3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
4 * 2000, 2001, 2002, 2003, 2004, 2005, 2006, 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 Manipulation of any of the PL_*root pointers is protected by enclosing
108 LOCK_SV_MUTEX; ... UNLOCK_SV_MUTEX calls which should Do the Right Thing
109 if threads are enabled.
111 The function visit() scans the SV arenas list, and calls a specified
112 function for each SV it finds which is still live - ie which has an SvTYPE
113 other than all 1's, and a non-zero SvREFCNT. visit() is used by the
114 following functions (specified as [function that calls visit()] / [function
115 called by visit() for each SV]):
117 sv_report_used() / do_report_used()
118 dump all remaining SVs (debugging aid)
120 sv_clean_objs() / do_clean_objs(),do_clean_named_objs()
121 Attempt to free all objects pointed to by RVs,
122 and, unless DISABLE_DESTRUCTOR_KLUDGE is defined,
123 try to do the same for all objects indirectly
124 referenced by typeglobs too. Called once from
125 perl_destruct(), prior to calling sv_clean_all()
128 sv_clean_all() / do_clean_all()
129 SvREFCNT_dec(sv) each remaining SV, possibly
130 triggering an sv_free(). It also sets the
131 SVf_BREAK flag on the SV to indicate that the
132 refcnt has been artificially lowered, and thus
133 stopping sv_free() from giving spurious warnings
134 about SVs which unexpectedly have a refcnt
135 of zero. called repeatedly from perl_destruct()
136 until there are no SVs left.
138 =head2 Arena allocator API Summary
140 Private API to rest of sv.c
144 new_XIV(), del_XIV(),
145 new_XNV(), del_XNV(),
150 sv_report_used(), sv_clean_objs(), sv_clean_all(), sv_free_arenas()
154 ============================================================================ */
157 * "A time to plant, and a time to uproot what was planted..."
161 * nice_chunk and nice_chunk size need to be set
162 * and queried under the protection of sv_mutex
165 Perl_offer_nice_chunk(pTHX_ void *chunk, U32 chunk_size)
171 new_chunk = (void *)(chunk);
172 new_chunk_size = (chunk_size);
173 if (new_chunk_size > PL_nice_chunk_size) {
174 Safefree(PL_nice_chunk);
175 PL_nice_chunk = (char *) new_chunk;
176 PL_nice_chunk_size = new_chunk_size;
183 #ifdef DEBUG_LEAKING_SCALARS
184 # define FREE_SV_DEBUG_FILE(sv) Safefree((sv)->sv_debug_file)
186 # define FREE_SV_DEBUG_FILE(sv)
190 # define SvARENA_CHAIN(sv) ((sv)->sv_u.svu_rv)
191 /* Whilst I'd love to do this, it seems that things like to check on
193 # define POSION_SV_HEAD(sv) PoisonNew(sv, 1, struct STRUCT_SV)
195 # define POSION_SV_HEAD(sv) PoisonNew(&SvANY(sv), 1, void *), \
196 PoisonNew(&SvREFCNT(sv), 1, U32)
198 # define SvARENA_CHAIN(sv) SvANY(sv)
199 # define POSION_SV_HEAD(sv)
202 #define plant_SV(p) \
204 FREE_SV_DEBUG_FILE(p); \
206 SvARENA_CHAIN(p) = (void *)PL_sv_root; \
207 SvFLAGS(p) = SVTYPEMASK; \
212 /* sv_mutex must be held while calling uproot_SV() */
213 #define uproot_SV(p) \
216 PL_sv_root = (SV*)SvARENA_CHAIN(p); \
221 /* make some more SVs by adding another arena */
223 /* sv_mutex must be held while calling more_sv() */
231 sv_add_arena(PL_nice_chunk, PL_nice_chunk_size, 0);
232 PL_nice_chunk = NULL;
233 PL_nice_chunk_size = 0;
236 char *chunk; /* must use New here to match call to */
237 Newx(chunk,PERL_ARENA_SIZE,char); /* Safefree() in sv_free_arenas() */
238 sv_add_arena(chunk, PERL_ARENA_SIZE, 0);
244 /* new_SV(): return a new, empty SV head */
246 #ifdef DEBUG_LEAKING_SCALARS
247 /* provide a real function for a debugger to play with */
257 sv = S_more_sv(aTHX);
262 sv->sv_debug_optype = PL_op ? PL_op->op_type : 0;
263 sv->sv_debug_line = (U16) ((PL_copline == NOLINE) ?
264 (PL_curcop ? CopLINE(PL_curcop) : 0) : PL_copline);
265 sv->sv_debug_inpad = 0;
266 sv->sv_debug_cloned = 0;
267 sv->sv_debug_file = PL_curcop ? savepv(CopFILE(PL_curcop)): NULL;
271 # define new_SV(p) (p)=S_new_SV(aTHX)
280 (p) = S_more_sv(aTHX); \
289 /* del_SV(): return an empty SV head to the free list */
304 S_del_sv(pTHX_ SV *p)
310 for (sva = PL_sv_arenaroot; sva; sva = (SV *) SvANY(sva)) {
311 const SV * const sv = sva + 1;
312 const SV * const svend = &sva[SvREFCNT(sva)];
313 if (p >= sv && p < svend) {
319 if (ckWARN_d(WARN_INTERNAL))
320 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
321 "Attempt to free non-arena SV: 0x%"UVxf
322 pTHX__FORMAT, PTR2UV(p) pTHX__VALUE);
329 #else /* ! DEBUGGING */
331 #define del_SV(p) plant_SV(p)
333 #endif /* DEBUGGING */
337 =head1 SV Manipulation Functions
339 =for apidoc sv_add_arena
341 Given a chunk of memory, link it to the head of the list of arenas,
342 and split it into a list of free SVs.
348 Perl_sv_add_arena(pTHX_ char *ptr, U32 size, U32 flags)
351 SV* const sva = (SV*)ptr;
355 /* The first SV in an arena isn't an SV. */
356 SvANY(sva) = (void *) PL_sv_arenaroot; /* ptr to next arena */
357 SvREFCNT(sva) = size / sizeof(SV); /* number of SV slots */
358 SvFLAGS(sva) = flags; /* FAKE if not to be freed */
360 PL_sv_arenaroot = sva;
361 PL_sv_root = sva + 1;
363 svend = &sva[SvREFCNT(sva) - 1];
366 SvARENA_CHAIN(sv) = (void *)(SV*)(sv + 1);
370 /* Must always set typemask because it's awlays checked in on cleanup
371 when the arenas are walked looking for objects. */
372 SvFLAGS(sv) = SVTYPEMASK;
375 SvARENA_CHAIN(sv) = 0;
379 SvFLAGS(sv) = SVTYPEMASK;
382 /* visit(): call the named function for each non-free SV in the arenas
383 * whose flags field matches the flags/mask args. */
386 S_visit(pTHX_ SVFUNC_t f, U32 flags, U32 mask)
392 for (sva = PL_sv_arenaroot; sva; sva = (SV*)SvANY(sva)) {
393 register const SV * const svend = &sva[SvREFCNT(sva)];
395 for (sv = sva + 1; sv < svend; ++sv) {
396 if (SvTYPE(sv) != SVTYPEMASK
397 && (sv->sv_flags & mask) == flags
410 /* called by sv_report_used() for each live SV */
413 do_report_used(pTHX_ SV *sv)
415 if (SvTYPE(sv) != SVTYPEMASK) {
416 PerlIO_printf(Perl_debug_log, "****\n");
423 =for apidoc sv_report_used
425 Dump the contents of all SVs not yet freed. (Debugging aid).
431 Perl_sv_report_used(pTHX)
434 visit(do_report_used, 0, 0);
440 /* called by sv_clean_objs() for each live SV */
443 do_clean_objs(pTHX_ SV *ref)
447 SV * const target = SvRV(ref);
448 if (SvOBJECT(target)) {
449 DEBUG_D((PerlIO_printf(Perl_debug_log, "Cleaning object ref:\n "), sv_dump(ref)));
450 if (SvWEAKREF(ref)) {
451 sv_del_backref(target, ref);
457 SvREFCNT_dec(target);
462 /* XXX Might want to check arrays, etc. */
465 /* called by sv_clean_objs() for each live SV */
467 #ifndef DISABLE_DESTRUCTOR_KLUDGE
469 do_clean_named_objs(pTHX_ SV *sv)
472 if (SvTYPE(sv) == SVt_PVGV && isGV_with_GP(sv) && GvGP(sv)) {
474 #ifdef PERL_DONT_CREATE_GVSV
477 SvOBJECT(GvSV(sv))) ||
478 (GvAV(sv) && SvOBJECT(GvAV(sv))) ||
479 (GvHV(sv) && SvOBJECT(GvHV(sv))) ||
480 (GvIO(sv) && SvOBJECT(GvIO(sv))) ||
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, SVTYPEMASK);
509 PL_in_clean_objs = FALSE;
512 /* called by sv_clean_all() for each live SV */
515 do_clean_all(pTHX_ SV *sv)
518 DEBUG_D((PerlIO_printf(Perl_debug_log, "Cleaning loops: SV at 0x%"UVxf"\n", PTR2UV(sv)) ));
519 SvFLAGS(sv) |= SVf_BREAK;
520 if (PL_comppad == (AV*)sv) {
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,
563 char *arena; /* the raw storage, allocated aligned */
564 size_t size; /* its size ~4k typ */
565 int unit_type; /* useful for arena audits */
566 /* info for sv-heads (eventually)
573 /* Get the maximum number of elements in set[] such that struct arena_set
574 will fit within PERL_ARENA_SIZE, which is probabably just under 4K, and
575 therefore likely to be 1 aligned memory page. */
577 #define ARENAS_PER_SET ((PERL_ARENA_SIZE - sizeof(struct arena_set*) \
578 - 2 * sizeof(int)) / sizeof (struct arena_desc))
581 struct arena_set* next;
582 int set_size; /* ie ARENAS_PER_SET */
583 int curr; /* index of next available arena-desc */
584 struct arena_desc set[ARENAS_PER_SET];
588 =for apidoc sv_free_arenas
590 Deallocate the memory used by all arenas. Note that all the individual SV
591 heads and bodies within the arenas must already have been freed.
596 Perl_sv_free_arenas(pTHX)
603 /* Free arenas here, but be careful about fake ones. (We assume
604 contiguity of the fake ones with the corresponding real ones.) */
606 for (sva = PL_sv_arenaroot; sva; sva = svanext) {
607 svanext = (SV*) SvANY(sva);
608 while (svanext && SvFAKE(svanext))
609 svanext = (SV*) SvANY(svanext);
616 struct arena_set *next, *aroot = (struct arena_set*) PL_body_arenas;
618 for (; aroot; aroot = next) {
619 const int max = aroot->curr;
620 for (i=0; i<max; i++) {
621 assert(aroot->set[i].arena);
622 Safefree(aroot->set[i].arena);
630 for (i=0; i<PERL_ARENA_ROOTS_SIZE; i++)
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_ int arena_size)
681 struct arena_desc* adesc;
682 struct arena_set *newroot, **aroot = (struct arena_set**) &PL_body_arenas;
685 /* shouldnt need this
686 if (!arena_size) arena_size = PERL_ARENA_SIZE;
689 /* may need new arena-set to hold new arena */
690 if (!*aroot || (*aroot)->curr >= (*aroot)->set_size) {
691 Newxz(newroot, 1, struct arena_set);
692 newroot->set_size = ARENAS_PER_SET;
693 newroot->next = *aroot;
695 DEBUG_m(PerlIO_printf(Perl_debug_log, "new arenaset %p\n", *aroot));
698 /* ok, now have arena-set with at least 1 empty/available arena-desc */
699 curr = (*aroot)->curr++;
700 adesc = &((*aroot)->set[curr]);
701 assert(!adesc->arena);
703 Newxz(adesc->arena, arena_size, char);
704 adesc->size = arena_size;
705 DEBUG_m(PerlIO_printf(Perl_debug_log, "arena %d added: %p size %d\n",
706 curr, adesc->arena, arena_size));
712 /* return a thing to the free list */
714 #define del_body(thing, root) \
716 void ** const thing_copy = (void **)thing;\
718 *thing_copy = *root; \
719 *root = (void*)thing_copy; \
725 =head1 SV-Body Allocation
727 Allocation of SV-bodies is similar to SV-heads, differing as follows;
728 the allocation mechanism is used for many body types, so is somewhat
729 more complicated, it uses arena-sets, and has no need for still-live
732 At the outermost level, (new|del)_X*V macros return bodies of the
733 appropriate type. These macros call either (new|del)_body_type or
734 (new|del)_body_allocated macro pairs, depending on specifics of the
735 type. Most body types use the former pair, the latter pair is used to
736 allocate body types with "ghost fields".
738 "ghost fields" are fields that are unused in certain types, and
739 consequently dont need to actually exist. They are declared because
740 they're part of a "base type", which allows use of functions as
741 methods. The simplest examples are AVs and HVs, 2 aggregate types
742 which don't use the fields which support SCALAR semantics.
744 For these types, the arenas are carved up into *_allocated size
745 chunks, we thus avoid wasted memory for those unaccessed members.
746 When bodies are allocated, we adjust the pointer back in memory by the
747 size of the bit not allocated, so it's as if we allocated the full
748 structure. (But things will all go boom if you write to the part that
749 is "not there", because you'll be overwriting the last members of the
750 preceding structure in memory.)
752 We calculate the correction using the STRUCT_OFFSET macro. For
753 example, if xpv_allocated is the same structure as XPV then the two
754 OFFSETs sum to zero, and the pointer is unchanged. If the allocated
755 structure is smaller (no initial NV actually allocated) then the net
756 effect is to subtract the size of the NV from the pointer, to return a
757 new pointer as if an initial NV were actually allocated.
759 This is the same trick as was used for NV and IV bodies. Ironically it
760 doesn't need to be used for NV bodies any more, because NV is now at
761 the start of the structure. IV bodies don't need it either, because
762 they are no longer allocated.
764 In turn, the new_body_* allocators call S_new_body(), which invokes
765 new_body_inline macro, which takes a lock, and takes a body off the
766 linked list at PL_body_roots[sv_type], calling S_more_bodies() if
767 necessary to refresh an empty list. Then the lock is released, and
768 the body is returned.
770 S_more_bodies calls get_arena(), and carves it up into an array of N
771 bodies, which it strings into a linked list. It looks up arena-size
772 and body-size from the body_details table described below, thus
773 supporting the multiple body-types.
775 If PURIFY is defined, or PERL_ARENA_SIZE=0, arenas are not used, and
776 the (new|del)_X*V macros are mapped directly to malloc/free.
782 For each sv-type, struct body_details bodies_by_type[] carries
783 parameters which control these aspects of SV handling:
785 Arena_size determines whether arenas are used for this body type, and if
786 so, how big they are. PURIFY or PERL_ARENA_SIZE=0 set this field to
787 zero, forcing individual mallocs and frees.
789 Body_size determines how big a body is, and therefore how many fit into
790 each arena. Offset carries the body-pointer adjustment needed for
791 *_allocated body types, and is used in *_allocated macros.
793 But its main purpose is to parameterize info needed in
794 Perl_sv_upgrade(). The info here dramatically simplifies the function
795 vs the implementation in 5.8.7, making it table-driven. All fields
796 are used for this, except for arena_size.
798 For the sv-types that have no bodies, arenas are not used, so those
799 PL_body_roots[sv_type] are unused, and can be overloaded. In
800 something of a special case, SVt_NULL is borrowed for HE arenas;
801 PL_body_roots[SVt_NULL] is filled by S_more_he, but the
802 bodies_by_type[SVt_NULL] slot is not used, as the table is not
805 PTEs also use arenas, but are never seen in Perl_sv_upgrade.
806 Nonetheless, they get their own slot in bodies_by_type[SVt_NULL], so
807 they can just use the same allocation semantics. At first, PTEs were
808 also overloaded to a non-body sv-type, but this yielded hard-to-find
809 malloc bugs, so was simplified by claiming a new slot. This choice
810 has no consequence at this time.
814 struct body_details {
815 U8 body_size; /* Size to allocate */
816 U8 copy; /* Size of structure to copy (may be shorter) */
818 unsigned int type : 4; /* We have space for a sanity check. */
819 unsigned int cant_upgrade : 1; /* Cannot upgrade this type */
820 unsigned int zero_nv : 1; /* zero the NV when upgrading from this */
821 unsigned int arena : 1; /* Allocated from an arena */
822 size_t arena_size; /* Size of arena to allocate */
830 /* With -DPURFIY we allocate everything directly, and don't use arenas.
831 This seems a rather elegant way to simplify some of the code below. */
832 #define HASARENA FALSE
834 #define HASARENA TRUE
836 #define NOARENA FALSE
838 /* Size the arenas to exactly fit a given number of bodies. A count
839 of 0 fits the max number bodies into a PERL_ARENA_SIZE.block,
840 simplifying the default. If count > 0, the arena is sized to fit
841 only that many bodies, allowing arenas to be used for large, rare
842 bodies (XPVFM, XPVIO) without undue waste. The arena size is
843 limited by PERL_ARENA_SIZE, so we can safely oversize the
846 #define FIT_ARENA0(body_size) \
847 ((size_t)(PERL_ARENA_SIZE / body_size) * body_size)
848 #define FIT_ARENAn(count,body_size) \
849 ( count * body_size <= PERL_ARENA_SIZE) \
850 ? count * body_size \
851 : FIT_ARENA0 (body_size)
852 #define FIT_ARENA(count,body_size) \
854 ? FIT_ARENAn (count, body_size) \
855 : FIT_ARENA0 (body_size)
857 /* A macro to work out the offset needed to subtract from a pointer to (say)
864 to make its members accessible via a pointer to (say)
874 #define relative_STRUCT_OFFSET(longer, shorter, member) \
875 (STRUCT_OFFSET(shorter, member) - STRUCT_OFFSET(longer, member))
877 /* Calculate the length to copy. Specifically work out the length less any
878 final padding the compiler needed to add. See the comment in sv_upgrade
879 for why copying the padding proved to be a bug. */
881 #define copy_length(type, last_member) \
882 STRUCT_OFFSET(type, last_member) \
883 + sizeof (((type*)SvANY((SV*)0))->last_member)
885 static const struct body_details bodies_by_type[] = {
886 { sizeof(HE), 0, 0, SVt_NULL,
887 FALSE, NONV, NOARENA, FIT_ARENA(0, sizeof(HE)) },
889 /* IVs are in the head, so the allocation size is 0.
890 However, the slot is overloaded for PTEs. */
891 { sizeof(struct ptr_tbl_ent), /* This is used for PTEs. */
892 sizeof(IV), /* This is used to copy out the IV body. */
893 STRUCT_OFFSET(XPVIV, xiv_iv), SVt_IV, FALSE, NONV,
894 NOARENA /* IVS don't need an arena */,
895 /* But PTEs need to know the size of their arena */
896 FIT_ARENA(0, sizeof(struct ptr_tbl_ent))
899 /* 8 bytes on most ILP32 with IEEE doubles */
900 { sizeof(NV), sizeof(NV), 0, SVt_NV, FALSE, HADNV, HASARENA,
901 FIT_ARENA(0, sizeof(NV)) },
903 /* RVs are in the head now. */
904 { 0, 0, 0, SVt_RV, FALSE, NONV, NOARENA, 0 },
906 /* 8 bytes on most ILP32 with IEEE doubles */
907 { sizeof(xpv_allocated),
908 copy_length(XPV, xpv_len)
909 - relative_STRUCT_OFFSET(xpv_allocated, XPV, xpv_cur),
910 + relative_STRUCT_OFFSET(xpv_allocated, XPV, xpv_cur),
911 SVt_PV, FALSE, NONV, HASARENA, FIT_ARENA(0, sizeof(xpv_allocated)) },
914 { sizeof(xpviv_allocated),
915 copy_length(XPVIV, xiv_u)
916 - relative_STRUCT_OFFSET(xpviv_allocated, XPVIV, xpv_cur),
917 + relative_STRUCT_OFFSET(xpviv_allocated, XPVIV, xpv_cur),
918 SVt_PVIV, FALSE, NONV, HASARENA, FIT_ARENA(0, sizeof(xpviv_allocated)) },
921 { sizeof(XPVNV), copy_length(XPVNV, xiv_u), 0, SVt_PVNV, FALSE, HADNV,
922 HASARENA, FIT_ARENA(0, sizeof(XPVNV)) },
925 { sizeof(XPVMG), copy_length(XPVMG, xmg_stash), 0, SVt_PVMG, FALSE, HADNV,
926 HASARENA, FIT_ARENA(0, sizeof(XPVMG)) },
929 { sizeof(XPVBM), sizeof(XPVBM), 0, SVt_PVBM, TRUE, HADNV,
930 HASARENA, FIT_ARENA(0, sizeof(XPVBM)) },
933 { sizeof(XPVGV), sizeof(XPVGV), 0, SVt_PVGV, TRUE, HADNV,
934 HASARENA, FIT_ARENA(0, sizeof(XPVGV)) },
937 { sizeof(XPVLV), sizeof(XPVLV), 0, SVt_PVLV, TRUE, HADNV,
938 HASARENA, FIT_ARENA(0, sizeof(XPVLV)) },
940 { sizeof(xpvav_allocated),
941 copy_length(XPVAV, xmg_stash)
942 - relative_STRUCT_OFFSET(xpvav_allocated, XPVAV, xav_fill),
943 + relative_STRUCT_OFFSET(xpvav_allocated, XPVAV, xav_fill),
944 SVt_PVAV, TRUE, HADNV, HASARENA, FIT_ARENA(0, sizeof(xpvav_allocated)) },
946 { sizeof(xpvhv_allocated),
947 copy_length(XPVHV, xmg_stash)
948 - relative_STRUCT_OFFSET(xpvhv_allocated, XPVHV, xhv_fill),
949 + relative_STRUCT_OFFSET(xpvhv_allocated, XPVHV, xhv_fill),
950 SVt_PVHV, TRUE, HADNV, HASARENA, FIT_ARENA(0, sizeof(xpvhv_allocated)) },
953 { sizeof(xpvcv_allocated), sizeof(xpvcv_allocated),
954 + relative_STRUCT_OFFSET(xpvcv_allocated, XPVCV, xpv_cur),
955 SVt_PVCV, TRUE, NONV, HASARENA, FIT_ARENA(0, sizeof(xpvcv_allocated)) },
957 { sizeof(xpvfm_allocated), sizeof(xpvfm_allocated),
958 + relative_STRUCT_OFFSET(xpvfm_allocated, XPVFM, xpv_cur),
959 SVt_PVFM, TRUE, NONV, NOARENA, FIT_ARENA(20, sizeof(xpvfm_allocated)) },
961 /* XPVIO is 84 bytes, fits 48x */
962 { sizeof(XPVIO), sizeof(XPVIO), 0, SVt_PVIO, TRUE, HADNV,
963 HASARENA, FIT_ARENA(24, sizeof(XPVIO)) },
966 #define new_body_type(sv_type) \
967 (void *)((char *)S_new_body(aTHX_ sv_type))
969 #define del_body_type(p, sv_type) \
970 del_body(p, &PL_body_roots[sv_type])
973 #define new_body_allocated(sv_type) \
974 (void *)((char *)S_new_body(aTHX_ sv_type) \
975 - bodies_by_type[sv_type].offset)
977 #define del_body_allocated(p, sv_type) \
978 del_body(p + bodies_by_type[sv_type].offset, &PL_body_roots[sv_type])
981 #define my_safemalloc(s) (void*)safemalloc(s)
982 #define my_safecalloc(s) (void*)safecalloc(s, 1)
983 #define my_safefree(p) safefree((char*)p)
987 #define new_XNV() my_safemalloc(sizeof(XPVNV))
988 #define del_XNV(p) my_safefree(p)
990 #define new_XPVNV() my_safemalloc(sizeof(XPVNV))
991 #define del_XPVNV(p) my_safefree(p)
993 #define new_XPVAV() my_safemalloc(sizeof(XPVAV))
994 #define del_XPVAV(p) my_safefree(p)
996 #define new_XPVHV() my_safemalloc(sizeof(XPVHV))
997 #define del_XPVHV(p) my_safefree(p)
999 #define new_XPVMG() my_safemalloc(sizeof(XPVMG))
1000 #define del_XPVMG(p) my_safefree(p)
1002 #define new_XPVGV() my_safemalloc(sizeof(XPVGV))
1003 #define del_XPVGV(p) my_safefree(p)
1007 #define new_XNV() new_body_type(SVt_NV)
1008 #define del_XNV(p) del_body_type(p, SVt_NV)
1010 #define new_XPVNV() new_body_type(SVt_PVNV)
1011 #define del_XPVNV(p) del_body_type(p, SVt_PVNV)
1013 #define new_XPVAV() new_body_allocated(SVt_PVAV)
1014 #define del_XPVAV(p) del_body_allocated(p, SVt_PVAV)
1016 #define new_XPVHV() new_body_allocated(SVt_PVHV)
1017 #define del_XPVHV(p) del_body_allocated(p, SVt_PVHV)
1019 #define new_XPVMG() new_body_type(SVt_PVMG)
1020 #define del_XPVMG(p) del_body_type(p, SVt_PVMG)
1022 #define new_XPVGV() new_body_type(SVt_PVGV)
1023 #define del_XPVGV(p) del_body_type(p, SVt_PVGV)
1027 /* no arena for you! */
1029 #define new_NOARENA(details) \
1030 my_safemalloc((details)->body_size + (details)->offset)
1031 #define new_NOARENAZ(details) \
1032 my_safecalloc((details)->body_size + (details)->offset)
1035 static bool done_sanity_check;
1039 S_more_bodies (pTHX_ svtype sv_type)
1042 void ** const root = &PL_body_roots[sv_type];
1043 const struct body_details * const bdp = &bodies_by_type[sv_type];
1044 const size_t body_size = bdp->body_size;
1048 assert(bdp->arena_size);
1051 if (!done_sanity_check) {
1052 unsigned int i = SVt_LAST;
1054 done_sanity_check = TRUE;
1057 assert (bodies_by_type[i].type == i);
1061 start = (char*) Perl_get_arena(aTHX_ bdp->arena_size);
1063 end = start + bdp->arena_size - body_size;
1065 /* computed count doesnt reflect the 1st slot reservation */
1066 DEBUG_m(PerlIO_printf(Perl_debug_log,
1067 "arena %p end %p arena-size %d type %d size %d ct %d\n",
1068 start, end, bdp->arena_size, sv_type, body_size,
1069 bdp->arena_size / body_size));
1071 *root = (void *)start;
1073 while (start < end) {
1074 char * const next = start + body_size;
1075 *(void**) start = (void *)next;
1078 *(void **)start = 0;
1083 /* grab a new thing from the free list, allocating more if necessary.
1084 The inline version is used for speed in hot routines, and the
1085 function using it serves the rest (unless PURIFY).
1087 #define new_body_inline(xpv, sv_type) \
1089 void ** const r3wt = &PL_body_roots[sv_type]; \
1091 xpv = *((void **)(r3wt)) \
1092 ? *((void **)(r3wt)) : more_bodies(sv_type); \
1093 *(r3wt) = *(void**)(xpv); \
1100 S_new_body(pTHX_ svtype sv_type)
1104 new_body_inline(xpv, sv_type);
1111 =for apidoc sv_upgrade
1113 Upgrade an SV to a more complex form. Generally adds a new body type to the
1114 SV, then copies across as much information as possible from the old body.
1115 You generally want to use the C<SvUPGRADE> macro wrapper. See also C<svtype>.
1121 Perl_sv_upgrade(pTHX_ register SV *sv, U32 new_type)
1126 const U32 old_type = SvTYPE(sv);
1127 const struct body_details *new_type_details;
1128 const struct body_details *const old_type_details
1129 = bodies_by_type + old_type;
1131 if (new_type != SVt_PV && SvIsCOW(sv)) {
1132 sv_force_normal_flags(sv, 0);
1135 if (old_type == new_type)
1138 if (old_type > new_type)
1139 Perl_croak(aTHX_ "sv_upgrade from type %d down to type %d",
1140 (int)old_type, (int)new_type);
1143 old_body = SvANY(sv);
1145 /* Copying structures onto other structures that have been neatly zeroed
1146 has a subtle gotcha. Consider XPVMG
1148 +------+------+------+------+------+-------+-------+
1149 | NV | CUR | LEN | IV | MAGIC | STASH |
1150 +------+------+------+------+------+-------+-------+
1151 0 4 8 12 16 20 24 28
1153 where NVs are aligned to 8 bytes, so that sizeof that structure is
1154 actually 32 bytes long, with 4 bytes of padding at the end:
1156 +------+------+------+------+------+-------+-------+------+
1157 | NV | CUR | LEN | IV | MAGIC | STASH | ??? |
1158 +------+------+------+------+------+-------+-------+------+
1159 0 4 8 12 16 20 24 28 32
1161 so what happens if you allocate memory for this structure:
1163 +------+------+------+------+------+-------+-------+------+------+...
1164 | NV | CUR | LEN | IV | MAGIC | STASH | GP | NAME |
1165 +------+------+------+------+------+-------+-------+------+------+...
1166 0 4 8 12 16 20 24 28 32 36
1168 zero it, then copy sizeof(XPVMG) bytes on top of it? Not quite what you
1169 expect, because you copy the area marked ??? onto GP. Now, ??? may have
1170 started out as zero once, but it's quite possible that it isn't. So now,
1171 rather than a nicely zeroed GP, you have it pointing somewhere random.
1174 (In fact, GP ends up pointing at a previous GP structure, because the
1175 principle cause of the padding in XPVMG getting garbage is a copy of
1176 sizeof(XPVMG) bytes from a XPVGV structure in sv_unglob)
1178 So we are careful and work out the size of used parts of all the
1185 if (new_type < SVt_PVIV) {
1186 new_type = (new_type == SVt_NV)
1187 ? SVt_PVNV : SVt_PVIV;
1191 if (new_type < SVt_PVNV) {
1192 new_type = SVt_PVNV;
1198 assert(new_type > SVt_PV);
1199 assert(SVt_IV < SVt_PV);
1200 assert(SVt_NV < SVt_PV);
1207 /* Because the XPVMG of PL_mess_sv isn't allocated from the arena,
1208 there's no way that it can be safely upgraded, because perl.c
1209 expects to Safefree(SvANY(PL_mess_sv)) */
1210 assert(sv != PL_mess_sv);
1211 /* This flag bit is used to mean other things in other scalar types.
1212 Given that it only has meaning inside the pad, it shouldn't be set
1213 on anything that can get upgraded. */
1214 assert(!SvPAD_TYPED(sv));
1217 if (old_type_details->cant_upgrade)
1218 Perl_croak(aTHX_ "Can't upgrade %s (%" UVuf ") to %" UVuf,
1219 sv_reftype(sv, 0), (UV) old_type, (UV) new_type);
1221 new_type_details = bodies_by_type + new_type;
1223 SvFLAGS(sv) &= ~SVTYPEMASK;
1224 SvFLAGS(sv) |= new_type;
1226 /* This can't happen, as SVt_NULL is <= all values of new_type, so one of
1227 the return statements above will have triggered. */
1228 assert (new_type != SVt_NULL);
1231 assert(old_type == SVt_NULL);
1232 SvANY(sv) = (XPVIV*)((char*)&(sv->sv_u.svu_iv) - STRUCT_OFFSET(XPVIV, xiv_iv));
1236 assert(old_type == SVt_NULL);
1237 SvANY(sv) = new_XNV();
1241 assert(old_type == SVt_NULL);
1242 SvANY(sv) = &sv->sv_u.svu_rv;
1247 assert(new_type_details->body_size);
1250 assert(new_type_details->arena);
1251 assert(new_type_details->arena_size);
1252 /* This points to the start of the allocated area. */
1253 new_body_inline(new_body, new_type);
1254 Zero(new_body, new_type_details->body_size, char);
1255 new_body = ((char *)new_body) - new_type_details->offset;
1257 /* We always allocated the full length item with PURIFY. To do this
1258 we fake things so that arena is false for all 16 types.. */
1259 new_body = new_NOARENAZ(new_type_details);
1261 SvANY(sv) = new_body;
1262 if (new_type == SVt_PVAV) {
1268 /* SVt_NULL isn't the only thing upgraded to AV or HV.
1269 The target created by newSVrv also is, and it can have magic.
1270 However, it never has SvPVX set.
1272 if (old_type >= SVt_RV) {
1273 assert(SvPVX_const(sv) == 0);
1276 /* Could put this in the else clause below, as PVMG must have SvPVX
1277 0 already (the assertion above) */
1280 if (old_type >= SVt_PVMG) {
1281 SvMAGIC_set(sv, ((XPVMG*)old_body)->xmg_u.xmg_magic);
1282 SvSTASH_set(sv, ((XPVMG*)old_body)->xmg_stash);
1288 /* XXX Is this still needed? Was it ever needed? Surely as there is
1289 no route from NV to PVIV, NOK can never be true */
1290 assert(!SvNOKp(sv));
1302 assert(new_type_details->body_size);
1303 /* We always allocated the full length item with PURIFY. To do this
1304 we fake things so that arena is false for all 16 types.. */
1305 if(new_type_details->arena) {
1306 /* This points to the start of the allocated area. */
1307 new_body_inline(new_body, new_type);
1308 Zero(new_body, new_type_details->body_size, char);
1309 new_body = ((char *)new_body) - new_type_details->offset;
1311 new_body = new_NOARENAZ(new_type_details);
1313 SvANY(sv) = new_body;
1315 if (old_type_details->copy) {
1316 /* There is now the potential for an upgrade from something without
1317 an offset (PVNV or PVMG) to something with one (PVCV, PVFM) */
1318 int offset = old_type_details->offset;
1319 int length = old_type_details->copy;
1321 if (new_type_details->offset > old_type_details->offset) {
1322 const int difference
1323 = new_type_details->offset - old_type_details->offset;
1324 offset += difference;
1325 length -= difference;
1327 assert (length >= 0);
1329 Copy((char *)old_body + offset, (char *)new_body + offset, length,
1333 #ifndef NV_ZERO_IS_ALLBITS_ZERO
1334 /* If NV 0.0 is stores as all bits 0 then Zero() already creates a
1335 * correct 0.0 for us. Otherwise, if the old body didn't have an
1336 * NV slot, but the new one does, then we need to initialise the
1337 * freshly created NV slot with whatever the correct bit pattern is
1339 if (old_type_details->zero_nv && !new_type_details->zero_nv)
1343 if (new_type == SVt_PVIO)
1344 IoPAGE_LEN(sv) = 60;
1345 if (old_type < SVt_RV)
1349 Perl_croak(aTHX_ "panic: sv_upgrade to unknown type %lu",
1350 (unsigned long)new_type);
1353 if (old_type_details->arena) {
1354 /* If there was an old body, then we need to free it.
1355 Note that there is an assumption that all bodies of types that
1356 can be upgraded came from arenas. Only the more complex non-
1357 upgradable types are allowed to be directly malloc()ed. */
1359 my_safefree(old_body);
1361 del_body((void*)((char*)old_body + old_type_details->offset),
1362 &PL_body_roots[old_type]);
1368 =for apidoc sv_backoff
1370 Remove any string offset. You should normally use the C<SvOOK_off> macro
1377 Perl_sv_backoff(pTHX_ register SV *sv)
1379 PERL_UNUSED_CONTEXT;
1381 assert(SvTYPE(sv) != SVt_PVHV);
1382 assert(SvTYPE(sv) != SVt_PVAV);
1384 const char * const s = SvPVX_const(sv);
1385 SvLEN_set(sv, SvLEN(sv) + SvIVX(sv));
1386 SvPV_set(sv, SvPVX(sv) - SvIVX(sv));
1388 Move(s, SvPVX(sv), SvCUR(sv)+1, char);
1390 SvFLAGS(sv) &= ~SVf_OOK;
1397 Expands the character buffer in the SV. If necessary, uses C<sv_unref> and
1398 upgrades the SV to C<SVt_PV>. Returns a pointer to the character buffer.
1399 Use the C<SvGROW> wrapper instead.
1405 Perl_sv_grow(pTHX_ register SV *sv, register STRLEN newlen)
1409 if (PL_madskills && newlen >= 0x100000) {
1410 PerlIO_printf(Perl_debug_log,
1411 "Allocation too large: %"UVxf"\n", (UV)newlen);
1413 #ifdef HAS_64K_LIMIT
1414 if (newlen >= 0x10000) {
1415 PerlIO_printf(Perl_debug_log,
1416 "Allocation too large: %"UVxf"\n", (UV)newlen);
1419 #endif /* HAS_64K_LIMIT */
1422 if (SvTYPE(sv) < SVt_PV) {
1423 sv_upgrade(sv, SVt_PV);
1424 s = SvPVX_mutable(sv);
1426 else if (SvOOK(sv)) { /* pv is offset? */
1428 s = SvPVX_mutable(sv);
1429 if (newlen > SvLEN(sv))
1430 newlen += 10 * (newlen - SvCUR(sv)); /* avoid copy each time */
1431 #ifdef HAS_64K_LIMIT
1432 if (newlen >= 0x10000)
1437 s = SvPVX_mutable(sv);
1439 if (newlen > SvLEN(sv)) { /* need more room? */
1440 newlen = PERL_STRLEN_ROUNDUP(newlen);
1441 if (SvLEN(sv) && s) {
1443 const STRLEN l = malloced_size((void*)SvPVX_const(sv));
1449 s = saferealloc(s, newlen);
1452 s = safemalloc(newlen);
1453 if (SvPVX_const(sv) && SvCUR(sv)) {
1454 Move(SvPVX_const(sv), s, (newlen < SvCUR(sv)) ? newlen : SvCUR(sv), char);
1458 SvLEN_set(sv, newlen);
1464 =for apidoc sv_setiv
1466 Copies an integer into the given SV, upgrading first if necessary.
1467 Does not handle 'set' magic. See also C<sv_setiv_mg>.
1473 Perl_sv_setiv(pTHX_ register SV *sv, IV i)
1476 SV_CHECK_THINKFIRST_COW_DROP(sv);
1477 switch (SvTYPE(sv)) {
1479 sv_upgrade(sv, SVt_IV);
1482 sv_upgrade(sv, SVt_PVNV);
1486 sv_upgrade(sv, SVt_PVIV);
1495 Perl_croak(aTHX_ "Can't coerce %s to integer in %s", sv_reftype(sv,0),
1498 (void)SvIOK_only(sv); /* validate number */
1504 =for apidoc sv_setiv_mg
1506 Like C<sv_setiv>, but also handles 'set' magic.
1512 Perl_sv_setiv_mg(pTHX_ register SV *sv, IV i)
1519 =for apidoc sv_setuv
1521 Copies an unsigned integer into the given SV, upgrading first if necessary.
1522 Does not handle 'set' magic. See also C<sv_setuv_mg>.
1528 Perl_sv_setuv(pTHX_ register SV *sv, UV u)
1530 /* With these two if statements:
1531 u=1.49 s=0.52 cu=72.49 cs=10.64 scripts=270 tests=20865
1534 u=1.35 s=0.47 cu=73.45 cs=11.43 scripts=270 tests=20865
1536 If you wish to remove them, please benchmark to see what the effect is
1538 if (u <= (UV)IV_MAX) {
1539 sv_setiv(sv, (IV)u);
1548 =for apidoc sv_setuv_mg
1550 Like C<sv_setuv>, but also handles 'set' magic.
1556 Perl_sv_setuv_mg(pTHX_ register SV *sv, UV u)
1565 =for apidoc sv_setnv
1567 Copies a double into the given SV, upgrading first if necessary.
1568 Does not handle 'set' magic. See also C<sv_setnv_mg>.
1574 Perl_sv_setnv(pTHX_ register SV *sv, NV num)
1577 SV_CHECK_THINKFIRST_COW_DROP(sv);
1578 switch (SvTYPE(sv)) {
1581 sv_upgrade(sv, SVt_NV);
1586 sv_upgrade(sv, SVt_PVNV);
1595 Perl_croak(aTHX_ "Can't coerce %s to number in %s", sv_reftype(sv,0),
1599 (void)SvNOK_only(sv); /* validate number */
1604 =for apidoc sv_setnv_mg
1606 Like C<sv_setnv>, but also handles 'set' magic.
1612 Perl_sv_setnv_mg(pTHX_ register SV *sv, NV num)
1618 /* Print an "isn't numeric" warning, using a cleaned-up,
1619 * printable version of the offending string
1623 S_not_a_number(pTHX_ SV *sv)
1631 dsv = sv_2mortal(newSVpvs(""));
1632 pv = sv_uni_display(dsv, sv, 10, 0);
1635 const char * const limit = tmpbuf + sizeof(tmpbuf) - 8;
1636 /* each *s can expand to 4 chars + "...\0",
1637 i.e. need room for 8 chars */
1639 const char *s = SvPVX_const(sv);
1640 const char * const end = s + SvCUR(sv);
1641 for ( ; s < end && d < limit; s++ ) {
1643 if (ch & 128 && !isPRINT_LC(ch)) {
1652 else if (ch == '\r') {
1656 else if (ch == '\f') {
1660 else if (ch == '\\') {
1664 else if (ch == '\0') {
1668 else if (isPRINT_LC(ch))
1685 Perl_warner(aTHX_ packWARN(WARN_NUMERIC),
1686 "Argument \"%s\" isn't numeric in %s", pv,
1689 Perl_warner(aTHX_ packWARN(WARN_NUMERIC),
1690 "Argument \"%s\" isn't numeric", pv);
1694 =for apidoc looks_like_number
1696 Test if the content of an SV looks like a number (or is a number).
1697 C<Inf> and C<Infinity> are treated as numbers (so will not issue a
1698 non-numeric warning), even if your atof() doesn't grok them.
1704 Perl_looks_like_number(pTHX_ SV *sv)
1706 register const char *sbegin;
1710 sbegin = SvPVX_const(sv);
1713 else if (SvPOKp(sv))
1714 sbegin = SvPV_const(sv, len);
1716 return SvFLAGS(sv) & (SVf_NOK|SVp_NOK|SVf_IOK|SVp_IOK);
1717 return grok_number(sbegin, len, NULL);
1721 S_glob_2inpuv(pTHX_ GV *gv, STRLEN *len, bool want_number)
1723 const U32 wasfake = SvFLAGS(gv) & SVf_FAKE;
1724 SV *const buffer = sv_newmortal();
1726 /* FAKE globs can get coerced, so need to turn this off temporarily if it
1729 gv_efullname3(buffer, gv, "*");
1730 SvFLAGS(gv) |= wasfake;
1733 /* We know that all GVs stringify to something that is not-a-number,
1734 so no need to test that. */
1735 if (ckWARN(WARN_NUMERIC))
1736 not_a_number(buffer);
1737 /* We just want something true to return, so that S_sv_2iuv_common
1738 can tail call us and return true. */
1741 assert(SvPOK(buffer));
1743 *len = SvCUR(buffer);
1745 return SvPVX(buffer);
1749 /* Actually, ISO C leaves conversion of UV to IV undefined, but
1750 until proven guilty, assume that things are not that bad... */
1755 As 64 bit platforms often have an NV that doesn't preserve all bits of
1756 an IV (an assumption perl has been based on to date) it becomes necessary
1757 to remove the assumption that the NV always carries enough precision to
1758 recreate the IV whenever needed, and that the NV is the canonical form.
1759 Instead, IV/UV and NV need to be given equal rights. So as to not lose
1760 precision as a side effect of conversion (which would lead to insanity
1761 and the dragon(s) in t/op/numconvert.t getting very angry) the intent is
1762 1) to distinguish between IV/UV/NV slots that have cached a valid
1763 conversion where precision was lost and IV/UV/NV slots that have a
1764 valid conversion which has lost no precision
1765 2) to ensure that if a numeric conversion to one form is requested that
1766 would lose precision, the precise conversion (or differently
1767 imprecise conversion) is also performed and cached, to prevent
1768 requests for different numeric formats on the same SV causing
1769 lossy conversion chains. (lossless conversion chains are perfectly
1774 SvIOKp is true if the IV slot contains a valid value
1775 SvIOK is true only if the IV value is accurate (UV if SvIOK_UV true)
1776 SvNOKp is true if the NV slot contains a valid value
1777 SvNOK is true only if the NV value is accurate
1780 while converting from PV to NV, check to see if converting that NV to an
1781 IV(or UV) would lose accuracy over a direct conversion from PV to
1782 IV(or UV). If it would, cache both conversions, return NV, but mark
1783 SV as IOK NOKp (ie not NOK).
1785 While converting from PV to IV, check to see if converting that IV to an
1786 NV would lose accuracy over a direct conversion from PV to NV. If it
1787 would, cache both conversions, flag similarly.
1789 Before, the SV value "3.2" could become NV=3.2 IV=3 NOK, IOK quite
1790 correctly because if IV & NV were set NV *always* overruled.
1791 Now, "3.2" will become NV=3.2 IV=3 NOK, IOKp, because the flag's meaning
1792 changes - now IV and NV together means that the two are interchangeable:
1793 SvIVX == (IV) SvNVX && SvNVX == (NV) SvIVX;
1795 The benefit of this is that operations such as pp_add know that if
1796 SvIOK is true for both left and right operands, then integer addition
1797 can be used instead of floating point (for cases where the result won't
1798 overflow). Before, floating point was always used, which could lead to
1799 loss of precision compared with integer addition.
1801 * making IV and NV equal status should make maths accurate on 64 bit
1803 * may speed up maths somewhat if pp_add and friends start to use
1804 integers when possible instead of fp. (Hopefully the overhead in
1805 looking for SvIOK and checking for overflow will not outweigh the
1806 fp to integer speedup)
1807 * will slow down integer operations (callers of SvIV) on "inaccurate"
1808 values, as the change from SvIOK to SvIOKp will cause a call into
1809 sv_2iv each time rather than a macro access direct to the IV slot
1810 * should speed up number->string conversion on integers as IV is
1811 favoured when IV and NV are equally accurate
1813 ####################################################################
1814 You had better be using SvIOK_notUV if you want an IV for arithmetic:
1815 SvIOK is true if (IV or UV), so you might be getting (IV)SvUV.
1816 On the other hand, SvUOK is true iff UV.
1817 ####################################################################
1819 Your mileage will vary depending your CPU's relative fp to integer
1823 #ifndef NV_PRESERVES_UV
1824 # define IS_NUMBER_UNDERFLOW_IV 1
1825 # define IS_NUMBER_UNDERFLOW_UV 2
1826 # define IS_NUMBER_IV_AND_UV 2
1827 # define IS_NUMBER_OVERFLOW_IV 4
1828 # define IS_NUMBER_OVERFLOW_UV 5
1830 /* sv_2iuv_non_preserve(): private routine for use by sv_2iv() and sv_2uv() */
1832 /* For sv_2nv these three cases are "SvNOK and don't bother casting" */
1834 S_sv_2iuv_non_preserve(pTHX_ register SV *sv, I32 numtype)
1837 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));
1838 if (SvNVX(sv) < (NV)IV_MIN) {
1839 (void)SvIOKp_on(sv);
1841 SvIV_set(sv, IV_MIN);
1842 return IS_NUMBER_UNDERFLOW_IV;
1844 if (SvNVX(sv) > (NV)UV_MAX) {
1845 (void)SvIOKp_on(sv);
1848 SvUV_set(sv, UV_MAX);
1849 return IS_NUMBER_OVERFLOW_UV;
1851 (void)SvIOKp_on(sv);
1853 /* Can't use strtol etc to convert this string. (See truth table in
1855 if (SvNVX(sv) <= (UV)IV_MAX) {
1856 SvIV_set(sv, I_V(SvNVX(sv)));
1857 if ((NV)(SvIVX(sv)) == SvNVX(sv)) {
1858 SvIOK_on(sv); /* Integer is precise. NOK, IOK */
1860 /* Integer is imprecise. NOK, IOKp */
1862 return SvNVX(sv) < 0 ? IS_NUMBER_UNDERFLOW_UV : IS_NUMBER_IV_AND_UV;
1865 SvUV_set(sv, U_V(SvNVX(sv)));
1866 if ((NV)(SvUVX(sv)) == SvNVX(sv)) {
1867 if (SvUVX(sv) == UV_MAX) {
1868 /* As we know that NVs don't preserve UVs, UV_MAX cannot
1869 possibly be preserved by NV. Hence, it must be overflow.
1871 return IS_NUMBER_OVERFLOW_UV;
1873 SvIOK_on(sv); /* Integer is precise. NOK, UOK */
1875 /* Integer is imprecise. NOK, IOKp */
1877 return IS_NUMBER_OVERFLOW_IV;
1879 #endif /* !NV_PRESERVES_UV*/
1882 S_sv_2iuv_common(pTHX_ SV *sv) {
1885 /* erm. not sure. *should* never get NOKp (without NOK) from sv_2nv
1886 * without also getting a cached IV/UV from it at the same time
1887 * (ie PV->NV conversion should detect loss of accuracy and cache
1888 * IV or UV at same time to avoid this. */
1889 /* IV-over-UV optimisation - choose to cache IV if possible */
1891 if (SvTYPE(sv) == SVt_NV)
1892 sv_upgrade(sv, SVt_PVNV);
1894 (void)SvIOKp_on(sv); /* Must do this first, to clear any SvOOK */
1895 /* < not <= as for NV doesn't preserve UV, ((NV)IV_MAX+1) will almost
1896 certainly cast into the IV range at IV_MAX, whereas the correct
1897 answer is the UV IV_MAX +1. Hence < ensures that dodgy boundary
1899 #if defined(NAN_COMPARE_BROKEN) && defined(Perl_isnan)
1900 if (Perl_isnan(SvNVX(sv))) {
1906 if (SvNVX(sv) < (NV)IV_MAX + 0.5) {
1907 SvIV_set(sv, I_V(SvNVX(sv)));
1908 if (SvNVX(sv) == (NV) SvIVX(sv)
1909 #ifndef NV_PRESERVES_UV
1910 && (((UV)1 << NV_PRESERVES_UV_BITS) >
1911 (UV)(SvIVX(sv) > 0 ? SvIVX(sv) : -SvIVX(sv)))
1912 /* Don't flag it as "accurately an integer" if the number
1913 came from a (by definition imprecise) NV operation, and
1914 we're outside the range of NV integer precision */
1917 SvIOK_on(sv); /* Can this go wrong with rounding? NWC */
1918 DEBUG_c(PerlIO_printf(Perl_debug_log,
1919 "0x%"UVxf" iv(%"NVgf" => %"IVdf") (precise)\n",
1925 /* IV not precise. No need to convert from PV, as NV
1926 conversion would already have cached IV if it detected
1927 that PV->IV would be better than PV->NV->IV
1928 flags already correct - don't set public IOK. */
1929 DEBUG_c(PerlIO_printf(Perl_debug_log,
1930 "0x%"UVxf" iv(%"NVgf" => %"IVdf") (imprecise)\n",
1935 /* Can the above go wrong if SvIVX == IV_MIN and SvNVX < IV_MIN,
1936 but the cast (NV)IV_MIN rounds to a the value less (more
1937 negative) than IV_MIN which happens to be equal to SvNVX ??
1938 Analogous to 0xFFFFFFFFFFFFFFFF rounding up to NV (2**64) and
1939 NV rounding back to 0xFFFFFFFFFFFFFFFF, so UVX == UV(NVX) and
1940 (NV)UVX == NVX are both true, but the values differ. :-(
1941 Hopefully for 2s complement IV_MIN is something like
1942 0x8000000000000000 which will be exact. NWC */
1945 SvUV_set(sv, U_V(SvNVX(sv)));
1947 (SvNVX(sv) == (NV) SvUVX(sv))
1948 #ifndef NV_PRESERVES_UV
1949 /* Make sure it's not 0xFFFFFFFFFFFFFFFF */
1950 /*&& (SvUVX(sv) != UV_MAX) irrelevant with code below */
1951 && (((UV)1 << NV_PRESERVES_UV_BITS) > SvUVX(sv))
1952 /* Don't flag it as "accurately an integer" if the number
1953 came from a (by definition imprecise) NV operation, and
1954 we're outside the range of NV integer precision */
1959 DEBUG_c(PerlIO_printf(Perl_debug_log,
1960 "0x%"UVxf" 2iv(%"UVuf" => %"IVdf") (as unsigned)\n",
1966 else if (SvPOKp(sv) && SvLEN(sv)) {
1968 const int numtype = grok_number(SvPVX_const(sv), SvCUR(sv), &value);
1969 /* We want to avoid a possible problem when we cache an IV/ a UV which
1970 may be later translated to an NV, and the resulting NV is not
1971 the same as the direct translation of the initial string
1972 (eg 123.456 can shortcut to the IV 123 with atol(), but we must
1973 be careful to ensure that the value with the .456 is around if the
1974 NV value is requested in the future).
1976 This means that if we cache such an IV/a UV, we need to cache the
1977 NV as well. Moreover, we trade speed for space, and do not
1978 cache the NV if we are sure it's not needed.
1981 /* SVt_PVNV is one higher than SVt_PVIV, hence this order */
1982 if ((numtype & (IS_NUMBER_IN_UV | IS_NUMBER_NOT_INT))
1983 == IS_NUMBER_IN_UV) {
1984 /* It's definitely an integer, only upgrade to PVIV */
1985 if (SvTYPE(sv) < SVt_PVIV)
1986 sv_upgrade(sv, SVt_PVIV);
1988 } else if (SvTYPE(sv) < SVt_PVNV)
1989 sv_upgrade(sv, SVt_PVNV);
1991 /* If NVs preserve UVs then we only use the UV value if we know that
1992 we aren't going to call atof() below. If NVs don't preserve UVs
1993 then the value returned may have more precision than atof() will
1994 return, even though value isn't perfectly accurate. */
1995 if ((numtype & (IS_NUMBER_IN_UV
1996 #ifdef NV_PRESERVES_UV
1999 )) == IS_NUMBER_IN_UV) {
2000 /* This won't turn off the public IOK flag if it was set above */
2001 (void)SvIOKp_on(sv);
2003 if (!(numtype & IS_NUMBER_NEG)) {
2005 if (value <= (UV)IV_MAX) {
2006 SvIV_set(sv, (IV)value);
2008 /* it didn't overflow, and it was positive. */
2009 SvUV_set(sv, value);
2013 /* 2s complement assumption */
2014 if (value <= (UV)IV_MIN) {
2015 SvIV_set(sv, -(IV)value);
2017 /* Too negative for an IV. This is a double upgrade, but
2018 I'm assuming it will be rare. */
2019 if (SvTYPE(sv) < SVt_PVNV)
2020 sv_upgrade(sv, SVt_PVNV);
2024 SvNV_set(sv, -(NV)value);
2025 SvIV_set(sv, IV_MIN);
2029 /* For !NV_PRESERVES_UV and IS_NUMBER_IN_UV and IS_NUMBER_NOT_INT we
2030 will be in the previous block to set the IV slot, and the next
2031 block to set the NV slot. So no else here. */
2033 if ((numtype & (IS_NUMBER_IN_UV | IS_NUMBER_NOT_INT))
2034 != IS_NUMBER_IN_UV) {
2035 /* It wasn't an (integer that doesn't overflow the UV). */
2036 SvNV_set(sv, Atof(SvPVX_const(sv)));
2038 if (! numtype && ckWARN(WARN_NUMERIC))
2041 #if defined(USE_LONG_DOUBLE)
2042 DEBUG_c(PerlIO_printf(Perl_debug_log, "0x%"UVxf" 2iv(%" PERL_PRIgldbl ")\n",
2043 PTR2UV(sv), SvNVX(sv)));
2045 DEBUG_c(PerlIO_printf(Perl_debug_log, "0x%"UVxf" 2iv(%"NVgf")\n",
2046 PTR2UV(sv), SvNVX(sv)));
2049 #ifdef NV_PRESERVES_UV
2050 (void)SvIOKp_on(sv);
2052 if (SvNVX(sv) < (NV)IV_MAX + 0.5) {
2053 SvIV_set(sv, I_V(SvNVX(sv)));
2054 if ((NV)(SvIVX(sv)) == SvNVX(sv)) {
2057 /*EMPTY*/; /* Integer is imprecise. NOK, IOKp */
2059 /* UV will not work better than IV */
2061 if (SvNVX(sv) > (NV)UV_MAX) {
2063 /* Integer is inaccurate. NOK, IOKp, is UV */
2064 SvUV_set(sv, UV_MAX);
2066 SvUV_set(sv, U_V(SvNVX(sv)));
2067 /* 0xFFFFFFFFFFFFFFFF not an issue in here, NVs
2068 NV preservse UV so can do correct comparison. */
2069 if ((NV)(SvUVX(sv)) == SvNVX(sv)) {
2072 /*EMPTY*/; /* Integer is imprecise. NOK, IOKp, is UV */
2077 #else /* NV_PRESERVES_UV */
2078 if ((numtype & (IS_NUMBER_IN_UV | IS_NUMBER_NOT_INT))
2079 == (IS_NUMBER_IN_UV | IS_NUMBER_NOT_INT)) {
2080 /* The IV/UV slot will have been set from value returned by
2081 grok_number above. The NV slot has just been set using
2084 assert (SvIOKp(sv));
2086 if (((UV)1 << NV_PRESERVES_UV_BITS) >
2087 U_V(SvNVX(sv) > 0 ? SvNVX(sv) : -SvNVX(sv))) {
2088 /* Small enough to preserve all bits. */
2089 (void)SvIOKp_on(sv);
2091 SvIV_set(sv, I_V(SvNVX(sv)));
2092 if ((NV)(SvIVX(sv)) == SvNVX(sv))
2094 /* Assumption: first non-preserved integer is < IV_MAX,
2095 this NV is in the preserved range, therefore: */
2096 if (!(U_V(SvNVX(sv) > 0 ? SvNVX(sv) : -SvNVX(sv))
2098 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);
2102 0 0 already failed to read UV.
2103 0 1 already failed to read UV.
2104 1 0 you won't get here in this case. IV/UV
2105 slot set, public IOK, Atof() unneeded.
2106 1 1 already read UV.
2107 so there's no point in sv_2iuv_non_preserve() attempting
2108 to use atol, strtol, strtoul etc. */
2109 sv_2iuv_non_preserve (sv, numtype);
2112 #endif /* NV_PRESERVES_UV */
2116 if (isGV_with_GP(sv)) {
2117 return (bool)PTR2IV(glob_2inpuv((GV *)sv, NULL, TRUE));
2120 if (!(SvFLAGS(sv) & SVs_PADTMP)) {
2121 if (!PL_localizing && ckWARN(WARN_UNINITIALIZED))
2124 if (SvTYPE(sv) < SVt_IV)
2125 /* Typically the caller expects that sv_any is not NULL now. */
2126 sv_upgrade(sv, SVt_IV);
2127 /* Return 0 from the caller. */
2134 =for apidoc sv_2iv_flags
2136 Return the integer value of an SV, doing any necessary string
2137 conversion. If flags includes SV_GMAGIC, does an mg_get() first.
2138 Normally used via the C<SvIV(sv)> and C<SvIVx(sv)> macros.
2144 Perl_sv_2iv_flags(pTHX_ register SV *sv, I32 flags)
2149 if (SvGMAGICAL(sv)) {
2150 if (flags & SV_GMAGIC)
2155 return I_V(SvNVX(sv));
2157 if (SvPOKp(sv) && SvLEN(sv)) {
2160 = grok_number(SvPVX_const(sv), SvCUR(sv), &value);
2162 if ((numtype & (IS_NUMBER_IN_UV | IS_NUMBER_NOT_INT))
2163 == IS_NUMBER_IN_UV) {
2164 /* It's definitely an integer */
2165 if (numtype & IS_NUMBER_NEG) {
2166 if (value < (UV)IV_MIN)
2169 if (value < (UV)IV_MAX)
2174 if (ckWARN(WARN_NUMERIC))
2177 return I_V(Atof(SvPVX_const(sv)));
2182 assert(SvTYPE(sv) >= SVt_PVMG);
2183 /* This falls through to the report_uninit inside S_sv_2iuv_common. */
2184 } else if (SvTHINKFIRST(sv)) {
2188 SV * const tmpstr=AMG_CALLun(sv,numer);
2189 if (tmpstr && (!SvROK(tmpstr) || (SvRV(tmpstr) != SvRV(sv)))) {
2190 return SvIV(tmpstr);
2193 return PTR2IV(SvRV(sv));
2196 sv_force_normal_flags(sv, 0);
2198 if (SvREADONLY(sv) && !SvOK(sv)) {
2199 if (ckWARN(WARN_UNINITIALIZED))
2205 if (S_sv_2iuv_common(aTHX_ sv))
2208 DEBUG_c(PerlIO_printf(Perl_debug_log, "0x%"UVxf" 2iv(%"IVdf")\n",
2209 PTR2UV(sv),SvIVX(sv)));
2210 return SvIsUV(sv) ? (IV)SvUVX(sv) : SvIVX(sv);
2214 =for apidoc sv_2uv_flags
2216 Return the unsigned integer value of an SV, doing any necessary string
2217 conversion. If flags includes SV_GMAGIC, does an mg_get() first.
2218 Normally used via the C<SvUV(sv)> and C<SvUVx(sv)> macros.
2224 Perl_sv_2uv_flags(pTHX_ register SV *sv, I32 flags)
2229 if (SvGMAGICAL(sv)) {
2230 if (flags & SV_GMAGIC)
2235 return U_V(SvNVX(sv));
2236 if (SvPOKp(sv) && SvLEN(sv)) {
2239 = grok_number(SvPVX_const(sv), SvCUR(sv), &value);
2241 if ((numtype & (IS_NUMBER_IN_UV | IS_NUMBER_NOT_INT))
2242 == IS_NUMBER_IN_UV) {
2243 /* It's definitely an integer */
2244 if (!(numtype & IS_NUMBER_NEG))
2248 if (ckWARN(WARN_NUMERIC))
2251 return U_V(Atof(SvPVX_const(sv)));
2256 assert(SvTYPE(sv) >= SVt_PVMG);
2257 /* This falls through to the report_uninit inside S_sv_2iuv_common. */
2258 } else if (SvTHINKFIRST(sv)) {
2262 SV *const tmpstr = AMG_CALLun(sv,numer);
2263 if (tmpstr && (!SvROK(tmpstr) || (SvRV(tmpstr) != SvRV(sv)))) {
2264 return SvUV(tmpstr);
2267 return PTR2UV(SvRV(sv));
2270 sv_force_normal_flags(sv, 0);
2272 if (SvREADONLY(sv) && !SvOK(sv)) {
2273 if (ckWARN(WARN_UNINITIALIZED))
2279 if (S_sv_2iuv_common(aTHX_ sv))
2283 DEBUG_c(PerlIO_printf(Perl_debug_log, "0x%"UVxf" 2uv(%"UVuf")\n",
2284 PTR2UV(sv),SvUVX(sv)));
2285 return SvIsUV(sv) ? SvUVX(sv) : (UV)SvIVX(sv);
2291 Return the num value of an SV, doing any necessary string or integer
2292 conversion, magic etc. Normally used via the C<SvNV(sv)> and C<SvNVx(sv)>
2299 Perl_sv_2nv(pTHX_ register SV *sv)
2304 if (SvGMAGICAL(sv)) {
2308 if ((SvPOKp(sv) && SvLEN(sv)) && !SvIOKp(sv)) {
2309 if (!SvIOKp(sv) && ckWARN(WARN_NUMERIC) &&
2310 !grok_number(SvPVX_const(sv), SvCUR(sv), NULL))
2312 return Atof(SvPVX_const(sv));
2316 return (NV)SvUVX(sv);
2318 return (NV)SvIVX(sv);
2323 assert(SvTYPE(sv) >= SVt_PVMG);
2324 /* This falls through to the report_uninit near the end of the
2326 } else if (SvTHINKFIRST(sv)) {
2330 SV *const tmpstr = AMG_CALLun(sv,numer);
2331 if (tmpstr && (!SvROK(tmpstr) || (SvRV(tmpstr) != SvRV(sv)))) {
2332 return SvNV(tmpstr);
2335 return PTR2NV(SvRV(sv));
2338 sv_force_normal_flags(sv, 0);
2340 if (SvREADONLY(sv) && !SvOK(sv)) {
2341 if (ckWARN(WARN_UNINITIALIZED))
2346 if (SvTYPE(sv) < SVt_NV) {
2347 /* The logic to use SVt_PVNV if necessary is in sv_upgrade. */
2348 sv_upgrade(sv, SVt_NV);
2349 #ifdef USE_LONG_DOUBLE
2351 STORE_NUMERIC_LOCAL_SET_STANDARD();
2352 PerlIO_printf(Perl_debug_log,
2353 "0x%"UVxf" num(%" PERL_PRIgldbl ")\n",
2354 PTR2UV(sv), SvNVX(sv));
2355 RESTORE_NUMERIC_LOCAL();
2359 STORE_NUMERIC_LOCAL_SET_STANDARD();
2360 PerlIO_printf(Perl_debug_log, "0x%"UVxf" num(%"NVgf")\n",
2361 PTR2UV(sv), SvNVX(sv));
2362 RESTORE_NUMERIC_LOCAL();
2366 else if (SvTYPE(sv) < SVt_PVNV)
2367 sv_upgrade(sv, SVt_PVNV);
2372 SvNV_set(sv, SvIsUV(sv) ? (NV)SvUVX(sv) : (NV)SvIVX(sv));
2373 #ifdef NV_PRESERVES_UV
2376 /* Only set the public NV OK flag if this NV preserves the IV */
2377 /* Check it's not 0xFFFFFFFFFFFFFFFF */
2378 if (SvIsUV(sv) ? ((SvUVX(sv) != UV_MAX)&&(SvUVX(sv) == U_V(SvNVX(sv))))
2379 : (SvIVX(sv) == I_V(SvNVX(sv))))
2385 else if (SvPOKp(sv) && SvLEN(sv)) {
2387 const int numtype = grok_number(SvPVX_const(sv), SvCUR(sv), &value);
2388 if (!SvIOKp(sv) && !numtype && ckWARN(WARN_NUMERIC))
2390 #ifdef NV_PRESERVES_UV
2391 if ((numtype & (IS_NUMBER_IN_UV | IS_NUMBER_NOT_INT))
2392 == IS_NUMBER_IN_UV) {
2393 /* It's definitely an integer */
2394 SvNV_set(sv, (numtype & IS_NUMBER_NEG) ? -(NV)value : (NV)value);
2396 SvNV_set(sv, Atof(SvPVX_const(sv)));
2399 SvNV_set(sv, Atof(SvPVX_const(sv)));
2400 /* Only set the public NV OK flag if this NV preserves the value in
2401 the PV at least as well as an IV/UV would.
2402 Not sure how to do this 100% reliably. */
2403 /* if that shift count is out of range then Configure's test is
2404 wonky. We shouldn't be in here with NV_PRESERVES_UV_BITS ==
2406 if (((UV)1 << NV_PRESERVES_UV_BITS) >
2407 U_V(SvNVX(sv) > 0 ? SvNVX(sv) : -SvNVX(sv))) {
2408 SvNOK_on(sv); /* Definitely small enough to preserve all bits */
2409 } else if (!(numtype & IS_NUMBER_IN_UV)) {
2410 /* Can't use strtol etc to convert this string, so don't try.
2411 sv_2iv and sv_2uv will use the NV to convert, not the PV. */
2414 /* value has been set. It may not be precise. */
2415 if ((numtype & IS_NUMBER_NEG) && (value > (UV)IV_MIN)) {
2416 /* 2s complement assumption for (UV)IV_MIN */
2417 SvNOK_on(sv); /* Integer is too negative. */
2422 if (numtype & IS_NUMBER_NEG) {
2423 SvIV_set(sv, -(IV)value);
2424 } else if (value <= (UV)IV_MAX) {
2425 SvIV_set(sv, (IV)value);
2427 SvUV_set(sv, value);
2431 if (numtype & IS_NUMBER_NOT_INT) {
2432 /* I believe that even if the original PV had decimals,
2433 they are lost beyond the limit of the FP precision.
2434 However, neither is canonical, so both only get p
2435 flags. NWC, 2000/11/25 */
2436 /* Both already have p flags, so do nothing */
2438 const NV nv = SvNVX(sv);
2439 if (SvNVX(sv) < (NV)IV_MAX + 0.5) {
2440 if (SvIVX(sv) == I_V(nv)) {
2443 /* It had no "." so it must be integer. */
2447 /* between IV_MAX and NV(UV_MAX).
2448 Could be slightly > UV_MAX */
2450 if (numtype & IS_NUMBER_NOT_INT) {
2451 /* UV and NV both imprecise. */
2453 const UV nv_as_uv = U_V(nv);
2455 if (value == nv_as_uv && SvUVX(sv) != UV_MAX) {
2464 #endif /* NV_PRESERVES_UV */
2467 if (isGV_with_GP(sv)) {
2468 glob_2inpuv((GV *)sv, NULL, TRUE);
2472 if (!PL_localizing && !(SvFLAGS(sv) & SVs_PADTMP) && ckWARN(WARN_UNINITIALIZED))
2474 assert (SvTYPE(sv) >= SVt_NV);
2475 /* Typically the caller expects that sv_any is not NULL now. */
2476 /* XXX Ilya implies that this is a bug in callers that assume this
2477 and ideally should be fixed. */
2480 #if defined(USE_LONG_DOUBLE)
2482 STORE_NUMERIC_LOCAL_SET_STANDARD();
2483 PerlIO_printf(Perl_debug_log, "0x%"UVxf" 2nv(%" PERL_PRIgldbl ")\n",
2484 PTR2UV(sv), SvNVX(sv));
2485 RESTORE_NUMERIC_LOCAL();
2489 STORE_NUMERIC_LOCAL_SET_STANDARD();
2490 PerlIO_printf(Perl_debug_log, "0x%"UVxf" 1nv(%"NVgf")\n",
2491 PTR2UV(sv), SvNVX(sv));
2492 RESTORE_NUMERIC_LOCAL();
2498 /* uiv_2buf(): private routine for use by sv_2pv_flags(): print an IV or
2499 * UV as a string towards the end of buf, and return pointers to start and
2502 * We assume that buf is at least TYPE_CHARS(UV) long.
2506 S_uiv_2buf(char *buf, IV iv, UV uv, int is_uv, char **peob)
2508 char *ptr = buf + TYPE_CHARS(UV);
2509 char * const ebuf = ptr;
2522 *--ptr = '0' + (char)(uv % 10);
2530 /* stringify_regexp(): private routine for use by sv_2pv_flags(): converts
2531 * a regexp to its stringified form.
2535 S_stringify_regexp(pTHX_ SV *sv, MAGIC *mg, STRLEN *lp) {
2537 const regexp * const re = (regexp *)mg->mg_obj;
2540 const char *fptr = "msix";
2545 bool need_newline = 0;
2546 U16 reganch = (U16)((re->reganch & PMf_COMPILETIME) >> 12);
2548 while((ch = *fptr++)) {
2550 reflags[left++] = ch;
2553 reflags[right--] = ch;
2558 reflags[left] = '-';
2562 mg->mg_len = re->prelen + 4 + left;
2564 * If /x was used, we have to worry about a regex ending with a
2565 * comment later being embedded within another regex. If so, we don't
2566 * want this regex's "commentization" to leak out to the right part of
2567 * the enclosing regex, we must cap it with a newline.
2569 * So, if /x was used, we scan backwards from the end of the regex. If
2570 * we find a '#' before we find a newline, we need to add a newline
2571 * ourself. If we find a '\n' first (or if we don't find '#' or '\n'),
2572 * we don't need to add anything. -jfriedl
2574 if (PMf_EXTENDED & re->reganch) {
2575 const char *endptr = re->precomp + re->prelen;
2576 while (endptr >= re->precomp) {
2577 const char c = *(endptr--);
2579 break; /* don't need another */
2581 /* we end while in a comment, so we need a newline */
2582 mg->mg_len++; /* save space for it */
2583 need_newline = 1; /* note to add it */
2589 Newx(mg->mg_ptr, mg->mg_len + 1 + left, char);
2590 mg->mg_ptr[0] = '(';
2591 mg->mg_ptr[1] = '?';
2592 Copy(reflags, mg->mg_ptr+2, left, char);
2593 *(mg->mg_ptr+left+2) = ':';
2594 Copy(re->precomp, mg->mg_ptr+3+left, re->prelen, char);
2596 mg->mg_ptr[mg->mg_len - 2] = '\n';
2597 mg->mg_ptr[mg->mg_len - 1] = ')';
2598 mg->mg_ptr[mg->mg_len] = 0;
2600 PL_reginterp_cnt += re->program[0].next_off;
2602 if (re->reganch & ROPT_UTF8)
2612 =for apidoc sv_2pv_flags
2614 Returns a pointer to the string value of an SV, and sets *lp to its length.
2615 If flags includes SV_GMAGIC, does an mg_get() first. Coerces sv to a string
2617 Normally invoked via the C<SvPV_flags> macro. C<sv_2pv()> and C<sv_2pv_nomg>
2618 usually end up here too.
2624 Perl_sv_2pv_flags(pTHX_ register SV *sv, STRLEN *lp, I32 flags)
2634 if (SvGMAGICAL(sv)) {
2635 if (flags & SV_GMAGIC)
2640 if (flags & SV_MUTABLE_RETURN)
2641 return SvPVX_mutable(sv);
2642 if (flags & SV_CONST_RETURN)
2643 return (char *)SvPVX_const(sv);
2646 if (SvIOKp(sv) || SvNOKp(sv)) {
2647 char tbuf[64]; /* Must fit sprintf/Gconvert of longest IV/NV */
2651 len = SvIsUV(sv) ? my_sprintf(tbuf,"%"UVuf, (UV)SvUVX(sv))
2652 : my_sprintf(tbuf,"%"IVdf, (IV)SvIVX(sv));
2654 Gconvert(SvNVX(sv), NV_DIG, 0, tbuf);
2661 #ifdef FIXNEGATIVEZERO
2662 if (len == 2 && tbuf[0] == '-' && tbuf[1] == '0') {
2668 SvUPGRADE(sv, SVt_PV);
2671 s = SvGROW_mutable(sv, len + 1);
2674 return memcpy(s, tbuf, len + 1);
2680 assert(SvTYPE(sv) >= SVt_PVMG);
2681 /* This falls through to the report_uninit near the end of the
2683 } else if (SvTHINKFIRST(sv)) {
2687 SV *const tmpstr = AMG_CALLun(sv,string);
2688 if (tmpstr && (!SvROK(tmpstr) || (SvRV(tmpstr) != SvRV(sv)))) {
2690 /* char *pv = lp ? SvPV(tmpstr, *lp) : SvPV_nolen(tmpstr);
2694 if ((SvFLAGS(tmpstr) & (SVf_POK)) == SVf_POK) {
2695 if (flags & SV_CONST_RETURN) {
2696 pv = (char *) SvPVX_const(tmpstr);
2698 pv = (flags & SV_MUTABLE_RETURN)
2699 ? SvPVX_mutable(tmpstr) : SvPVX(tmpstr);
2702 *lp = SvCUR(tmpstr);
2704 pv = sv_2pv_flags(tmpstr, lp, flags);
2716 const SV *const referent = (SV*)SvRV(sv);
2719 tsv = sv_2mortal(newSVpvs("NULLREF"));
2720 } else if (SvTYPE(referent) == SVt_PVMG
2721 && ((SvFLAGS(referent) &
2722 (SVs_OBJECT|SVf_OK|SVs_GMG|SVs_SMG|SVs_RMG))
2723 == (SVs_OBJECT|SVs_SMG))
2724 && (mg = mg_find(referent, PERL_MAGIC_qr))) {
2725 return stringify_regexp(sv, mg, lp);
2727 const char *const typestr = sv_reftype(referent, 0);
2729 tsv = sv_newmortal();
2730 if (SvOBJECT(referent)) {
2731 const char *const name = HvNAME_get(SvSTASH(referent));
2732 Perl_sv_setpvf(aTHX_ tsv, "%s=%s(0x%"UVxf")",
2733 name ? name : "__ANON__" , typestr,
2737 Perl_sv_setpvf(aTHX_ tsv, "%s(0x%"UVxf")", typestr,
2745 if (SvREADONLY(sv) && !SvOK(sv)) {
2746 if (ckWARN(WARN_UNINITIALIZED))
2753 if (SvIOK(sv) || ((SvIOKp(sv) && !SvNOKp(sv)))) {
2754 /* I'm assuming that if both IV and NV are equally valid then
2755 converting the IV is going to be more efficient */
2756 const U32 isIOK = SvIOK(sv);
2757 const U32 isUIOK = SvIsUV(sv);
2758 char buf[TYPE_CHARS(UV)];
2761 if (SvTYPE(sv) < SVt_PVIV)
2762 sv_upgrade(sv, SVt_PVIV);
2763 ptr = uiv_2buf(buf, SvIVX(sv), SvUVX(sv), isUIOK, &ebuf);
2764 /* inlined from sv_setpvn */
2765 SvGROW_mutable(sv, (STRLEN)(ebuf - ptr + 1));
2766 Move(ptr,SvPVX_mutable(sv),ebuf - ptr,char);
2767 SvCUR_set(sv, ebuf - ptr);
2777 else if (SvNOKp(sv)) {
2778 const int olderrno = errno;
2779 if (SvTYPE(sv) < SVt_PVNV)
2780 sv_upgrade(sv, SVt_PVNV);
2781 /* The +20 is pure guesswork. Configure test needed. --jhi */
2782 s = SvGROW_mutable(sv, NV_DIG + 20);
2783 /* some Xenix systems wipe out errno here */
2785 if (SvNVX(sv) == 0.0)
2786 (void)strcpy(s,"0");
2790 Gconvert(SvNVX(sv), NV_DIG, 0, s);
2793 #ifdef FIXNEGATIVEZERO
2794 if (*s == '-' && s[1] == '0' && !s[2])
2804 if (isGV_with_GP(sv)) {
2805 return glob_2inpuv((GV *)sv, lp, FALSE);
2808 if (!PL_localizing && !(SvFLAGS(sv) & SVs_PADTMP) && ckWARN(WARN_UNINITIALIZED))
2812 if (SvTYPE(sv) < SVt_PV)
2813 /* Typically the caller expects that sv_any is not NULL now. */
2814 sv_upgrade(sv, SVt_PV);
2818 const STRLEN len = s - SvPVX_const(sv);
2824 DEBUG_c(PerlIO_printf(Perl_debug_log, "0x%"UVxf" 2pv(%s)\n",
2825 PTR2UV(sv),SvPVX_const(sv)));
2826 if (flags & SV_CONST_RETURN)
2827 return (char *)SvPVX_const(sv);
2828 if (flags & SV_MUTABLE_RETURN)
2829 return SvPVX_mutable(sv);
2834 =for apidoc sv_copypv
2836 Copies a stringified representation of the source SV into the
2837 destination SV. Automatically performs any necessary mg_get and
2838 coercion of numeric values into strings. Guaranteed to preserve
2839 UTF-8 flag even from overloaded objects. Similar in nature to
2840 sv_2pv[_flags] but operates directly on an SV instead of just the
2841 string. Mostly uses sv_2pv_flags to do its work, except when that
2842 would lose the UTF-8'ness of the PV.
2848 Perl_sv_copypv(pTHX_ SV *dsv, register SV *ssv)
2851 const char * const s = SvPV_const(ssv,len);
2852 sv_setpvn(dsv,s,len);
2860 =for apidoc sv_2pvbyte
2862 Return a pointer to the byte-encoded representation of the SV, and set *lp
2863 to its length. May cause the SV to be downgraded from UTF-8 as a
2866 Usually accessed via the C<SvPVbyte> macro.
2872 Perl_sv_2pvbyte(pTHX_ register SV *sv, STRLEN *lp)
2874 sv_utf8_downgrade(sv,0);
2875 return lp ? SvPV(sv,*lp) : SvPV_nolen(sv);
2879 =for apidoc sv_2pvutf8
2881 Return a pointer to the UTF-8-encoded representation of the SV, and set *lp
2882 to its length. May cause the SV to be upgraded to UTF-8 as a side-effect.
2884 Usually accessed via the C<SvPVutf8> macro.
2890 Perl_sv_2pvutf8(pTHX_ register SV *sv, STRLEN *lp)
2892 sv_utf8_upgrade(sv);
2893 return lp ? SvPV(sv,*lp) : SvPV_nolen(sv);
2898 =for apidoc sv_2bool
2900 This function is only called on magical items, and is only used by
2901 sv_true() or its macro equivalent.
2907 Perl_sv_2bool(pTHX_ register SV *sv)
2916 SV * const tmpsv = AMG_CALLun(sv,bool_);
2917 if (tmpsv && (!SvROK(tmpsv) || (SvRV(tmpsv) != SvRV(sv))))
2918 return (bool)SvTRUE(tmpsv);
2920 return SvRV(sv) != 0;
2923 register XPV* const Xpvtmp = (XPV*)SvANY(sv);
2925 (*sv->sv_u.svu_pv > '0' ||
2926 Xpvtmp->xpv_cur > 1 ||
2927 (Xpvtmp->xpv_cur && *sv->sv_u.svu_pv != '0')))
2934 return SvIVX(sv) != 0;
2937 return SvNVX(sv) != 0.0;
2939 if (isGV_with_GP(sv))
2949 =for apidoc sv_utf8_upgrade
2951 Converts the PV of an SV to its UTF-8-encoded form.
2952 Forces the SV to string form if it is not already.
2953 Always sets the SvUTF8 flag to avoid future validity checks even
2954 if all the bytes have hibit clear.
2956 This is not as a general purpose byte encoding to Unicode interface:
2957 use the Encode extension for that.
2959 =for apidoc sv_utf8_upgrade_flags
2961 Converts the PV of an SV to its UTF-8-encoded form.
2962 Forces the SV to string form if it is not already.
2963 Always sets the SvUTF8 flag to avoid future validity checks even
2964 if all the bytes have hibit clear. If C<flags> has C<SV_GMAGIC> bit set,
2965 will C<mg_get> on C<sv> if appropriate, else not. C<sv_utf8_upgrade> and
2966 C<sv_utf8_upgrade_nomg> are implemented in terms of this function.
2968 This is not as a general purpose byte encoding to Unicode interface:
2969 use the Encode extension for that.
2975 Perl_sv_utf8_upgrade_flags(pTHX_ register SV *sv, I32 flags)
2978 if (sv == &PL_sv_undef)
2982 if (SvREADONLY(sv) && (SvPOKp(sv) || SvIOKp(sv) || SvNOKp(sv))) {
2983 (void) sv_2pv_flags(sv,&len, flags);
2987 (void) SvPV_force(sv,len);
2996 sv_force_normal_flags(sv, 0);
2999 if (PL_encoding && !(flags & SV_UTF8_NO_ENCODING))
3000 sv_recode_to_utf8(sv, PL_encoding);
3001 else { /* Assume Latin-1/EBCDIC */
3002 /* This function could be much more efficient if we
3003 * had a FLAG in SVs to signal if there are any hibit
3004 * chars in the PV. Given that there isn't such a flag
3005 * make the loop as fast as possible. */
3006 const U8 * const s = (U8 *) SvPVX_const(sv);
3007 const U8 * const e = (U8 *) SvEND(sv);
3012 /* Check for hi bit */
3013 if (!NATIVE_IS_INVARIANT(ch)) {
3014 STRLEN len = SvCUR(sv) + 1; /* Plus the \0 */
3015 U8 * const recoded = bytes_to_utf8((U8*)s, &len);
3017 SvPV_free(sv); /* No longer using what was there before. */
3018 SvPV_set(sv, (char*)recoded);
3019 SvCUR_set(sv, len - 1);
3020 SvLEN_set(sv, len); /* No longer know the real size. */
3024 /* Mark as UTF-8 even if no hibit - saves scanning loop */
3031 =for apidoc sv_utf8_downgrade
3033 Attempts to convert the PV of an SV from characters to bytes.
3034 If the PV contains a character beyond byte, this conversion will fail;
3035 in this case, either returns false or, if C<fail_ok> is not
3038 This is not as a general purpose Unicode to byte encoding interface:
3039 use the Encode extension for that.
3045 Perl_sv_utf8_downgrade(pTHX_ register SV* sv, bool fail_ok)
3048 if (SvPOKp(sv) && SvUTF8(sv)) {
3054 sv_force_normal_flags(sv, 0);
3056 s = (U8 *) SvPV(sv, len);
3057 if (!utf8_to_bytes(s, &len)) {
3062 Perl_croak(aTHX_ "Wide character in %s",
3065 Perl_croak(aTHX_ "Wide character");
3076 =for apidoc sv_utf8_encode
3078 Converts the PV of an SV to UTF-8, but then turns the C<SvUTF8>
3079 flag off so that it looks like octets again.
3085 Perl_sv_utf8_encode(pTHX_ register SV *sv)
3087 (void) sv_utf8_upgrade(sv);
3089 sv_force_normal_flags(sv, 0);
3091 if (SvREADONLY(sv)) {
3092 Perl_croak(aTHX_ PL_no_modify);
3098 =for apidoc sv_utf8_decode
3100 If the PV of the SV is an octet sequence in UTF-8
3101 and contains a multiple-byte character, the C<SvUTF8> flag is turned on
3102 so that it looks like a character. If the PV contains only single-byte
3103 characters, the C<SvUTF8> flag stays being off.
3104 Scans PV for validity and returns false if the PV is invalid UTF-8.
3110 Perl_sv_utf8_decode(pTHX_ register SV *sv)
3116 /* The octets may have got themselves encoded - get them back as
3119 if (!sv_utf8_downgrade(sv, TRUE))
3122 /* it is actually just a matter of turning the utf8 flag on, but
3123 * we want to make sure everything inside is valid utf8 first.
3125 c = (const U8 *) SvPVX_const(sv);
3126 if (!is_utf8_string(c, SvCUR(sv)+1))
3128 e = (const U8 *) SvEND(sv);
3131 if (!UTF8_IS_INVARIANT(ch)) {
3141 =for apidoc sv_setsv
3143 Copies the contents of the source SV C<ssv> into the destination SV
3144 C<dsv>. The source SV may be destroyed if it is mortal, so don't use this
3145 function if the source SV needs to be reused. Does not handle 'set' magic.
3146 Loosely speaking, it performs a copy-by-value, obliterating any previous
3147 content of the destination.
3149 You probably want to use one of the assortment of wrappers, such as
3150 C<SvSetSV>, C<SvSetSV_nosteal>, C<SvSetMagicSV> and
3151 C<SvSetMagicSV_nosteal>.
3153 =for apidoc sv_setsv_flags
3155 Copies the contents of the source SV C<ssv> into the destination SV
3156 C<dsv>. The source SV may be destroyed if it is mortal, so don't use this
3157 function if the source SV needs to be reused. Does not handle 'set' magic.
3158 Loosely speaking, it performs a copy-by-value, obliterating any previous
3159 content of the destination.
3160 If the C<flags> parameter has the C<SV_GMAGIC> bit set, will C<mg_get> on
3161 C<ssv> if appropriate, else not. If the C<flags> parameter has the
3162 C<NOSTEAL> bit set then the buffers of temps will not be stolen. <sv_setsv>
3163 and C<sv_setsv_nomg> are implemented in terms of this function.
3165 You probably want to use one of the assortment of wrappers, such as
3166 C<SvSetSV>, C<SvSetSV_nosteal>, C<SvSetMagicSV> and
3167 C<SvSetMagicSV_nosteal>.
3169 This is the primary function for copying scalars, and most other
3170 copy-ish functions and macros use this underneath.
3176 S_glob_assign_glob(pTHX_ SV *dstr, SV *sstr, const int dtype)
3178 if (dtype != SVt_PVGV) {
3179 const char * const name = GvNAME(sstr);
3180 const STRLEN len = GvNAMELEN(sstr);
3181 /* don't upgrade SVt_PVLV: it can hold a glob */
3182 if (dtype != SVt_PVLV) {
3183 if (dtype >= SVt_PV) {
3189 sv_upgrade(dstr, SVt_PVGV);
3190 (void)SvOK_off(dstr);
3193 GvSTASH(dstr) = GvSTASH(sstr);
3195 Perl_sv_add_backref(aTHX_ (SV*)GvSTASH(dstr), dstr);
3196 gv_name_set((GV *)dstr, name, len, GV_ADD);
3197 SvFAKE_on(dstr); /* can coerce to non-glob */
3200 #ifdef GV_UNIQUE_CHECK
3201 if (GvUNIQUE((GV*)dstr)) {
3202 Perl_croak(aTHX_ PL_no_modify);
3208 (void)SvOK_off(dstr);
3210 GvINTRO_off(dstr); /* one-shot flag */
3211 GvGP(dstr) = gp_ref(GvGP(sstr));
3212 if (SvTAINTED(sstr))
3214 if (GvIMPORTED(dstr) != GVf_IMPORTED
3215 && CopSTASH_ne(PL_curcop, GvSTASH(dstr)))
3217 GvIMPORTED_on(dstr);
3224 S_glob_assign_ref(pTHX_ SV *dstr, SV *sstr) {
3225 SV * const sref = SvREFCNT_inc(SvRV(sstr));
3227 const int intro = GvINTRO(dstr);
3230 const U32 stype = SvTYPE(sref);
3233 #ifdef GV_UNIQUE_CHECK
3234 if (GvUNIQUE((GV*)dstr)) {
3235 Perl_croak(aTHX_ PL_no_modify);
3240 GvINTRO_off(dstr); /* one-shot flag */
3241 GvLINE(dstr) = CopLINE(PL_curcop);
3242 GvEGV(dstr) = (GV*)dstr;
3247 location = (SV **) &GvCV(dstr);
3248 import_flag = GVf_IMPORTED_CV;
3251 location = (SV **) &GvHV(dstr);
3252 import_flag = GVf_IMPORTED_HV;
3255 location = (SV **) &GvAV(dstr);
3256 import_flag = GVf_IMPORTED_AV;
3259 location = (SV **) &GvIOp(dstr);
3262 location = (SV **) &GvFORM(dstr);
3264 location = &GvSV(dstr);
3265 import_flag = GVf_IMPORTED_SV;
3268 if (stype == SVt_PVCV) {
3269 if (GvCVGEN(dstr) && GvCV(dstr) != (CV*)sref) {
3270 SvREFCNT_dec(GvCV(dstr));
3272 GvCVGEN(dstr) = 0; /* Switch off cacheness. */
3273 PL_sub_generation++;
3276 SAVEGENERICSV(*location);
3280 if (stype == SVt_PVCV && *location != sref) {
3281 CV* const cv = (CV*)*location;
3283 if (!GvCVGEN((GV*)dstr) &&
3284 (CvROOT(cv) || CvXSUB(cv)))
3286 /* Redefining a sub - warning is mandatory if
3287 it was a const and its value changed. */
3288 if (CvCONST(cv) && CvCONST((CV*)sref)
3289 && cv_const_sv(cv) == cv_const_sv((CV*)sref)) {
3291 /* They are 2 constant subroutines generated from
3292 the same constant. This probably means that
3293 they are really the "same" proxy subroutine
3294 instantiated in 2 places. Most likely this is
3295 when a constant is exported twice. Don't warn.
3298 else if (ckWARN(WARN_REDEFINE)
3300 && (!CvCONST((CV*)sref)
3301 || sv_cmp(cv_const_sv(cv),
3302 cv_const_sv((CV*)sref))))) {
3303 Perl_warner(aTHX_ packWARN(WARN_REDEFINE),
3305 ? "Constant subroutine %s::%s redefined"
3306 : "Subroutine %s::%s redefined",
3307 HvNAME_get(GvSTASH((GV*)dstr)),
3308 GvENAME((GV*)dstr));
3312 cv_ckproto(cv, (GV*)dstr,
3313 SvPOK(sref) ? SvPVX_const(sref) : NULL);
3315 GvCVGEN(dstr) = 0; /* Switch off cacheness. */
3316 GvASSUMECV_on(dstr);
3317 PL_sub_generation++;
3320 if (import_flag && !(GvFLAGS(dstr) & import_flag)
3321 && CopSTASH_ne(PL_curcop, GvSTASH(dstr))) {
3322 GvFLAGS(dstr) |= import_flag;
3327 if (SvTAINTED(sstr))
3333 Perl_sv_setsv_flags(pTHX_ SV *dstr, register SV *sstr, I32 flags)
3336 register U32 sflags;
3342 SV_CHECK_THINKFIRST_COW_DROP(dstr);
3344 sstr = &PL_sv_undef;
3345 stype = SvTYPE(sstr);
3346 dtype = SvTYPE(dstr);
3351 /* need to nuke the magic */
3353 SvRMAGICAL_off(dstr);
3356 /* There's a lot of redundancy below but we're going for speed here */
3361 if (dtype != SVt_PVGV) {
3362 (void)SvOK_off(dstr);
3370 sv_upgrade(dstr, SVt_IV);
3375 sv_upgrade(dstr, SVt_PVIV);
3378 (void)SvIOK_only(dstr);
3379 SvIV_set(dstr, SvIVX(sstr));
3382 /* SvTAINTED can only be true if the SV has taint magic, which in
3383 turn means that the SV type is PVMG (or greater). This is the
3384 case statement for SVt_IV, so this cannot be true (whatever gcov
3386 assert(!SvTAINTED(sstr));
3396 sv_upgrade(dstr, SVt_NV);
3401 sv_upgrade(dstr, SVt_PVNV);
3404 SvNV_set(dstr, SvNVX(sstr));
3405 (void)SvNOK_only(dstr);
3406 /* SvTAINTED can only be true if the SV has taint magic, which in
3407 turn means that the SV type is PVMG (or greater). This is the
3408 case statement for SVt_NV, so this cannot be true (whatever gcov
3410 assert(!SvTAINTED(sstr));
3417 sv_upgrade(dstr, SVt_RV);
3420 #ifdef PERL_OLD_COPY_ON_WRITE
3421 if ((SvFLAGS(sstr) & CAN_COW_MASK) == CAN_COW_FLAGS) {
3422 if (dtype < SVt_PVIV)
3423 sv_upgrade(dstr, SVt_PVIV);
3430 sv_upgrade(dstr, SVt_PV);
3433 if (dtype < SVt_PVIV)
3434 sv_upgrade(dstr, SVt_PVIV);
3437 if (dtype < SVt_PVNV)
3438 sv_upgrade(dstr, SVt_PVNV);
3442 const char * const type = sv_reftype(sstr,0);
3444 Perl_croak(aTHX_ "Bizarre copy of %s in %s", type, OP_NAME(PL_op));
3446 Perl_croak(aTHX_ "Bizarre copy of %s", type);
3451 if (dtype <= SVt_PVGV) {
3452 glob_assign_glob(dstr, sstr, dtype);
3460 if (SvGMAGICAL(sstr) && (flags & SV_GMAGIC)) {
3462 if ((int)SvTYPE(sstr) != stype) {
3463 stype = SvTYPE(sstr);
3464 if (stype == SVt_PVGV && dtype <= SVt_PVGV) {
3465 glob_assign_glob(dstr, sstr, dtype);
3470 if (stype == SVt_PVLV)
3471 SvUPGRADE(dstr, SVt_PVNV);
3473 SvUPGRADE(dstr, (U32)stype);
3476 /* dstr may have been upgraded. */
3477 dtype = SvTYPE(dstr);
3478 sflags = SvFLAGS(sstr);
3480 if (sflags & SVf_ROK) {
3481 if (dtype == SVt_PVGV &&
3482 SvROK(sstr) && SvTYPE(SvRV(sstr)) == SVt_PVGV) {
3485 if (GvIMPORTED(dstr) != GVf_IMPORTED
3486 && CopSTASH_ne(PL_curcop, GvSTASH(dstr)))
3488 GvIMPORTED_on(dstr);
3493 glob_assign_glob(dstr, sstr, dtype);
3497 if (dtype >= SVt_PV) {
3498 if (dtype == SVt_PVGV) {
3499 glob_assign_ref(dstr, sstr);
3502 if (SvPVX_const(dstr)) {
3508 (void)SvOK_off(dstr);
3509 SvRV_set(dstr, SvREFCNT_inc(SvRV(sstr)));
3510 SvFLAGS(dstr) |= sflags & (SVf_ROK|SVf_AMAGIC);
3511 assert(!(sflags & SVp_NOK));
3512 assert(!(sflags & SVp_IOK));
3513 assert(!(sflags & SVf_NOK));
3514 assert(!(sflags & SVf_IOK));
3516 else if (dtype == SVt_PVGV) {
3517 if (!(sflags & SVf_OK)) {
3518 if (ckWARN(WARN_MISC))
3519 Perl_warner(aTHX_ packWARN(WARN_MISC),
3520 "Undefined value assigned to typeglob");
3523 GV *gv = gv_fetchsv(sstr, GV_ADD, SVt_PVGV);
3524 if (dstr != (SV*)gv) {
3527 GvGP(dstr) = gp_ref(GvGP(gv));
3531 else if (sflags & SVp_POK) {
3535 * Check to see if we can just swipe the string. If so, it's a
3536 * possible small lose on short strings, but a big win on long ones.
3537 * It might even be a win on short strings if SvPVX_const(dstr)
3538 * has to be allocated and SvPVX_const(sstr) has to be freed.
3541 /* Whichever path we take through the next code, we want this true,
3542 and doing it now facilitates the COW check. */
3543 (void)SvPOK_only(dstr);
3546 /* We're not already COW */
3547 ((sflags & (SVf_FAKE | SVf_READONLY)) != (SVf_FAKE | SVf_READONLY)
3548 #ifndef PERL_OLD_COPY_ON_WRITE
3549 /* or we are, but dstr isn't a suitable target. */
3550 || (SvFLAGS(dstr) & CAN_COW_MASK) != CAN_COW_FLAGS
3555 (sflags & SVs_TEMP) && /* slated for free anyway? */
3556 !(sflags & SVf_OOK) && /* and not involved in OOK hack? */
3557 (!(flags & SV_NOSTEAL)) &&
3558 /* and we're allowed to steal temps */
3559 SvREFCNT(sstr) == 1 && /* and no other references to it? */
3560 SvLEN(sstr) && /* and really is a string */
3561 /* and won't be needed again, potentially */
3562 !(PL_op && PL_op->op_type == OP_AASSIGN))
3563 #ifdef PERL_OLD_COPY_ON_WRITE
3564 && !((sflags & CAN_COW_MASK) == CAN_COW_FLAGS
3565 && (SvFLAGS(dstr) & CAN_COW_MASK) == CAN_COW_FLAGS
3566 && SvTYPE(sstr) >= SVt_PVIV)
3569 /* Failed the swipe test, and it's not a shared hash key either.
3570 Have to copy the string. */
3571 STRLEN len = SvCUR(sstr);
3572 SvGROW(dstr, len + 1); /* inlined from sv_setpvn */
3573 Move(SvPVX_const(sstr),SvPVX(dstr),len,char);
3574 SvCUR_set(dstr, len);
3575 *SvEND(dstr) = '\0';
3577 /* If PERL_OLD_COPY_ON_WRITE is not defined, then isSwipe will always
3579 /* Either it's a shared hash key, or it's suitable for
3580 copy-on-write or we can swipe the string. */
3582 PerlIO_printf(Perl_debug_log, "Copy on write: sstr --> dstr\n");
3586 #ifdef PERL_OLD_COPY_ON_WRITE
3588 /* I believe I should acquire a global SV mutex if
3589 it's a COW sv (not a shared hash key) to stop
3590 it going un copy-on-write.
3591 If the source SV has gone un copy on write between up there
3592 and down here, then (assert() that) it is of the correct
3593 form to make it copy on write again */
3594 if ((sflags & (SVf_FAKE | SVf_READONLY))
3595 != (SVf_FAKE | SVf_READONLY)) {
3596 SvREADONLY_on(sstr);
3598 /* Make the source SV into a loop of 1.
3599 (about to become 2) */
3600 SV_COW_NEXT_SV_SET(sstr, sstr);
3604 /* Initial code is common. */
3605 if (SvPVX_const(dstr)) { /* we know that dtype >= SVt_PV */
3610 /* making another shared SV. */
3611 STRLEN cur = SvCUR(sstr);
3612 STRLEN len = SvLEN(sstr);
3613 #ifdef PERL_OLD_COPY_ON_WRITE
3615 assert (SvTYPE(dstr) >= SVt_PVIV);
3616 /* SvIsCOW_normal */
3617 /* splice us in between source and next-after-source. */
3618 SV_COW_NEXT_SV_SET(dstr, SV_COW_NEXT_SV(sstr));
3619 SV_COW_NEXT_SV_SET(sstr, dstr);
3620 SvPV_set(dstr, SvPVX_mutable(sstr));
3624 /* SvIsCOW_shared_hash */
3625 DEBUG_C(PerlIO_printf(Perl_debug_log,
3626 "Copy on write: Sharing hash\n"));
3628 assert (SvTYPE(dstr) >= SVt_PV);
3630 HEK_KEY(share_hek_hek(SvSHARED_HEK_FROM_PV(SvPVX_const(sstr)))));
3632 SvLEN_set(dstr, len);
3633 SvCUR_set(dstr, cur);
3634 SvREADONLY_on(dstr);
3636 /* Relesase a global SV mutex. */
3639 { /* Passes the swipe test. */
3640 SvPV_set(dstr, SvPVX_mutable(sstr));
3641 SvLEN_set(dstr, SvLEN(sstr));
3642 SvCUR_set(dstr, SvCUR(sstr));
3645 (void)SvOK_off(sstr); /* NOTE: nukes most SvFLAGS on sstr */
3646 SvPV_set(sstr, NULL);
3652 if (sflags & SVp_NOK) {
3653 SvNV_set(dstr, SvNVX(sstr));
3655 if (sflags & SVp_IOK) {
3656 SvRELEASE_IVX(dstr);
3657 SvIV_set(dstr, SvIVX(sstr));
3658 /* Must do this otherwise some other overloaded use of 0x80000000
3659 gets confused. I guess SVpbm_VALID */
3660 if (sflags & SVf_IVisUV)
3663 SvFLAGS(dstr) |= sflags & (SVf_IOK|SVp_IOK|SVf_NOK|SVp_NOK|SVf_UTF8
3666 const MAGIC * const smg = SvVOK(sstr);
3668 sv_magic(dstr, NULL, PERL_MAGIC_vstring,
3669 smg->mg_ptr, smg->mg_len);
3670 SvRMAGICAL_on(dstr);
3674 else if (sflags & (SVp_IOK|SVp_NOK)) {
3675 (void)SvOK_off(dstr);
3676 SvFLAGS(dstr) |= sflags & (SVf_IOK|SVp_IOK|SVf_IVisUV|SVf_NOK|SVp_NOK
3678 if (sflags & SVp_IOK) {
3679 /* XXXX Do we want to set IsUV for IV(ROK)? Be extra safe... */
3680 SvIV_set(dstr, SvIVX(sstr));
3682 if (sflags & SVp_NOK) {
3683 SvNV_set(dstr, SvNVX(sstr));
3687 if (isGV_with_GP(sstr)) {
3688 /* This stringification rule for globs is spread in 3 places.
3689 This feels bad. FIXME. */
3690 const U32 wasfake = sflags & SVf_FAKE;
3692 /* FAKE globs can get coerced, so need to turn this off
3693 temporarily if it is on. */
3695 gv_efullname3(dstr, (GV *)sstr, "*");
3696 SvFLAGS(sstr) |= wasfake;
3697 SvFLAGS(dstr) |= sflags & SVf_AMAGIC;
3700 (void)SvOK_off(dstr);
3702 if (SvTAINTED(sstr))
3707 =for apidoc sv_setsv_mg
3709 Like C<sv_setsv>, but also handles 'set' magic.
3715 Perl_sv_setsv_mg(pTHX_ SV *dstr, register SV *sstr)
3717 sv_setsv(dstr,sstr);
3721 #ifdef PERL_OLD_COPY_ON_WRITE
3723 Perl_sv_setsv_cow(pTHX_ SV *dstr, SV *sstr)
3725 STRLEN cur = SvCUR(sstr);
3726 STRLEN len = SvLEN(sstr);
3727 register char *new_pv;
3730 PerlIO_printf(Perl_debug_log, "Fast copy on write: %p -> %p\n",
3738 if (SvTHINKFIRST(dstr))
3739 sv_force_normal_flags(dstr, SV_COW_DROP_PV);
3740 else if (SvPVX_const(dstr))
3741 Safefree(SvPVX_const(dstr));
3745 SvUPGRADE(dstr, SVt_PVIV);
3747 assert (SvPOK(sstr));
3748 assert (SvPOKp(sstr));
3749 assert (!SvIOK(sstr));
3750 assert (!SvIOKp(sstr));
3751 assert (!SvNOK(sstr));
3752 assert (!SvNOKp(sstr));
3754 if (SvIsCOW(sstr)) {
3756 if (SvLEN(sstr) == 0) {
3757 /* source is a COW shared hash key. */
3758 DEBUG_C(PerlIO_printf(Perl_debug_log,
3759 "Fast copy on write: Sharing hash\n"));
3760 new_pv = HEK_KEY(share_hek_hek(SvSHARED_HEK_FROM_PV(SvPVX_const(sstr))));
3763 SV_COW_NEXT_SV_SET(dstr, SV_COW_NEXT_SV(sstr));
3765 assert ((SvFLAGS(sstr) & CAN_COW_MASK) == CAN_COW_FLAGS);
3766 SvUPGRADE(sstr, SVt_PVIV);
3767 SvREADONLY_on(sstr);
3769 DEBUG_C(PerlIO_printf(Perl_debug_log,
3770 "Fast copy on write: Converting sstr to COW\n"));
3771 SV_COW_NEXT_SV_SET(dstr, sstr);
3773 SV_COW_NEXT_SV_SET(sstr, dstr);
3774 new_pv = SvPVX_mutable(sstr);
3777 SvPV_set(dstr, new_pv);
3778 SvFLAGS(dstr) = (SVt_PVIV|SVf_POK|SVp_POK|SVf_FAKE|SVf_READONLY);
3781 SvLEN_set(dstr, len);
3782 SvCUR_set(dstr, cur);
3791 =for apidoc sv_setpvn
3793 Copies a string into an SV. The C<len> parameter indicates the number of
3794 bytes to be copied. If the C<ptr> argument is NULL the SV will become
3795 undefined. Does not handle 'set' magic. See C<sv_setpvn_mg>.
3801 Perl_sv_setpvn(pTHX_ register SV *sv, register const char *ptr, register STRLEN len)
3804 register char *dptr;
3806 SV_CHECK_THINKFIRST_COW_DROP(sv);
3812 /* len is STRLEN which is unsigned, need to copy to signed */
3815 Perl_croak(aTHX_ "panic: sv_setpvn called with negative strlen");
3817 SvUPGRADE(sv, SVt_PV);
3819 dptr = SvGROW(sv, len + 1);
3820 Move(ptr,dptr,len,char);
3823 (void)SvPOK_only_UTF8(sv); /* validate pointer */
3828 =for apidoc sv_setpvn_mg
3830 Like C<sv_setpvn>, but also handles 'set' magic.
3836 Perl_sv_setpvn_mg(pTHX_ register SV *sv, register const char *ptr, register STRLEN len)
3838 sv_setpvn(sv,ptr,len);
3843 =for apidoc sv_setpv
3845 Copies a string into an SV. The string must be null-terminated. Does not
3846 handle 'set' magic. See C<sv_setpv_mg>.
3852 Perl_sv_setpv(pTHX_ register SV *sv, register const char *ptr)
3855 register STRLEN len;
3857 SV_CHECK_THINKFIRST_COW_DROP(sv);
3863 SvUPGRADE(sv, SVt_PV);
3865 SvGROW(sv, len + 1);
3866 Move(ptr,SvPVX(sv),len+1,char);
3868 (void)SvPOK_only_UTF8(sv); /* validate pointer */
3873 =for apidoc sv_setpv_mg
3875 Like C<sv_setpv>, but also handles 'set' magic.
3881 Perl_sv_setpv_mg(pTHX_ register SV *sv, register const char *ptr)
3888 =for apidoc sv_usepvn
3890 Tells an SV to use C<ptr> to find its string value. Normally the
3891 string is stored inside the SV but sv_usepvn allows the SV to use an
3892 outside string. The C<ptr> should point to memory that was allocated
3893 by C<malloc>. The string length, C<len>, must be supplied. This
3894 function will realloc (i.e. move) the memory pointed to by C<ptr>,
3895 so that pointer should not be freed or used by the programmer after
3896 giving it to sv_usepvn, and neither should any pointers from "behind"
3897 that pointer (e.g. ptr + 1) be used. Does not handle 'set' magic.
3898 See C<sv_usepvn_mg>.
3904 Perl_sv_usepvn(pTHX_ register SV *sv, register char *ptr, register STRLEN len)
3908 SV_CHECK_THINKFIRST_COW_DROP(sv);
3909 SvUPGRADE(sv, SVt_PV);
3914 if (SvPVX_const(sv))
3917 allocate = PERL_STRLEN_ROUNDUP(len + 1);
3918 ptr = saferealloc (ptr, allocate);
3921 SvLEN_set(sv, allocate);
3923 (void)SvPOK_only_UTF8(sv); /* validate pointer */
3928 =for apidoc sv_usepvn_mg
3930 Like C<sv_usepvn>, but also handles 'set' magic.
3936 Perl_sv_usepvn_mg(pTHX_ register SV *sv, register char *ptr, register STRLEN len)
3938 sv_usepvn(sv,ptr,len);
3942 #ifdef PERL_OLD_COPY_ON_WRITE
3943 /* Need to do this *after* making the SV normal, as we need the buffer
3944 pointer to remain valid until after we've copied it. If we let go too early,
3945 another thread could invalidate it by unsharing last of the same hash key
3946 (which it can do by means other than releasing copy-on-write Svs)
3947 or by changing the other copy-on-write SVs in the loop. */
3949 S_sv_release_COW(pTHX_ register SV *sv, const char *pvx, STRLEN len, SV *after)
3951 if (len) { /* this SV was SvIsCOW_normal(sv) */
3952 /* we need to find the SV pointing to us. */
3953 SV *current = SV_COW_NEXT_SV(after);
3955 if (current == sv) {
3956 /* The SV we point to points back to us (there were only two of us
3958 Hence other SV is no longer copy on write either. */
3960 SvREADONLY_off(after);
3962 /* We need to follow the pointers around the loop. */
3964 while ((next = SV_COW_NEXT_SV(current)) != sv) {
3967 /* don't loop forever if the structure is bust, and we have
3968 a pointer into a closed loop. */
3969 assert (current != after);
3970 assert (SvPVX_const(current) == pvx);
3972 /* Make the SV before us point to the SV after us. */
3973 SV_COW_NEXT_SV_SET(current, after);
3976 unshare_hek(SvSHARED_HEK_FROM_PV(pvx));
3981 Perl_sv_release_IVX(pTHX_ register SV *sv)
3984 sv_force_normal_flags(sv, 0);
3990 =for apidoc sv_force_normal_flags
3992 Undo various types of fakery on an SV: if the PV is a shared string, make
3993 a private copy; if we're a ref, stop refing; if we're a glob, downgrade to
3994 an xpvmg; if we're a copy-on-write scalar, this is the on-write time when
3995 we do the copy, and is also used locally. If C<SV_COW_DROP_PV> is set
3996 then a copy-on-write scalar drops its PV buffer (if any) and becomes
3997 SvPOK_off rather than making a copy. (Used where this scalar is about to be
3998 set to some other value.) In addition, the C<flags> parameter gets passed to
3999 C<sv_unref_flags()> when unrefing. C<sv_force_normal> calls this function
4000 with flags set to 0.
4006 Perl_sv_force_normal_flags(pTHX_ register SV *sv, U32 flags)
4009 #ifdef PERL_OLD_COPY_ON_WRITE
4010 if (SvREADONLY(sv)) {
4011 /* At this point I believe I should acquire a global SV mutex. */
4013 const char * const pvx = SvPVX_const(sv);
4014 const STRLEN len = SvLEN(sv);
4015 const STRLEN cur = SvCUR(sv);
4016 SV * const next = SV_COW_NEXT_SV(sv); /* next COW sv in the loop. */
4018 PerlIO_printf(Perl_debug_log,
4019 "Copy on write: Force normal %ld\n",
4025 /* This SV doesn't own the buffer, so need to Newx() a new one: */
4028 if (flags & SV_COW_DROP_PV) {
4029 /* OK, so we don't need to copy our buffer. */
4032 SvGROW(sv, cur + 1);
4033 Move(pvx,SvPVX(sv),cur,char);
4037 sv_release_COW(sv, pvx, len, next);
4042 else if (IN_PERL_RUNTIME)
4043 Perl_croak(aTHX_ PL_no_modify);
4044 /* At this point I believe that I can drop the global SV mutex. */
4047 if (SvREADONLY(sv)) {
4049 const char * const pvx = SvPVX_const(sv);
4050 const STRLEN len = SvCUR(sv);
4055 SvGROW(sv, len + 1);
4056 Move(pvx,SvPVX(sv),len,char);
4058 unshare_hek(SvSHARED_HEK_FROM_PV(pvx));
4060 else if (IN_PERL_RUNTIME)
4061 Perl_croak(aTHX_ PL_no_modify);
4065 sv_unref_flags(sv, flags);
4066 else if (SvFAKE(sv) && SvTYPE(sv) == SVt_PVGV)
4073 Efficient removal of characters from the beginning of the string buffer.
4074 SvPOK(sv) must be true and the C<ptr> must be a pointer to somewhere inside
4075 the string buffer. The C<ptr> becomes the first character of the adjusted
4076 string. Uses the "OOK hack".
4077 Beware: after this function returns, C<ptr> and SvPVX_const(sv) may no longer
4078 refer to the same chunk of data.
4084 Perl_sv_chop(pTHX_ register SV *sv, register const char *ptr)
4086 register STRLEN delta;
4087 if (!ptr || !SvPOKp(sv))
4089 delta = ptr - SvPVX_const(sv);
4090 SV_CHECK_THINKFIRST(sv);
4091 if (SvTYPE(sv) < SVt_PVIV)
4092 sv_upgrade(sv,SVt_PVIV);
4095 if (!SvLEN(sv)) { /* make copy of shared string */
4096 const char *pvx = SvPVX_const(sv);
4097 const STRLEN len = SvCUR(sv);
4098 SvGROW(sv, len + 1);
4099 Move(pvx,SvPVX(sv),len,char);
4103 /* Same SvOOK_on but SvOOK_on does a SvIOK_off
4104 and we do that anyway inside the SvNIOK_off
4106 SvFLAGS(sv) |= SVf_OOK;
4109 SvLEN_set(sv, SvLEN(sv) - delta);
4110 SvCUR_set(sv, SvCUR(sv) - delta);
4111 SvPV_set(sv, SvPVX(sv) + delta);
4112 SvIV_set(sv, SvIVX(sv) + delta);
4116 =for apidoc sv_catpvn
4118 Concatenates the string onto the end of the string which is in the SV. The
4119 C<len> indicates number of bytes to copy. If the SV has the UTF-8
4120 status set, then the bytes appended should be valid UTF-8.
4121 Handles 'get' magic, but not 'set' magic. See C<sv_catpvn_mg>.
4123 =for apidoc sv_catpvn_flags
4125 Concatenates the string onto the end of the string which is in the SV. The
4126 C<len> indicates number of bytes to copy. If the SV has the UTF-8
4127 status set, then the bytes appended should be valid UTF-8.
4128 If C<flags> has C<SV_GMAGIC> bit set, will C<mg_get> on C<dsv> if
4129 appropriate, else not. C<sv_catpvn> and C<sv_catpvn_nomg> are implemented
4130 in terms of this function.
4136 Perl_sv_catpvn_flags(pTHX_ register SV *dsv, register const char *sstr, register STRLEN slen, I32 flags)
4140 const char * const dstr = SvPV_force_flags(dsv, dlen, flags);
4142 SvGROW(dsv, dlen + slen + 1);
4144 sstr = SvPVX_const(dsv);
4145 Move(sstr, SvPVX(dsv) + dlen, slen, char);
4146 SvCUR_set(dsv, SvCUR(dsv) + slen);
4148 (void)SvPOK_only_UTF8(dsv); /* validate pointer */
4150 if (flags & SV_SMAGIC)
4155 =for apidoc sv_catsv
4157 Concatenates the string from SV C<ssv> onto the end of the string in
4158 SV C<dsv>. Modifies C<dsv> but not C<ssv>. Handles 'get' magic, but
4159 not 'set' magic. See C<sv_catsv_mg>.
4161 =for apidoc sv_catsv_flags
4163 Concatenates the string from SV C<ssv> onto the end of the string in
4164 SV C<dsv>. Modifies C<dsv> but not C<ssv>. If C<flags> has C<SV_GMAGIC>
4165 bit set, will C<mg_get> on the SVs if appropriate, else not. C<sv_catsv>
4166 and C<sv_catsv_nomg> are implemented in terms of this function.
4171 Perl_sv_catsv_flags(pTHX_ SV *dsv, register SV *ssv, I32 flags)
4176 const char *spv = SvPV_const(ssv, slen);
4178 /* sutf8 and dutf8 were type bool, but under USE_ITHREADS,
4179 gcc version 2.95.2 20000220 (Debian GNU/Linux) for
4180 Linux xxx 2.2.17 on sparc64 with gcc -O2, we erroneously
4181 get dutf8 = 0x20000000, (i.e. SVf_UTF8) even though
4182 dsv->sv_flags doesn't have that bit set.
4183 Andy Dougherty 12 Oct 2001
4185 const I32 sutf8 = DO_UTF8(ssv);
4188 if (SvGMAGICAL(dsv) && (flags & SV_GMAGIC))
4190 dutf8 = DO_UTF8(dsv);
4192 if (dutf8 != sutf8) {
4194 /* Not modifying source SV, so taking a temporary copy. */
4195 SV* const csv = sv_2mortal(newSVpvn(spv, slen));
4197 sv_utf8_upgrade(csv);
4198 spv = SvPV_const(csv, slen);
4201 sv_utf8_upgrade_nomg(dsv);
4203 sv_catpvn_nomg(dsv, spv, slen);
4206 if (flags & SV_SMAGIC)
4211 =for apidoc sv_catpv
4213 Concatenates the string onto the end of the string which is in the SV.
4214 If the SV has the UTF-8 status set, then the bytes appended should be
4215 valid UTF-8. Handles 'get' magic, but not 'set' magic. See C<sv_catpv_mg>.
4220 Perl_sv_catpv(pTHX_ register SV *sv, register const char *ptr)
4223 register STRLEN len;
4229 junk = SvPV_force(sv, tlen);
4231 SvGROW(sv, tlen + len + 1);
4233 ptr = SvPVX_const(sv);
4234 Move(ptr,SvPVX(sv)+tlen,len+1,char);
4235 SvCUR_set(sv, SvCUR(sv) + len);
4236 (void)SvPOK_only_UTF8(sv); /* validate pointer */
4241 =for apidoc sv_catpv_mg
4243 Like C<sv_catpv>, but also handles 'set' magic.
4249 Perl_sv_catpv_mg(pTHX_ register SV *sv, register const char *ptr)
4258 Creates a new SV. A non-zero C<len> parameter indicates the number of
4259 bytes of preallocated string space the SV should have. An extra byte for a
4260 trailing NUL is also reserved. (SvPOK is not set for the SV even if string
4261 space is allocated.) The reference count for the new SV is set to 1.
4263 In 5.9.3, newSV() replaces the older NEWSV() API, and drops the first
4264 parameter, I<x>, a debug aid which allowed callers to identify themselves.
4265 This aid has been superseded by a new build option, PERL_MEM_LOG (see
4266 L<perlhack/PERL_MEM_LOG>). The older API is still there for use in XS
4267 modules supporting older perls.
4273 Perl_newSV(pTHX_ STRLEN len)
4280 sv_upgrade(sv, SVt_PV);
4281 SvGROW(sv, len + 1);
4286 =for apidoc sv_magicext
4288 Adds magic to an SV, upgrading it if necessary. Applies the
4289 supplied vtable and returns a pointer to the magic added.
4291 Note that C<sv_magicext> will allow things that C<sv_magic> will not.
4292 In particular, you can add magic to SvREADONLY SVs, and add more than
4293 one instance of the same 'how'.
4295 If C<namlen> is greater than zero then a C<savepvn> I<copy> of C<name> is
4296 stored, if C<namlen> is zero then C<name> is stored as-is and - as another
4297 special case - if C<(name && namlen == HEf_SVKEY)> then C<name> is assumed
4298 to contain an C<SV*> and is stored as-is with its REFCNT incremented.
4300 (This is now used as a subroutine by C<sv_magic>.)
4305 Perl_sv_magicext(pTHX_ SV* sv, SV* obj, int how, MGVTBL *vtable,
4306 const char* name, I32 namlen)
4311 if (SvTYPE(sv) < SVt_PVMG) {
4312 SvUPGRADE(sv, SVt_PVMG);
4314 Newxz(mg, 1, MAGIC);
4315 mg->mg_moremagic = SvMAGIC(sv);
4316 SvMAGIC_set(sv, mg);
4318 /* Sometimes a magic contains a reference loop, where the sv and
4319 object refer to each other. To prevent a reference loop that
4320 would prevent such objects being freed, we look for such loops
4321 and if we find one we avoid incrementing the object refcount.
4323 Note we cannot do this to avoid self-tie loops as intervening RV must
4324 have its REFCNT incremented to keep it in existence.
4327 if (!obj || obj == sv ||
4328 how == PERL_MAGIC_arylen ||
4329 how == PERL_MAGIC_qr ||
4330 how == PERL_MAGIC_symtab ||
4331 (SvTYPE(obj) == SVt_PVGV &&
4332 (GvSV(obj) == sv || GvHV(obj) == (HV*)sv || GvAV(obj) == (AV*)sv ||
4333 GvCV(obj) == (CV*)sv || GvIOp(obj) == (IO*)sv ||
4334 GvFORM(obj) == (CV*)sv)))
4339 mg->mg_obj = SvREFCNT_inc_simple(obj);
4340 mg->mg_flags |= MGf_REFCOUNTED;
4343 /* Normal self-ties simply pass a null object, and instead of
4344 using mg_obj directly, use the SvTIED_obj macro to produce a
4345 new RV as needed. For glob "self-ties", we are tieing the PVIO
4346 with an RV obj pointing to the glob containing the PVIO. In
4347 this case, to avoid a reference loop, we need to weaken the
4351 if (how == PERL_MAGIC_tiedscalar && SvTYPE(sv) == SVt_PVIO &&
4352 obj && SvROK(obj) && GvIO(SvRV(obj)) == (IO*)sv)
4358 mg->mg_len = namlen;
4361 mg->mg_ptr = savepvn(name, namlen);
4362 else if (namlen == HEf_SVKEY)
4363 mg->mg_ptr = (char*)SvREFCNT_inc_simple_NN((SV*)name);
4365 mg->mg_ptr = (char *) name;
4367 mg->mg_virtual = vtable;
4371 SvFLAGS(sv) &= ~(SVf_IOK|SVf_NOK|SVf_POK);
4376 =for apidoc sv_magic
4378 Adds magic to an SV. First upgrades C<sv> to type C<SVt_PVMG> if necessary,
4379 then adds a new magic item of type C<how> to the head of the magic list.
4381 See C<sv_magicext> (which C<sv_magic> now calls) for a description of the
4382 handling of the C<name> and C<namlen> arguments.
4384 You need to use C<sv_magicext> to add magic to SvREADONLY SVs and also
4385 to add more than one instance of the same 'how'.
4391 Perl_sv_magic(pTHX_ register SV *sv, SV *obj, int how, const char *name, I32 namlen)
4397 #ifdef PERL_OLD_COPY_ON_WRITE
4399 sv_force_normal_flags(sv, 0);
4401 if (SvREADONLY(sv)) {
4403 /* its okay to attach magic to shared strings; the subsequent
4404 * upgrade to PVMG will unshare the string */
4405 !(SvFAKE(sv) && SvTYPE(sv) < SVt_PVMG)
4408 && how != PERL_MAGIC_regex_global
4409 && how != PERL_MAGIC_bm
4410 && how != PERL_MAGIC_fm
4411 && how != PERL_MAGIC_sv
4412 && how != PERL_MAGIC_backref
4415 Perl_croak(aTHX_ PL_no_modify);
4418 if (SvMAGICAL(sv) || (how == PERL_MAGIC_taint && SvTYPE(sv) >= SVt_PVMG)) {
4419 if (SvMAGIC(sv) && (mg = mg_find(sv, how))) {
4420 /* sv_magic() refuses to add a magic of the same 'how' as an
4423 if (how == PERL_MAGIC_taint) {
4425 /* Any scalar which already had taint magic on which someone
4426 (erroneously?) did SvIOK_on() or similar will now be
4427 incorrectly sporting public "OK" flags. */
4428 SvFLAGS(sv) &= ~(SVf_IOK|SVf_NOK|SVf_POK);
4436 vtable = &PL_vtbl_sv;
4438 case PERL_MAGIC_overload:
4439 vtable = &PL_vtbl_amagic;
4441 case PERL_MAGIC_overload_elem:
4442 vtable = &PL_vtbl_amagicelem;
4444 case PERL_MAGIC_overload_table:
4445 vtable = &PL_vtbl_ovrld;
4448 vtable = &PL_vtbl_bm;
4450 case PERL_MAGIC_regdata:
4451 vtable = &PL_vtbl_regdata;
4453 case PERL_MAGIC_regdatum:
4454 vtable = &PL_vtbl_regdatum;
4456 case PERL_MAGIC_env:
4457 vtable = &PL_vtbl_env;
4460 vtable = &PL_vtbl_fm;
4462 case PERL_MAGIC_envelem:
4463 vtable = &PL_vtbl_envelem;
4465 case PERL_MAGIC_regex_global:
4466 vtable = &PL_vtbl_mglob;
4468 case PERL_MAGIC_isa:
4469 vtable = &PL_vtbl_isa;
4471 case PERL_MAGIC_isaelem:
4472 vtable = &PL_vtbl_isaelem;
4474 case PERL_MAGIC_nkeys:
4475 vtable = &PL_vtbl_nkeys;
4477 case PERL_MAGIC_dbfile:
4480 case PERL_MAGIC_dbline:
4481 vtable = &PL_vtbl_dbline;
4483 #ifdef USE_LOCALE_COLLATE
4484 case PERL_MAGIC_collxfrm:
4485 vtable = &PL_vtbl_collxfrm;
4487 #endif /* USE_LOCALE_COLLATE */
4488 case PERL_MAGIC_tied:
4489 vtable = &PL_vtbl_pack;
4491 case PERL_MAGIC_tiedelem:
4492 case PERL_MAGIC_tiedscalar:
4493 vtable = &PL_vtbl_packelem;
4496 vtable = &PL_vtbl_regexp;
4498 case PERL_MAGIC_hints:
4499 /* As this vtable is all NULL, we can reuse it. */
4500 case PERL_MAGIC_sig:
4501 vtable = &PL_vtbl_sig;
4503 case PERL_MAGIC_sigelem:
4504 vtable = &PL_vtbl_sigelem;
4506 case PERL_MAGIC_taint:
4507 vtable = &PL_vtbl_taint;
4509 case PERL_MAGIC_uvar:
4510 vtable = &PL_vtbl_uvar;
4512 case PERL_MAGIC_vec:
4513 vtable = &PL_vtbl_vec;
4515 case PERL_MAGIC_arylen_p:
4516 case PERL_MAGIC_rhash:
4517 case PERL_MAGIC_symtab:
4518 case PERL_MAGIC_vstring:
4521 case PERL_MAGIC_utf8:
4522 vtable = &PL_vtbl_utf8;
4524 case PERL_MAGIC_substr:
4525 vtable = &PL_vtbl_substr;
4527 case PERL_MAGIC_defelem:
4528 vtable = &PL_vtbl_defelem;
4530 case PERL_MAGIC_arylen:
4531 vtable = &PL_vtbl_arylen;
4533 case PERL_MAGIC_pos:
4534 vtable = &PL_vtbl_pos;
4536 case PERL_MAGIC_backref:
4537 vtable = &PL_vtbl_backref;
4539 case PERL_MAGIC_hintselem:
4540 vtable = &PL_vtbl_hintselem;
4542 case PERL_MAGIC_ext:
4543 /* Reserved for use by extensions not perl internals. */
4544 /* Useful for attaching extension internal data to perl vars. */
4545 /* Note that multiple extensions may clash if magical scalars */
4546 /* etc holding private data from one are passed to another. */
4550 Perl_croak(aTHX_ "Don't know how to handle magic of type \\%o", how);
4553 /* Rest of work is done else where */
4554 mg = sv_magicext(sv,obj,how,vtable,name,namlen);
4557 case PERL_MAGIC_taint:
4560 case PERL_MAGIC_ext:
4561 case PERL_MAGIC_dbfile:
4568 =for apidoc sv_unmagic
4570 Removes all magic of type C<type> from an SV.
4576 Perl_sv_unmagic(pTHX_ SV *sv, int type)
4580 if (SvTYPE(sv) < SVt_PVMG || !SvMAGIC(sv))
4582 mgp = &(((XPVMG*) SvANY(sv))->xmg_u.xmg_magic);
4583 for (mg = *mgp; mg; mg = *mgp) {
4584 if (mg->mg_type == type) {
4585 const MGVTBL* const vtbl = mg->mg_virtual;
4586 *mgp = mg->mg_moremagic;
4587 if (vtbl && vtbl->svt_free)
4588 CALL_FPTR(vtbl->svt_free)(aTHX_ sv, mg);
4589 if (mg->mg_ptr && mg->mg_type != PERL_MAGIC_regex_global) {
4591 Safefree(mg->mg_ptr);
4592 else if (mg->mg_len == HEf_SVKEY)
4593 SvREFCNT_dec((SV*)mg->mg_ptr);
4594 else if (mg->mg_type == PERL_MAGIC_utf8)
4595 Safefree(mg->mg_ptr);
4597 if (mg->mg_flags & MGf_REFCOUNTED)
4598 SvREFCNT_dec(mg->mg_obj);
4602 mgp = &mg->mg_moremagic;
4606 SvFLAGS(sv) |= (SvFLAGS(sv) & (SVp_IOK|SVp_NOK|SVp_POK)) >> PRIVSHIFT;
4607 SvMAGIC_set(sv, NULL);
4614 =for apidoc sv_rvweaken
4616 Weaken a reference: set the C<SvWEAKREF> flag on this RV; give the
4617 referred-to SV C<PERL_MAGIC_backref> magic if it hasn't already; and
4618 push a back-reference to this RV onto the array of backreferences
4619 associated with that magic.
4625 Perl_sv_rvweaken(pTHX_ SV *sv)
4628 if (!SvOK(sv)) /* let undefs pass */
4631 Perl_croak(aTHX_ "Can't weaken a nonreference");
4632 else if (SvWEAKREF(sv)) {
4633 if (ckWARN(WARN_MISC))
4634 Perl_warner(aTHX_ packWARN(WARN_MISC), "Reference is already weak");
4638 Perl_sv_add_backref(aTHX_ tsv, sv);
4644 /* Give tsv backref magic if it hasn't already got it, then push a
4645 * back-reference to sv onto the array associated with the backref magic.
4649 Perl_sv_add_backref(pTHX_ SV *tsv, SV *sv)
4654 if (SvTYPE(tsv) == SVt_PVHV) {
4655 AV **const avp = Perl_hv_backreferences_p(aTHX_ (HV*)tsv);
4659 /* There is no AV in the offical place - try a fixup. */
4660 MAGIC *const mg = mg_find(tsv, PERL_MAGIC_backref);
4663 /* Aha. They've got it stowed in magic. Bring it back. */
4664 av = (AV*)mg->mg_obj;
4665 /* Stop mg_free decreasing the refernce count. */
4667 /* Stop mg_free even calling the destructor, given that
4668 there's no AV to free up. */
4670 sv_unmagic(tsv, PERL_MAGIC_backref);
4674 SvREFCNT_inc_simple_void(av);
4679 const MAGIC *const mg
4680 = SvMAGICAL(tsv) ? mg_find(tsv, PERL_MAGIC_backref) : NULL;
4682 av = (AV*)mg->mg_obj;
4686 sv_magic(tsv, (SV*)av, PERL_MAGIC_backref, NULL, 0);
4687 /* av now has a refcnt of 2, which avoids it getting freed
4688 * before us during global cleanup. The extra ref is removed
4689 * by magic_killbackrefs() when tsv is being freed */
4692 if (AvFILLp(av) >= AvMAX(av)) {
4693 av_extend(av, AvFILLp(av)+1);
4695 AvARRAY(av)[++AvFILLp(av)] = sv; /* av_push() */
4698 /* delete a back-reference to ourselves from the backref magic associated
4699 * with the SV we point to.
4703 S_sv_del_backref(pTHX_ SV *tsv, SV *sv)
4710 if (SvTYPE(tsv) == SVt_PVHV && SvOOK(tsv)) {
4711 av = *Perl_hv_backreferences_p(aTHX_ (HV*)tsv);
4712 /* We mustn't attempt to "fix up" the hash here by moving the
4713 backreference array back to the hv_aux structure, as that is stored
4714 in the main HvARRAY(), and hfreentries assumes that no-one
4715 reallocates HvARRAY() while it is running. */
4718 const MAGIC *const mg
4719 = SvMAGICAL(tsv) ? mg_find(tsv, PERL_MAGIC_backref) : NULL;
4721 av = (AV *)mg->mg_obj;
4724 if (PL_in_clean_all)
4726 Perl_croak(aTHX_ "panic: del_backref");
4733 /* We shouldn't be in here more than once, but for paranoia reasons lets
4735 for (i = AvFILLp(av); i >= 0; i--) {
4737 const SSize_t fill = AvFILLp(av);
4739 /* We weren't the last entry.
4740 An unordered list has this property that you can take the
4741 last element off the end to fill the hole, and it's still
4742 an unordered list :-)
4747 AvFILLp(av) = fill - 1;
4753 Perl_sv_kill_backrefs(pTHX_ SV *sv, AV *av)
4755 SV **svp = AvARRAY(av);
4757 PERL_UNUSED_ARG(sv);
4759 /* Not sure why the av can get freed ahead of its sv, but somehow it does
4760 in ext/B/t/bytecode.t test 15 (involving print <DATA>) */
4761 if (svp && !SvIS_FREED(av)) {
4762 SV *const *const last = svp + AvFILLp(av);
4764 while (svp <= last) {
4766 SV *const referrer = *svp;
4767 if (SvWEAKREF(referrer)) {
4768 /* XXX Should we check that it hasn't changed? */
4769 SvRV_set(referrer, 0);
4771 SvWEAKREF_off(referrer);
4772 } else if (SvTYPE(referrer) == SVt_PVGV ||
4773 SvTYPE(referrer) == SVt_PVLV) {
4774 /* You lookin' at me? */
4775 assert(GvSTASH(referrer));
4776 assert(GvSTASH(referrer) == (HV*)sv);
4777 GvSTASH(referrer) = 0;
4780 "panic: magic_killbackrefs (flags=%"UVxf")",
4781 (UV)SvFLAGS(referrer));
4789 SvREFCNT_dec(av); /* remove extra count added by sv_add_backref() */
4794 =for apidoc sv_insert
4796 Inserts a string at the specified offset/length within the SV. Similar to
4797 the Perl substr() function.