(GvSTASH((GV*)dstr)),
3498 GvENAME((GV*)dstr));
3502 cv_ckproto_len(cv, (GV*)dstr,
3503 SvPOK(sref) ? SvPVX_const(sref) : NULL,
3504 SvPOK(sref) ? SvCUR(sref) : 0);
3506 GvCVGEN(dstr) = 0; /* Switch off cacheness. */
3507 GvASSUMECV_on(dstr);
3508 if(GvSTASH(dstr)) mro_method_changed_in(GvSTASH(dstr)); /* sub foo { 1 } sub bar { 2 } *bar = \&foo */
3511 if (import_flag && !(GvFLAGS(dstr) & import_flag)
3512 && CopSTASH_ne(PL_curcop, GvSTASH(dstr))) {
3513 GvFLAGS(dstr) |= import_flag;
3518 if (SvTAINTED(sstr))
3524 Perl_sv_setsv_flags(pTHX_ SV *dstr, register SV* sstr, const I32 flags)
3527 register U32 sflags;
3529 register svtype stype;
3531 PERL_ARGS_ASSERT_SV_SETSV_FLAGS;
3536 if (SvIS_FREED(dstr)) {
3537 Perl_croak(aTHX_ "panic: attempt to copy value %" SVf
3538 " to a freed scalar %p", SVfARG(sstr), (void *)dstr);
3540 SV_CHECK_THINKFIRST_COW_DROP(dstr);
3542 sstr = &PL_sv_undef;
3543 if (SvIS_FREED(sstr)) {
3544 Perl_croak(aTHX_ "panic: attempt to copy freed scalar %p to %p",
3545 (void*)sstr, (void*)dstr);
3547 stype = SvTYPE(sstr);
3548 dtype = SvTYPE(dstr);
3550 (void)SvAMAGIC_off(dstr);
3553 /* need to nuke the magic */
3557 /* There's a lot of redundancy below but we're going for speed here */
3562 if (dtype != SVt_PVGV) {
3563 (void)SvOK_off(dstr);
3571 sv_upgrade(dstr, SVt_IV);
3575 sv_upgrade(dstr, SVt_PVIV);
3578 goto end_of_first_switch;
3580 (void)SvIOK_only(dstr);
3581 SvIV_set(dstr, SvIVX(sstr));
3584 /* SvTAINTED can only be true if the SV has taint magic, which in
3585 turn means that the SV type is PVMG (or greater). This is the
3586 case statement for SVt_IV, so this cannot be true (whatever gcov
3588 assert(!SvTAINTED(sstr));
3593 if (dtype < SVt_PV && dtype != SVt_IV)
3594 sv_upgrade(dstr, SVt_IV);
3602 sv_upgrade(dstr, SVt_NV);
3606 sv_upgrade(dstr, SVt_PVNV);
3609 goto end_of_first_switch;
3611 SvNV_set(dstr, SvNVX(sstr));
3612 (void)SvNOK_only(dstr);
3613 /* SvTAINTED can only be true if the SV has taint magic, which in
3614 turn means that the SV type is PVMG (or greater). This is the
3615 case statement for SVt_NV, so this cannot be true (whatever gcov
3617 assert(!SvTAINTED(sstr));
3623 #ifdef PERL_OLD_COPY_ON_WRITE
3624 if ((SvFLAGS(sstr) & CAN_COW_MASK) == CAN_COW_FLAGS) {
3625 if (dtype < SVt_PVIV)
3626 sv_upgrade(dstr, SVt_PVIV);
3634 sv_upgrade(dstr, SVt_PV);
3637 if (dtype < SVt_PVIV)
3638 sv_upgrade(dstr, SVt_PVIV);
3641 if (dtype < SVt_PVNV)
3642 sv_upgrade(dstr, SVt_PVNV);
3646 const char * const type = sv_reftype(sstr,0);
3648 Perl_croak(aTHX_ "Bizarre copy of %s in %s", type, OP_NAME(PL_op));
3650 Perl_croak(aTHX_ "Bizarre copy of %s", type);
3654 /* case SVt_BIND: */
3657 if (isGV_with_GP(sstr) && dtype <= SVt_PVGV) {
3658 glob_assign_glob(dstr, sstr, dtype);
3661 /* SvVALID means that this PVGV is playing at being an FBM. */
3665 if (SvGMAGICAL(sstr) && (flags & SV_GMAGIC)) {
3667 if (SvTYPE(sstr) != stype) {
3668 stype = SvTYPE(sstr);
3669 if (isGV_with_GP(sstr) && stype == SVt_PVGV && dtype <= SVt_PVGV) {
3670 glob_assign_glob(dstr, sstr, dtype);
3675 if (stype == SVt_PVLV)
3676 SvUPGRADE(dstr, SVt_PVNV);
3678 SvUPGRADE(dstr, (svtype)stype);
3680 end_of_first_switch:
3682 /* dstr may have been upgraded. */
3683 dtype = SvTYPE(dstr);
3684 sflags = SvFLAGS(sstr);
3686 if (dtype == SVt_PVCV || dtype == SVt_PVFM) {
3687 /* Assigning to a subroutine sets the prototype. */
3690 const char *const ptr = SvPV_const(sstr, len);
3692 SvGROW(dstr, len + 1);
3693 Copy(ptr, SvPVX(dstr), len + 1, char);
3694 SvCUR_set(dstr, len);
3696 SvFLAGS(dstr) |= sflags & SVf_UTF8;
3700 } else if (dtype == SVt_PVAV || dtype == SVt_PVHV) {
3701 const char * const type = sv_reftype(dstr,0);
3703 Perl_croak(aTHX_ "Cannot copy to %s in %s", type, OP_NAME(PL_op));
3705 Perl_croak(aTHX_ "Cannot copy to %s", type);
3706 } else if (sflags & SVf_ROK) {
3707 if (isGV_with_GP(dstr) && dtype == SVt_PVGV
3708 && SvTYPE(SvRV(sstr)) == SVt_PVGV) {
3711 if (GvIMPORTED(dstr) != GVf_IMPORTED
3712 && CopSTASH_ne(PL_curcop, GvSTASH(dstr)))
3714 GvIMPORTED_on(dstr);
3719 if (isGV_with_GP(sstr)) {
3720 glob_assign_glob(dstr, sstr, dtype);
3725 if (dtype >= SVt_PV) {
3726 if (dtype == SVt_PVGV && isGV_with_GP(dstr)) {
3727 glob_assign_ref(dstr, sstr);
3730 if (SvPVX_const(dstr)) {
3736 (void)SvOK_off(dstr);
3737 SvRV_set(dstr, SvREFCNT_inc(SvRV(sstr)));
3738 SvFLAGS(dstr) |= sflags & SVf_ROK;
3739 assert(!(sflags & SVp_NOK));
3740 assert(!(sflags & SVp_IOK));
3741 assert(!(sflags & SVf_NOK));
3742 assert(!(sflags & SVf_IOK));
3744 else if (dtype == SVt_PVGV && isGV_with_GP(dstr)) {
3745 if (!(sflags & SVf_OK)) {
3746 if (ckWARN(WARN_MISC))
3747 Perl_warner(aTHX_ packWARN(WARN_MISC),
3748 "Undefined value assigned to typeglob");
3751 GV *gv = gv_fetchsv(sstr, GV_ADD, SVt_PVGV);
3752 if (dstr != (SV*)gv) {
3755 GvGP(dstr) = gp_ref(GvGP(gv));
3759 else if (sflags & SVp_POK) {
3763 * Check to see if we can just swipe the string. If so, it's a
3764 * possible small lose on short strings, but a big win on long ones.
3765 * It might even be a win on short strings if SvPVX_const(dstr)
3766 * has to be allocated and SvPVX_const(sstr) has to be freed.
3767 * Likewise if we can set up COW rather than doing an actual copy, we
3768 * drop to the else clause, as the swipe code and the COW setup code
3769 * have much in common.
3772 /* Whichever path we take through the next code, we want this true,
3773 and doing it now facilitates the COW check. */
3774 (void)SvPOK_only(dstr);
3777 /* If we're already COW then this clause is not true, and if COW
3778 is allowed then we drop down to the else and make dest COW
3779 with us. If caller hasn't said that we're allowed to COW
3780 shared hash keys then we don't do the COW setup, even if the
3781 source scalar is a shared hash key scalar. */
3782 (((flags & SV_COW_SHARED_HASH_KEYS)
3783 ? (sflags & (SVf_FAKE|SVf_READONLY)) != (SVf_FAKE|SVf_READONLY)
3784 : 1 /* If making a COW copy is forbidden then the behaviour we
3785 desire is as if the source SV isn't actually already
3786 COW, even if it is. So we act as if the source flags
3787 are not COW, rather than actually testing them. */
3789 #ifndef PERL_OLD_COPY_ON_WRITE
3790 /* The change that added SV_COW_SHARED_HASH_KEYS makes the logic
3791 when PERL_OLD_COPY_ON_WRITE is defined a little wrong.
3792 Conceptually PERL_OLD_COPY_ON_WRITE being defined should
3793 override SV_COW_SHARED_HASH_KEYS, because it means "always COW"
3794 but in turn, it's somewhat dead code, never expected to go
3795 live, but more kept as a placeholder on how to do it better
3796 in a newer implementation. */
3797 /* If we are COW and dstr is a suitable target then we drop down
3798 into the else and make dest a COW of us. */
3799 || (SvFLAGS(dstr) & CAN_COW_MASK) != CAN_COW_FLAGS
3804 (sflags & SVs_TEMP) && /* slated for free anyway? */
3805 !(sflags & SVf_OOK) && /* and not involved in OOK hack? */
3806 (!(flags & SV_NOSTEAL)) &&
3807 /* and we're allowed to steal temps */
3808 SvREFCNT(sstr) == 1 && /* and no other references to it? */
3809 SvLEN(sstr) && /* and really is a string */
3810 /* and won't be needed again, potentially */
3811 !(PL_op && PL_op->op_type == OP_AASSIGN))
3812 #ifdef PERL_OLD_COPY_ON_WRITE
3813 && ((flags & SV_COW_SHARED_HASH_KEYS)
3814 ? (!((sflags & CAN_COW_MASK) == CAN_COW_FLAGS
3815 && (SvFLAGS(dstr) & CAN_COW_MASK) == CAN_COW_FLAGS
3816 && SvTYPE(sstr) >= SVt_PVIV))
3820 /* Failed the swipe test, and it's not a shared hash key either.
3821 Have to copy the string. */
3822 STRLEN len = SvCUR(sstr);
3823 SvGROW(dstr, len + 1); /* inlined from sv_setpvn */
3824 Move(SvPVX_const(sstr),SvPVX(dstr),len,char);
3825 SvCUR_set(dstr, len);
3826 *SvEND(dstr) = '\0';
3828 /* If PERL_OLD_COPY_ON_WRITE is not defined, then isSwipe will always
3830 /* Either it's a shared hash key, or it's suitable for
3831 copy-on-write or we can swipe the string. */
3833 PerlIO_printf(Perl_debug_log, "Copy on write: sstr --> dstr\n");
3837 #ifdef PERL_OLD_COPY_ON_WRITE
3839 /* I believe I should acquire a global SV mutex if
3840 it's a COW sv (not a shared hash key) to stop
3841 it going un copy-on-write.
3842 If the source SV has gone un copy on write between up there
3843 and down here, then (assert() that) it is of the correct
3844 form to make it copy on write again */
3845 if ((sflags & (SVf_FAKE | SVf_READONLY))
3846 != (SVf_FAKE | SVf_READONLY)) {
3847 SvREADONLY_on(sstr);
3849 /* Make the source SV into a loop of 1.
3850 (about to become 2) */
3851 SV_COW_NEXT_SV_SET(sstr, sstr);
3855 /* Initial code is common. */
3856 if (SvPVX_const(dstr)) { /* we know that dtype >= SVt_PV */
3861 /* making another shared SV. */
3862 STRLEN cur = SvCUR(sstr);
3863 STRLEN len = SvLEN(sstr);
3864 #ifdef PERL_OLD_COPY_ON_WRITE
3866 assert (SvTYPE(dstr) >= SVt_PVIV);
3867 /* SvIsCOW_normal */
3868 /* splice us in between source and next-after-source. */
3869 SV_COW_NEXT_SV_SET(dstr, SV_COW_NEXT_SV(sstr));
3870 SV_COW_NEXT_SV_SET(sstr, dstr);
3871 SvPV_set(dstr, SvPVX_mutable(sstr));
3875 /* SvIsCOW_shared_hash */
3876 DEBUG_C(PerlIO_printf(Perl_debug_log,
3877 "Copy on write: Sharing hash\n"));
3879 assert (SvTYPE(dstr) >= SVt_PV);
3881 HEK_KEY(share_hek_hek(SvSHARED_HEK_FROM_PV(SvPVX_const(sstr)))));
3883 SvLEN_set(dstr, len);
3884 SvCUR_set(dstr, cur);
3885 SvREADONLY_on(dstr);
3887 /* Relesase a global SV mutex. */
3890 { /* Passes the swipe test. */
3891 SvPV_set(dstr, SvPVX_mutable(sstr));
3892 SvLEN_set(dstr, SvLEN(sstr));
3893 SvCUR_set(dstr, SvCUR(sstr));
3896 (void)SvOK_off(sstr); /* NOTE: nukes most SvFLAGS on sstr */
3897 SvPV_set(sstr, NULL);
3903 if (sflags & SVp_NOK) {
3904 SvNV_set(dstr, SvNVX(sstr));
3906 if (sflags & SVp_IOK) {
3907 SvIV_set(dstr, SvIVX(sstr));
3908 /* Must do this otherwise some other overloaded use of 0x80000000
3909 gets confused. I guess SVpbm_VALID */
3910 if (sflags & SVf_IVisUV)
3913 SvFLAGS(dstr) |= sflags & (SVf_IOK|SVp_IOK|SVf_NOK|SVp_NOK|SVf_UTF8);
3915 const MAGIC * const smg = SvVSTRING_mg(sstr);
3917 sv_magic(dstr, NULL, PERL_MAGIC_vstring,
3918 smg->mg_ptr, smg->mg_len);
3919 SvRMAGICAL_on(dstr);
3923 else if (sflags & (SVp_IOK|SVp_NOK)) {
3924 (void)SvOK_off(dstr);
3925 SvFLAGS(dstr) |= sflags & (SVf_IOK|SVp_IOK|SVf_IVisUV|SVf_NOK|SVp_NOK);
3926 if (sflags & SVp_IOK) {
3927 /* XXXX Do we want to set IsUV for IV(ROK)? Be extra safe... */
3928 SvIV_set(dstr, SvIVX(sstr));
3930 if (sflags & SVp_NOK) {
3931 SvNV_set(dstr, SvNVX(sstr));
3935 if (isGV_with_GP(sstr)) {
3936 /* This stringification rule for globs is spread in 3 places.
3937 This feels bad. FIXME. */
3938 const U32 wasfake = sflags & SVf_FAKE;
3940 /* FAKE globs can get coerced, so need to turn this off
3941 temporarily if it is on. */
3943 gv_efullname3(dstr, (GV *)sstr, "*");
3944 SvFLAGS(sstr) |= wasfake;
3947 (void)SvOK_off(dstr);
3949 if (SvTAINTED(sstr))
3954 =for apidoc sv_setsv_mg
3956 Like C<sv_setsv>, but also handles 'set' magic.
3962 Perl_sv_setsv_mg(pTHX_ SV *const dstr, register SV *const sstr)
3964 PERL_ARGS_ASSERT_SV_SETSV_MG;
3966 sv_setsv(dstr,sstr);
3970 #ifdef PERL_OLD_COPY_ON_WRITE
3972 Perl_sv_setsv_cow(pTHX_ SV *dstr, SV *sstr)
3974 STRLEN cur = SvCUR(sstr);
3975 STRLEN len = SvLEN(sstr);
3976 register char *new_pv;
3978 PERL_ARGS_ASSERT_SV_SETSV_COW;
3981 PerlIO_printf(Perl_debug_log, "Fast copy on write: %p -> %p\n",
3982 (void*)sstr, (void*)dstr);
3989 if (SvTHINKFIRST(dstr))
3990 sv_force_normal_flags(dstr, SV_COW_DROP_PV);
3991 else if (SvPVX_const(dstr))
3992 Safefree(SvPVX_const(dstr));
3996 SvUPGRADE(dstr, SVt_PVIV);
3998 assert (SvPOK(sstr));
3999 assert (SvPOKp(sstr));
4000 assert (!SvIOK(sstr));
4001 assert (!SvIOKp(sstr));
4002 assert (!SvNOK(sstr));
4003 assert (!SvNOKp(sstr));
4005 if (SvIsCOW(sstr)) {
4007 if (SvLEN(sstr) == 0) {
4008 /* source is a COW shared hash key. */
4009 DEBUG_C(PerlIO_printf(Perl_debug_log,
4010 "Fast copy on write: Sharing hash\n"));
4011 new_pv = HEK_KEY(share_hek_hek(SvSHARED_HEK_FROM_PV(SvPVX_const(sstr))));
4014 SV_COW_NEXT_SV_SET(dstr, SV_COW_NEXT_SV(sstr));
4016 assert ((SvFLAGS(sstr) & CAN_COW_MASK) == CAN_COW_FLAGS);
4017 SvUPGRADE(sstr, SVt_PVIV);
4018 SvREADONLY_on(sstr);
4020 DEBUG_C(PerlIO_printf(Perl_debug_log,
4021 "Fast copy on write: Converting sstr to COW\n"));
4022 SV_COW_NEXT_SV_SET(dstr, sstr);
4024 SV_COW_NEXT_SV_SET(sstr, dstr);
4025 new_pv = SvPVX_mutable(sstr);
4028 SvPV_set(dstr, new_pv);
4029 SvFLAGS(dstr) = (SVt_PVIV|SVf_POK|SVp_POK|SVf_FAKE|SVf_READONLY);
4032 SvLEN_set(dstr, len);
4033 SvCUR_set(dstr, cur);
4042 =for apidoc sv_setpvn
4044 Copies a string into an SV. The C<len> parameter indicates the number of
4045 bytes to be copied. If the C<ptr> argument is NULL the SV will become
4046 undefined. Does not handle 'set' magic. See C<sv_setpvn_mg>.
4052 Perl_sv_setpvn(pTHX_ register SV *const sv, register const char *const ptr, register const STRLEN len)
4055 register char *dptr;
4057 PERL_ARGS_ASSERT_SV_SETPVN;
4059 SV_CHECK_THINKFIRST_COW_DROP(sv);
4065 /* len is STRLEN which is unsigned, need to copy to signed */
4068 Perl_croak(aTHX_ "panic: sv_setpvn called with negative strlen");
4070 SvUPGRADE(sv, SVt_PV);
4072 dptr = SvGROW(sv, len + 1);
4073 Move(ptr,dptr,len,char);
4076 (void)SvPOK_only_UTF8(sv); /* validate pointer */
4081 =for apidoc sv_setpvn_mg
4083 Like C<sv_setpvn>, but also handles 'set' magic.
4089 Perl_sv_setpvn_mg(pTHX_ register SV *const sv, register const char *const ptr, register const STRLEN len)
4091 PERL_ARGS_ASSERT_SV_SETPVN_MG;
4093 sv_setpvn(sv,ptr,len);
4098 =for apidoc sv_setpv
4100 Copies a string into an SV. The string must be null-terminated. Does not
4101 handle 'set' magic. See C<sv_setpv_mg>.
4107 Perl_sv_setpv(pTHX_ register SV *const sv, register const char *const ptr)
4110 register STRLEN len;
4112 PERL_ARGS_ASSERT_SV_SETPV;
4114 SV_CHECK_THINKFIRST_COW_DROP(sv);
4120 SvUPGRADE(sv, SVt_PV);
4122 SvGROW(sv, len + 1);
4123 Move(ptr,SvPVX(sv),len+1,char);
4125 (void)SvPOK_only_UTF8(sv); /* validate pointer */
4130 =for apidoc sv_setpv_mg
4132 Like C<sv_setpv>, but also handles 'set' magic.
4138 Perl_sv_setpv_mg(pTHX_ register SV *const sv, register const char *const ptr)
4140 PERL_ARGS_ASSERT_SV_SETPV_MG;
4147 =for apidoc sv_usepvn_flags
4149 Tells an SV to use C<ptr> to find its string value. Normally the
4150 string is stored inside the SV but sv_usepvn allows the SV to use an
4151 outside string. The C<ptr> should point to memory that was allocated
4152 by C<malloc>. The string length, C<len>, must be supplied. By default
4153 this function will realloc (i.e. move) the memory pointed to by C<ptr>,
4154 so that pointer should not be freed or used by the programmer after
4155 giving it to sv_usepvn, and neither should any pointers from "behind"
4156 that pointer (e.g. ptr + 1) be used.
4158 If C<flags> & SV_SMAGIC is true, will call SvSETMAGIC. If C<flags> &
4159 SV_HAS_TRAILING_NUL is true, then C<ptr[len]> must be NUL, and the realloc
4160 will be skipped. (i.e. the buffer is actually at least 1 byte longer than
4161 C<len>, and already meets the requirements for storing in C<SvPVX>)
4167 Perl_sv_usepvn_flags(pTHX_ SV *const sv, char *ptr, const STRLEN len, const U32 flags)
4172 PERL_ARGS_ASSERT_SV_USEPVN_FLAGS;
4174 SV_CHECK_THINKFIRST_COW_DROP(sv);
4175 SvUPGRADE(sv, SVt_PV);
4178 if (flags & SV_SMAGIC)
4182 if (SvPVX_const(sv))
4186 if (flags & SV_HAS_TRAILING_NUL)
4187 assert(ptr[len] == '\0');
4190 allocate = (flags & SV_HAS_TRAILING_NUL)
4192 #ifdef Perl_safesysmalloc_size
4195 PERL_STRLEN_ROUNDUP(len + 1);
4197 if (flags & SV_HAS_TRAILING_NUL) {
4198 /* It's long enough - do nothing.
4199 Specfically Perl_newCONSTSUB is relying on this. */
4202 /* Force a move to shake out bugs in callers. */
4203 char *new_ptr = (char*)safemalloc(allocate);
4204 Copy(ptr, new_ptr, len, char);
4205 PoisonFree(ptr,len,char);
4209 ptr = (char*) saferealloc (ptr, allocate);
4212 #ifdef Perl_safesysmalloc_size
4213 SvLEN_set(sv, Perl_safesysmalloc_size(ptr));
4215 SvLEN_set(sv, allocate);
4219 if (!(flags & SV_HAS_TRAILING_NUL)) {
4222 (void)SvPOK_only_UTF8(sv); /* validate pointer */
4224 if (flags & SV_SMAGIC)
4228 #ifdef PERL_OLD_COPY_ON_WRITE
4229 /* Need to do this *after* making the SV normal, as we need the buffer
4230 pointer to remain valid until after we've copied it. If we let go too early,
4231 another thread could invalidate it by unsharing last of the same hash key
4232 (which it can do by means other than releasing copy-on-write Svs)
4233 or by changing the other copy-on-write SVs in the loop. */
4235 S_sv_release_COW(pTHX_ register SV *sv, const char *pvx, SV *after)
4237 PERL_ARGS_ASSERT_SV_RELEASE_COW;
4239 { /* this SV was SvIsCOW_normal(sv) */
4240 /* we need to find the SV pointing to us. */
4241 SV *current = SV_COW_NEXT_SV(after);
4243 if (current == sv) {
4244 /* The SV we point to points back to us (there were only two of us
4246 Hence other SV is no longer copy on write either. */
4248 SvREADONLY_off(after);
4250 /* We need to follow the pointers around the loop. */
4252 while ((next = SV_COW_NEXT_SV(current)) != sv) {
4255 /* don't loop forever if the structure is bust, and we have
4256 a pointer into a closed loop. */
4257 assert (current != after);
4258 assert (SvPVX_const(current) == pvx);
4260 /* Make the SV before us point to the SV after us. */
4261 SV_COW_NEXT_SV_SET(current, after);
4267 =for apidoc sv_force_normal_flags
4269 Undo various types of fakery on an SV: if the PV is a shared string, make
4270 a private copy; if we're a ref, stop refing; if we're a glob, downgrade to
4271 an xpvmg; if we're a copy-on-write scalar, this is the on-write time when
4272 we do the copy, and is also used locally. If C<SV_COW_DROP_PV> is set
4273 then a copy-on-write scalar drops its PV buffer (if any) and becomes
4274 SvPOK_off rather than making a copy. (Used where this scalar is about to be
4275 set to some other value.) In addition, the C<flags> parameter gets passed to
4276 C<sv_unref_flags()> when unrefing. C<sv_force_normal> calls this function
4277 with flags set to 0.
4283 Perl_sv_force_normal_flags(pTHX_ register SV *const sv, const U32 flags)
4287 PERL_ARGS_ASSERT_SV_FORCE_NORMAL_FLAGS;
4289 #ifdef PERL_OLD_COPY_ON_WRITE
4290 if (SvREADONLY(sv)) {
4291 /* At this point I believe I should acquire a global SV mutex. */
4293 const char * const pvx = SvPVX_const(sv);
4294 const STRLEN len = SvLEN(sv);
4295 const STRLEN cur = SvCUR(sv);
4296 /* next COW sv in the loop. If len is 0 then this is a shared-hash
4297 key scalar, so we mustn't attempt to call SV_COW_NEXT_SV(), as
4298 we'll fail an assertion. */
4299 SV * const next = len ? SV_COW_NEXT_SV(sv) : 0;
4302 PerlIO_printf(Perl_debug_log,
4303 "Copy on write: Force normal %ld\n",
4309 /* This SV doesn't own the buffer, so need to Newx() a new one: */
4312 if (flags & SV_COW_DROP_PV) {
4313 /* OK, so we don't need to copy our buffer. */
4316 SvGROW(sv, cur + 1);
4317 Move(pvx,SvPVX(sv),cur,char);
4322 sv_release_COW(sv, pvx, next);
4324 unshare_hek(SvSHARED_HEK_FROM_PV(pvx));
4330 else if (IN_PERL_RUNTIME)
4331 Perl_croak(aTHX_ PL_no_modify);
4332 /* At this point I believe that I can drop the global SV mutex. */
4335 if (SvREADONLY(sv)) {
4337 const char * const pvx = SvPVX_const(sv);
4338 const STRLEN len = SvCUR(sv);
4343 SvGROW(sv, len + 1);
4344 Move(pvx,SvPVX(sv),len,char);
4346 unshare_hek(SvSHARED_HEK_FROM_PV(pvx));
4348 else if (IN_PERL_RUNTIME)
4349 Perl_croak(aTHX_ PL_no_modify);
4353 sv_unref_flags(sv, flags);
4354 else if (SvFAKE(sv) && SvTYPE(sv) == SVt_PVGV)
4361 Efficient removal of characters from the beginning of the string buffer.
4362 SvPOK(sv) must be true and the C<ptr> must be a pointer to somewhere inside
4363 the string buffer. The C<ptr> becomes the first character of the adjusted
4364 string. Uses the "OOK hack".
4365 Beware: after this function returns, C<ptr> and SvPVX_const(sv) may no longer
4366 refer to the same chunk of data.
4372 Perl_sv_chop(pTHX_ register SV *const sv, register const char *const ptr)
4378 const U8 *real_start;
4381 PERL_ARGS_ASSERT_SV_CHOP;
4383 if (!ptr || !SvPOKp(sv))
4385 delta = ptr - SvPVX_const(sv);
4387 /* Nothing to do. */
4390 assert(ptr > SvPVX_const(sv));
4391 SV_CHECK_THINKFIRST(sv);
4394 if (!SvLEN(sv)) { /* make copy of shared string */
4395 const char *pvx = SvPVX_const(sv);
4396 const STRLEN len = SvCUR(sv);
4397 SvGROW(sv, len + 1);
4398 Move(pvx,SvPVX(sv),len,char);
4401 SvFLAGS(sv) |= SVf_OOK;
4404 SvOOK_offset(sv, old_delta);
4406 SvLEN_set(sv, SvLEN(sv) - delta);
4407 SvCUR_set(sv, SvCUR(sv) - delta);
4408 SvPV_set(sv, SvPVX(sv) + delta);
4410 p = (U8 *)SvPVX_const(sv);
4415 real_start = p - delta;
4419 if (delta < 0x100) {
4423 p -= sizeof(STRLEN);
4424 Copy((U8*)&delta, p, sizeof(STRLEN), U8);
4428 /* Fill the preceding buffer with sentinals to verify that no-one is
4430 while (p > real_start) {
4438 =for apidoc sv_catpvn
4440 Concatenates the string onto the end of the string which is in the SV. The
4441 C<len> indicates number of bytes to copy. If the SV has the UTF-8
4442 status set, then the bytes appended should be valid UTF-8.
4443 Handles 'get' magic, but not 'set' magic. See C<sv_catpvn_mg>.
4445 =for apidoc sv_catpvn_flags
4447 Concatenates the string onto the end of the string which is in the SV. The
4448 C<len> indicates number of bytes to copy. If the SV has the UTF-8
4449 status set, then the bytes appended should be valid UTF-8.
4450 If C<flags> has C<SV_GMAGIC> bit set, will C<mg_get> on C<dsv> if
4451 appropriate, else not. C<sv_catpvn> and C<sv_catpvn_nomg> are implemented
4452 in terms of this function.
4458 Perl_sv_catpvn_flags(pTHX_ register SV *const dsv, register const char *sstr, register const STRLEN slen, const I32 flags)
4462 const char * const dstr = SvPV_force_flags(dsv, dlen, flags);
4464 PERL_ARGS_ASSERT_SV_CATPVN_FLAGS;
4466 SvGROW(dsv, dlen + slen + 1);
4468 sstr = SvPVX_const(dsv);
4469 Move(sstr, SvPVX(dsv) + dlen, slen, char);
4470 SvCUR_set(dsv, SvCUR(dsv) + slen);
4472 (void)SvPOK_only_UTF8(dsv); /* validate pointer */
4474 if (flags & SV_SMAGIC)
4479 =for apidoc sv_catsv
4481 Concatenates the string from SV C<ssv> onto the end of the string in
4482 SV C<dsv>. Modifies C<dsv> but not C<ssv>. Handles 'get' magic, but
4483 not 'set' magic. See C<sv_catsv_mg>.
4485 =for apidoc sv_catsv_flags
4487 Concatenates the string from SV C<ssv> onto the end of the string in
4488 SV C<dsv>. Modifies C<dsv> but not C<ssv>. If C<flags> has C<SV_GMAGIC>
4489 bit set, will C<mg_get> on the SVs if appropriate, else not. C<sv_catsv>
4490 and C<sv_catsv_nomg> are implemented in terms of this function.
4495 Perl_sv_catsv_flags(pTHX_ SV *const dsv, register SV *const ssv, const I32 flags)
4499 PERL_ARGS_ASSERT_SV_CATSV_FLAGS;
4503 const char *spv = SvPV_const(ssv, slen);
4505 /* sutf8 and dutf8 were type bool, but under USE_ITHREADS,
4506 gcc version 2.95.2 20000220 (Debian GNU/Linux) for
4507 Linux xxx 2.2.17 on sparc64 with gcc -O2, we erroneously
4508 get dutf8 = 0x20000000, (i.e. SVf_UTF8) even though
4509 dsv->sv_flags doesn't have that bit set.
4510 Andy Dougherty 12 Oct 2001
4512 const I32 sutf8 = DO_UTF8(ssv);
4515 if (SvGMAGICAL(dsv) && (flags & SV_GMAGIC))
4517 dutf8 = DO_UTF8(dsv);
4519 if (dutf8 != sutf8) {
4521 /* Not modifying source SV, so taking a temporary copy. */
4522 SV* const csv = newSVpvn_flags(spv, slen, SVs_TEMP);
4524 sv_utf8_upgrade(csv);
4525 spv = SvPV_const(csv, slen);
4528 sv_utf8_upgrade_nomg(dsv);
4530 sv_catpvn_nomg(dsv, spv, slen);
4533 if (flags & SV_SMAGIC)
4538 =for apidoc sv_catpv
4540 Concatenates the string onto the end of the string which is in the SV.
4541 If the SV has the UTF-8 status set, then the bytes appended should be
4542 valid UTF-8. Handles 'get' magic, but not 'set' magic. See C<sv_catpv_mg>.
4547 Perl_sv_catpv(pTHX_ register SV *const sv, register const char *ptr)
4550 register STRLEN len;
4554 PERL_ARGS_ASSERT_SV_CATPV;
4558 junk = SvPV_force(sv, tlen);
4560 SvGROW(sv, tlen + len + 1);
4562 ptr = SvPVX_const(sv);
4563 Move(ptr,SvPVX(sv)+tlen,len+1,char);
4564 SvCUR_set(sv, SvCUR(sv) + len);
4565 (void)SvPOK_only_UTF8(sv); /* validate pointer */
4570 =for apidoc sv_catpv_mg
4572 Like C<sv_catpv>, but also handles 'set' magic.
4578 Perl_sv_catpv_mg(pTHX_ register SV *const sv, register const char *const ptr)
4580 PERL_ARGS_ASSERT_SV_CATPV_MG;
4589 Creates a new SV. A non-zero C<len> parameter indicates the number of
4590 bytes of preallocated string space the SV should have. An extra byte for a
4591 trailing NUL is also reserved. (SvPOK is not set for the SV even if string
4592 space is allocated.) The reference count for the new SV is set to 1.
4594 In 5.9.3, newSV() replaces the older NEWSV() API, and drops the first
4595 parameter, I<x>, a debug aid which allowed callers to identify themselves.
4596 This aid has been superseded by a new build option, PERL_MEM_LOG (see
4597 L<perlhack/PERL_MEM_LOG>). The older API is still there for use in XS
4598 modules supporting older perls.
4604 Perl_newSV(pTHX_ const STRLEN len)
4611 sv_upgrade(sv, SVt_PV);
4612 SvGROW(sv, len + 1);
4617 =for apidoc sv_magicext
4619 Adds magic to an SV, upgrading it if necessary. Applies the
4620 supplied vtable and returns a pointer to the magic added.
4622 Note that C<sv_magicext> will allow things that C<sv_magic> will not.
4623 In particular, you can add magic to SvREADONLY SVs, and add more than
4624 one instance of the same 'how'.
4626 If C<namlen> is greater than zero then a C<savepvn> I<copy> of C<name> is
4627 stored, if C<namlen> is zero then C<name> is stored as-is and - as another
4628 special case - if C<(name && namlen == HEf_SVKEY)> then C<name> is assumed
4629 to contain an C<SV*> and is stored as-is with its REFCNT incremented.
4631 (This is now used as a subroutine by C<sv_magic>.)
4636 Perl_sv_magicext(pTHX_ SV *const sv, SV *const obj, const int how,
4637 const MGVTBL *const vtable, const char *const name, const I32 namlen)
4642 PERL_ARGS_ASSERT_SV_MAGICEXT;
4644 SvUPGRADE(sv, SVt_PVMG);
4645 Newxz(mg, 1, MAGIC);
4646 mg->mg_moremagic = SvMAGIC(sv);
4647 SvMAGIC_set(sv, mg);
4649 /* Sometimes a magic contains a reference loop, where the sv and
4650 object refer to each other. To prevent a reference loop that
4651 would prevent such objects being freed, we look for such loops
4652 and if we find one we avoid incrementing the object refcount.
4654 Note we cannot do this to avoid self-tie loops as intervening RV must
4655 have its REFCNT incremented to keep it in existence.
4658 if (!obj || obj == sv ||
4659 how == PERL_MAGIC_arylen ||
4660 how == PERL_MAGIC_symtab ||
4661 (SvTYPE(obj) == SVt_PVGV &&
4662 (GvSV(obj) == sv || GvHV(obj) == (HV*)sv || GvAV(obj) == (AV*)sv ||
4663 GvCV(obj) == (CV*)sv || GvIOp(obj) == (IO*)sv ||
4664 GvFORM(obj) == (CV*)sv)))
4669 mg->mg_obj = SvREFCNT_inc_simple(obj);
4670 mg->mg_flags |= MGf_REFCOUNTED;
4673 /* Normal self-ties simply pass a null object, and instead of
4674 using mg_obj directly, use the SvTIED_obj macro to produce a
4675 new RV as needed. For glob "self-ties", we are tieing the PVIO
4676 with an RV obj pointing to the glob containing the PVIO. In
4677 this case, to avoid a reference loop, we need to weaken the
4681 if (how == PERL_MAGIC_tiedscalar && SvTYPE(sv) == SVt_PVIO &&
4682 obj && SvROK(obj) && GvIO(SvRV(obj)) == (IO*)sv)
4688 mg->mg_len = namlen;
4691 mg->mg_ptr = savepvn(name, namlen);
4692 else if (namlen == HEf_SVKEY)
4693 mg->mg_ptr = (char*)SvREFCNT_inc_simple_NN((SV*)name);
4695 mg->mg_ptr = (char *) name;
4697 mg->mg_virtual = (MGVTBL *) vtable;
4701 SvFLAGS(sv) &= ~(SVf_IOK|SVf_NOK|SVf_POK);
4706 =for apidoc sv_magic
4708 Adds magic to an SV. First upgrades C<sv> to type C<SVt_PVMG> if necessary,
4709 then adds a new magic item of type C<how> to the head of the magic list.
4711 See C<sv_magicext> (which C<sv_magic> now calls) for a description of the
4712 handling of the C<name> and C<namlen> arguments.
4714 You need to use C<sv_magicext> to add magic to SvREADONLY SVs and also
4715 to add more than one instance of the same 'how'.
4721 Perl_sv_magic(pTHX_ register SV *const sv, SV *const obj, const int how,
4722 const char *const name, const I32 namlen)
4725 const MGVTBL *vtable;
4728 PERL_ARGS_ASSERT_SV_MAGIC;
4730 #ifdef PERL_OLD_COPY_ON_WRITE
4732 sv_force_normal_flags(sv, 0);
4734 if (SvREADONLY(sv)) {
4736 /* its okay to attach magic to shared strings; the subsequent
4737 * upgrade to PVMG will unshare the string */
4738 !(SvFAKE(sv) && SvTYPE(sv) < SVt_PVMG)
4741 && how != PERL_MAGIC_regex_global
4742 && how != PERL_MAGIC_bm
4743 && how != PERL_MAGIC_fm
4744 && how != PERL_MAGIC_sv
4745 && how != PERL_MAGIC_backref
4748 Perl_croak(aTHX_ PL_no_modify);
4751 if (SvMAGICAL(sv) || (how == PERL_MAGIC_taint && SvTYPE(sv) >= SVt_PVMG)) {
4752 if (SvMAGIC(sv) && (mg = mg_find(sv, how))) {
4753 /* sv_magic() refuses to add a magic of the same 'how' as an
4756 if (how == PERL_MAGIC_taint) {
4758 /* Any scalar which already had taint magic on which someone
4759 (erroneously?) did SvIOK_on() or similar will now be
4760 incorrectly sporting public "OK" flags. */
4761 SvFLAGS(sv) &= ~(SVf_IOK|SVf_NOK|SVf_POK);
4769 vtable = &PL_vtbl_sv;
4771 case PERL_MAGIC_overload:
4772 vtable = &PL_vtbl_amagic;
4774 case PERL_MAGIC_overload_elem:
4775 vtable = &PL_vtbl_amagicelem;