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)
682 struct arena_desc* adesc;
683 struct arena_set *newroot, **aroot = (struct arena_set**) &PL_body_arenas;
686 /* shouldnt need this
687 if (!arena_size) arena_size = PERL_ARENA_SIZE;
690 /* may need new arena-set to hold new arena */
691 if (!*aroot || (*aroot)->curr >= (*aroot)->set_size) {
692 Newxz(newroot, 1, struct arena_set);
693 newroot->set_size = ARENAS_PER_SET;
694 newroot->next = *aroot;
696 DEBUG_m(PerlIO_printf(Perl_debug_log, "new arenaset %p\n", (void*)*aroot));
699 /* ok, now have arena-set with at least 1 empty/available arena-desc */
700 curr = (*aroot)->curr++;
701 adesc = &((*aroot)->set[curr]);
702 assert(!adesc->arena);
704 Newxz(adesc->arena, arena_size, char);
705 adesc->size = arena_size;
706 DEBUG_m(PerlIO_printf(Perl_debug_log, "arena %d added: %p size %d\n",
707 curr, adesc->arena, arena_size));
713 /* return a thing to the free list */
715 #define del_body(thing, root) \
717 void ** const thing_copy = (void **)thing;\
719 *thing_copy = *root; \
720 *root = (void*)thing_copy; \
726 =head1 SV-Body Allocation
728 Allocation of SV-bodies is similar to SV-heads, differing as follows;
729 the allocation mechanism is used for many body types, so is somewhat
730 more complicated, it uses arena-sets, and has no need for still-live
733 At the outermost level, (new|del)_X*V macros return bodies of the
734 appropriate type. These macros call either (new|del)_body_type or
735 (new|del)_body_allocated macro pairs, depending on specifics of the
736 type. Most body types use the former pair, the latter pair is used to
737 allocate body types with "ghost fields".
739 "ghost fields" are fields that are unused in certain types, and
740 consequently dont need to actually exist. They are declared because
741 they're part of a "base type", which allows use of functions as
742 methods. The simplest examples are AVs and HVs, 2 aggregate types
743 which don't use the fields which support SCALAR semantics.
745 For these types, the arenas are carved up into *_allocated size
746 chunks, we thus avoid wasted memory for those unaccessed members.
747 When bodies are allocated, we adjust the pointer back in memory by the
748 size of the bit not allocated, so it's as if we allocated the full
749 structure. (But things will all go boom if you write to the part that
750 is "not there", because you'll be overwriting the last members of the
751 preceding structure in memory.)
753 We calculate the correction using the STRUCT_OFFSET macro. For
754 example, if xpv_allocated is the same structure as XPV then the two
755 OFFSETs sum to zero, and the pointer is unchanged. If the allocated
756 structure is smaller (no initial NV actually allocated) then the net
757 effect is to subtract the size of the NV from the pointer, to return a
758 new pointer as if an initial NV were actually allocated.
760 This is the same trick as was used for NV and IV bodies. Ironically it
761 doesn't need to be used for NV bodies any more, because NV is now at
762 the start of the structure. IV bodies don't need it either, because
763 they are no longer allocated.
765 In turn, the new_body_* allocators call S_new_body(), which invokes
766 new_body_inline macro, which takes a lock, and takes a body off the
767 linked list at PL_body_roots[sv_type], calling S_more_bodies() if
768 necessary to refresh an empty list. Then the lock is released, and
769 the body is returned.
771 S_more_bodies calls get_arena(), and carves it up into an array of N
772 bodies, which it strings into a linked list. It looks up arena-size
773 and body-size from the body_details table described below, thus
774 supporting the multiple body-types.
776 If PURIFY is defined, or PERL_ARENA_SIZE=0, arenas are not used, and
777 the (new|del)_X*V macros are mapped directly to malloc/free.
783 For each sv-type, struct body_details bodies_by_type[] carries
784 parameters which control these aspects of SV handling:
786 Arena_size determines whether arenas are used for this body type, and if
787 so, how big they are. PURIFY or PERL_ARENA_SIZE=0 set this field to
788 zero, forcing individual mallocs and frees.
790 Body_size determines how big a body is, and therefore how many fit into
791 each arena. Offset carries the body-pointer adjustment needed for
792 *_allocated body types, and is used in *_allocated macros.
794 But its main purpose is to parameterize info needed in
795 Perl_sv_upgrade(). The info here dramatically simplifies the function
796 vs the implementation in 5.8.7, making it table-driven. All fields
797 are used for this, except for arena_size.
799 For the sv-types that have no bodies, arenas are not used, so those
800 PL_body_roots[sv_type] are unused, and can be overloaded. In
801 something of a special case, SVt_NULL is borrowed for HE arenas;
802 PL_body_roots[SVt_NULL] is filled by S_more_he, but the
803 bodies_by_type[SVt_NULL] slot is not used, as the table is not
806 PTEs also use arenas, but are never seen in Perl_sv_upgrade.
807 Nonetheless, they get their own slot in bodies_by_type[SVt_NULL], so
808 they can just use the same allocation semantics. At first, PTEs were
809 also overloaded to a non-body sv-type, but this yielded hard-to-find
810 malloc bugs, so was simplified by claiming a new slot. This choice
811 has no consequence at this time.
815 struct body_details {
816 U8 body_size; /* Size to allocate */
817 U8 copy; /* Size of structure to copy (may be shorter) */
819 unsigned int type : 4; /* We have space for a sanity check. */
820 unsigned int cant_upgrade : 1; /* Cannot upgrade this type */
821 unsigned int zero_nv : 1; /* zero the NV when upgrading from this */
822 unsigned int arena : 1; /* Allocated from an arena */
823 size_t arena_size; /* Size of arena to allocate */
831 /* With -DPURFIY we allocate everything directly, and don't use arenas.
832 This seems a rather elegant way to simplify some of the code below. */
833 #define HASARENA FALSE
835 #define HASARENA TRUE
837 #define NOARENA FALSE
839 /* Size the arenas to exactly fit a given number of bodies. A count
840 of 0 fits the max number bodies into a PERL_ARENA_SIZE.block,
841 simplifying the default. If count > 0, the arena is sized to fit
842 only that many bodies, allowing arenas to be used for large, rare
843 bodies (XPVFM, XPVIO) without undue waste. The arena size is
844 limited by PERL_ARENA_SIZE, so we can safely oversize the
847 #define FIT_ARENA0(body_size) \
848 ((size_t)(PERL_ARENA_SIZE / body_size) * body_size)
849 #define FIT_ARENAn(count,body_size) \
850 ( count * body_size <= PERL_ARENA_SIZE) \
851 ? count * body_size \
852 : FIT_ARENA0 (body_size)
853 #define FIT_ARENA(count,body_size) \
855 ? FIT_ARENAn (count, body_size) \
856 : FIT_ARENA0 (body_size)
858 /* A macro to work out the offset needed to subtract from a pointer to (say)
865 to make its members accessible via a pointer to (say)
875 #define relative_STRUCT_OFFSET(longer, shorter, member) \
876 (STRUCT_OFFSET(shorter, member) - STRUCT_OFFSET(longer, member))
878 /* Calculate the length to copy. Specifically work out the length less any
879 final padding the compiler needed to add. See the comment in sv_upgrade
880 for why copying the padding proved to be a bug. */
882 #define copy_length(type, last_member) \
883 STRUCT_OFFSET(type, last_member) \
884 + sizeof (((type*)SvANY((SV*)0))->last_member)
886 static const struct body_details bodies_by_type[] = {
887 { sizeof(HE), 0, 0, SVt_NULL,
888 FALSE, NONV, NOARENA, FIT_ARENA(0, sizeof(HE)) },
890 /* IVs are in the head, so the allocation size is 0.
891 However, the slot is overloaded for PTEs. */
892 { sizeof(struct ptr_tbl_ent), /* This is used for PTEs. */
893 sizeof(IV), /* This is used to copy out the IV body. */
894 STRUCT_OFFSET(XPVIV, xiv_iv), SVt_IV, FALSE, NONV,
895 NOARENA /* IVS don't need an arena */,
896 /* But PTEs need to know the size of their arena */
897 FIT_ARENA(0, sizeof(struct ptr_tbl_ent))
900 /* 8 bytes on most ILP32 with IEEE doubles */
901 { sizeof(NV), sizeof(NV), 0, SVt_NV, FALSE, HADNV, HASARENA,
902 FIT_ARENA(0, sizeof(NV)) },
904 /* RVs are in the head now. */
905 { 0, 0, 0, SVt_RV, FALSE, NONV, NOARENA, 0 },
907 /* 8 bytes on most ILP32 with IEEE doubles */
908 { sizeof(xpv_allocated),
909 copy_length(XPV, xpv_len)
910 - relative_STRUCT_OFFSET(xpv_allocated, XPV, xpv_cur),
911 + relative_STRUCT_OFFSET(xpv_allocated, XPV, xpv_cur),
912 SVt_PV, FALSE, NONV, HASARENA, FIT_ARENA(0, sizeof(xpv_allocated)) },
915 { sizeof(xpviv_allocated),
916 copy_length(XPVIV, xiv_u)
917 - relative_STRUCT_OFFSET(xpviv_allocated, XPVIV, xpv_cur),
918 + relative_STRUCT_OFFSET(xpviv_allocated, XPVIV, xpv_cur),
919 SVt_PVIV, FALSE, NONV, HASARENA, FIT_ARENA(0, sizeof(xpviv_allocated)) },
922 { sizeof(XPVNV), copy_length(XPVNV, xiv_u), 0, SVt_PVNV, FALSE, HADNV,
923 HASARENA, FIT_ARENA(0, sizeof(XPVNV)) },
926 { sizeof(XPVMG), copy_length(XPVMG, xmg_stash), 0, SVt_PVMG, FALSE, HADNV,
927 HASARENA, FIT_ARENA(0, sizeof(XPVMG)) },
930 { sizeof(XPVBM), sizeof(XPVBM), 0, SVt_PVBM, TRUE, HADNV,
931 HASARENA, FIT_ARENA(0, sizeof(XPVBM)) },
934 { sizeof(XPVGV), sizeof(XPVGV), 0, SVt_PVGV, TRUE, HADNV,
935 HASARENA, FIT_ARENA(0, sizeof(XPVGV)) },
938 { sizeof(XPVLV), sizeof(XPVLV), 0, SVt_PVLV, TRUE, HADNV,
939 HASARENA, FIT_ARENA(0, sizeof(XPVLV)) },
941 { sizeof(xpvav_allocated),
942 copy_length(XPVAV, xmg_stash)
943 - relative_STRUCT_OFFSET(xpvav_allocated, XPVAV, xav_fill),
944 + relative_STRUCT_OFFSET(xpvav_allocated, XPVAV, xav_fill),
945 SVt_PVAV, TRUE, HADNV, HASARENA, FIT_ARENA(0, sizeof(xpvav_allocated)) },
947 { sizeof(xpvhv_allocated),
948 copy_length(XPVHV, xmg_stash)
949 - relative_STRUCT_OFFSET(xpvhv_allocated, XPVHV, xhv_fill),
950 + relative_STRUCT_OFFSET(xpvhv_allocated, XPVHV, xhv_fill),
951 SVt_PVHV, TRUE, HADNV, HASARENA, FIT_ARENA(0, sizeof(xpvhv_allocated)) },
954 { sizeof(xpvcv_allocated), sizeof(xpvcv_allocated),
955 + relative_STRUCT_OFFSET(xpvcv_allocated, XPVCV, xpv_cur),
956 SVt_PVCV, TRUE, NONV, HASARENA, FIT_ARENA(0, sizeof(xpvcv_allocated)) },
958 { sizeof(xpvfm_allocated), sizeof(xpvfm_allocated),
959 + relative_STRUCT_OFFSET(xpvfm_allocated, XPVFM, xpv_cur),
960 SVt_PVFM, TRUE, NONV, NOARENA, FIT_ARENA(20, sizeof(xpvfm_allocated)) },
962 /* XPVIO is 84 bytes, fits 48x */
963 { sizeof(XPVIO), sizeof(XPVIO), 0, SVt_PVIO, TRUE, HADNV,
964 HASARENA, FIT_ARENA(24, sizeof(XPVIO)) },
967 #define new_body_type(sv_type) \
968 (void *)((char *)S_new_body(aTHX_ sv_type))
970 #define del_body_type(p, sv_type) \
971 del_body(p, &PL_body_roots[sv_type])
974 #define new_body_allocated(sv_type) \
975 (void *)((char *)S_new_body(aTHX_ sv_type) \
976 - bodies_by_type[sv_type].offset)
978 #define del_body_allocated(p, sv_type) \
979 del_body(p + bodies_by_type[sv_type].offset, &PL_body_roots[sv_type])
982 #define my_safemalloc(s) (void*)safemalloc(s)
983 #define my_safecalloc(s) (void*)safecalloc(s, 1)
984 #define my_safefree(p) safefree((char*)p)
988 #define new_XNV() my_safemalloc(sizeof(XPVNV))
989 #define del_XNV(p) my_safefree(p)
991 #define new_XPVNV() my_safemalloc(sizeof(XPVNV))
992 #define del_XPVNV(p) my_safefree(p)
994 #define new_XPVAV() my_safemalloc(sizeof(XPVAV))
995 #define del_XPVAV(p) my_safefree(p)
997 #define new_XPVHV() my_safemalloc(sizeof(XPVHV))
998 #define del_XPVHV(p) my_safefree(p)
1000 #define new_XPVMG() my_safemalloc(sizeof(XPVMG))
1001 #define del_XPVMG(p) my_safefree(p)
1003 #define new_XPVGV() my_safemalloc(sizeof(XPVGV))
1004 #define del_XPVGV(p) my_safefree(p)
1008 #define new_XNV() new_body_type(SVt_NV)
1009 #define del_XNV(p) del_body_type(p, SVt_NV)
1011 #define new_XPVNV() new_body_type(SVt_PVNV)
1012 #define del_XPVNV(p) del_body_type(p, SVt_PVNV)
1014 #define new_XPVAV() new_body_allocated(SVt_PVAV)
1015 #define del_XPVAV(p) del_body_allocated(p, SVt_PVAV)
1017 #define new_XPVHV() new_body_allocated(SVt_PVHV)
1018 #define del_XPVHV(p) del_body_allocated(p, SVt_PVHV)
1020 #define new_XPVMG() new_body_type(SVt_PVMG)
1021 #define del_XPVMG(p) del_body_type(p, SVt_PVMG)
1023 #define new_XPVGV() new_body_type(SVt_PVGV)
1024 #define del_XPVGV(p) del_body_type(p, SVt_PVGV)
1028 /* no arena for you! */
1030 #define new_NOARENA(details) \
1031 my_safemalloc((details)->body_size + (details)->offset)
1032 #define new_NOARENAZ(details) \
1033 my_safecalloc((details)->body_size + (details)->offset)
1035 #if defined(DEBUGGING) && !defined(PERL_GLOBAL_STRUCT_PRIVATE)
1036 static bool done_sanity_check;
1040 S_more_bodies (pTHX_ svtype sv_type)
1043 void ** const root = &PL_body_roots[sv_type];
1044 const struct body_details * const bdp = &bodies_by_type[sv_type];
1045 const size_t body_size = bdp->body_size;
1049 assert(bdp->arena_size);
1051 #if defined(DEBUGGING) && !defined(PERL_GLOBAL_STRUCT_PRIVATE)
1052 /* PERL_GLOBAL_STRUCT_PRIVATE cannot coexist with global
1053 * variables like done_sanity_check. */
1054 if (!done_sanity_check) {
1055 unsigned int i = SVt_LAST;
1057 done_sanity_check = TRUE;
1060 assert (bodies_by_type[i].type == i);
1064 start = (char*) Perl_get_arena(aTHX_ bdp->arena_size);
1066 end = start + bdp->arena_size - body_size;
1068 /* computed count doesnt reflect the 1st slot reservation */
1069 DEBUG_m(PerlIO_printf(Perl_debug_log,
1070 "arena %p end %p arena-size %d type %d size %d ct %d\n",
1072 (int)bdp->arena_size, sv_type, (int)body_size,
1073 (int)bdp->arena_size / (int)body_size));
1075 *root = (void *)start;
1077 while (start < end) {
1078 char * const next = start + body_size;
1079 *(void**) start = (void *)next;
1082 *(void **)start = 0;
1087 /* grab a new thing from the free list, allocating more if necessary.
1088 The inline version is used for speed in hot routines, and the
1089 function using it serves the rest (unless PURIFY).
1091 #define new_body_inline(xpv, sv_type) \
1093 void ** const r3wt = &PL_body_roots[sv_type]; \
1095 xpv = (PTR_TBL_ENT_t*) (*((void **)(r3wt)) \
1096 ? *((void **)(r3wt)) : more_bodies(sv_type)); \
1097 *(r3wt) = *(void**)(xpv); \
1104 S_new_body(pTHX_ svtype sv_type)
1108 new_body_inline(xpv, sv_type);
1115 =for apidoc sv_upgrade
1117 Upgrade an SV to a more complex form. Generally adds a new body type to the
1118 SV, then copies across as much information as possible from the old body.
1119 You generally want to use the C<SvUPGRADE> macro wrapper. See also C<svtype>.
1125 Perl_sv_upgrade(pTHX_ register SV *sv, svtype new_type)
1130 const svtype old_type = SvTYPE(sv);
1131 const struct body_details *new_type_details;
1132 const struct body_details *const old_type_details
1133 = bodies_by_type + old_type;
1135 if (new_type != SVt_PV && SvIsCOW(sv)) {
1136 sv_force_normal_flags(sv, 0);
1139 if (old_type == new_type)
1142 if (old_type > new_type)
1143 Perl_croak(aTHX_ "sv_upgrade from type %d down to type %d",
1144 (int)old_type, (int)new_type);
1147 old_body = SvANY(sv);
1149 /* Copying structures onto other structures that have been neatly zeroed
1150 has a subtle gotcha. Consider XPVMG
1152 +------+------+------+------+------+-------+-------+
1153 | NV | CUR | LEN | IV | MAGIC | STASH |
1154 +------+------+------+------+------+-------+-------+
1155 0 4 8 12 16 20 24 28
1157 where NVs are aligned to 8 bytes, so that sizeof that structure is
1158 actually 32 bytes long, with 4 bytes of padding at the end:
1160 +------+------+------+------+------+-------+-------+------+
1161 | NV | CUR | LEN | IV | MAGIC | STASH | ??? |
1162 +------+------+------+------+------+-------+-------+------+
1163 0 4 8 12 16 20 24 28 32
1165 so what happens if you allocate memory for this structure:
1167 +------+------+------+------+------+-------+-------+------+------+...
1168 | NV | CUR | LEN | IV | MAGIC | STASH | GP | NAME |
1169 +------+------+------+------+------+-------+-------+------+------+...
1170 0 4 8 12 16 20 24 28 32 36
1172 zero it, then copy sizeof(XPVMG) bytes on top of it? Not quite what you
1173 expect, because you copy the area marked ??? onto GP. Now, ??? may have
1174 started out as zero once, but it's quite possible that it isn't. So now,
1175 rather than a nicely zeroed GP, you have it pointing somewhere random.
1178 (In fact, GP ends up pointing at a previous GP structure, because the
1179 principle cause of the padding in XPVMG getting garbage is a copy of
1180 sizeof(XPVMG) bytes from a XPVGV structure in sv_unglob)
1182 So we are careful and work out the size of used parts of all the
1189 if (new_type < SVt_PVIV) {
1190 new_type = (new_type == SVt_NV)
1191 ? SVt_PVNV : SVt_PVIV;
1195 if (new_type < SVt_PVNV) {
1196 new_type = SVt_PVNV;
1202 assert(new_type > SVt_PV);
1203 assert(SVt_IV < SVt_PV);
1204 assert(SVt_NV < SVt_PV);
1211 /* Because the XPVMG of PL_mess_sv isn't allocated from the arena,
1212 there's no way that it can be safely upgraded, because perl.c
1213 expects to Safefree(SvANY(PL_mess_sv)) */
1214 assert(sv != PL_mess_sv);
1215 /* This flag bit is used to mean other things in other scalar types.
1216 Given that it only has meaning inside the pad, it shouldn't be set
1217 on anything that can get upgraded. */
1218 assert(!SvPAD_TYPED(sv));
1221 if (old_type_details->cant_upgrade)
1222 Perl_croak(aTHX_ "Can't upgrade %s (%" UVuf ") to %" UVuf,
1223 sv_reftype(sv, 0), (UV) old_type, (UV) new_type);
1225 new_type_details = bodies_by_type + new_type;
1227 SvFLAGS(sv) &= ~SVTYPEMASK;
1228 SvFLAGS(sv) |= new_type;
1230 /* This can't happen, as SVt_NULL is <= all values of new_type, so one of
1231 the return statements above will have triggered. */
1232 assert (new_type != SVt_NULL);
1235 assert(old_type == SVt_NULL);
1236 SvANY(sv) = (XPVIV*)((char*)&(sv->sv_u.svu_iv) - STRUCT_OFFSET(XPVIV, xiv_iv));
1240 assert(old_type == SVt_NULL);
1241 SvANY(sv) = new_XNV();
1245 assert(old_type == SVt_NULL);
1246 SvANY(sv) = &sv->sv_u.svu_rv;
1251 assert(new_type_details->body_size);
1254 assert(new_type_details->arena);
1255 assert(new_type_details->arena_size);
1256 /* This points to the start of the allocated area. */
1257 new_body_inline(new_body, new_type);
1258 Zero(new_body, new_type_details->body_size, char);
1259 new_body = ((char *)new_body) - new_type_details->offset;
1261 /* We always allocated the full length item with PURIFY. To do this
1262 we fake things so that arena is false for all 16 types.. */
1263 new_body = new_NOARENAZ(new_type_details);
1265 SvANY(sv) = new_body;
1266 if (new_type == SVt_PVAV) {
1272 /* SVt_NULL isn't the only thing upgraded to AV or HV.
1273 The target created by newSVrv also is, and it can have magic.
1274 However, it never has SvPVX set.
1276 if (old_type >= SVt_RV) {
1277 assert(SvPVX_const(sv) == 0);
1280 /* Could put this in the else clause below, as PVMG must have SvPVX
1281 0 already (the assertion above) */
1284 if (old_type >= SVt_PVMG) {
1285 SvMAGIC_set(sv, ((XPVMG*)old_body)->xmg_u.xmg_magic);
1286 SvSTASH_set(sv, ((XPVMG*)old_body)->xmg_stash);
1292 /* XXX Is this still needed? Was it ever needed? Surely as there is
1293 no route from NV to PVIV, NOK can never be true */
1294 assert(!SvNOKp(sv));
1306 assert(new_type_details->body_size);
1307 /* We always allocated the full length item with PURIFY. To do this
1308 we fake things so that arena is false for all 16 types.. */
1309 if(new_type_details->arena) {
1310 /* This points to the start of the allocated area. */
1311 new_body_inline(new_body, new_type);
1312 Zero(new_body, new_type_details->body_size, char);
1313 new_body = ((char *)new_body) - new_type_details->offset;
1315 new_body = new_NOARENAZ(new_type_details);
1317 SvANY(sv) = new_body;
1319 if (old_type_details->copy) {
1320 /* There is now the potential for an upgrade from something without
1321 an offset (PVNV or PVMG) to something with one (PVCV, PVFM) */
1322 int offset = old_type_details->offset;
1323 int length = old_type_details->copy;
1325 if (new_type_details->offset > old_type_details->offset) {
1326 const int difference
1327 = new_type_details->offset - old_type_details->offset;
1328 offset += difference;
1329 length -= difference;
1331 assert (length >= 0);
1333 Copy((char *)old_body + offset, (char *)new_body + offset, length,
1337 #ifndef NV_ZERO_IS_ALLBITS_ZERO
1338 /* If NV 0.0 is stores as all bits 0 then Zero() already creates a
1339 * correct 0.0 for us. Otherwise, if the old body didn't have an
1340 * NV slot, but the new one does, then we need to initialise the
1341 * freshly created NV slot with whatever the correct bit pattern is
1343 if (old_type_details->zero_nv && !new_type_details->zero_nv)
1347 if (new_type == SVt_PVIO)
1348 IoPAGE_LEN(sv) = 60;
1349 if (old_type < SVt_RV)
1353 Perl_croak(aTHX_ "panic: sv_upgrade to unknown type %lu",
1354 (unsigned long)new_type);
1357 if (old_type_details->arena) {
1358 /* If there was an old body, then we need to free it.
1359 Note that there is an assumption that all bodies of types that
1360 can be upgraded came from arenas. Only the more complex non-
1361 upgradable types are allowed to be directly malloc()ed. */
1363 my_safefree(old_body);
1365 del_body((void*)((char*)old_body + old_type_details->offset),
1366 &PL_body_roots[old_type]);
1372 =for apidoc sv_backoff
1374 Remove any string offset. You should normally use the C<SvOOK_off> macro
1381 Perl_sv_backoff(pTHX_ register SV *sv)
1383 PERL_UNUSED_CONTEXT;
1385 assert(SvTYPE(sv) != SVt_PVHV);
1386 assert(SvTYPE(sv) != SVt_PVAV);
1388 const char * const s = SvPVX_const(sv);
1389 SvLEN_set(sv, SvLEN(sv) + SvIVX(sv));
1390 SvPV_set(sv, SvPVX(sv) - SvIVX(sv));
1392 Move(s, SvPVX(sv), SvCUR(sv)+1, char);
1394 SvFLAGS(sv) &= ~SVf_OOK;
1401 Expands the character buffer in the SV. If necessary, uses C<sv_unref> and
1402 upgrades the SV to C<SVt_PV>. Returns a pointer to the character buffer.
1403 Use the C<SvGROW> wrapper instead.
1409 Perl_sv_grow(pTHX_ register SV *sv, register STRLEN newlen)
1413 if (PL_madskills && newlen >= 0x100000) {
1414 PerlIO_printf(Perl_debug_log,
1415 "Allocation too large: %"UVxf"\n", (UV)newlen);
1417 #ifdef HAS_64K_LIMIT
1418 if (newlen >= 0x10000) {
1419 PerlIO_printf(Perl_debug_log,
1420 "Allocation too large: %"UVxf"\n", (UV)newlen);
1423 #endif /* HAS_64K_LIMIT */
1426 if (SvTYPE(sv) < SVt_PV) {
1427 sv_upgrade(sv, SVt_PV);
1428 s = SvPVX_mutable(sv);
1430 else if (SvOOK(sv)) { /* pv is offset? */
1432 s = SvPVX_mutable(sv);
1433 if (newlen > SvLEN(sv))
1434 newlen += 10 * (newlen - SvCUR(sv)); /* avoid copy each time */
1435 #ifdef HAS_64K_LIMIT
1436 if (newlen >= 0x10000)
1441 s = SvPVX_mutable(sv);
1443 if (newlen > SvLEN(sv)) { /* need more room? */
1444 newlen = PERL_STRLEN_ROUNDUP(newlen);
1445 if (SvLEN(sv) && s) {
1447 const STRLEN l = malloced_size((void*)SvPVX_const(sv));
1453 s = (char*)saferealloc(s, newlen);
1456 s = (char*)safemalloc(newlen);
1457 if (SvPVX_const(sv) && SvCUR(sv)) {
1458 Move(SvPVX_const(sv), s, (newlen < SvCUR(sv)) ? newlen : SvCUR(sv), char);
1462 SvLEN_set(sv, newlen);
1468 =for apidoc sv_setiv
1470 Copies an integer into the given SV, upgrading first if necessary.
1471 Does not handle 'set' magic. See also C<sv_setiv_mg>.
1477 Perl_sv_setiv(pTHX_ register SV *sv, IV i)
1480 SV_CHECK_THINKFIRST_COW_DROP(sv);
1481 switch (SvTYPE(sv)) {
1483 sv_upgrade(sv, SVt_IV);
1486 sv_upgrade(sv, SVt_PVNV);
1490 sv_upgrade(sv, SVt_PVIV);
1499 Perl_croak(aTHX_ "Can't coerce %s to integer in %s", sv_reftype(sv,0),
1503 (void)SvIOK_only(sv); /* validate number */
1509 =for apidoc sv_setiv_mg
1511 Like C<sv_setiv>, but also handles 'set' magic.
1517 Perl_sv_setiv_mg(pTHX_ register SV *sv, IV i)
1524 =for apidoc sv_setuv
1526 Copies an unsigned integer into the given SV, upgrading first if necessary.
1527 Does not handle 'set' magic. See also C<sv_setuv_mg>.
1533 Perl_sv_setuv(pTHX_ register SV *sv, UV u)
1535 /* With these two if statements:
1536 u=1.49 s=0.52 cu=72.49 cs=10.64 scripts=270 tests=20865
1539 u=1.35 s=0.47 cu=73.45 cs=11.43 scripts=270 tests=20865
1541 If you wish to remove them, please benchmark to see what the effect is
1543 if (u <= (UV)IV_MAX) {
1544 sv_setiv(sv, (IV)u);
1553 =for apidoc sv_setuv_mg
1555 Like C<sv_setuv>, but also handles 'set' magic.
1561 Perl_sv_setuv_mg(pTHX_ register SV *sv, UV u)
1570 =for apidoc sv_setnv
1572 Copies a double into the given SV, upgrading first if necessary.
1573 Does not handle 'set' magic. See also C<sv_setnv_mg>.
1579 Perl_sv_setnv(pTHX_ register SV *sv, NV num)
1582 SV_CHECK_THINKFIRST_COW_DROP(sv);
1583 switch (SvTYPE(sv)) {
1586 sv_upgrade(sv, SVt_NV);
1591 sv_upgrade(sv, SVt_PVNV);
1600 Perl_croak(aTHX_ "Can't coerce %s to number in %s", sv_reftype(sv,0),
1605 (void)SvNOK_only(sv); /* validate number */
1610 =for apidoc sv_setnv_mg
1612 Like C<sv_setnv>, but also handles 'set' magic.
1618 Perl_sv_setnv_mg(pTHX_ register SV *sv, NV num)
1624 /* Print an "isn't numeric" warning, using a cleaned-up,
1625 * printable version of the offending string
1629 S_not_a_number(pTHX_ SV *sv)
1637 dsv = sv_2mortal(newSVpvs(""));
1638 pv = sv_uni_display(dsv, sv, 10, 0);
1641 const char * const limit = tmpbuf + sizeof(tmpbuf) - 8;
1642 /* each *s can expand to 4 chars + "...\0",
1643 i.e. need room for 8 chars */
1645 const char *s = SvPVX_const(sv);
1646 const char * const end = s + SvCUR(sv);
1647 for ( ; s < end && d < limit; s++ ) {
1649 if (ch & 128 && !isPRINT_LC(ch)) {
1658 else if (ch == '\r') {
1662 else if (ch == '\f') {
1666 else if (ch == '\\') {
1670 else if (ch == '\0') {
1674 else if (isPRINT_LC(ch))
1691 Perl_warner(aTHX_ packWARN(WARN_NUMERIC),
1692 "Argument \"%s\" isn't numeric in %s", pv,
1695 Perl_warner(aTHX_ packWARN(WARN_NUMERIC),
1696 "Argument \"%s\" isn't numeric", pv);
1700 =for apidoc looks_like_number
1702 Test if the content of an SV looks like a number (or is a number).
1703 C<Inf> and C<Infinity> are treated as numbers (so will not issue a
1704 non-numeric warning), even if your atof() doesn't grok them.
1710 Perl_looks_like_number(pTHX_ SV *sv)
1712 register const char *sbegin;
1716 sbegin = SvPVX_const(sv);
1719 else if (SvPOKp(sv))
1720 sbegin = SvPV_const(sv, len);
1722 return SvFLAGS(sv) & (SVf_NOK|SVp_NOK|SVf_IOK|SVp_IOK);
1723 return grok_number(sbegin, len, NULL);
1727 S_glob_2number(pTHX_ GV * const gv)
1729 const U32 wasfake = SvFLAGS(gv) & SVf_FAKE;
1730 SV *const buffer = sv_newmortal();
1732 /* FAKE globs can get coerced, so need to turn this off temporarily if it
1735 gv_efullname3(buffer, gv, "*");
1736 SvFLAGS(gv) |= wasfake;
1738 /* We know that all GVs stringify to something that is not-a-number,
1739 so no need to test that. */
1740 if (ckWARN(WARN_NUMERIC))
1741 not_a_number(buffer);
1742 /* We just want something true to return, so that S_sv_2iuv_common
1743 can tail call us and return true. */
1748 S_glob_2pv(pTHX_ GV * const gv, STRLEN * const len)
1750 const U32 wasfake = SvFLAGS(gv) & SVf_FAKE;
1751 SV *const buffer = sv_newmortal();
1753 /* FAKE globs can get coerced, so need to turn this off temporarily if it
1756 gv_efullname3(buffer, gv, "*");
1757 SvFLAGS(gv) |= wasfake;
1759 assert(SvPOK(buffer));
1761 *len = SvCUR(buffer);
1763 return SvPVX(buffer);
1766 /* Actually, ISO C leaves conversion of UV to IV undefined, but
1767 until proven guilty, assume that things are not that bad... */
1772 As 64 bit platforms often have an NV that doesn't preserve all bits of
1773 an IV (an assumption perl has been based on to date) it becomes necessary
1774 to remove the assumption that the NV always carries enough precision to
1775 recreate the IV whenever needed, and that the NV is the canonical form.
1776 Instead, IV/UV and NV need to be given equal rights. So as to not lose
1777 precision as a side effect of conversion (which would lead to insanity
1778 and the dragon(s) in t/op/numconvert.t getting very angry) the intent is
1779 1) to distinguish between IV/UV/NV slots that have cached a valid
1780 conversion where precision was lost and IV/UV/NV slots that have a
1781 valid conversion which has lost no precision
1782 2) to ensure that if a numeric conversion to one form is requested that
1783 would lose precision, the precise conversion (or differently
1784 imprecise conversion) is also performed and cached, to prevent
1785 requests for different numeric formats on the same SV causing
1786 lossy conversion chains. (lossless conversion chains are perfectly
1791 SvIOKp is true if the IV slot contains a valid value
1792 SvIOK is true only if the IV value is accurate (UV if SvIOK_UV true)
1793 SvNOKp is true if the NV slot contains a valid value
1794 SvNOK is true only if the NV value is accurate
1797 while converting from PV to NV, check to see if converting that NV to an
1798 IV(or UV) would lose accuracy over a direct conversion from PV to
1799 IV(or UV). If it would, cache both conversions, return NV, but mark
1800 SV as IOK NOKp (ie not NOK).
1802 While converting from PV to IV, check to see if converting that IV to an
1803 NV would lose accuracy over a direct conversion from PV to NV. If it
1804 would, cache both conversions, flag similarly.
1806 Before, the SV value "3.2" could become NV=3.2 IV=3 NOK, IOK quite
1807 correctly because if IV & NV were set NV *always* overruled.
1808 Now, "3.2" will become NV=3.2 IV=3 NOK, IOKp, because the flag's meaning
1809 changes - now IV and NV together means that the two are interchangeable:
1810 SvIVX == (IV) SvNVX && SvNVX == (NV) SvIVX;
1812 The benefit of this is that operations such as pp_add know that if
1813 SvIOK is true for both left and right operands, then integer addition
1814 can be used instead of floating point (for cases where the result won't
1815 overflow). Before, floating point was always used, which could lead to
1816 loss of precision compared with integer addition.
1818 * making IV and NV equal status should make maths accurate on 64 bit
1820 * may speed up maths somewhat if pp_add and friends start to use
1821 integers when possible instead of fp. (Hopefully the overhead in
1822 looking for SvIOK and checking for overflow will not outweigh the
1823 fp to integer speedup)
1824 * will slow down integer operations (callers of SvIV) on "inaccurate"
1825 values, as the change from SvIOK to SvIOKp will cause a call into
1826 sv_2iv each time rather than a macro access direct to the IV slot
1827 * should speed up number->string conversion on integers as IV is
1828 favoured when IV and NV are equally accurate
1830 ####################################################################
1831 You had better be using SvIOK_notUV if you want an IV for arithmetic:
1832 SvIOK is true if (IV or UV), so you might be getting (IV)SvUV.
1833 On the other hand, SvUOK is true iff UV.
1834 ####################################################################
1836 Your mileage will vary depending your CPU's relative fp to integer
1840 #ifndef NV_PRESERVES_UV
1841 # define IS_NUMBER_UNDERFLOW_IV 1
1842 # define IS_NUMBER_UNDERFLOW_UV 2
1843 # define IS_NUMBER_IV_AND_UV 2
1844 # define IS_NUMBER_OVERFLOW_IV 4
1845 # define IS_NUMBER_OVERFLOW_UV 5
1847 /* sv_2iuv_non_preserve(): private routine for use by sv_2iv() and sv_2uv() */
1849 /* For sv_2nv these three cases are "SvNOK and don't bother casting" */
1851 S_sv_2iuv_non_preserve(pTHX_ register SV *sv, I32 numtype)
1854 PERL_UNUSED_ARG(numtype); /* Used only under DEBUGGING? */
1855 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));
1856 if (SvNVX(sv) < (NV)IV_MIN) {
1857 (void)SvIOKp_on(sv);
1859 SvIV_set(sv, IV_MIN);
1860 return IS_NUMBER_UNDERFLOW_IV;
1862 if (SvNVX(sv) > (NV)UV_MAX) {
1863 (void)SvIOKp_on(sv);
1866 SvUV_set(sv, UV_MAX);
1867 return IS_NUMBER_OVERFLOW_UV;
1869 (void)SvIOKp_on(sv);
1871 /* Can't use strtol etc to convert this string. (See truth table in
1873 if (SvNVX(sv) <= (UV)IV_MAX) {
1874 SvIV_set(sv, I_V(SvNVX(sv)));
1875 if ((NV)(SvIVX(sv)) == SvNVX(sv)) {
1876 SvIOK_on(sv); /* Integer is precise. NOK, IOK */
1878 /* Integer is imprecise. NOK, IOKp */
1880 return SvNVX(sv) < 0 ? IS_NUMBER_UNDERFLOW_UV : IS_NUMBER_IV_AND_UV;
1883 SvUV_set(sv, U_V(SvNVX(sv)));
1884 if ((NV)(SvUVX(sv)) == SvNVX(sv)) {
1885 if (SvUVX(sv) == UV_MAX) {
1886 /* As we know that NVs don't preserve UVs, UV_MAX cannot
1887 possibly be preserved by NV. Hence, it must be overflow.
1889 return IS_NUMBER_OVERFLOW_UV;
1891 SvIOK_on(sv); /* Integer is precise. NOK, UOK */
1893 /* Integer is imprecise. NOK, IOKp */
1895 return IS_NUMBER_OVERFLOW_IV;
1897 #endif /* !NV_PRESERVES_UV*/
1900 S_sv_2iuv_common(pTHX_ SV *sv) {
1903 /* erm. not sure. *should* never get NOKp (without NOK) from sv_2nv
1904 * without also getting a cached IV/UV from it at the same time
1905 * (ie PV->NV conversion should detect loss of accuracy and cache
1906 * IV or UV at same time to avoid this. */
1907 /* IV-over-UV optimisation - choose to cache IV if possible */
1909 if (SvTYPE(sv) == SVt_NV)
1910 sv_upgrade(sv, SVt_PVNV);
1912 (void)SvIOKp_on(sv); /* Must do this first, to clear any SvOOK */
1913 /* < not <= as for NV doesn't preserve UV, ((NV)IV_MAX+1) will almost
1914 certainly cast into the IV range at IV_MAX, whereas the correct
1915 answer is the UV IV_MAX +1. Hence < ensures that dodgy boundary
1917 #if defined(NAN_COMPARE_BROKEN) && defined(Perl_isnan)
1918 if (Perl_isnan(SvNVX(sv))) {
1924 if (SvNVX(sv) < (NV)IV_MAX + 0.5) {
1925 SvIV_set(sv, I_V(SvNVX(sv)));
1926 if (SvNVX(sv) == (NV) SvIVX(sv)
1927 #ifndef NV_PRESERVES_UV
1928 && (((UV)1 << NV_PRESERVES_UV_BITS) >
1929 (UV)(SvIVX(sv) > 0 ? SvIVX(sv) : -SvIVX(sv)))
1930 /* Don't flag it as "accurately an integer" if the number
1931 came from a (by definition imprecise) NV operation, and
1932 we're outside the range of NV integer precision */
1935 SvIOK_on(sv); /* Can this go wrong with rounding? NWC */
1936 DEBUG_c(PerlIO_printf(Perl_debug_log,
1937 "0x%"UVxf" iv(%"NVgf" => %"IVdf") (precise)\n",
1943 /* IV not precise. No need to convert from PV, as NV
1944 conversion would already have cached IV if it detected
1945 that PV->IV would be better than PV->NV->IV
1946 flags already correct - don't set public IOK. */
1947 DEBUG_c(PerlIO_printf(Perl_debug_log,
1948 "0x%"UVxf" iv(%"NVgf" => %"IVdf") (imprecise)\n",
1953 /* Can the above go wrong if SvIVX == IV_MIN and SvNVX < IV_MIN,
1954 but the cast (NV)IV_MIN rounds to a the value less (more
1955 negative) than IV_MIN which happens to be equal to SvNVX ??
1956 Analogous to 0xFFFFFFFFFFFFFFFF rounding up to NV (2**64) and
1957 NV rounding back to 0xFFFFFFFFFFFFFFFF, so UVX == UV(NVX) and
1958 (NV)UVX == NVX are both true, but the values differ. :-(
1959 Hopefully for 2s complement IV_MIN is something like
1960 0x8000000000000000 which will be exact. NWC */
1963 SvUV_set(sv, U_V(SvNVX(sv)));
1965 (SvNVX(sv) == (NV) SvUVX(sv))
1966 #ifndef NV_PRESERVES_UV
1967 /* Make sure it's not 0xFFFFFFFFFFFFFFFF */
1968 /*&& (SvUVX(sv) != UV_MAX) irrelevant with code below */
1969 && (((UV)1 << NV_PRESERVES_UV_BITS) > SvUVX(sv))
1970 /* Don't flag it as "accurately an integer" if the number
1971 came from a (by definition imprecise) NV operation, and
1972 we're outside the range of NV integer precision */
1977 DEBUG_c(PerlIO_printf(Perl_debug_log,
1978 "0x%"UVxf" 2iv(%"UVuf" => %"IVdf") (as unsigned)\n",
1984 else if (SvPOKp(sv) && SvLEN(sv)) {
1986 const int numtype = grok_number(SvPVX_const(sv), SvCUR(sv), &value);
1987 /* We want to avoid a possible problem when we cache an IV/ a UV which
1988 may be later translated to an NV, and the resulting NV is not
1989 the same as the direct translation of the initial string
1990 (eg 123.456 can shortcut to the IV 123 with atol(), but we must
1991 be careful to ensure that the value with the .456 is around if the
1992 NV value is requested in the future).
1994 This means that if we cache such an IV/a UV, we need to cache the
1995 NV as well. Moreover, we trade speed for space, and do not
1996 cache the NV if we are sure it's not needed.
1999 /* SVt_PVNV is one higher than SVt_PVIV, hence this order */
2000 if ((numtype & (IS_NUMBER_IN_UV | IS_NUMBER_NOT_INT))
2001 == IS_NUMBER_IN_UV) {
2002 /* It's definitely an integer, only upgrade to PVIV */
2003 if (SvTYPE(sv) < SVt_PVIV)
2004 sv_upgrade(sv, SVt_PVIV);
2006 } else if (SvTYPE(sv) < SVt_PVNV)
2007 sv_upgrade(sv, SVt_PVNV);
2009 /* If NVs preserve UVs then we only use the UV value if we know that
2010 we aren't going to call atof() below. If NVs don't preserve UVs
2011 then the value returned may have more precision than atof() will
2012 return, even though value isn't perfectly accurate. */
2013 if ((numtype & (IS_NUMBER_IN_UV
2014 #ifdef NV_PRESERVES_UV
2017 )) == IS_NUMBER_IN_UV) {
2018 /* This won't turn off the public IOK flag if it was set above */
2019 (void)SvIOKp_on(sv);
2021 if (!(numtype & IS_NUMBER_NEG)) {
2023 if (value <= (UV)IV_MAX) {
2024 SvIV_set(sv, (IV)value);
2026 /* it didn't overflow, and it was positive. */
2027 SvUV_set(sv, value);
2031 /* 2s complement assumption */
2032 if (value <= (UV)IV_MIN) {
2033 SvIV_set(sv, -(IV)value);
2035 /* Too negative for an IV. This is a double upgrade, but
2036 I'm assuming it will be rare. */
2037 if (SvTYPE(sv) < SVt_PVNV)
2038 sv_upgrade(sv, SVt_PVNV);
2042 SvNV_set(sv, -(NV)value);
2043 SvIV_set(sv, IV_MIN);
2047 /* For !NV_PRESERVES_UV and IS_NUMBER_IN_UV and IS_NUMBER_NOT_INT we
2048 will be in the previous block to set the IV slot, and the next
2049 block to set the NV slot. So no else here. */
2051 if ((numtype & (IS_NUMBER_IN_UV | IS_NUMBER_NOT_INT))
2052 != IS_NUMBER_IN_UV) {
2053 /* It wasn't an (integer that doesn't overflow the UV). */
2054 SvNV_set(sv, Atof(SvPVX_const(sv)));
2056 if (! numtype && ckWARN(WARN_NUMERIC))
2059 #if defined(USE_LONG_DOUBLE)
2060 DEBUG_c(PerlIO_printf(Perl_debug_log, "0x%"UVxf" 2iv(%" PERL_PRIgldbl ")\n",
2061 PTR2UV(sv), SvNVX(sv)));
2063 DEBUG_c(PerlIO_printf(Perl_debug_log, "0x%"UVxf" 2iv(%"NVgf")\n",
2064 PTR2UV(sv), SvNVX(sv)));
2067 #ifdef NV_PRESERVES_UV
2068 (void)SvIOKp_on(sv);
2070 if (SvNVX(sv) < (NV)IV_MAX + 0.5) {
2071 SvIV_set(sv, I_V(SvNVX(sv)));
2072 if ((NV)(SvIVX(sv)) == SvNVX(sv)) {
2075 NOOP; /* Integer is imprecise. NOK, IOKp */
2077 /* UV will not work better than IV */
2079 if (SvNVX(sv) > (NV)UV_MAX) {
2081 /* Integer is inaccurate. NOK, IOKp, is UV */
2082 SvUV_set(sv, UV_MAX);
2084 SvUV_set(sv, U_V(SvNVX(sv)));
2085 /* 0xFFFFFFFFFFFFFFFF not an issue in here, NVs
2086 NV preservse UV so can do correct comparison. */
2087 if ((NV)(SvUVX(sv)) == SvNVX(sv)) {
2090 NOOP; /* Integer is imprecise. NOK, IOKp, is UV */
2095 #else /* NV_PRESERVES_UV */
2096 if ((numtype & (IS_NUMBER_IN_UV | IS_NUMBER_NOT_INT))
2097 == (IS_NUMBER_IN_UV | IS_NUMBER_NOT_INT)) {
2098 /* The IV/UV slot will have been set from value returned by
2099 grok_number above. The NV slot has just been set using
2102 assert (SvIOKp(sv));
2104 if (((UV)1 << NV_PRESERVES_UV_BITS) >
2105 U_V(SvNVX(sv) > 0 ? SvNVX(sv) : -SvNVX(sv))) {
2106 /* Small enough to preserve all bits. */
2107 (void)SvIOKp_on(sv);
2109 SvIV_set(sv, I_V(SvNVX(sv)));
2110 if ((NV)(SvIVX(sv)) == SvNVX(sv))
2112 /* Assumption: first non-preserved integer is < IV_MAX,
2113 this NV is in the preserved range, therefore: */
2114 if (!(U_V(SvNVX(sv) > 0 ? SvNVX(sv) : -SvNVX(sv))
2116 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);
2120 0 0 already failed to read UV.
2121 0 1 already failed to read UV.
2122 1 0 you won't get here in this case. IV/UV
2123 slot set, public IOK, Atof() unneeded.
2124 1 1 already read UV.
2125 so there's no point in sv_2iuv_non_preserve() attempting
2126 to use atol, strtol, strtoul etc. */
2127 sv_2iuv_non_preserve (sv, numtype);
2130 #endif /* NV_PRESERVES_UV */
2134 if (isGV_with_GP(sv))
2135 return glob_2number((GV *)sv);
2137 if (!(SvFLAGS(sv) & SVs_PADTMP)) {
2138 if (!PL_localizing && ckWARN(WARN_UNINITIALIZED))
2141 if (SvTYPE(sv) < SVt_IV)
2142 /* Typically the caller expects that sv_any is not NULL now. */
2143 sv_upgrade(sv, SVt_IV);
2144 /* Return 0 from the caller. */
2151 =for apidoc sv_2iv_flags
2153 Return the integer value of an SV, doing any necessary string
2154 conversion. If flags includes SV_GMAGIC, does an mg_get() first.
2155 Normally used via the C<SvIV(sv)> and C<SvIVx(sv)> macros.
2161 Perl_sv_2iv_flags(pTHX_ register SV *sv, I32 flags)
2166 if (SvGMAGICAL(sv)) {
2167 if (flags & SV_GMAGIC)
2172 return I_V(SvNVX(sv));
2174 if (SvPOKp(sv) && SvLEN(sv)) {
2177 = grok_number(SvPVX_const(sv), SvCUR(sv), &value);
2179 if ((numtype & (IS_NUMBER_IN_UV | IS_NUMBER_NOT_INT))
2180 == IS_NUMBER_IN_UV) {
2181 /* It's definitely an integer */
2182 if (numtype & IS_NUMBER_NEG) {
2183 if (value < (UV)IV_MIN)
2186 if (value < (UV)IV_MAX)
2191 if (ckWARN(WARN_NUMERIC))
2194 return I_V(Atof(SvPVX_const(sv)));
2199 assert(SvTYPE(sv) >= SVt_PVMG);
2200 /* This falls through to the report_uninit inside S_sv_2iuv_common. */
2201 } else if (SvTHINKFIRST(sv)) {
2205 SV * const tmpstr=AMG_CALLun(sv,numer);
2206 if (tmpstr && (!SvROK(tmpstr) || (SvRV(tmpstr) != SvRV(sv)))) {
2207 return SvIV(tmpstr);
2210 return PTR2IV(SvRV(sv));
2213 sv_force_normal_flags(sv, 0);
2215 if (SvREADONLY(sv) && !SvOK(sv)) {
2216 if (ckWARN(WARN_UNINITIALIZED))
2222 if (S_sv_2iuv_common(aTHX_ sv))
2225 DEBUG_c(PerlIO_printf(Perl_debug_log, "0x%"UVxf" 2iv(%"IVdf")\n",
2226 PTR2UV(sv),SvIVX(sv)));
2227 return SvIsUV(sv) ? (IV)SvUVX(sv) : SvIVX(sv);
2231 =for apidoc sv_2uv_flags
2233 Return the unsigned integer value of an SV, doing any necessary string
2234 conversion. If flags includes SV_GMAGIC, does an mg_get() first.
2235 Normally used via the C<SvUV(sv)> and C<SvUVx(sv)> macros.
2241 Perl_sv_2uv_flags(pTHX_ register SV *sv, I32 flags)
2246 if (SvGMAGICAL(sv)) {
2247 if (flags & SV_GMAGIC)
2252 return U_V(SvNVX(sv));
2253 if (SvPOKp(sv) && SvLEN(sv)) {
2256 = grok_number(SvPVX_const(sv), SvCUR(sv), &value);
2258 if ((numtype & (IS_NUMBER_IN_UV | IS_NUMBER_NOT_INT))
2259 == IS_NUMBER_IN_UV) {
2260 /* It's definitely an integer */
2261 if (!(numtype & IS_NUMBER_NEG))
2265 if (ckWARN(WARN_NUMERIC))
2268 return U_V(Atof(SvPVX_const(sv)));
2273 assert(SvTYPE(sv) >= SVt_PVMG);
2274 /* This falls through to the report_uninit inside S_sv_2iuv_common. */
2275 } else if (SvTHINKFIRST(sv)) {
2279 SV *const tmpstr = AMG_CALLun(sv,numer);
2280 if (tmpstr && (!SvROK(tmpstr) || (SvRV(tmpstr) != SvRV(sv)))) {
2281 return SvUV(tmpstr);
2284 return PTR2UV(SvRV(sv));
2287 sv_force_normal_flags(sv, 0);
2289 if (SvREADONLY(sv) && !SvOK(sv)) {
2290 if (ckWARN(WARN_UNINITIALIZED))
2296 if (S_sv_2iuv_common(aTHX_ sv))
2300 DEBUG_c(PerlIO_printf(Perl_debug_log, "0x%"UVxf" 2uv(%"UVuf")\n",
2301 PTR2UV(sv),SvUVX(sv)));
2302 return SvIsUV(sv) ? SvUVX(sv) : (UV)SvIVX(sv);
2308 Return the num value of an SV, doing any necessary string or integer
2309 conversion, magic etc. Normally used via the C<SvNV(sv)> and C<SvNVx(sv)>
2316 Perl_sv_2nv(pTHX_ register SV *sv)
2321 if (SvGMAGICAL(sv)) {
2325 if ((SvPOKp(sv) && SvLEN(sv)) && !SvIOKp(sv)) {
2326 if (!SvIOKp(sv) && ckWARN(WARN_NUMERIC) &&
2327 !grok_number(SvPVX_const(sv), SvCUR(sv), NULL))
2329 return Atof(SvPVX_const(sv));
2333 return (NV)SvUVX(sv);
2335 return (NV)SvIVX(sv);
2340 assert(SvTYPE(sv) >= SVt_PVMG);
2341 /* This falls through to the report_uninit near the end of the
2343 } else if (SvTHINKFIRST(sv)) {
2347 SV *const tmpstr = AMG_CALLun(sv,numer);
2348 if (tmpstr && (!SvROK(tmpstr) || (SvRV(tmpstr) != SvRV(sv)))) {
2349 return SvNV(tmpstr);
2352 return PTR2NV(SvRV(sv));
2355 sv_force_normal_flags(sv, 0);
2357 if (SvREADONLY(sv) && !SvOK(sv)) {
2358 if (ckWARN(WARN_UNINITIALIZED))
2363 if (SvTYPE(sv) < SVt_NV) {
2364 /* The logic to use SVt_PVNV if necessary is in sv_upgrade. */
2365 sv_upgrade(sv, SVt_NV);
2366 #ifdef USE_LONG_DOUBLE
2368 STORE_NUMERIC_LOCAL_SET_STANDARD();
2369 PerlIO_printf(Perl_debug_log,
2370 "0x%"UVxf" num(%" PERL_PRIgldbl ")\n",
2371 PTR2UV(sv), SvNVX(sv));
2372 RESTORE_NUMERIC_LOCAL();
2376 STORE_NUMERIC_LOCAL_SET_STANDARD();
2377 PerlIO_printf(Perl_debug_log, "0x%"UVxf" num(%"NVgf")\n",
2378 PTR2UV(sv), SvNVX(sv));
2379 RESTORE_NUMERIC_LOCAL();
2383 else if (SvTYPE(sv) < SVt_PVNV)
2384 sv_upgrade(sv, SVt_PVNV);
2389 SvNV_set(sv, SvIsUV(sv) ? (NV)SvUVX(sv) : (NV)SvIVX(sv));
2390 #ifdef NV_PRESERVES_UV
2393 /* Only set the public NV OK flag if this NV preserves the IV */
2394 /* Check it's not 0xFFFFFFFFFFFFFFFF */
2395 if (SvIsUV(sv) ? ((SvUVX(sv) != UV_MAX)&&(SvUVX(sv) == U_V(SvNVX(sv))))
2396 : (SvIVX(sv) == I_V(SvNVX(sv))))
2402 else if (SvPOKp(sv) && SvLEN(sv)) {
2404 const int numtype = grok_number(SvPVX_const(sv), SvCUR(sv), &value);
2405 if (!SvIOKp(sv) && !numtype && ckWARN(WARN_NUMERIC))
2407 #ifdef NV_PRESERVES_UV
2408 if ((numtype & (IS_NUMBER_IN_UV | IS_NUMBER_NOT_INT))
2409 == IS_NUMBER_IN_UV) {
2410 /* It's definitely an integer */
2411 SvNV_set(sv, (numtype & IS_NUMBER_NEG) ? -(NV)value : (NV)value);
2413 SvNV_set(sv, Atof(SvPVX_const(sv)));
2416 SvNV_set(sv, Atof(SvPVX_const(sv)));
2417 /* Only set the public NV OK flag if this NV preserves the value in
2418 the PV at least as well as an IV/UV would.
2419 Not sure how to do this 100% reliably. */
2420 /* if that shift count is out of range then Configure's test is
2421 wonky. We shouldn't be in here with NV_PRESERVES_UV_BITS ==
2423 if (((UV)1 << NV_PRESERVES_UV_BITS) >
2424 U_V(SvNVX(sv) > 0 ? SvNVX(sv) : -SvNVX(sv))) {
2425 SvNOK_on(sv); /* Definitely small enough to preserve all bits */
2426 } else if (!(numtype & IS_NUMBER_IN_UV)) {
2427 /* Can't use strtol etc to convert this string, so don't try.
2428 sv_2iv and sv_2uv will use the NV to convert, not the PV. */
2431 /* value has been set. It may not be precise. */
2432 if ((numtype & IS_NUMBER_NEG) && (value > (UV)IV_MIN)) {
2433 /* 2s complement assumption for (UV)IV_MIN */
2434 SvNOK_on(sv); /* Integer is too negative. */
2439 if (numtype & IS_NUMBER_NEG) {
2440 SvIV_set(sv, -(IV)value);
2441 } else if (value <= (UV)IV_MAX) {
2442 SvIV_set(sv, (IV)value);
2444 SvUV_set(sv, value);
2448 if (numtype & IS_NUMBER_NOT_INT) {
2449 /* I believe that even if the original PV had decimals,
2450 they are lost beyond the limit of the FP precision.
2451 However, neither is canonical, so both only get p
2452 flags. NWC, 2000/11/25 */
2453 /* Both already have p flags, so do nothing */
2455 const NV nv = SvNVX(sv);
2456 if (SvNVX(sv) < (NV)IV_MAX + 0.5) {
2457 if (SvIVX(sv) == I_V(nv)) {
2460 /* It had no "." so it must be integer. */
2464 /* between IV_MAX and NV(UV_MAX).
2465 Could be slightly > UV_MAX */
2467 if (numtype & IS_NUMBER_NOT_INT) {
2468 /* UV and NV both imprecise. */
2470 const UV nv_as_uv = U_V(nv);
2472 if (value == nv_as_uv && SvUVX(sv) != UV_MAX) {
2481 #endif /* NV_PRESERVES_UV */
2484 if (isGV_with_GP(sv)) {
2485 glob_2number((GV *)sv);
2489 if (!PL_localizing && !(SvFLAGS(sv) & SVs_PADTMP) && ckWARN(WARN_UNINITIALIZED))
2491 assert (SvTYPE(sv) >= SVt_NV);
2492 /* Typically the caller expects that sv_any is not NULL now. */
2493 /* XXX Ilya implies that this is a bug in callers that assume this
2494 and ideally should be fixed. */
2497 #if defined(USE_LONG_DOUBLE)
2499 STORE_NUMERIC_LOCAL_SET_STANDARD();
2500 PerlIO_printf(Perl_debug_log, "0x%"UVxf" 2nv(%" PERL_PRIgldbl ")\n",
2501 PTR2UV(sv), SvNVX(sv));
2502 RESTORE_NUMERIC_LOCAL();
2506 STORE_NUMERIC_LOCAL_SET_STANDARD();
2507 PerlIO_printf(Perl_debug_log, "0x%"UVxf" 1nv(%"NVgf")\n",
2508 PTR2UV(sv), SvNVX(sv));
2509 RESTORE_NUMERIC_LOCAL();
2515 /* uiv_2buf(): private routine for use by sv_2pv_flags(): print an IV or
2516 * UV as a string towards the end of buf, and return pointers to start and
2519 * We assume that buf is at least TYPE_CHARS(UV) long.
2523 S_uiv_2buf(char *buf, IV iv, UV uv, int is_uv, char **peob)
2525 char *ptr = buf + TYPE_CHARS(UV);
2526 char * const ebuf = ptr;
2539 *--ptr = '0' + (char)(uv % 10);
2547 /* stringify_regexp(): private routine for use by sv_2pv_flags(): converts
2548 * a regexp to its stringified form.
2552 S_stringify_regexp(pTHX_ SV *sv, MAGIC *mg, STRLEN *lp) {
2554 const regexp * const re = (regexp *)mg->mg_obj;
2557 const char *fptr = "msix";
2562 bool need_newline = 0;
2563 U16 reganch = (U16)((re->reganch & PMf_COMPILETIME) >> 12);
2565 while((ch = *fptr++)) {
2567 reflags[left++] = ch;
2570 reflags[right--] = ch;
2575 reflags[left] = '-';
2579 mg->mg_len = re->prelen + 4 + left;
2581 * If /x was used, we have to worry about a regex ending with a
2582 * comment later being embedded within another regex. If so, we don't
2583 * want this regex's "commentization" to leak out to the right part of
2584 * the enclosing regex, we must cap it with a newline.
2586 * So, if /x was used, we scan backwards from the end of the regex. If
2587 * we find a '#' before we find a newline, we need to add a newline
2588 * ourself. If we find a '\n' first (or if we don't find '#' or '\n'),
2589 * we don't need to add anything. -jfriedl
2591 if (PMf_EXTENDED & re->reganch) {
2592 const char *endptr = re->precomp + re->prelen;
2593 while (endptr >= re->precomp) {
2594 const char c = *(endptr--);
2596 break; /* don't need another */
2598 /* we end while in a comment, so we need a newline */
2599 mg->mg_len++; /* save space for it */
2600 need_newline = 1; /* note to add it */
2606 Newx(mg->mg_ptr, mg->mg_len + 1 + left, char);
2607 mg->mg_ptr[0] = '(';
2608 mg->mg_ptr[1] = '?';
2609 Copy(reflags, mg->mg_ptr+2, left, char);
2610 *(mg->mg_ptr+left+2) = ':';
2611 Copy(re->precomp, mg->mg_ptr+3+left, re->prelen, char);
2613 mg->mg_ptr[mg->mg_len - 2] = '\n';
2614 mg->mg_ptr[mg->mg_len - 1] = ')';
2615 mg->mg_ptr[mg->mg_len] = 0;
2617 PL_reginterp_cnt += re->program[0].next_off;
2619 if (re->reganch & ROPT_UTF8)
2629 =for apidoc sv_2pv_flags
2631 Returns a pointer to the string value of an SV, and sets *lp to its length.
2632 If flags includes SV_GMAGIC, does an mg_get() first. Coerces sv to a string
2634 Normally invoked via the C<SvPV_flags> macro. C<sv_2pv()> and C<sv_2pv_nomg>
2635 usually end up here too.
2641 Perl_sv_2pv_flags(pTHX_ register SV *sv, STRLEN *lp, I32 flags)
2651 if (SvGMAGICAL(sv)) {
2652 if (flags & SV_GMAGIC)
2657 if (flags & SV_MUTABLE_RETURN)
2658 return SvPVX_mutable(sv);
2659 if (flags & SV_CONST_RETURN)
2660 return (char *)SvPVX_const(sv);
2663 if (SvIOKp(sv) || SvNOKp(sv)) {
2664 char tbuf[64]; /* Must fit sprintf/Gconvert of longest IV/NV */
2669 ? my_snprintf(tbuf, sizeof(tbuf), "%"UVuf, (UV)SvUVX(sv))
2670 : my_snprintf(tbuf, sizeof(tbuf), "%"IVdf, (IV)SvIVX(sv));
2672 Gconvert(SvNVX(sv), NV_DIG, 0, tbuf);
2679 #ifdef FIXNEGATIVEZERO
2680 if (len == 2 && tbuf[0] == '-' && tbuf[1] == '0') {
2686 SvUPGRADE(sv, SVt_PV);
2689 s = SvGROW_mutable(sv, len + 1);
2692 return (char*)memcpy(s, tbuf, len + 1);
2698 assert(SvTYPE(sv) >= SVt_PVMG);
2699 /* This falls through to the report_uninit near the end of the
2701 } else if (SvTHINKFIRST(sv)) {
2705 SV *const tmpstr = AMG_CALLun(sv,string);
2706 if (tmpstr && (!SvROK(tmpstr) || (SvRV(tmpstr) != SvRV(sv)))) {
2708 /* char *pv = lp ? SvPV(tmpstr, *lp) : SvPV_nolen(tmpstr);
2712 if ((SvFLAGS(tmpstr) & (SVf_POK)) == SVf_POK) {
2713 if (flags & SV_CONST_RETURN) {
2714 pv = (char *) SvPVX_const(tmpstr);
2716 pv = (flags & SV_MUTABLE_RETURN)
2717 ? SvPVX_mutable(tmpstr) : SvPVX(tmpstr);
2720 *lp = SvCUR(tmpstr);
2722 pv = sv_2pv_flags(tmpstr, lp, flags);
2736 const SV *const referent = (SV*)SvRV(sv);
2740 retval = buffer = savepvn("NULLREF", len);
2741 } else if (SvTYPE(referent) == SVt_PVMG
2742 && ((SvFLAGS(referent) &
2743 (SVs_OBJECT|SVf_OK|SVs_GMG|SVs_SMG|SVs_RMG))
2744 == (SVs_OBJECT|SVs_SMG))
2745 && (mg = mg_find(referent, PERL_MAGIC_qr))) {
2746 return stringify_regexp(sv, mg, lp);
2748 const char *const typestr = sv_reftype(referent, 0);
2749 const STRLEN typelen = strlen(typestr);
2750 UV addr = PTR2UV(referent);
2751 const char *stashname = NULL;
2752 STRLEN stashnamelen = 0; /* hush, gcc */
2753 const char *buffer_end;
2755 if (SvOBJECT(referent)) {
2756 const HEK *const name = HvNAME_HEK(SvSTASH(referent));
2759 stashname = HEK_KEY(name);
2760 stashnamelen = HEK_LEN(name);
2762 if (HEK_UTF8(name)) {
2768 stashname = "__ANON__";
2771 len = stashnamelen + 1 /* = */ + typelen + 3 /* (0x */
2772 + 2 * sizeof(UV) + 2 /* )\0 */;
2774 len = typelen + 3 /* (0x */
2775 + 2 * sizeof(UV) + 2 /* )\0 */;
2778 Newx(buffer, len, char);
2779 buffer_end = retval = buffer + len;
2781 /* Working backwards */
2785 *--retval = PL_hexdigit[addr & 15];
2786 } while (addr >>= 4);
2792 memcpy(retval, typestr, typelen);
2796 retval -= stashnamelen;
2797 memcpy(retval, stashname, stashnamelen);
2799 /* retval may not neccesarily have reached the start of the
2801 assert (retval >= buffer);
2803 len = buffer_end - retval - 1; /* -1 for that \0 */
2811 if (SvREADONLY(sv) && !SvOK(sv)) {
2812 if (ckWARN(WARN_UNINITIALIZED))
2819 if (SvIOK(sv) || ((SvIOKp(sv) && !SvNOKp(sv)))) {
2820 /* I'm assuming that if both IV and NV are equally valid then
2821 converting the IV is going to be more efficient */
2822 const U32 isIOK = SvIOK(sv);
2823 const U32 isUIOK = SvIsUV(sv);
2824 char buf[TYPE_CHARS(UV)];
2827 if (SvTYPE(sv) < SVt_PVIV)
2828 sv_upgrade(sv, SVt_PVIV);
2829 ptr = uiv_2buf(buf, SvIVX(sv), SvUVX(sv), isUIOK, &ebuf);
2830 /* inlined from sv_setpvn */
2831 SvGROW_mutable(sv, (STRLEN)(ebuf - ptr + 1));
2832 Move(ptr,SvPVX_mutable(sv),ebuf - ptr,char);
2833 SvCUR_set(sv, ebuf - ptr);
2843 else if (SvNOKp(sv)) {
2844 const int olderrno = errno;
2845 if (SvTYPE(sv) < SVt_PVNV)
2846 sv_upgrade(sv, SVt_PVNV);
2847 /* The +20 is pure guesswork. Configure test needed. --jhi */
2848 s = SvGROW_mutable(sv, NV_DIG + 20);
2849 /* some Xenix systems wipe out errno here */
2851 if (SvNVX(sv) == 0.0)
2852 my_strlcpy(s, "0", SvLEN(sv));
2856 Gconvert(SvNVX(sv), NV_DIG, 0, s);
2859 #ifdef FIXNEGATIVEZERO
2860 if (*s == '-' && s[1] == '0' && !s[2])
2861 my_strlcpy(s, "0", SvLEN(s));
2870 if (isGV_with_GP(sv))
2871 return glob_2pv((GV *)sv, lp);
2873 if (!PL_localizing && !(SvFLAGS(sv) & SVs_PADTMP) && ckWARN(WARN_UNINITIALIZED))
2877 if (SvTYPE(sv) < SVt_PV)
2878 /* Typically the caller expects that sv_any is not NULL now. */
2879 sv_upgrade(sv, SVt_PV);
2883 const STRLEN len = s - SvPVX_const(sv);
2889 DEBUG_c(PerlIO_printf(Perl_debug_log, "0x%"UVxf" 2pv(%s)\n",
2890 PTR2UV(sv),SvPVX_const(sv)));
2891 if (flags & SV_CONST_RETURN)
2892 return (char *)SvPVX_const(sv);
2893 if (flags & SV_MUTABLE_RETURN)
2894 return SvPVX_mutable(sv);
2899 =for apidoc sv_copypv
2901 Copies a stringified representation of the source SV into the
2902 destination SV. Automatically performs any necessary mg_get and
2903 coercion of numeric values into strings. Guaranteed to preserve
2904 UTF-8 flag even from overloaded objects. Similar in nature to
2905 sv_2pv[_flags] but operates directly on an SV instead of just the
2906 string. Mostly uses sv_2pv_flags to do its work, except when that
2907 would lose the UTF-8'ness of the PV.
2913 Perl_sv_copypv(pTHX_ SV *dsv, register SV *ssv)
2916 const char * const s = SvPV_const(ssv,len);
2917 sv_setpvn(dsv,s,len);
2925 =for apidoc sv_2pvbyte
2927 Return a pointer to the byte-encoded representation of the SV, and set *lp
2928 to its length. May cause the SV to be downgraded from UTF-8 as a
2931 Usually accessed via the C<SvPVbyte> macro.
2937 Perl_sv_2pvbyte(pTHX_ register SV *sv, STRLEN *lp)
2939 sv_utf8_downgrade(sv,0);
2940 return lp ? SvPV(sv,*lp) : SvPV_nolen(sv);
2944 =for apidoc sv_2pvutf8
2946 Return a pointer to the UTF-8-encoded representation of the SV, and set *lp
2947 to its length. May cause the SV to be upgraded to UTF-8 as a side-effect.
2949 Usually accessed via the C<SvPVutf8> macro.
2955 Perl_sv_2pvutf8(pTHX_ register SV *sv, STRLEN *lp)
2957 sv_utf8_upgrade(sv);
2958 return lp ? SvPV(sv,*lp) : SvPV_nolen(sv);
2963 =for apidoc sv_2bool
2965 This function is only called on magical items, and is only used by
2966 sv_true() or its macro equivalent.
2972 Perl_sv_2bool(pTHX_ register SV *sv)
2981 SV * const tmpsv = AMG_CALLun(sv,bool_);
2982 if (tmpsv && (!SvROK(tmpsv) || (SvRV(tmpsv) != SvRV(sv))))
2983 return (bool)SvTRUE(tmpsv);
2985 return SvRV(sv) != 0;
2988 register XPV* const Xpvtmp = (XPV*)SvANY(sv);
2990 (*sv->sv_u.svu_pv > '0' ||
2991 Xpvtmp->xpv_cur > 1 ||
2992 (Xpvtmp->xpv_cur && *sv->sv_u.svu_pv != '0')))
2999 return SvIVX(sv) != 0;
3002 return SvNVX(sv) != 0.0;
3004 if (isGV_with_GP(sv))
3014 =for apidoc sv_utf8_upgrade
3016 Converts the PV of an SV to its UTF-8-encoded form.
3017 Forces the SV to string form if it is not already.
3018 Always sets the SvUTF8 flag to avoid future validity checks even
3019 if all the bytes have hibit clear.
3021 This is not as a general purpose byte encoding to Unicode interface:
3022 use the Encode extension for that.
3024 =for apidoc sv_utf8_upgrade_flags
3026 Converts the PV of an SV to its UTF-8-encoded form.
3027 Forces the SV to string form if it is not already.
3028 Always sets the SvUTF8 flag to avoid future validity checks even
3029 if all the bytes have hibit clear. If C<flags> has C<SV_GMAGIC> bit set,
3030 will C<mg_get> on C<sv> if appropriate, else not. C<sv_utf8_upgrade> and
3031 C<sv_utf8_upgrade_nomg> are implemented in terms of this function.
3033 This is not as a general purpose byte encoding to Unicode interface:
3034 use the Encode extension for that.
3040 Perl_sv_utf8_upgrade_flags(pTHX_ register SV *sv, I32 flags)
3043 if (sv == &PL_sv_undef)
3047 if (SvREADONLY(sv) && (SvPOKp(sv) || SvIOKp(sv) || SvNOKp(sv))) {
3048 (void) sv_2pv_flags(sv,&len, flags);
3052 (void) SvPV_force(sv,len);
3061 sv_force_normal_flags(sv, 0);
3064 if (PL_encoding && !(flags & SV_UTF8_NO_ENCODING))
3065 sv_recode_to_utf8(sv, PL_encoding);
3066 else { /* Assume Latin-1/EBCDIC */
3067 /* This function could be much more efficient if we
3068 * had a FLAG in SVs to signal if there are any hibit
3069 * chars in the PV. Given that there isn't such a flag
3070 * make the loop as fast as possible. */
3071 const U8 * const s = (U8 *) SvPVX_const(sv);
3072 const U8 * const e = (U8 *) SvEND(sv);
3077 /* Check for hi bit */
3078 if (!NATIVE_IS_INVARIANT(ch)) {
3079 STRLEN len = SvCUR(sv) + 1; /* Plus the \0 */
3080 U8 * const recoded = bytes_to_utf8((U8*)s, &len);
3082 SvPV_free(sv); /* No longer using what was there before. */
3083 SvPV_set(sv, (char*)recoded);
3084 SvCUR_set(sv, len - 1);
3085 SvLEN_set(sv, len); /* No longer know the real size. */
3089 /* Mark as UTF-8 even if no hibit - saves scanning loop */
3096 =for apidoc sv_utf8_downgrade
3098 Attempts to convert the PV of an SV from characters to bytes.
3099 If the PV contains a character beyond byte, this conversion will fail;
3100 in this case, either returns false or, if C<fail_ok> is not
3103 This is not as a general purpose Unicode to byte encoding interface:
3104 use the Encode extension for that.
3110 Perl_sv_utf8_downgrade(pTHX_ register SV* sv, bool fail_ok)
3113 if (SvPOKp(sv) && SvUTF8(sv)) {
3119 sv_force_normal_flags(sv, 0);
3121 s = (U8 *) SvPV(sv, len);
3122 if (!utf8_to_bytes(s, &len)) {
3127 Perl_croak(aTHX_ "Wide character in %s",
3130 Perl_croak(aTHX_ "Wide character");
3141 =for apidoc sv_utf8_encode
3143 Converts the PV of an SV to UTF-8, but then turns the C<SvUTF8>
3144 flag off so that it looks like octets again.
3150 Perl_sv_utf8_encode(pTHX_ register SV *sv)
3153 sv_force_normal_flags(sv, 0);
3155 if (SvREADONLY(sv)) {
3156 Perl_croak(aTHX_ PL_no_modify);
3158 (void) sv_utf8_upgrade(sv);
3163 =for apidoc sv_utf8_decode
3165 If the PV of the SV is an octet sequence in UTF-8
3166 and contains a multiple-byte character, the C<SvUTF8> flag is turned on
3167 so that it looks like a character. If the PV contains only single-byte
3168 characters, the C<SvUTF8> flag stays being off.
3169 Scans PV for validity and returns false if the PV is invalid UTF-8.
3175 Perl_sv_utf8_decode(pTHX_ register SV *sv)
3181 /* The octets may have got themselves encoded - get them back as
3184 if (!sv_utf8_downgrade(sv, TRUE))
3187 /* it is actually just a matter of turning the utf8 flag on, but
3188 * we want to make sure everything inside is valid utf8 first.
3190 c = (const U8 *) SvPVX_const(sv);
3191 if (!is_utf8_string(c, SvCUR(sv)+1))
3193 e = (const U8 *) SvEND(sv);
3196 if (!UTF8_IS_INVARIANT(ch)) {
3206 =for apidoc sv_setsv
3208 Copies the contents of the source SV C<ssv> into the destination SV
3209 C<dsv>. The source SV may be destroyed if it is mortal, so don't use this
3210 function if the source SV needs to be reused. Does not handle 'set' magic.
3211 Loosely speaking, it performs a copy-by-value, obliterating any previous
3212 content of the destination.
3214 You probably want to use one of the assortment of wrappers, such as
3215 C<SvSetSV>, C<SvSetSV_nosteal>, C<SvSetMagicSV> and
3216 C<SvSetMagicSV_nosteal>.
3218 =for apidoc sv_setsv_flags
3220 Copies the contents of the source SV C<ssv> into the destination SV
3221 C<dsv>. The source SV may be destroyed if it is mortal, so don't use this
3222 function if the source SV needs to be reused. Does not handle 'set' magic.
3223 Loosely speaking, it performs a copy-by-value, obliterating any previous
3224 content of the destination.
3225 If the C<flags> parameter has the C<SV_GMAGIC> bit set, will C<mg_get> on
3226 C<ssv> if appropriate, else not. If the C<flags> parameter has the
3227 C<NOSTEAL> bit set then the buffers of temps will not be stolen. <sv_setsv>
3228 and C<sv_setsv_nomg> are implemented in terms of this function.
3230 You probably want to use one of the assortment of wrappers, such as
3231 C<SvSetSV>, C<SvSetSV_nosteal>, C<SvSetMagicSV> and
3232 C<SvSetMagicSV_nosteal>.
3234 This is the primary function for copying scalars, and most other
3235 copy-ish functions and macros use this underneath.
3241 S_glob_assign_glob(pTHX_ SV *dstr, SV *sstr, const int dtype)
3243 if (dtype != SVt_PVGV) {
3244 const char * const name = GvNAME(sstr);
3245 const STRLEN len = GvNAMELEN(sstr);
3246 /* don't upgrade SVt_PVLV: it can hold a glob */
3247 if (dtype != SVt_PVLV) {
3248 if (dtype >= SVt_PV) {
3254 sv_upgrade(dstr, SVt_PVGV);
3255 (void)SvOK_off(dstr);
3258 GvSTASH(dstr) = GvSTASH(sstr);
3260 Perl_sv_add_backref(aTHX_ (SV*)GvSTASH(dstr), dstr);
3261 gv_name_set((GV *)dstr, name, len, GV_ADD);
3262 SvFAKE_on(dstr); /* can coerce to non-glob */
3265 #ifdef GV_UNIQUE_CHECK
3266 if (GvUNIQUE((GV*)dstr)) {
3267 Perl_croak(aTHX_ PL_no_modify);
3273 (void)SvOK_off(dstr);
3275 GvINTRO_off(dstr); /* one-shot flag */
3276 GvGP(dstr) = gp_ref(GvGP(sstr));
3277 if (SvTAINTED(sstr))
3279 if (GvIMPORTED(dstr) != GVf_IMPORTED
3280 && CopSTASH_ne(PL_curcop, GvSTASH(dstr)))
3282 GvIMPORTED_on(dstr);
3289 S_glob_assign_ref(pTHX_ SV *dstr, SV *sstr) {
3290 SV * const sref = SvREFCNT_inc(SvRV(sstr));
3292 const int intro = GvINTRO(dstr);
3295 const U32 stype = SvTYPE(sref);
3298 #ifdef GV_UNIQUE_CHECK
3299 if (GvUNIQUE((GV*)dstr)) {
3300 Perl_croak(aTHX_ PL_no_modify);
3305 GvINTRO_off(dstr); /* one-shot flag */
3306 GvLINE(dstr) = CopLINE(PL_curcop);
3307 GvEGV(dstr) = (GV*)dstr;
3312 location = (SV **) &GvCV(dstr);
3313 import_flag = GVf_IMPORTED_CV;
3316 location = (SV **) &GvHV(dstr);
3317 import_flag = GVf_IMPORTED_HV;
3320 location = (SV **) &GvAV(dstr);
3321 import_flag = GVf_IMPORTED_AV;
3324 location = (SV **) &GvIOp(dstr);
3327 location = (SV **) &GvFORM(dstr);
3329 location = &GvSV(dstr);
3330 import_flag = GVf_IMPORTED_SV;
3333 if (stype == SVt_PVCV) {
3334 if (GvCVGEN(dstr) && GvCV(dstr) != (CV*)sref) {
3335 SvREFCNT_dec(GvCV(dstr));
3337 GvCVGEN(dstr) = 0; /* Switch off cacheness. */
3338 PL_sub_generation++;
3341 SAVEGENERICSV(*location);
3345 if (stype == SVt_PVCV && *location != sref) {
3346 CV* const cv = (CV*)*location;
3348 if (!GvCVGEN((GV*)dstr) &&
3349 (CvROOT(cv) || CvXSUB(cv)))
3351 /* Redefining a sub - warning is mandatory if
3352 it was a const and its value changed. */
3353 if (CvCONST(cv) && CvCONST((CV*)sref)
3354 && cv_const_sv(cv) == cv_const_sv((CV*)sref)) {
3356 /* They are 2 constant subroutines generated from
3357 the same constant. This probably means that
3358 they are really the "same" proxy subroutine
3359 instantiated in 2 places. Most likely this is
3360 when a constant is exported twice. Don't warn.
3363 else if (ckWARN(WARN_REDEFINE)
3365 && (!CvCONST((CV*)sref)
3366 || sv_cmp(cv_const_sv(cv),
3367 cv_const_sv((CV*)sref))))) {
3368 Perl_warner(aTHX_ packWARN(WARN_REDEFINE),
3371 ? "Constant subroutine %s::%s redefined"
3372 : "Subroutine %s::%s redefined"),
3373 HvNAME_get(GvSTASH((GV*)dstr)),
3374 GvENAME((GV*)dstr));
3378 cv_ckproto_len(cv, (GV*)dstr,
3379 SvPOK(sref) ? SvPVX_const(sref) : NULL,
3380 SvPOK(sref) ? SvCUR(sref) : 0);
3382 GvCVGEN(dstr) = 0; /* Switch off cacheness. */
3383 GvASSUMECV_on(dstr);
3384 PL_sub_generation++;
3387 if (import_flag && !(GvFLAGS(dstr) & import_flag)
3388 && CopSTASH_ne(PL_curcop, GvSTASH(dstr))) {
3389 GvFLAGS(dstr) |= import_flag;
3394 if (SvTAINTED(sstr))
3400 Perl_sv_setsv_flags(pTHX_ SV *dstr, register SV *sstr, I32 flags)
3403 register U32 sflags;
3405 register svtype stype;
3409 SV_CHECK_THINKFIRST_COW_DROP(dstr);
3411 sstr = &PL_sv_undef;
3412 stype = SvTYPE(sstr);
3413 dtype = SvTYPE(dstr);
3418 /* need to nuke the magic */
3420 SvRMAGICAL_off(dstr);
3423 /* There's a lot of redundancy below but we're going for speed here */
3428 if (dtype != SVt_PVGV) {
3429 (void)SvOK_off(dstr);
3437 sv_upgrade(dstr, SVt_IV);
3442 sv_upgrade(dstr, SVt_PVIV);
3445 (void)SvIOK_only(dstr);
3446 SvIV_set(dstr, SvIVX(sstr));
3449 /* SvTAINTED can only be true if the SV has taint magic, which in
3450 turn means that the SV type is PVMG (or greater). This is the
3451 case statement for SVt_IV, so this cannot be true (whatever gcov
3453 assert(!SvTAINTED(sstr));
3463 sv_upgrade(dstr, SVt_NV);
3468 sv_upgrade(dstr, SVt_PVNV);
3471 SvNV_set(dstr, SvNVX(sstr));
3472 (void)SvNOK_only(dstr);
3473 /* SvTAINTED can only be true if the SV has taint magic, which in
3474 turn means that the SV type is PVMG (or greater). This is the
3475 case statement for SVt_NV, so this cannot be true (whatever gcov
3477 assert(!SvTAINTED(sstr));
3484 sv_upgrade(dstr, SVt_RV);
3487 #ifdef PERL_OLD_COPY_ON_WRITE
3488 if ((SvFLAGS(sstr) & CAN_COW_MASK) == CAN_COW_FLAGS) {
3489 if (dtype < SVt_PVIV)
3490 sv_upgrade(dstr, SVt_PVIV);
3497 sv_upgrade(dstr, SVt_PV);
3500 if (dtype < SVt_PVIV)
3501 sv_upgrade(dstr, SVt_PVIV);
3504 if (dtype < SVt_PVNV)
3505 sv_upgrade(dstr, SVt_PVNV);
3509 const char * const type = sv_reftype(sstr,0);
3511 Perl_croak(aTHX_ "Bizarre copy of %s in %s", type, OP_NAME(PL_op));
3513 Perl_croak(aTHX_ "Bizarre copy of %s", type);
3518 if (dtype <= SVt_PVGV) {
3519 glob_assign_glob(dstr, sstr, dtype);
3527 if (SvGMAGICAL(sstr) && (flags & SV_GMAGIC)) {
3529 if (SvTYPE(sstr) != stype) {
3530 stype = SvTYPE(sstr);
3531 if (stype == SVt_PVGV && dtype <= SVt_PVGV) {
3532 glob_assign_glob(dstr, sstr, dtype);
3537 if (stype == SVt_PVLV)
3538 SvUPGRADE(dstr, SVt_PVNV);
3540 SvUPGRADE(dstr, (svtype)stype);
3543 /* dstr may have been upgraded. */
3544 dtype = SvTYPE(dstr);
3545 sflags = SvFLAGS(sstr);
3547 if (sflags & SVf_ROK) {
3548 if (dtype == SVt_PVGV &&
3549 SvROK(sstr) && SvTYPE(SvRV(sstr)) == SVt_PVGV) {
3552 if (GvIMPORTED(dstr) != GVf_IMPORTED
3553 && CopSTASH_ne(PL_curcop, GvSTASH(dstr)))
3555 GvIMPORTED_on(dstr);
3560 glob_assign_glob(dstr, sstr, dtype);
3564 if (dtype >= SVt_PV) {
3565 if (dtype == SVt_PVGV) {
3566 glob_assign_ref(dstr, sstr);
3569 if (SvPVX_const(dstr)) {
3575 (void)SvOK_off(dstr);
3576 SvRV_set(dstr, SvREFCNT_inc(SvRV(sstr)));
3577 SvFLAGS(dstr) |= sflags & (SVf_ROK|SVf_AMAGIC);
3578 assert(!(sflags & SVp_NOK));
3579 assert(!(sflags & SVp_IOK));
3580 assert(!(sflags & SVf_NOK));
3581 assert(!(sflags & SVf_IOK));
3583 else if (dtype == SVt_PVGV) {
3584 if (!(sflags & SVf_OK)) {
3585 if (ckWARN(WARN_MISC))
3586 Perl_warner(aTHX_ packWARN(WARN_MISC),
3587 "Undefined value assigned to typeglob");
3590 GV *gv = gv_fetchsv(sstr, GV_ADD, SVt_PVGV);
3591 if (dstr != (SV*)gv) {
3594 GvGP(dstr) = gp_ref(GvGP(gv));
3598 else if (sflags & SVp_POK) {
3602 * Check to see if we can just swipe the string. If so, it's a
3603 * possible small lose on short strings, but a big win on long ones.
3604 * It might even be a win on short strings if SvPVX_const(dstr)
3605 * has to be allocated and SvPVX_const(sstr) has to be freed.
3608 /* Whichever path we take through the next code, we want this true,
3609 and doing it now facilitates the COW check. */
3610 (void)SvPOK_only(dstr);
3613 /* We're not already COW */
3614 ((sflags & (SVf_FAKE | SVf_READONLY)) != (SVf_FAKE | SVf_READONLY)
3615 #ifndef PERL_OLD_COPY_ON_WRITE
3616 /* or we are, but dstr isn't a suitable target. */
3617 || (SvFLAGS(dstr) & CAN_COW_MASK) != CAN_COW_FLAGS
3622 (sflags & SVs_TEMP) && /* slated for free anyway? */
3623 !(sflags & SVf_OOK) && /* and not involved in OOK hack? */
3624 (!(flags & SV_NOSTEAL)) &&
3625 /* and we're allowed to steal temps */
3626 SvREFCNT(sstr) == 1 && /* and no other references to it? */
3627 SvLEN(sstr) && /* and really is a string */
3628 /* and won't be needed again, potentially */
3629 !(PL_op && PL_op->op_type == OP_AASSIGN))
3630 #ifdef PERL_OLD_COPY_ON_WRITE
3631 && !((sflags & CAN_COW_MASK) == CAN_COW_FLAGS
3632 && (SvFLAGS(dstr) & CAN_COW_MASK) == CAN_COW_FLAGS
3633 && SvTYPE(sstr) >= SVt_PVIV)
3636 /* Failed the swipe test, and it's not a shared hash key either.
3637 Have to copy the string. */
3638 STRLEN len = SvCUR(sstr);
3639 SvGROW(dstr, len + 1); /* inlined from sv_setpvn */
3640 Move(SvPVX_const(sstr),SvPVX(dstr),len,char);
3641 SvCUR_set(dstr, len);
3642 *SvEND(dstr) = '\0';
3644 /* If PERL_OLD_COPY_ON_WRITE is not defined, then isSwipe will always
3646 /* Either it's a shared hash key, or it's suitable for
3647 copy-on-write or we can swipe the string. */
3649 PerlIO_printf(Perl_debug_log, "Copy on write: sstr --> dstr\n");
3653 #ifdef PERL_OLD_COPY_ON_WRITE
3655 /* I believe I should acquire a global SV mutex if
3656 it's a COW sv (not a shared hash key) to stop
3657 it going un copy-on-write.
3658 If the source SV has gone un copy on write between up there
3659 and down here, then (assert() that) it is of the correct
3660 form to make it copy on write again */
3661 if ((sflags & (SVf_FAKE | SVf_READONLY))
3662 != (SVf_FAKE | SVf_READONLY)) {
3663 SvREADONLY_on(sstr);
3665 /* Make the source SV into a loop of 1.
3666 (about to become 2) */
3667 SV_COW_NEXT_SV_SET(sstr, sstr);
3671 /* Initial code is common. */
3672 if (SvPVX_const(dstr)) { /* we know that dtype >= SVt_PV */
3677 /* making another shared SV. */
3678 STRLEN cur = SvCUR(sstr);
3679 STRLEN len = SvLEN(sstr);
3680 #ifdef PERL_OLD_COPY_ON_WRITE
3682 assert (SvTYPE(dstr) >= SVt_PVIV);
3683 /* SvIsCOW_normal */
3684 /* splice us in between source and next-after-source. */
3685 SV_COW_NEXT_SV_SET(dstr, SV_COW_NEXT_SV(sstr));
3686 SV_COW_NEXT_SV_SET(sstr, dstr);
3687 SvPV_set(dstr, SvPVX_mutable(sstr));
3691 /* SvIsCOW_shared_hash */
3692 DEBUG_C(PerlIO_printf(Perl_debug_log,
3693 "Copy on write: Sharing hash\n"));
3695 assert (SvTYPE(dstr) >= SVt_PV);
3697 HEK_KEY(share_hek_hek(SvSHARED_HEK_FROM_PV(SvPVX_const(sstr)))));
3699 SvLEN_set(dstr, len);
3700 SvCUR_set(dstr, cur);
3701 SvREADONLY_on(dstr);
3703 /* Relesase a global SV mutex. */
3706 { /* Passes the swipe test. */
3707 SvPV_set(dstr, SvPVX_mutable(sstr));
3708 SvLEN_set(dstr, SvLEN(sstr));
3709 SvCUR_set(dstr, SvCUR(sstr));
3712 (void)SvOK_off(sstr); /* NOTE: nukes most SvFLAGS on sstr */
3713 SvPV_set(sstr, NULL);
3719 if (sflags & SVp_NOK) {
3720 SvNV_set(dstr, SvNVX(sstr));
3722 if (sflags & SVp_IOK) {
3723 SvRELEASE_IVX(dstr);
3724 SvIV_set(dstr, SvIVX(sstr));
3725 /* Must do this otherwise some other overloaded use of 0x80000000
3726 gets confused. I guess SVpbm_VALID */
3727 if (sflags & SVf_IVisUV)
3730 SvFLAGS(dstr) |= sflags & (SVf_IOK|SVp_IOK|SVf_NOK|SVp_NOK|SVf_UTF8
3733 const MAGIC * const smg = SvVSTRING_mg(sstr);
3735 sv_magic(dstr, NULL, PERL_MAGIC_vstring,
3736 smg->mg_ptr, smg->mg_len);
3737 SvRMAGICAL_on(dstr);
3741 else if (sflags & (SVp_IOK|SVp_NOK)) {
3742 (void)SvOK_off(dstr);
3743 SvFLAGS(dstr) |= sflags & (SVf_IOK|SVp_IOK|SVf_IVisUV|SVf_NOK|SVp_NOK
3745 if (sflags & SVp_IOK) {
3746 /* XXXX Do we want to set IsUV for IV(ROK)? Be extra safe... */
3747 SvIV_set(dstr, SvIVX(sstr));
3749 if (sflags & SVp_NOK) {
3750 SvNV_set(dstr, SvNVX(sstr));
3754 if (isGV_with_GP(sstr)) {
3755 /* This stringification rule for globs is spread in 3 places.
3756 This feels bad. FIXME. */
3757 const U32 wasfake = sflags & SVf_FAKE;
3759 /* FAKE globs can get coerced, so need to turn this off
3760 temporarily if it is on. */
3762 gv_efullname3(dstr, (GV *)sstr, "*");
3763 SvFLAGS(sstr) |= wasfake;
3764 SvFLAGS(dstr) |= sflags & SVf_AMAGIC;
3767 (void)SvOK_off(dstr);
3769 if (SvTAINTED(sstr))
3774 =for apidoc sv_setsv_mg
3776 Like C<sv_setsv>, but also handles 'set' magic.
3782 Perl_sv_setsv_mg(pTHX_ SV *dstr, register SV *sstr)
3784 sv_setsv(dstr,sstr);
3788 #ifdef PERL_OLD_COPY_ON_WRITE
3790 Perl_sv_setsv_cow(pTHX_ SV *dstr, SV *sstr)
3792 STRLEN cur = SvCUR(sstr);
3793 STRLEN len = SvLEN(sstr);
3794 register char *new_pv;
3797 PerlIO_printf(Perl_debug_log, "Fast copy on write: %p -> %p\n",
3805 if (SvTHINKFIRST(dstr))
3806 sv_force_normal_flags(dstr, SV_COW_DROP_PV);
3807 else if (SvPVX_const(dstr))
3808 Safefree(SvPVX_const(dstr));
3812 SvUPGRADE(dstr, SVt_PVIV);
3814 assert (SvPOK(sstr));
3815 assert (SvPOKp(sstr));
3816 assert (!SvIOK(sstr));
3817 assert (!SvIOKp(sstr));
3818 assert (!SvNOK(sstr));
3819 assert (!SvNOKp(sstr));
3821 if (SvIsCOW(sstr)) {
3823 if (SvLEN(sstr) == 0) {
3824 /* source is a COW shared hash key. */
3825 DEBUG_C(PerlIO_printf(Perl_debug_log,
3826 "Fast copy on write: Sharing hash\n"));
3827 new_pv = HEK_KEY(share_hek_hek(SvSHARED_HEK_FROM_PV(SvPVX_const(sstr))));
3830 SV_COW_NEXT_SV_SET(dstr, SV_COW_NEXT_SV(sstr));
3832 assert ((SvFLAGS(sstr) & CAN_COW_MASK) == CAN_COW_FLAGS);
3833 SvUPGRADE(sstr, SVt_PVIV);
3834 SvREADONLY_on(sstr);
3836 DEBUG_C(PerlIO_printf(Perl_debug_log,
3837 "Fast copy on write: Converting sstr to COW\n"));
3838 SV_COW_NEXT_SV_SET(dstr, sstr);
3840 SV_COW_NEXT_SV_SET(sstr, dstr);
3841 new_pv = SvPVX_mutable(sstr);
3844 SvPV_set(dstr, new_pv);
3845 SvFLAGS(dstr) = (SVt_PVIV|SVf_POK|SVp_POK|SVf_FAKE|SVf_READONLY);
3848 SvLEN_set(dstr, len);
3849 SvCUR_set(dstr, cur);
3858 =for apidoc sv_setpvn
3860 Copies a string into an SV. The C<len> parameter indicates the number of
3861 bytes to be copied. If the C<ptr> argument is NULL the SV will become
3862 undefined. Does not handle 'set' magic. See C<sv_setpvn_mg>.
3868 Perl_sv_setpvn(pTHX_ register SV *sv, register const char *ptr, register STRLEN len)
3871 register char *dptr;
3873 SV_CHECK_THINKFIRST_COW_DROP(sv);
3879 /* len is STRLEN which is unsigned, need to copy to signed */
3882 Perl_croak(aTHX_ "panic: sv_setpvn called with negative strlen");
3884 SvUPGRADE(sv, SVt_PV);
3886 dptr = SvGROW(sv, len + 1);
3887 Move(ptr,dptr,len,char);
3890 (void)SvPOK_only_UTF8(sv); /* validate pointer */
3895 =for apidoc sv_setpvn_mg
3897 Like C<sv_setpvn>, but also handles 'set' magic.
3903 Perl_sv_setpvn_mg(pTHX_ register SV *sv, register const char *ptr, register STRLEN len)
3905 sv_setpvn(sv,ptr,len);
3910 =for apidoc sv_setpv
3912 Copies a string into an SV. The string must be null-terminated. Does not
3913 handle 'set' magic. See C<sv_setpv_mg>.
3919 Perl_sv_setpv(pTHX_ register SV *sv, register const char *ptr)
3922 register STRLEN len;
3924 SV_CHECK_THINKFIRST_COW_DROP(sv);
3930 SvUPGRADE(sv, SVt_PV);
3932 SvGROW(sv, len + 1);
3933 Move(ptr,SvPVX(sv),len+1,char);
3935 (void)SvPOK_only_UTF8(sv); /* validate pointer */
3940 =for apidoc sv_setpv_mg
3942 Like C<sv_setpv>, but also handles 'set' magic.
3948 Perl_sv_setpv_mg(pTHX_ register SV *sv, register const char *ptr)
3955 =for apidoc sv_usepvn_flags
3957 Tells an SV to use C<ptr> to find its string value. Normally the
3958 string is stored inside the SV but sv_usepvn allows the SV to use an
3959 outside string. The C<ptr> should point to memory that was allocated
3960 by C<malloc>. The string length, C<len>, must be supplied. By default
3961 this function will realloc (i.e. move) the memory pointed to by C<ptr>,
3962 so that pointer should not be freed or used by the programmer after
3963 giving it to sv_usepvn, and neither should any pointers from "behind"
3964 that pointer (e.g. ptr + 1) be used.
3966 If C<flags> & SV_SMAGIC is true, will call SvSETMAGIC. If C<flags> &
3967 SV_HAS_TRAILING_NUL is true, then C<ptr[len]> must be NUL, and the realloc
3968 will be skipped. (i.e. the buffer is actually at least 1 byte longer than
3969 C<len>, and already meets the requirements for storing in C<SvPVX>)
3975 Perl_sv_usepvn_flags(pTHX_ SV *sv, char *ptr, STRLEN len, U32 flags)
3979 SV_CHECK_THINKFIRST_COW_DROP(sv);
3980 SvUPGRADE(sv, SVt_PV);
3983 if (flags & SV_SMAGIC)
3987 if (SvPVX_const(sv))
3991 if (flags & SV_HAS_TRAILING_NUL)
3992 assert(ptr[len] == '\0');
3995 allocate = (flags & SV_HAS_TRAILING_NUL)
3996 ? len + 1: PERL_STRLEN_ROUNDUP(len + 1);
3997 if (flags & SV_HAS_TRAILING_NUL) {
3998 /* It's long enough - do nothing.
3999 Specfically Perl_newCONSTSUB is relying on this. */
4002 /* Force a move to shake out bugs in callers. */
4003 char *new_ptr = (char*)safemalloc(allocate);
4004 Copy(ptr, new_ptr, len, char);
4005 PoisonFree(ptr,len,char);
4009 ptr = (char*) saferealloc (ptr, allocate);
4014 SvLEN_set(sv, allocate);
4015 if (!(flags & SV_HAS_TRAILING_NUL)) {
4018 (void)SvPOK_only_UTF8(sv); /* validate pointer */
4020 if (flags & SV_SMAGIC)
4024 #ifdef PERL_OLD_COPY_ON_WRITE
4025 /* Need to do this *after* making the SV normal, as we need the buffer
4026 pointer to remain valid until after we've copied it. If we let go too early,
4027 another thread could invalidate it by unsharing last of the same hash key
4028 (which it can do by means other than releasing copy-on-write Svs)
4029 or by changing the other copy-on-write SVs in the loop. */
4031 S_sv_release_COW(pTHX_ register SV *sv, const char *pvx, STRLEN len, SV *after)
4033 if (len) { /* this SV was SvIsCOW_normal(sv) */
4034 /* we need to find the SV pointing to us. */
4035 SV *current = SV_COW_NEXT_SV(after);
4037 if (current == sv) {
4038 /* The SV we point to points back to us (there were only two of us
4040 Hence other SV is no longer copy on write either. */
4042 SvREADONLY_off(after);
4044 /* We need to follow the pointers around the loop. */
4046 while ((next = SV_COW_NEXT_SV(current)) != sv) {
4049 /* don't loop forever if the structure is bust, and we have
4050 a pointer into a closed loop. */
4051 assert (current != after);
4052 assert (SvPVX_const(current) == pvx);
4054 /* Make the SV before us point to the SV after us. */
4055 SV_COW_NEXT_SV_SET(current, after);
4058 unshare_hek(SvSHARED_HEK_FROM_PV(pvx));
4063 Perl_sv_release_IVX(pTHX_ register SV *sv)
4066 sv_force_normal_flags(sv, 0);
4072 =for apidoc sv_force_normal_flags
4074 Undo various types of fakery on an SV: if the PV is a shared string, make
4075 a private copy; if we're a ref, stop refing; if we're a glob, downgrade to
4076 an xpvmg; if we're a copy-on-write scalar, this is the on-write time when
4077 we do the copy, and is also used locally. If C<SV_COW_DROP_PV> is set
4078 then a copy-on-write scalar drops its PV buffer (if any) and becomes
4079 SvPOK_off rather than making a copy. (Used where this scalar is about to be
4080 set to some other value.) In addition, the C<flags> parameter gets passed to
4081 C<sv_unref_flags()> when unrefing. C<sv_force_normal> calls this function
4082 with flags set to 0.
4088 Perl_sv_force_normal_flags(pTHX_ register SV *sv, U32 flags)
4091 #ifdef PERL_OLD_COPY_ON_WRITE
4092 if (SvREADONLY(sv)) {
4093 /* At this point I believe I should acquire a global SV mutex. */
4095 const char * const pvx = SvPVX_const(sv);
4096 const STRLEN len = SvLEN(sv);
4097 const STRLEN cur = SvCUR(sv);
4098 SV * const next = SV_COW_NEXT_SV(sv); /* next COW sv in the loop. */
4100 PerlIO_printf(Perl_debug_log,
4101 "Copy on write: Force normal %ld\n",
4107 /* This SV doesn't own the buffer, so need to Newx() a new one: */
4110 if (flags & SV_COW_DROP_PV) {
4111 /* OK, so we don't need to copy our buffer. */
4114 SvGROW(sv, cur + 1);
4115 Move(pvx,SvPVX(sv),cur,char);
4119 sv_release_COW(sv, pvx, len, next);
4124 else if (IN_PERL_RUNTIME)
4125 Perl_croak(aTHX_ PL_no_modify);
4126 /* At this point I believe that I can drop the global SV mutex. */
4129 if (SvREADONLY(sv)) {
4131 const char * const pvx = SvPVX_const(sv);
4132 const STRLEN len = SvCUR(sv);
4137 SvGROW(sv, len + 1);
4138 Move(pvx,SvPVX(sv),len,char);
4140 unshare_hek(SvSHARED_HEK_FROM_PV(pvx));
4142 else if (IN_PERL_RUNTIME)
4143 Perl_croak(aTHX_ PL_no_modify);
4147 sv_unref_flags(sv, flags);
4148 else if (SvFAKE(sv) && SvTYPE(sv) == SVt_PVGV)
4155 Efficient removal of characters from the beginning of the string buffer.
4156 SvPOK(sv) must be true and the C<ptr> must be a pointer to somewhere inside
4157 the string buffer. The C<ptr> becomes the first character of the adjusted
4158 string. Uses the "OOK hack".
4159 Beware: after this function returns, C<ptr> and SvPVX_const(sv) may no longer
4160 refer to the same chunk of data.
4166 Perl_sv_chop(pTHX_ register SV *sv, register const char *ptr)
4168 register STRLEN delta;
4169 if (!ptr || !SvPOKp(sv))
4171 delta = ptr - SvPVX_const(sv);
4172 SV_CHECK_THINKFIRST(sv);
4173 if (SvTYPE(sv) < SVt_PVIV)
4174 sv_upgrade(sv,SVt_PVIV);
4177 if (!SvLEN(sv)) { /* make copy of shared string */
4178 const char *pvx = SvPVX_const(sv);
4179 const STRLEN len = SvCUR(sv);
4180 SvGROW(sv, len + 1);
4181 Move(pvx,SvPVX(sv),len,char);
4185 /* Same SvOOK_on but SvOOK_on does a SvIOK_off
4186 and we do that anyway inside the SvNIOK_off
4188 SvFLAGS(sv) |= SVf_OOK;
4191 SvLEN_set(sv, SvLEN(sv) - delta);
4192 SvCUR_set(sv, SvCUR(sv) - delta);
4193 SvPV_set(sv, SvPVX(sv) + delta);
4194 SvIV_set(sv, SvIVX(sv) + delta);
4198 =for apidoc sv_catpvn
4200 Concatenates the string onto the end of the string which is in the SV. The
4201 C<len> indicates number of bytes to copy. If the SV has the UTF-8
4202 status set, then the bytes appended should be valid UTF-8.
4203 Handles 'get' magic, but not 'set' magic. See C<sv_catpvn_mg>.
4205 =for apidoc sv_catpvn_flags
4207 Concatenates the string onto the end of the string which is in the SV. The
4208 C<len> indicates number of bytes to copy. If the SV has the UTF-8
4209 status set, then the bytes appended should be valid UTF-8.
4210 If C<flags> has C<SV_GMAGIC> bit set, will C<mg_get> on C<dsv> if
4211 appropriate, else not. C<sv_catpvn> and C<sv_catpvn_nomg> are implemented
4212 in terms of this function.
4218 Perl_sv_catpvn_flags(pTHX_ register SV *dsv, register const char *sstr, register STRLEN slen, I32 flags)
4222 const char * const dstr = SvPV_force_flags(dsv, dlen, flags);
4224 SvGROW(dsv, dlen + slen + 1);
4226 sstr = SvPVX_const(dsv);
4227 Move(sstr, SvPVX(dsv) + dlen, slen, char);
4228 SvCUR_set(dsv, SvCUR(dsv) + slen);
4230 (void)SvPOK_only_UTF8(dsv); /* validate pointer */
4232 if (flags & SV_SMAGIC)
4237 =for apidoc sv_catsv
4239 Concatenates the string from SV C<ssv> onto the end of the string in
4240 SV C<dsv>. Modifies C<dsv> but not C<ssv>. Handles 'get' magic, but
4241 not 'set' magic. See C<sv_catsv_mg>.
4243 =for apidoc sv_catsv_flags
4245 Concatenates the string from SV C<ssv> onto the end of the string in
4246 SV C<dsv>. Modifies C<dsv> but not C<ssv>. If C<flags> has C<SV_GMAGIC>
4247 bit set, will C<mg_get> on the SVs if appropriate, else not. C<sv_catsv>
4248 and C<sv_catsv_nomg> are implemented in terms of this function.
4253 Perl_sv_catsv_flags(pTHX_ SV *dsv, register SV *ssv, I32 flags)
4258 const char *spv = SvPV_const(ssv, slen);
4260 /* sutf8 and dutf8 were type bool, but under USE_ITHREADS,
4261 gcc version 2.95.2 20000220 (Debian GNU/Linux) for
4262 Linux xxx 2.2.17 on sparc64 with gcc -O2, we erroneously
4263 get dutf8 = 0x20000000, (i.e. SVf_UTF8) even though
4264 dsv->sv_flags doesn't have that bit set.
4265 Andy Dougherty 12 Oct 2001
4267 const I32 sutf8 = DO_UTF8(ssv);
4270 if (SvGMAGICAL(dsv) && (flags & SV_GMAGIC))
4272 dutf8 = DO_UTF8(dsv);
4274 if (dutf8 != sutf8) {
4276 /* Not modifying source SV, so taking a temporary copy. */
4277 SV* const csv = sv_2mortal(newSVpvn(spv, slen));
4279 sv_utf8_upgrade(csv);
4280 spv = SvPV_const(csv, slen);
4283 sv_utf8_upgrade_nomg(dsv);
4285 sv_catpvn_nomg(dsv, spv, slen);
4288 if (flags & SV_SMAGIC)
4293 =for apidoc sv_catpv
4295 Concatenates the string onto the end of the string which is in the SV.
4296 If the SV has the UTF-8 status set, then the bytes appended should be
4297 valid UTF-8. Handles 'get' magic, but not 'set' magic. See C<sv_catpv_mg>.
4302 Perl_sv_catpv(pTHX_ register SV *sv, register const char *ptr)
4305 register STRLEN len;
4311 junk = SvPV_force(sv, tlen);
4313 SvGROW(sv, tlen + len + 1);
4315 ptr = SvPVX_const(sv);
4316 Move(ptr,SvPVX(sv)+tlen,len+1,char);
4317 SvCUR_set(sv, SvCUR(sv) + len);
4318 (void)SvPOK_only_UTF8(sv); /* validate pointer */
4323 =for apidoc sv_catpv_mg
4325 Like C<sv_catpv>, but also handles 'set' magic.
4331 Perl_sv_catpv_mg(pTHX_ register SV *sv, register const char *ptr)
4340 Creates a new SV. A non-zero C<len> parameter indicates the number of
4341 bytes of preallocated string space the SV should have. An extra byte for a
4342 trailing NUL is also reserved. (SvPOK is not set for the SV even if string
4343 space is allocated.) The reference count for the new SV is set to 1.
4345 In 5.9.3, newSV() replaces the older NEWSV() API, and drops the first
4346 parameter, I<x>, a debug aid which allowed callers to identify themselves.
4347 This aid has been superseded by a new build option, PERL_MEM_LOG (see
4348 L<perlhack/PERL_MEM_LOG>). The older API is still there for use in XS
4349 modules supporting older perls.
4355 Perl_newSV(pTHX_ STRLEN len)
4362 sv_upgrade(sv, SVt_PV);
4363 SvGROW(sv, len + 1);
4368 =for apidoc sv_magicext
4370 Adds magic to an SV, upgrading it if necessary. Applies the
4371 supplied vtable and returns a pointer to the magic added.
4373 Note that C<sv_magicext> will allow things that C<sv_magic> will not.
4374 In particular, you can add magic to SvREADONLY SVs, and add more than
4375 one instance of the same 'how'.
4377 If C<namlen> is greater than zero then a C<savepvn> I<copy> of C<name> is
4378 stored, if C<namlen> is zero then C<name> is stored as-is and - as another
4379 special case - if C<(name && namlen == HEf_SVKEY)> then C<name> is assumed
4380 to contain an C<SV*> and is stored as-is with its REFCNT incremented.
4382 (This is now used as a subroutine by C<sv_magic>.)
4387 Perl_sv_magicext(pTHX_ SV* sv, SV* obj, int how, MGVTBL *vtable,
4388 const char* name, I32 namlen)
4393 if (SvTYPE(sv) < SVt_PVMG) {
4394 SvUPGRADE(sv, SVt_PVMG);
4396 Newxz(mg, 1, MAGIC);
4397 mg->mg_moremagic = SvMAGIC(sv);
4398 SvMAGIC_set(sv, mg);
4400 /* Sometimes a magic contains a reference loop, where the sv and
4401 object refer to each other. To prevent a reference loop that
4402 would prevent such objects being freed, we look for such loops
4403 and if we find one we avoid incrementing the object refcount.
4405 Note we cannot do this to avoid self-tie loops as intervening RV must
4406 have its REFCNT incremented to keep it in existence.
4409 if (!obj || obj == sv ||
4410 how == PERL_MAGIC_arylen ||
4411 how == PERL_MAGIC_qr ||
4412 how == PERL_MAGIC_symtab ||
4413 (SvTYPE(obj) == SVt_PVGV &&
4414 (GvSV(obj) == sv || GvHV(obj) == (HV*)sv || GvAV(obj) == (AV*)sv ||
4415 GvCV(obj) == (CV*)sv || GvIOp(obj) == (IO*)sv ||
4416 GvFORM(obj) == (CV*)sv)))
4421 mg->mg_obj = SvREFCNT_inc_simple(obj);
4422 mg->mg_flags |= MGf_REFCOUNTED;
4425 /* Normal self-ties simply pass a null object, and instead of
4426 using mg_obj directly, use the SvTIED_obj macro to produce a
4427 new RV as needed. For glob "self-ties", we are tieing the PVIO
4428 with an RV obj pointing to the glob containing the PVIO. In
4429 this case, to avoid a reference loop, we need to weaken the
4433 if (how == PERL_MAGIC_tiedscalar && SvTYPE(sv) == SVt_PVIO &&
4434 obj && SvROK(obj) && GvIO(SvRV(obj)) == (IO*)sv)
4440 mg->mg_len = namlen;
4443 mg->mg_ptr = savepvn(name, namlen);
4444 else if (namlen == HEf_SVKEY)
4445 mg->mg_ptr = (char*)SvREFCNT_inc_simple_NN((SV*)name);
4447 mg->mg_ptr = (char *) name;
4449 mg->mg_virtual = vtable;
4453 SvFLAGS(sv) &= ~(SVf_IOK|SVf_NOK|SVf_POK);
4458 =for apidoc sv_magic
4460 Adds magic to an SV. First upgrades C<sv> to type C<SVt_PVMG> if necessary,
4461 then adds a new magic item of type C<how> to the head of the magic list.
4463 See C<sv_magicext> (which C<sv_magic> now calls) for a description of the
4464 handling of the C<name> and C<namlen> arguments.
4466 You need to use C<sv_magicext> to add magic to SvREADONLY SVs and also
4467 to add more than one instance of the same 'how'.
4473 Perl_sv_magic(pTHX_ register SV *sv, SV *obj, int how, const char *name, I32 namlen)
4479 #ifdef PERL_OLD_COPY_ON_WRITE
4481 sv_force_normal_flags(sv, 0);
4483 if (SvREADONLY(sv)) {
4485 /* its okay to attach magic to shared strings; the subsequent
4486 * upgrade to PVMG will unshare the string */
4487 !(SvFAKE(sv) && SvTYPE(sv) < SVt_PVMG)
4490 && how != PERL_MAGIC_regex_global
4491 && how != PERL_MAGIC_bm
4492 && how != PERL_MAGIC_fm
4493 && how != PERL_MAGIC_sv
4494 && how != PERL_MAGIC_backref
4497 Perl_croak(aTHX_ PL_no_modify);
4500 if (SvMAGICAL(sv) || (how == PERL_MAGIC_taint && SvTYPE(sv) >= SVt_PVMG)) {
4501 if (SvMAGIC(sv) && (mg = mg_find(sv, how))) {
4502 /* sv_magic() refuses to add a magic of the same 'how' as an
4505 if (how == PERL_MAGIC_taint) {
4507 /* Any scalar which already had taint magic on which someone
4508 (erroneously?) did SvIOK_on() or similar will now be
4509 incorrectly sporting public "OK" flags. */
4510 SvFLAGS(sv) &= ~(SVf_IOK|SVf_NOK|SVf_POK);
4518 vtable = &PL_vtbl_sv;
4520 case PERL_MAGIC_overload:
4521 vtable = &PL_vtbl_amagic;
4523 case PERL_MAGIC_overload_elem:
4524 vtable = &PL_vtbl_amagicelem;
4526 case PERL_MAGIC_overload_table:
4527 vtable = &PL_vtbl_ovrld;
4530 vtable = &PL_vtbl_bm;
4532 case PERL_MAGIC_regdata:
4533 vtable = &PL_vtbl_regdata;
4535 case PERL_MAGIC_regdata_names:
4536 vtable = &PL_vtbl_regdata_names;
4538 case PERL_MAGIC_regdatum:
4539 vtable = &PL_vtbl_regdatum;
4541 case PERL_MAGIC_env:
4542 vtable = &PL_vtbl_env;
4545 vtable = &PL_vtbl_fm;
4547 case PERL_MAGIC_envelem:
4548 vtable = &PL_vtbl_envelem;
4550 case PERL_MAGIC_regex_global:
4551 vtable = &PL_vtbl_mglob;
4553 case PERL_MAGIC_isa:
4554 vtable = &PL_vtbl_isa;
4556 case PERL_MAGIC_isaelem:
4557 vtable = &PL_vtbl_isaelem;
4559 case PERL_MAGIC_nkeys:
4560 vtable = &PL_vtbl_nkeys;
4562 case PERL_MAGIC_dbfile:
4565 case PERL_MAGIC_dbline:
4566 vtable = &PL_vtbl_dbline;
4568 #ifdef USE_LOCALE_COLLATE
4569 case PERL_MAGIC_collxfrm:
4570 vtable = &PL_vtbl_collxfrm;
4572 #endif /* USE_LOCALE_COLLATE */
4573 case PERL_MAGIC_tied:
4574 vtable = &PL_vtbl_pack;
4576 case PERL_MAGIC_tiedelem:
4577 case PERL_MAGIC_tiedscalar:
4578 vtable = &PL_vtbl_packelem;
4581 vtable = &PL_vtbl_regexp;
4583 case PERL_MAGIC_hints:
4584 /* As this vtable is all NULL, we can reuse it. */
4585 case PERL_MAGIC_sig:
4586 vtable = &PL_vtbl_sig;
4588 case PERL_MAGIC_sigelem:
4589 vtable = &PL_vtbl_sigelem;
4591 case PERL_MAGIC_taint:
4592 vtable = &PL_vtbl_taint;
4594 case PERL_MAGIC_uvar:
4595 vtable = &PL_vtbl_uvar;
4597 case PERL_MAGIC_vec:
4598 vtable = &PL_vtbl_vec;
4600 case PERL_MAGIC_arylen_p:
4601 case PERL_MAGIC_rhash:
4602 case PERL_MAGIC_symtab:
4603 case PERL_MAGIC_vstring:
4606 case PERL_MAGIC_utf8:
4607 vtable = &PL_vtbl_utf8;
4609 case PERL_MAGIC_substr:
4610 vtable = &PL_vtbl_substr;
4612 case PERL_MAGIC_defelem:
4613 vtable = &PL_vtbl_defelem;
4615 case PERL_MAGIC_arylen:
4616 vtable = &PL_vtbl_arylen;
4618 case PERL_MAGIC_pos:
4619 vtable = &PL_vtbl_pos;
4621 case PERL_MAGIC_backref:
4622 vtable = &PL_vtbl_backref;
4624 case PERL_MAGIC_hintselem:
4625 vtable = &PL_vtbl_hintselem;
4627 case PERL_MAGIC_ext:
4628 /* Reserved for use by extensions not perl internals. */
4629 /* Useful for attaching extension internal data to perl vars. */
4630 /* Note that multiple extensions may clash if magical scalars */
4631 /* etc holding private data from one are passed to another. */
4635 Perl_croak(aTHX_ "Don't know how to handle magic of type \\%o", how);
4638 /* Rest of work is done else where */
4639 mg = sv_magicext(sv,obj,how,vtable,name,namlen);
4642 case PERL_MAGIC_taint:
4645 case PERL_MAGIC_ext:
4646 case PERL_MAGIC_dbfile:
4653 =for apidoc sv_unmagic
4655 Removes all magic of type C<type> from an SV.
4661 Perl_sv_unmagic(pTHX_ SV *sv, int type)
4665 if (SvTYPE(sv) < SVt_PVMG || !SvMAGIC(sv))
4667 mgp = &(((XPVMG*) SvANY(sv))->xmg_u.xmg_magic);
4668 for (mg = *mgp; mg; mg = *mgp) {
4669 if (mg->mg_type == type) {
4670 const MGVTBL* const vtbl = mg->mg_virtual;
4671 *mgp = mg->mg_moremagic;
4672 if (vtbl && vtbl->svt_free)
4673 CALL_FPTR(vtbl->svt_free)(aTHX_ sv, mg);
4674 if (mg->mg_ptr && mg->mg_type != PERL_MAGIC_regex_global) {
4676 Safefree(mg->mg_ptr);
4677 else if (mg->mg_len == HEf_SVKEY)
4678 SvREFCNT_dec((SV*)mg->mg_ptr);
4679 else if (mg->mg_type == PERL_MAGIC_utf8)
4680 Safefree(mg->mg_ptr);
4682 if (mg->mg_flags & MGf_REFCOUNTED)
4683 SvREFCNT_dec(mg->mg_obj);
4687 mgp = &mg->mg_moremagic;
4691 SvFLAGS(sv) |= (SvFLAGS(sv) & (SVp_IOK|SVp_NOK|SVp_POK)) >> PRIVSHIFT;
4692 SvMAGIC_set(sv, NULL);
4699 =for apidoc sv_rvweaken
4701 Weaken a reference: set the C<SvWEAKREF> flag on this RV; give the
4702 referred-to SV C<PERL_MAGIC_backref> magic if it hasn't already; and
4703 push a back-reference to this RV onto the array of backreferences
4704 associated with that magic. If the RV is magical, set magic will be
4705 called after the RV is cleared.
4711 Perl_sv_rvweaken(pTHX_ SV *sv)
4714 if (!SvOK(sv)) /* let undefs pass */
4717 Perl_croak(aTHX_ "Can't weaken a nonreference");
4718 else if (SvWEAKREF(sv)) {
4719 if (ckWARN(WARN_MISC))
4720 Perl_warner(aTHX_ packWARN(WARN_MISC), "Reference is already weak");
4724 Perl_sv_add_backref(aTHX_ tsv, sv);
4730 /* Give tsv backref magic if it hasn't already got it, then push a
4731 * back-reference to sv onto the array associated with the backref magic.
4735 Perl_sv_add_backref(pTHX_ SV *tsv, SV *sv)
4740 if (SvTYPE(tsv) == SVt_PVHV) {
4741 AV **const avp = Perl_hv_backreferences_p(aTHX_ (HV*)tsv);
4745 /* There is no AV in the offical place - try a fixup. */
4746 MAGIC *const mg = mg_find(tsv, PERL_MAGIC_backref);
4749 /* Aha. They've got it stowed in magic. Bring it back. */
4750 av = (AV*)mg->mg_obj;
4751 /* Stop mg_free decreasing the refernce count. */
4753 /* Stop mg_free even calling the destructor, given that
4754 there's no AV to free up. */
4756 sv_unmagic(tsv, PERL_MAGIC_backref);
4760 SvREFCNT_inc_simple_void(av);
4765 const MAGIC *const mg
4766 = SvMAGICAL(tsv) ? mg_find(tsv, PERL_MAGIC_backref) : NULL;
https://perl5.git.perl.org / perl5.git / blob