3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
4 * 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 by Larry Wall
7 * You may distribute under the terms of either the GNU General Public
8 * License or the Artistic License, as specified in the README file.
13 * 'I wonder what the Entish is for "yes" and "no",' he thought.
16 * [p.480 of _The Lord of the Rings_, III/iv: "Treebeard"]
22 * This file contains the code that creates, manipulates and destroys
23 * scalar values (SVs). The other types (AV, HV, GV, etc.) reuse the
24 * structure of an SV, so their creation and destruction is handled
25 * here; higher-level functions are in av.c, hv.c, and so on. Opcode
26 * level functions (eg. substr, split, join) for each of the types are
36 # if __STDC_VERSION__ >= 199901L && !defined(VMS)
47 /* Missing proto on LynxOS */
48 char *gconvert(double, int, int, char *);
51 #ifdef PERL_UTF8_CACHE_ASSERT
52 /* if adding more checks watch out for the following tests:
53 * t/op/index.t t/op/length.t t/op/pat.t t/op/substr.t
54 * lib/utf8.t lib/Unicode/Collate/t/index.t
57 # define ASSERT_UTF8_CACHE(cache) \
58 STMT_START { if (cache) { assert((cache)[0] <= (cache)[1]); \
59 assert((cache)[2] <= (cache)[3]); \
60 assert((cache)[3] <= (cache)[1]);} \
63 # define ASSERT_UTF8_CACHE(cache) NOOP
66 #ifdef PERL_OLD_COPY_ON_WRITE
67 #define SV_COW_NEXT_SV(sv) INT2PTR(SV *,SvUVX(sv))
68 #define SV_COW_NEXT_SV_SET(current,next) SvUV_set(current, PTR2UV(next))
69 /* This is a pessimistic view. Scalar must be purely a read-write PV to copy-
73 /* ============================================================================
75 =head1 Allocation and deallocation of SVs.
77 An SV (or AV, HV, etc.) is allocated in two parts: the head (struct
78 sv, av, hv...) contains type and reference count information, and for
79 many types, a pointer to the body (struct xrv, xpv, xpviv...), which
80 contains fields specific to each type. Some types store all they need
81 in the head, so don't have a body.
83 In all but the most memory-paranoid configurations (ex: PURIFY), heads
84 and bodies are allocated out of arenas, which by default are
85 approximately 4K chunks of memory parcelled up into N heads or bodies.
86 Sv-bodies are allocated by their sv-type, guaranteeing size
87 consistency needed to allocate safely from arrays.
89 For SV-heads, the first slot in each arena is reserved, and holds a
90 link to the next arena, some flags, and a note of the number of slots.
91 Snaked through each arena chain is a linked list of free items; when
92 this becomes empty, an extra arena is allocated and divided up into N
93 items which are threaded into the free list.
95 SV-bodies are similar, but they use arena-sets by default, which
96 separate the link and info from the arena itself, and reclaim the 1st
97 slot in the arena. SV-bodies are further described later.
99 The following global variables are associated with arenas:
101 PL_sv_arenaroot pointer to list of SV arenas
102 PL_sv_root pointer to list of free SV structures
104 PL_body_arenas head of linked-list of body arenas
105 PL_body_roots[] array of pointers to list of free bodies of svtype
106 arrays are indexed by the svtype needed
108 A few special SV heads are not allocated from an arena, but are
109 instead directly created in the interpreter structure, eg PL_sv_undef.
110 The size of arenas can be changed from the default by setting
111 PERL_ARENA_SIZE appropriately at compile time.
113 The SV arena serves the secondary purpose of allowing still-live SVs
114 to be located and destroyed during final cleanup.
116 At the lowest level, the macros new_SV() and del_SV() grab and free
117 an SV head. (If debugging with -DD, del_SV() calls the function S_del_sv()
118 to return the SV to the free list with error checking.) new_SV() calls
119 more_sv() / sv_add_arena() to add an extra arena if the free list is empty.
120 SVs in the free list have their SvTYPE field set to all ones.
122 At the time of very final cleanup, sv_free_arenas() is called from
123 perl_destruct() to physically free all the arenas allocated since the
124 start of the interpreter.
126 The function visit() scans the SV arenas list, and calls a specified
127 function for each SV it finds which is still live - ie which has an SvTYPE
128 other than all 1's, and a non-zero SvREFCNT. visit() is used by the
129 following functions (specified as [function that calls visit()] / [function
130 called by visit() for each SV]):
132 sv_report_used() / do_report_used()
133 dump all remaining SVs (debugging aid)
135 sv_clean_objs() / do_clean_objs(),do_clean_named_objs(),
136 do_clean_named_io_objs()
137 Attempt to free all objects pointed to by RVs,
138 and try to do the same for all objects indirectly
139 referenced by typeglobs too. Called once from
140 perl_destruct(), prior to calling sv_clean_all()
143 sv_clean_all() / do_clean_all()
144 SvREFCNT_dec(sv) each remaining SV, possibly
145 triggering an sv_free(). It also sets the
146 SVf_BREAK flag on the SV to indicate that the
147 refcnt has been artificially lowered, and thus
148 stopping sv_free() from giving spurious warnings
149 about SVs which unexpectedly have a refcnt
150 of zero. called repeatedly from perl_destruct()
151 until there are no SVs left.
153 =head2 Arena allocator API Summary
155 Private API to rest of sv.c
159 new_XPVNV(), del_XPVGV(),
164 sv_report_used(), sv_clean_objs(), sv_clean_all(), sv_free_arenas()
168 * ========================================================================= */
171 * "A time to plant, and a time to uproot what was planted..."
175 # define MEM_LOG_NEW_SV(sv, file, line, func) \
176 Perl_mem_log_new_sv(sv, file, line, func)
177 # define MEM_LOG_DEL_SV(sv, file, line, func) \
178 Perl_mem_log_del_sv(sv, file, line, func)
180 # define MEM_LOG_NEW_SV(sv, file, line, func) NOOP
181 # define MEM_LOG_DEL_SV(sv, file, line, func) NOOP
184 #ifdef DEBUG_LEAKING_SCALARS
185 # define FREE_SV_DEBUG_FILE(sv) Safefree((sv)->sv_debug_file)
186 # define DEBUG_SV_SERIAL(sv) \
187 DEBUG_m(PerlIO_printf(Perl_debug_log, "0x%"UVxf": (%05ld) del_SV\n", \
188 PTR2UV(sv), (long)(sv)->sv_debug_serial))
190 # define FREE_SV_DEBUG_FILE(sv)
191 # define DEBUG_SV_SERIAL(sv) NOOP
195 # define SvARENA_CHAIN(sv) ((sv)->sv_u.svu_rv)
196 # define SvARENA_CHAIN_SET(sv,val) (sv)->sv_u.svu_rv = MUTABLE_SV((val))
197 /* Whilst I'd love to do this, it seems that things like to check on
199 # define POSION_SV_HEAD(sv) PoisonNew(sv, 1, struct STRUCT_SV)
201 # define POSION_SV_HEAD(sv) PoisonNew(&SvANY(sv), 1, void *), \
202 PoisonNew(&SvREFCNT(sv), 1, U32)
204 # define SvARENA_CHAIN(sv) SvANY(sv)
205 # define SvARENA_CHAIN_SET(sv,val) SvANY(sv) = (void *)(val)
206 # define POSION_SV_HEAD(sv)
209 /* Mark an SV head as unused, and add to free list.
211 * If SVf_BREAK is set, skip adding it to the free list, as this SV had
212 * its refcount artificially decremented during global destruction, so
213 * there may be dangling pointers to it. The last thing we want in that
214 * case is for it to be reused. */
216 #define plant_SV(p) \
218 const U32 old_flags = SvFLAGS(p); \
219 MEM_LOG_DEL_SV(p, __FILE__, __LINE__, FUNCTION__); \
220 DEBUG_SV_SERIAL(p); \
221 FREE_SV_DEBUG_FILE(p); \
223 SvFLAGS(p) = SVTYPEMASK; \
224 if (!(old_flags & SVf_BREAK)) { \
225 SvARENA_CHAIN_SET(p, PL_sv_root); \
231 #define uproot_SV(p) \
234 PL_sv_root = MUTABLE_SV(SvARENA_CHAIN(p)); \
239 /* make some more SVs by adding another arena */
246 char *chunk; /* must use New here to match call to */
247 Newx(chunk,PERL_ARENA_SIZE,char); /* Safefree() in sv_free_arenas() */
248 sv_add_arena(chunk, PERL_ARENA_SIZE, 0);
253 /* new_SV(): return a new, empty SV head */
255 #ifdef DEBUG_LEAKING_SCALARS
256 /* provide a real function for a debugger to play with */
258 S_new_SV(pTHX_ const char *file, int line, const char *func)
265 sv = S_more_sv(aTHX);
269 sv->sv_debug_optype = PL_op ? PL_op->op_type : 0;
270 sv->sv_debug_line = (U16) (PL_parser && PL_parser->copline != NOLINE
276 sv->sv_debug_inpad = 0;
277 sv->sv_debug_parent = NULL;
278 sv->sv_debug_file = PL_curcop ? savepv(CopFILE(PL_curcop)): NULL;
280 sv->sv_debug_serial = PL_sv_serial++;
282 MEM_LOG_NEW_SV(sv, file, line, func);
283 DEBUG_m(PerlIO_printf(Perl_debug_log, "0x%"UVxf": (%05ld) new_SV (from %s:%d [%s])\n",
284 PTR2UV(sv), (long)sv->sv_debug_serial, file, line, func));
288 # define new_SV(p) (p)=S_new_SV(aTHX_ __FILE__, __LINE__, FUNCTION__)
296 (p) = S_more_sv(aTHX); \
300 MEM_LOG_NEW_SV(p, __FILE__, __LINE__, FUNCTION__); \
305 /* del_SV(): return an empty SV head to the free list */
318 S_del_sv(pTHX_ SV *p)
322 PERL_ARGS_ASSERT_DEL_SV;
327 for (sva = PL_sv_arenaroot; sva; sva = MUTABLE_SV(SvANY(sva))) {
328 const SV * const sv = sva + 1;
329 const SV * const svend = &sva[SvREFCNT(sva)];
330 if (p >= sv && p < svend) {
336 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
337 "Attempt to free non-arena SV: 0x%"UVxf
338 pTHX__FORMAT, PTR2UV(p) pTHX__VALUE);
345 #else /* ! DEBUGGING */
347 #define del_SV(p) plant_SV(p)
349 #endif /* DEBUGGING */
353 =head1 SV Manipulation Functions
355 =for apidoc sv_add_arena
357 Given a chunk of memory, link it to the head of the list of arenas,
358 and split it into a list of free SVs.
364 S_sv_add_arena(pTHX_ char *const ptr, const U32 size, const U32 flags)
367 SV *const sva = MUTABLE_SV(ptr);
371 PERL_ARGS_ASSERT_SV_ADD_ARENA;
373 /* The first SV in an arena isn't an SV. */
374 SvANY(sva) = (void *) PL_sv_arenaroot; /* ptr to next arena */
375 SvREFCNT(sva) = size / sizeof(SV); /* number of SV slots */
376 SvFLAGS(sva) = flags; /* FAKE if not to be freed */
378 PL_sv_arenaroot = sva;
379 PL_sv_root = sva + 1;
381 svend = &sva[SvREFCNT(sva) - 1];
384 SvARENA_CHAIN_SET(sv, (sv + 1));
388 /* Must always set typemask because it's always checked in on cleanup
389 when the arenas are walked looking for objects. */
390 SvFLAGS(sv) = SVTYPEMASK;
393 SvARENA_CHAIN_SET(sv, 0);
397 SvFLAGS(sv) = SVTYPEMASK;
400 /* visit(): call the named function for each non-free SV in the arenas
401 * whose flags field matches the flags/mask args. */
404 S_visit(pTHX_ SVFUNC_t f, const U32 flags, const U32 mask)
410 PERL_ARGS_ASSERT_VISIT;
412 for (sva = PL_sv_arenaroot; sva; sva = MUTABLE_SV(SvANY(sva))) {
413 register const SV * const svend = &sva[SvREFCNT(sva)];
415 for (sv = sva + 1; sv < svend; ++sv) {
416 if (SvTYPE(sv) != (svtype)SVTYPEMASK
417 && (sv->sv_flags & mask) == flags
430 /* called by sv_report_used() for each live SV */
433 do_report_used(pTHX_ SV *const sv)
435 if (SvTYPE(sv) != (svtype)SVTYPEMASK) {
436 PerlIO_printf(Perl_debug_log, "****\n");
443 =for apidoc sv_report_used
445 Dump the contents of all SVs not yet freed (debugging aid).
451 Perl_sv_report_used(pTHX)
454 visit(do_report_used, 0, 0);
460 /* called by sv_clean_objs() for each live SV */
463 do_clean_objs(pTHX_ SV *const ref)
468 SV * const target = SvRV(ref);
469 if (SvOBJECT(target)) {
470 DEBUG_D((PerlIO_printf(Perl_debug_log, "Cleaning object ref:\n "), sv_dump(ref)));
471 if (SvWEAKREF(ref)) {
472 sv_del_backref(target, ref);
478 SvREFCNT_dec(target);
483 /* XXX Might want to check arrays, etc. */
487 /* clear any slots in a GV which hold objects - except IO;
488 * called by sv_clean_objs() for each live GV */
491 do_clean_named_objs(pTHX_ SV *const sv)
495 assert(SvTYPE(sv) == SVt_PVGV);
496 assert(isGV_with_GP(sv));
500 /* freeing GP entries may indirectly free the current GV;
501 * hold onto it while we mess with the GP slots */
504 if ( ((obj = GvSV(sv) )) && SvOBJECT(obj)) {
505 DEBUG_D((PerlIO_printf(Perl_debug_log,
506 "Cleaning named glob SV object:\n "), sv_dump(obj)));
510 if ( ((obj = MUTABLE_SV(GvAV(sv)) )) && SvOBJECT(obj)) {
511 DEBUG_D((PerlIO_printf(Perl_debug_log,
512 "Cleaning named glob AV object:\n "), sv_dump(obj)));
516 if ( ((obj = MUTABLE_SV(GvHV(sv)) )) && SvOBJECT(obj)) {
517 DEBUG_D((PerlIO_printf(Perl_debug_log,
518 "Cleaning named glob HV object:\n "), sv_dump(obj)));
522 if ( ((obj = MUTABLE_SV(GvCV(sv)) )) && SvOBJECT(obj)) {
523 DEBUG_D((PerlIO_printf(Perl_debug_log,
524 "Cleaning named glob CV object:\n "), sv_dump(obj)));
528 SvREFCNT_dec(sv); /* undo the inc above */
531 /* clear any IO slots in a GV which hold objects (except stderr, defout);
532 * called by sv_clean_objs() for each live GV */
535 do_clean_named_io_objs(pTHX_ SV *const sv)
539 assert(SvTYPE(sv) == SVt_PVGV);
540 assert(isGV_with_GP(sv));
541 if (!GvGP(sv) || sv == (SV*)PL_stderrgv || sv == (SV*)PL_defoutgv)
545 if ( ((obj = MUTABLE_SV(GvIO(sv)) )) && SvOBJECT(obj)) {
546 DEBUG_D((PerlIO_printf(Perl_debug_log,
547 "Cleaning named glob IO object:\n "), sv_dump(obj)));
551 SvREFCNT_dec(sv); /* undo the inc above */
554 /* Void wrapper to pass to visit() */
556 do_curse(pTHX_ SV * const sv) {
557 if ((PL_stderrgv && GvGP(PL_stderrgv) && (SV*)GvIO(PL_stderrgv) == sv)
558 || (PL_defoutgv && GvGP(PL_defoutgv) && (SV*)GvIO(PL_defoutgv) == sv))
564 =for apidoc sv_clean_objs
566 Attempt to destroy all objects not yet freed.
572 Perl_sv_clean_objs(pTHX)
576 PL_in_clean_objs = TRUE;
577 visit(do_clean_objs, SVf_ROK, SVf_ROK);
578 /* Some barnacles may yet remain, clinging to typeglobs.
579 * Run the non-IO destructors first: they may want to output
580 * error messages, close files etc */
581 visit(do_clean_named_objs, SVt_PVGV|SVpgv_GP, SVTYPEMASK|SVp_POK|SVpgv_GP);
582 visit(do_clean_named_io_objs, SVt_PVGV|SVpgv_GP, SVTYPEMASK|SVp_POK|SVpgv_GP);
583 /* And if there are some very tenacious barnacles clinging to arrays,
584 closures, or what have you.... */
585 visit(do_curse, SVs_OBJECT, SVs_OBJECT);
586 olddef = PL_defoutgv;
587 PL_defoutgv = NULL; /* disable skip of PL_defoutgv */
588 if (olddef && isGV_with_GP(olddef))
589 do_clean_named_io_objs(aTHX_ MUTABLE_SV(olddef));
590 olderr = PL_stderrgv;
591 PL_stderrgv = NULL; /* disable skip of PL_stderrgv */
592 if (olderr && isGV_with_GP(olderr))
593 do_clean_named_io_objs(aTHX_ MUTABLE_SV(olderr));
594 SvREFCNT_dec(olddef);
595 PL_in_clean_objs = FALSE;
598 /* called by sv_clean_all() for each live SV */
601 do_clean_all(pTHX_ SV *const sv)
604 if (sv == (const SV *) PL_fdpid || sv == (const SV *)PL_strtab) {
605 /* don't clean pid table and strtab */
608 DEBUG_D((PerlIO_printf(Perl_debug_log, "Cleaning loops: SV at 0x%"UVxf"\n", PTR2UV(sv)) ));
609 SvFLAGS(sv) |= SVf_BREAK;
614 =for apidoc sv_clean_all
616 Decrement the refcnt of each remaining SV, possibly triggering a
617 cleanup. This function may have to be called multiple times to free
618 SVs which are in complex self-referential hierarchies.
624 Perl_sv_clean_all(pTHX)
628 PL_in_clean_all = TRUE;
629 cleaned = visit(do_clean_all, 0,0);
634 ARENASETS: a meta-arena implementation which separates arena-info
635 into struct arena_set, which contains an array of struct
636 arena_descs, each holding info for a single arena. By separating
637 the meta-info from the arena, we recover the 1st slot, formerly
638 borrowed for list management. The arena_set is about the size of an
639 arena, avoiding the needless malloc overhead of a naive linked-list.
641 The cost is 1 arena-set malloc per ~320 arena-mallocs, + the unused
642 memory in the last arena-set (1/2 on average). In trade, we get
643 back the 1st slot in each arena (ie 1.7% of a CV-arena, less for
644 smaller types). The recovery of the wasted space allows use of
645 small arenas for large, rare body types, by changing array* fields
646 in body_details_by_type[] below.
649 char *arena; /* the raw storage, allocated aligned */
650 size_t size; /* its size ~4k typ */
651 svtype utype; /* bodytype stored in arena */
656 /* Get the maximum number of elements in set[] such that struct arena_set
657 will fit within PERL_ARENA_SIZE, which is probably just under 4K, and
658 therefore likely to be 1 aligned memory page. */
660 #define ARENAS_PER_SET ((PERL_ARENA_SIZE - sizeof(struct arena_set*) \
661 - 2 * sizeof(int)) / sizeof (struct arena_desc))
664 struct arena_set* next;
665 unsigned int set_size; /* ie ARENAS_PER_SET */
666 unsigned int curr; /* index of next available arena-desc */
667 struct arena_desc set[ARENAS_PER_SET];
671 =for apidoc sv_free_arenas
673 Deallocate the memory used by all arenas. Note that all the individual SV
674 heads and bodies within the arenas must already have been freed.
679 Perl_sv_free_arenas(pTHX)
686 /* Free arenas here, but be careful about fake ones. (We assume
687 contiguity of the fake ones with the corresponding real ones.) */
689 for (sva = PL_sv_arenaroot; sva; sva = svanext) {
690 svanext = MUTABLE_SV(SvANY(sva));
691 while (svanext && SvFAKE(svanext))
692 svanext = MUTABLE_SV(SvANY(svanext));
699 struct arena_set *aroot = (struct arena_set*) PL_body_arenas;
702 struct arena_set *current = aroot;
705 assert(aroot->set[i].arena);
706 Safefree(aroot->set[i].arena);
714 i = PERL_ARENA_ROOTS_SIZE;
716 PL_body_roots[i] = 0;
723 Here are mid-level routines that manage the allocation of bodies out
724 of the various arenas. There are 5 kinds of arenas:
726 1. SV-head arenas, which are discussed and handled above
727 2. regular body arenas
728 3. arenas for reduced-size bodies
731 Arena types 2 & 3 are chained by body-type off an array of
732 arena-root pointers, which is indexed by svtype. Some of the
733 larger/less used body types are malloced singly, since a large
734 unused block of them is wasteful. Also, several svtypes dont have
735 bodies; the data fits into the sv-head itself. The arena-root
736 pointer thus has a few unused root-pointers (which may be hijacked
737 later for arena types 4,5)
739 3 differs from 2 as an optimization; some body types have several
740 unused fields in the front of the structure (which are kept in-place
741 for consistency). These bodies can be allocated in smaller chunks,
742 because the leading fields arent accessed. Pointers to such bodies
743 are decremented to point at the unused 'ghost' memory, knowing that
744 the pointers are used with offsets to the real memory.
747 =head1 SV-Body Allocation
749 Allocation of SV-bodies is similar to SV-heads, differing as follows;
750 the allocation mechanism is used for many body types, so is somewhat
751 more complicated, it uses arena-sets, and has no need for still-live
754 At the outermost level, (new|del)_X*V macros return bodies of the
755 appropriate type. These macros call either (new|del)_body_type or
756 (new|del)_body_allocated macro pairs, depending on specifics of the
757 type. Most body types use the former pair, the latter pair is used to
758 allocate body types with "ghost fields".
760 "ghost fields" are fields that are unused in certain types, and
761 consequently don't need to actually exist. They are declared because
762 they're part of a "base type", which allows use of functions as
763 methods. The simplest examples are AVs and HVs, 2 aggregate types
764 which don't use the fields which support SCALAR semantics.
766 For these types, the arenas are carved up into appropriately sized
767 chunks, we thus avoid wasted memory for those unaccessed members.
768 When bodies are allocated, we adjust the pointer back in memory by the
769 size of the part not allocated, so it's as if we allocated the full
770 structure. (But things will all go boom if you write to the part that
771 is "not there", because you'll be overwriting the last members of the
772 preceding structure in memory.)
774 We calculate the correction using the STRUCT_OFFSET macro on the first
775 member present. If the allocated structure is smaller (no initial NV
776 actually allocated) then the net effect is to subtract the size of the NV
777 from the pointer, to return a new pointer as if an initial NV were actually
778 allocated. (We were using structures named *_allocated for this, but
779 this turned out to be a subtle bug, because a structure without an NV
780 could have a lower alignment constraint, but the compiler is allowed to
781 optimised accesses based on the alignment constraint of the actual pointer
782 to the full structure, for example, using a single 64 bit load instruction
783 because it "knows" that two adjacent 32 bit members will be 8-byte aligned.)
785 This is the same trick as was used for NV and IV bodies. Ironically it
786 doesn't need to be used for NV bodies any more, because NV is now at
787 the start of the structure. IV bodies don't need it either, because
788 they are no longer allocated.
790 In turn, the new_body_* allocators call S_new_body(), which invokes
791 new_body_inline macro, which takes a lock, and takes a body off the
792 linked list at PL_body_roots[sv_type], calling Perl_more_bodies() if
793 necessary to refresh an empty list. Then the lock is released, and
794 the body is returned.
796 Perl_more_bodies allocates a new arena, and carves it up into an array of N
797 bodies, which it strings into a linked list. It looks up arena-size
798 and body-size from the body_details table described below, thus
799 supporting the multiple body-types.
801 If PURIFY is defined, or PERL_ARENA_SIZE=0, arenas are not used, and
802 the (new|del)_X*V macros are mapped directly to malloc/free.
804 For each sv-type, struct body_details bodies_by_type[] carries
805 parameters which control these aspects of SV handling:
807 Arena_size determines whether arenas are used for this body type, and if
808 so, how big they are. PURIFY or PERL_ARENA_SIZE=0 set this field to
809 zero, forcing individual mallocs and frees.
811 Body_size determines how big a body is, and therefore how many fit into
812 each arena. Offset carries the body-pointer adjustment needed for
813 "ghost fields", and is used in *_allocated macros.
815 But its main purpose is to parameterize info needed in
816 Perl_sv_upgrade(). The info here dramatically simplifies the function
817 vs the implementation in 5.8.8, making it table-driven. All fields
818 are used for this, except for arena_size.
820 For the sv-types that have no bodies, arenas are not used, so those
821 PL_body_roots[sv_type] are unused, and can be overloaded. In
822 something of a special case, SVt_NULL is borrowed for HE arenas;
823 PL_body_roots[HE_SVSLOT=SVt_NULL] is filled by S_more_he, but the
824 bodies_by_type[SVt_NULL] slot is not used, as the table is not
829 struct body_details {
830 U8 body_size; /* Size to allocate */
831 U8 copy; /* Size of structure to copy (may be shorter) */
833 unsigned int type : 4; /* We have space for a sanity check. */
834 unsigned int cant_upgrade : 1; /* Cannot upgrade this type */
835 unsigned int zero_nv : 1; /* zero the NV when upgrading from this */
836 unsigned int arena : 1; /* Allocated from an arena */
837 size_t arena_size; /* Size of arena to allocate */
845 /* With -DPURFIY we allocate everything directly, and don't use arenas.
846 This seems a rather elegant way to simplify some of the code below. */
847 #define HASARENA FALSE
849 #define HASARENA TRUE
851 #define NOARENA FALSE
853 /* Size the arenas to exactly fit a given number of bodies. A count
854 of 0 fits the max number bodies into a PERL_ARENA_SIZE.block,
855 simplifying the default. If count > 0, the arena is sized to fit
856 only that many bodies, allowing arenas to be used for large, rare
857 bodies (XPVFM, XPVIO) without undue waste. The arena size is
858 limited by PERL_ARENA_SIZE, so we can safely oversize the
861 #define FIT_ARENA0(body_size) \
862 ((size_t)(PERL_ARENA_SIZE / body_size) * body_size)
863 #define FIT_ARENAn(count,body_size) \
864 ( count * body_size <= PERL_ARENA_SIZE) \
865 ? count * body_size \
866 : FIT_ARENA0 (body_size)
867 #define FIT_ARENA(count,body_size) \
869 ? FIT_ARENAn (count, body_size) \
870 : FIT_ARENA0 (body_size)
872 /* Calculate the length to copy. Specifically work out the length less any
873 final padding the compiler needed to add. See the comment in sv_upgrade
874 for why copying the padding proved to be a bug. */
876 #define copy_length(type, last_member) \
877 STRUCT_OFFSET(type, last_member) \
878 + sizeof (((type*)SvANY((const SV *)0))->last_member)
880 static const struct body_details bodies_by_type[] = {
881 /* HEs use this offset for their arena. */
882 { 0, 0, 0, SVt_NULL, FALSE, NONV, NOARENA, 0 },
884 /* The bind placeholder pretends to be an RV for now.
885 Also it's marked as "can't upgrade" to stop anyone using it before it's
887 { 0, 0, 0, SVt_BIND, TRUE, NONV, NOARENA, 0 },
889 /* IVs are in the head, so the allocation size is 0. */
891 sizeof(IV), /* This is used to copy out the IV body. */
892 STRUCT_OFFSET(XPVIV, xiv_iv), SVt_IV, FALSE, NONV,
893 NOARENA /* IVS don't need an arena */, 0
896 { sizeof(NV), sizeof(NV),
897 STRUCT_OFFSET(XPVNV, xnv_u),
898 SVt_NV, FALSE, HADNV, HASARENA, FIT_ARENA(0, sizeof(NV)) },
900 { sizeof(XPV) - STRUCT_OFFSET(XPV, xpv_cur),
901 copy_length(XPV, xpv_len) - STRUCT_OFFSET(XPV, xpv_cur),
902 + STRUCT_OFFSET(XPV, xpv_cur),
903 SVt_PV, FALSE, NONV, HASARENA,
904 FIT_ARENA(0, sizeof(XPV) - STRUCT_OFFSET(XPV, xpv_cur)) },
906 { sizeof(XPVIV) - STRUCT_OFFSET(XPV, xpv_cur),
907 copy_length(XPVIV, xiv_u) - STRUCT_OFFSET(XPV, xpv_cur),
908 + STRUCT_OFFSET(XPV, xpv_cur),
909 SVt_PVIV, FALSE, NONV, HASARENA,
910 FIT_ARENA(0, sizeof(XPVIV) - STRUCT_OFFSET(XPV, xpv_cur)) },
912 { sizeof(XPVNV) - STRUCT_OFFSET(XPV, xpv_cur),
913 copy_length(XPVNV, xnv_u) - STRUCT_OFFSET(XPV, xpv_cur),
914 + STRUCT_OFFSET(XPV, xpv_cur),
915 SVt_PVNV, FALSE, HADNV, HASARENA,
916 FIT_ARENA(0, sizeof(XPVNV) - STRUCT_OFFSET(XPV, xpv_cur)) },
918 { sizeof(XPVMG), copy_length(XPVMG, xnv_u), 0, SVt_PVMG, FALSE, HADNV,
919 HASARENA, FIT_ARENA(0, sizeof(XPVMG)) },
924 SVt_REGEXP, FALSE, NONV, HASARENA,
925 FIT_ARENA(0, sizeof(regexp))
928 { sizeof(XPVGV), sizeof(XPVGV), 0, SVt_PVGV, TRUE, HADNV,
929 HASARENA, FIT_ARENA(0, sizeof(XPVGV)) },
931 { sizeof(XPVLV), sizeof(XPVLV), 0, SVt_PVLV, TRUE, HADNV,
932 HASARENA, FIT_ARENA(0, sizeof(XPVLV)) },
935 copy_length(XPVAV, xav_alloc),
937 SVt_PVAV, TRUE, NONV, HASARENA,
938 FIT_ARENA(0, sizeof(XPVAV)) },
941 copy_length(XPVHV, xhv_max),
943 SVt_PVHV, TRUE, NONV, HASARENA,
944 FIT_ARENA(0, sizeof(XPVHV)) },
949 SVt_PVCV, TRUE, NONV, HASARENA,
950 FIT_ARENA(0, sizeof(XPVCV)) },
955 SVt_PVFM, TRUE, NONV, NOARENA,
956 FIT_ARENA(20, sizeof(XPVFM)) },
961 SVt_PVIO, TRUE, NONV, HASARENA,
962 FIT_ARENA(24, sizeof(XPVIO)) },
965 #define new_body_allocated(sv_type) \
966 (void *)((char *)S_new_body(aTHX_ sv_type) \
967 - bodies_by_type[sv_type].offset)
969 /* return a thing to the free list */
971 #define del_body(thing, root) \
973 void ** const thing_copy = (void **)thing; \
974 *thing_copy = *root; \
975 *root = (void*)thing_copy; \
980 #define new_XNV() safemalloc(sizeof(XPVNV))
981 #define new_XPVNV() safemalloc(sizeof(XPVNV))
982 #define new_XPVMG() safemalloc(sizeof(XPVMG))
984 #define del_XPVGV(p) safefree(p)
988 #define new_XNV() new_body_allocated(SVt_NV)
989 #define new_XPVNV() new_body_allocated(SVt_PVNV)
990 #define new_XPVMG() new_body_allocated(SVt_PVMG)
992 #define del_XPVGV(p) del_body(p + bodies_by_type[SVt_PVGV].offset, \
993 &PL_body_roots[SVt_PVGV])
997 /* no arena for you! */
999 #define new_NOARENA(details) \
1000 safemalloc((details)->body_size + (details)->offset)
1001 #define new_NOARENAZ(details) \
1002 safecalloc((details)->body_size + (details)->offset, 1)
1005 Perl_more_bodies (pTHX_ const svtype sv_type, const size_t body_size,
1006 const size_t arena_size)
1009 void ** const root = &PL_body_roots[sv_type];
1010 struct arena_desc *adesc;
1011 struct arena_set *aroot = (struct arena_set *) PL_body_arenas;
1015 const size_t good_arena_size = Perl_malloc_good_size(arena_size);
1016 #if defined(DEBUGGING) && !defined(PERL_GLOBAL_STRUCT_PRIVATE)
1017 static bool done_sanity_check;
1019 /* PERL_GLOBAL_STRUCT_PRIVATE cannot coexist with global
1020 * variables like done_sanity_check. */
1021 if (!done_sanity_check) {
1022 unsigned int i = SVt_LAST;
1024 done_sanity_check = TRUE;
1027 assert (bodies_by_type[i].type == i);
1033 /* may need new arena-set to hold new arena */
1034 if (!aroot || aroot->curr >= aroot->set_size) {
1035 struct arena_set *newroot;
1036 Newxz(newroot, 1, struct arena_set);
1037 newroot->set_size = ARENAS_PER_SET;
1038 newroot->next = aroot;
1040 PL_body_arenas = (void *) newroot;
1041 DEBUG_m(PerlIO_printf(Perl_debug_log, "new arenaset %p\n", (void*)aroot));
1044 /* ok, now have arena-set with at least 1 empty/available arena-desc */
1045 curr = aroot->curr++;
1046 adesc = &(aroot->set[curr]);
1047 assert(!adesc->arena);
1049 Newx(adesc->arena, good_arena_size, char);
1050 adesc->size = good_arena_size;
1051 adesc->utype = sv_type;
1052 DEBUG_m(PerlIO_printf(Perl_debug_log, "arena %d added: %p size %"UVuf"\n",
1053 curr, (void*)adesc->arena, (UV)good_arena_size));
1055 start = (char *) adesc->arena;
1057 /* Get the address of the byte after the end of the last body we can fit.
1058 Remember, this is integer division: */
1059 end = start + good_arena_size / body_size * body_size;
1061 /* computed count doesn't reflect the 1st slot reservation */
1062 #if defined(MYMALLOC) || defined(HAS_MALLOC_GOOD_SIZE)
1063 DEBUG_m(PerlIO_printf(Perl_debug_log,
1064 "arena %p end %p arena-size %d (from %d) type %d "
1066 (void*)start, (void*)end, (int)good_arena_size,
1067 (int)arena_size, sv_type, (int)body_size,
1068 (int)good_arena_size / (int)body_size));
1070 DEBUG_m(PerlIO_printf(Perl_debug_log,
1071 "arena %p end %p arena-size %d type %d size %d ct %d\n",
1072 (void*)start, (void*)end,
1073 (int)arena_size, sv_type, (int)body_size,
1074 (int)good_arena_size / (int)body_size));
1076 *root = (void *)start;
1079 /* Where the next body would start: */
1080 char * const next = start + body_size;
1083 /* This is the last body: */
1084 assert(next == end);
1086 *(void **)start = 0;
1090 *(void**) start = (void *)next;
1095 /* grab a new thing from the free list, allocating more if necessary.
1096 The inline version is used for speed in hot routines, and the
1097 function using it serves the rest (unless PURIFY).
1099 #define new_body_inline(xpv, sv_type) \
1101 void ** const r3wt = &PL_body_roots[sv_type]; \
1102 xpv = (PTR_TBL_ENT_t*) (*((void **)(r3wt)) \
1103 ? *((void **)(r3wt)) : Perl_more_bodies(aTHX_ sv_type, \
1104 bodies_by_type[sv_type].body_size,\
1105 bodies_by_type[sv_type].arena_size)); \
1106 *(r3wt) = *(void**)(xpv); \
1112 S_new_body(pTHX_ const svtype sv_type)
1116 new_body_inline(xpv, sv_type);
1122 static const struct body_details fake_rv =
1123 { 0, 0, 0, SVt_IV, FALSE, NONV, NOARENA, 0 };
1126 =for apidoc sv_upgrade
1128 Upgrade an SV to a more complex form. Generally adds a new body type to the
1129 SV, then copies across as much information as possible from the old body.
1130 It croaks if the SV is already in a more complex form than requested. You
1131 generally want to use the C<SvUPGRADE> macro wrapper, which checks the type
1132 before calling C<sv_upgrade>, and hence does not croak. See also
1139 Perl_sv_upgrade(pTHX_ register SV *const sv, svtype new_type)
1144 const svtype old_type = SvTYPE(sv);
1145 const struct body_details *new_type_details;
1146 const struct body_details *old_type_details
1147 = bodies_by_type + old_type;
1148 SV *referant = NULL;
1150 PERL_ARGS_ASSERT_SV_UPGRADE;
1152 if (old_type == new_type)
1155 /* This clause was purposefully added ahead of the early return above to
1156 the shared string hackery for (sort {$a <=> $b} keys %hash), with the
1157 inference by Nick I-S that it would fix other troublesome cases. See
1158 changes 7162, 7163 (f130fd4589cf5fbb24149cd4db4137c8326f49c1 and parent)
1160 Given that shared hash key scalars are no longer PVIV, but PV, there is
1161 no longer need to unshare so as to free up the IVX slot for its proper
1162 purpose. So it's safe to move the early return earlier. */
1164 if (new_type != SVt_PV && SvIsCOW(sv)) {
1165 sv_force_normal_flags(sv, 0);
1168 old_body = SvANY(sv);
1170 /* Copying structures onto other structures that have been neatly zeroed
1171 has a subtle gotcha. Consider XPVMG
1173 +------+------+------+------+------+-------+-------+
1174 | NV | CUR | LEN | IV | MAGIC | STASH |
1175 +------+------+------+------+------+-------+-------+
1176 0 4 8 12 16 20 24 28
1178 where NVs are aligned to 8 bytes, so that sizeof that structure is
1179 actually 32 bytes long, with 4 bytes of padding at the end:
1181 +------+------+------+------+------+-------+-------+------+
1182 | NV | CUR | LEN | IV | MAGIC | STASH | ??? |
1183 +------+------+------+------+------+-------+-------+------+
1184 0 4 8 12 16 20 24 28 32
1186 so what happens if you allocate memory for this structure:
1188 +------+------+------+------+------+-------+-------+------+------+...
1189 | NV | CUR | LEN | IV | MAGIC | STASH | GP | NAME |
1190 +------+------+------+------+------+-------+-------+------+------+...
1191 0 4 8 12 16 20 24 28 32 36
1193 zero it, then copy sizeof(XPVMG) bytes on top of it? Not quite what you
1194 expect, because you copy the area marked ??? onto GP. Now, ??? may have
1195 started out as zero once, but it's quite possible that it isn't. So now,
1196 rather than a nicely zeroed GP, you have it pointing somewhere random.
1199 (In fact, GP ends up pointing at a previous GP structure, because the
1200 principle cause of the padding in XPVMG getting garbage is a copy of
1201 sizeof(XPVMG) bytes from a XPVGV structure in sv_unglob. Right now
1202 this happens to be moot because XPVGV has been re-ordered, with GP
1203 no longer after STASH)
1205 So we are careful and work out the size of used parts of all the
1213 referant = SvRV(sv);
1214 old_type_details = &fake_rv;
1215 if (new_type == SVt_NV)
1216 new_type = SVt_PVNV;
1218 if (new_type < SVt_PVIV) {
1219 new_type = (new_type == SVt_NV)
1220 ? SVt_PVNV : SVt_PVIV;
1225 if (new_type < SVt_PVNV) {
1226 new_type = SVt_PVNV;
1230 assert(new_type > SVt_PV);
1231 assert(SVt_IV < SVt_PV);
1232 assert(SVt_NV < SVt_PV);
1239 /* Because the XPVMG of PL_mess_sv isn't allocated from the arena,
1240 there's no way that it can be safely upgraded, because perl.c
1241 expects to Safefree(SvANY(PL_mess_sv)) */
1242 assert(sv != PL_mess_sv);
1243 /* This flag bit is used to mean other things in other scalar types.
1244 Given that it only has meaning inside the pad, it shouldn't be set
1245 on anything that can get upgraded. */
1246 assert(!SvPAD_TYPED(sv));
1249 if (old_type_details->cant_upgrade)
1250 Perl_croak(aTHX_ "Can't upgrade %s (%" UVuf ") to %" UVuf,
1251 sv_reftype(sv, 0), (UV) old_type, (UV) new_type);
1254 if (old_type > new_type)
1255 Perl_croak(aTHX_ "sv_upgrade from type %d down to type %d",
1256 (int)old_type, (int)new_type);
1258 new_type_details = bodies_by_type + new_type;
1260 SvFLAGS(sv) &= ~SVTYPEMASK;
1261 SvFLAGS(sv) |= new_type;
1263 /* This can't happen, as SVt_NULL is <= all values of new_type, so one of
1264 the return statements above will have triggered. */
1265 assert (new_type != SVt_NULL);
1268 assert(old_type == SVt_NULL);
1269 SvANY(sv) = (XPVIV*)((char*)&(sv->sv_u.svu_iv) - STRUCT_OFFSET(XPVIV, xiv_iv));
1273 assert(old_type == SVt_NULL);
1274 SvANY(sv) = new_XNV();
1279 assert(new_type_details->body_size);
1282 assert(new_type_details->arena);
1283 assert(new_type_details->arena_size);
1284 /* This points to the start of the allocated area. */
1285 new_body_inline(new_body, new_type);
1286 Zero(new_body, new_type_details->body_size, char);
1287 new_body = ((char *)new_body) - new_type_details->offset;
1289 /* We always allocated the full length item with PURIFY. To do this
1290 we fake things so that arena is false for all 16 types.. */
1291 new_body = new_NOARENAZ(new_type_details);
1293 SvANY(sv) = new_body;
1294 if (new_type == SVt_PVAV) {
1298 if (old_type_details->body_size) {
1301 /* It will have been zeroed when the new body was allocated.
1302 Lets not write to it, in case it confuses a write-back
1308 #ifndef NODEFAULT_SHAREKEYS
1309 HvSHAREKEYS_on(sv); /* key-sharing on by default */
1311 HvMAX(sv) = 7; /* (start with 8 buckets) */
1314 /* SVt_NULL isn't the only thing upgraded to AV or HV.
1315 The target created by newSVrv also is, and it can have magic.
1316 However, it never has SvPVX set.
1318 if (old_type == SVt_IV) {
1320 } else if (old_type >= SVt_PV) {
1321 assert(SvPVX_const(sv) == 0);
1324 if (old_type >= SVt_PVMG) {
1325 SvMAGIC_set(sv, ((XPVMG*)old_body)->xmg_u.xmg_magic);
1326 SvSTASH_set(sv, ((XPVMG*)old_body)->xmg_stash);
1328 sv->sv_u.svu_array = NULL; /* or svu_hash */
1334 /* This ensures that SvTHINKFIRST(sv) is true, and hence that
1335 sv_force_normal_flags(sv) is called. */
1338 /* XXX Is this still needed? Was it ever needed? Surely as there is
1339 no route from NV to PVIV, NOK can never be true */
1340 assert(!SvNOKp(sv));
1351 assert(new_type_details->body_size);
1352 /* We always allocated the full length item with PURIFY. To do this
1353 we fake things so that arena is false for all 16 types.. */
1354 if(new_type_details->arena) {
1355 /* This points to the start of the allocated area. */
1356 new_body_inline(new_body, new_type);
1357 Zero(new_body, new_type_details->body_size, char);
1358 new_body = ((char *)new_body) - new_type_details->offset;
1360 new_body = new_NOARENAZ(new_type_details);
1362 SvANY(sv) = new_body;
1364 if (old_type_details->copy) {
1365 /* There is now the potential for an upgrade from something without
1366 an offset (PVNV or PVMG) to something with one (PVCV, PVFM) */
1367 int offset = old_type_details->offset;
1368 int length = old_type_details->copy;
1370 if (new_type_details->offset > old_type_details->offset) {
1371 const int difference
1372 = new_type_details->offset - old_type_details->offset;
1373 offset += difference;
1374 length -= difference;
1376 assert (length >= 0);
1378 Copy((char *)old_body + offset, (char *)new_body + offset, length,
1382 #ifndef NV_ZERO_IS_ALLBITS_ZERO
1383 /* If NV 0.0 is stores as all bits 0 then Zero() already creates a
1384 * correct 0.0 for us. Otherwise, if the old body didn't have an
1385 * NV slot, but the new one does, then we need to initialise the
1386 * freshly created NV slot with whatever the correct bit pattern is
1388 if (old_type_details->zero_nv && !new_type_details->zero_nv
1389 && !isGV_with_GP(sv))
1393 if (new_type == SVt_PVIO) {
1394 IO * const io = MUTABLE_IO(sv);
1395 GV *iogv = gv_fetchpvs("IO::File::", GV_ADD, SVt_PVHV);
1398 /* Clear the stashcache because a new IO could overrule a package
1400 hv_clear(PL_stashcache);
1402 SvSTASH_set(io, MUTABLE_HV(SvREFCNT_inc(GvHV(iogv))));
1403 IoPAGE_LEN(sv) = 60;
1405 if (old_type < SVt_PV) {
1406 /* referant will be NULL unless the old type was SVt_IV emulating
1408 sv->sv_u.svu_rv = referant;
1412 Perl_croak(aTHX_ "panic: sv_upgrade to unknown type %lu",
1413 (unsigned long)new_type);
1416 if (old_type > SVt_IV) {
1420 /* Note that there is an assumption that all bodies of types that
1421 can be upgraded came from arenas. Only the more complex non-
1422 upgradable types are allowed to be directly malloc()ed. */
1423 assert(old_type_details->arena);
1424 del_body((void*)((char*)old_body + old_type_details->offset),
1425 &PL_body_roots[old_type]);
1431 =for apidoc sv_backoff
1433 Remove any string offset. You should normally use the C<SvOOK_off> macro
1440 Perl_sv_backoff(pTHX_ register SV *const sv)
1443 const char * const s = SvPVX_const(sv);
1445 PERL_ARGS_ASSERT_SV_BACKOFF;
1446 PERL_UNUSED_CONTEXT;
1449 assert(SvTYPE(sv) != SVt_PVHV);
1450 assert(SvTYPE(sv) != SVt_PVAV);
1452 SvOOK_offset(sv, delta);
1454 SvLEN_set(sv, SvLEN(sv) + delta);
1455 SvPV_set(sv, SvPVX(sv) - delta);
1456 Move(s, SvPVX(sv), SvCUR(sv)+1, char);
1457 SvFLAGS(sv) &= ~SVf_OOK;
1464 Expands the character buffer in the SV. If necessary, uses C<sv_unref> and
1465 upgrades the SV to C<SVt_PV>. Returns a pointer to the character buffer.
1466 Use the C<SvGROW> wrapper instead.
1472 Perl_sv_grow(pTHX_ register SV *const sv, register STRLEN newlen)
1476 PERL_ARGS_ASSERT_SV_GROW;
1478 if (PL_madskills && newlen >= 0x100000) {
1479 PerlIO_printf(Perl_debug_log,
1480 "Allocation too large: %"UVxf"\n", (UV)newlen);
1482 #ifdef HAS_64K_LIMIT
1483 if (newlen >= 0x10000) {
1484 PerlIO_printf(Perl_debug_log,
1485 "Allocation too large: %"UVxf"\n", (UV)newlen);
1488 #endif /* HAS_64K_LIMIT */
1491 if (SvTYPE(sv) < SVt_PV) {
1492 sv_upgrade(sv, SVt_PV);
1493 s = SvPVX_mutable(sv);
1495 else if (SvOOK(sv)) { /* pv is offset? */
1497 s = SvPVX_mutable(sv);
1498 if (newlen > SvLEN(sv))
1499 newlen += 10 * (newlen - SvCUR(sv)); /* avoid copy each time */
1500 #ifdef HAS_64K_LIMIT
1501 if (newlen >= 0x10000)
1506 s = SvPVX_mutable(sv);
1508 if (newlen > SvLEN(sv)) { /* need more room? */
1509 STRLEN minlen = SvCUR(sv);
1510 minlen += (minlen >> PERL_STRLEN_EXPAND_SHIFT) + 10;
1511 if (newlen < minlen)
1513 #ifndef Perl_safesysmalloc_size
1514 newlen = PERL_STRLEN_ROUNDUP(newlen);
1516 if (SvLEN(sv) && s) {
1517 s = (char*)saferealloc(s, newlen);
1520 s = (char*)safemalloc(newlen);
1521 if (SvPVX_const(sv) && SvCUR(sv)) {
1522 Move(SvPVX_const(sv), s, (newlen < SvCUR(sv)) ? newlen : SvCUR(sv), char);
1526 #ifdef Perl_safesysmalloc_size
1527 /* Do this here, do it once, do it right, and then we will never get
1528 called back into sv_grow() unless there really is some growing
1530 SvLEN_set(sv, Perl_safesysmalloc_size(s));
1532 SvLEN_set(sv, newlen);
1539 =for apidoc sv_setiv
1541 Copies an integer into the given SV, upgrading first if necessary.
1542 Does not handle 'set' magic. See also C<sv_setiv_mg>.
1548 Perl_sv_setiv(pTHX_ register SV *const sv, const IV i)
1552 PERL_ARGS_ASSERT_SV_SETIV;
1554 SV_CHECK_THINKFIRST_COW_DROP(sv);
1555 switch (SvTYPE(sv)) {
1558 sv_upgrade(sv, SVt_IV);
1561 sv_upgrade(sv, SVt_PVIV);
1565 if (!isGV_with_GP(sv))
1572 /* diag_listed_as: Can't coerce %s to %s in %s */
1573 Perl_croak(aTHX_ "Can't coerce %s to integer in %s", sv_reftype(sv,0),
1577 (void)SvIOK_only(sv); /* validate number */
1583 =for apidoc sv_setiv_mg
1585 Like C<sv_setiv>, but also handles 'set' magic.
1591 Perl_sv_setiv_mg(pTHX_ register SV *const sv, const IV i)
1593 PERL_ARGS_ASSERT_SV_SETIV_MG;
1600 =for apidoc sv_setuv
1602 Copies an unsigned integer into the given SV, upgrading first if necessary.
1603 Does not handle 'set' magic. See also C<sv_setuv_mg>.
1609 Perl_sv_setuv(pTHX_ register SV *const sv, const UV u)
1611 PERL_ARGS_ASSERT_SV_SETUV;
1613 /* With these two if statements:
1614 u=1.49 s=0.52 cu=72.49 cs=10.64 scripts=270 tests=20865
1617 u=1.35 s=0.47 cu=73.45 cs=11.43 scripts=270 tests=20865
1619 If you wish to remove them, please benchmark to see what the effect is
1621 if (u <= (UV)IV_MAX) {
1622 sv_setiv(sv, (IV)u);
1631 =for apidoc sv_setuv_mg
1633 Like C<sv_setuv>, but also handles 'set' magic.
1639 Perl_sv_setuv_mg(pTHX_ register SV *const sv, const UV u)
1641 PERL_ARGS_ASSERT_SV_SETUV_MG;
1648 =for apidoc sv_setnv
1650 Copies a double into the given SV, upgrading first if necessary.
1651 Does not handle 'set' magic. See also C<sv_setnv_mg>.
1657 Perl_sv_setnv(pTHX_ register SV *const sv, const NV num)
1661 PERL_ARGS_ASSERT_SV_SETNV;
1663 SV_CHECK_THINKFIRST_COW_DROP(sv);
1664 switch (SvTYPE(sv)) {
1667 sv_upgrade(sv, SVt_NV);
1671 sv_upgrade(sv, SVt_PVNV);
1675 if (!isGV_with_GP(sv))
1682 /* diag_listed_as: Can't coerce %s to %s in %s */
1683 Perl_croak(aTHX_ "Can't coerce %s to number in %s", sv_reftype(sv,0),
1688 (void)SvNOK_only(sv); /* validate number */
1693 =for apidoc sv_setnv_mg
1695 Like C<sv_setnv>, but also handles 'set' magic.
1701 Perl_sv_setnv_mg(pTHX_ register SV *const sv, const NV num)
1703 PERL_ARGS_ASSERT_SV_SETNV_MG;
1709 /* Print an "isn't numeric" warning, using a cleaned-up,
1710 * printable version of the offending string
1714 S_not_a_number(pTHX_ SV *const sv)
1721 PERL_ARGS_ASSERT_NOT_A_NUMBER;
1724 dsv = newSVpvs_flags("", SVs_TEMP);
1725 pv = sv_uni_display(dsv, sv, 10, UNI_DISPLAY_ISPRINT);
1728 const char * const limit = tmpbuf + sizeof(tmpbuf) - 8;
1729 /* each *s can expand to 4 chars + "...\0",
1730 i.e. need room for 8 chars */
1732 const char *s = SvPVX_const(sv);
1733 const char * const end = s + SvCUR(sv);
1734 for ( ; s < end && d < limit; s++ ) {
1736 if (ch & 128 && !isPRINT_LC(ch)) {
1745 else if (ch == '\r') {
1749 else if (ch == '\f') {
1753 else if (ch == '\\') {
1757 else if (ch == '\0') {
1761 else if (isPRINT_LC(ch))
1778 Perl_warner(aTHX_ packWARN(WARN_NUMERIC),
1779 "Argument \"%s\" isn't numeric in %s", pv,
1782 Perl_warner(aTHX_ packWARN(WARN_NUMERIC),
1783 "Argument \"%s\" isn't numeric", pv);
1787 =for apidoc looks_like_number
1789 Test if the content of an SV looks like a number (or is a number).
1790 C<Inf> and C<Infinity> are treated as numbers (so will not issue a
1791 non-numeric warning), even if your atof() doesn't grok them. Get-magic is
1798 Perl_looks_like_number(pTHX_ SV *const sv)
1800 register const char *sbegin;
1803 PERL_ARGS_ASSERT_LOOKS_LIKE_NUMBER;
1805 if (SvPOK(sv) || SvPOKp(sv)) {
1806 sbegin = SvPV_nomg_const(sv, len);
1809 return SvFLAGS(sv) & (SVf_NOK|SVp_NOK|SVf_IOK|SVp_IOK);
1810 return grok_number(sbegin, len, NULL);
1814 S_glob_2number(pTHX_ GV * const gv)
1816 SV *const buffer = sv_newmortal();
1818 PERL_ARGS_ASSERT_GLOB_2NUMBER;
1820 gv_efullname3(buffer, gv, "*");
1822 /* We know that all GVs stringify to something that is not-a-number,
1823 so no need to test that. */
1824 if (ckWARN(WARN_NUMERIC))
1825 not_a_number(buffer);
1826 /* We just want something true to return, so that S_sv_2iuv_common
1827 can tail call us and return true. */
1831 /* Actually, ISO C leaves conversion of UV to IV undefined, but
1832 until proven guilty, assume that things are not that bad... */
1837 As 64 bit platforms often have an NV that doesn't preserve all bits of
1838 an IV (an assumption perl has been based on to date) it becomes necessary
1839 to remove the assumption that the NV always carries enough precision to
1840 recreate the IV whenever needed, and that the NV is the canonical form.
1841 Instead, IV/UV and NV need to be given equal rights. So as to not lose
1842 precision as a side effect of conversion (which would lead to insanity
1843 and the dragon(s) in t/op/numconvert.t getting very angry) the intent is
1844 1) to distinguish between IV/UV/NV slots that have cached a valid
1845 conversion where precision was lost and IV/UV/NV slots that have a
1846 valid conversion which has lost no precision
1847 2) to ensure that if a numeric conversion to one form is requested that
1848 would lose precision, the precise conversion (or differently
1849 imprecise conversion) is also performed and cached, to prevent
1850 requests for different numeric formats on the same SV causing
1851 lossy conversion chains. (lossless conversion chains are perfectly
1856 SvIOKp is true if the IV slot contains a valid value
1857 SvIOK is true only if the IV value is accurate (UV if SvIOK_UV true)
1858 SvNOKp is true if the NV slot contains a valid value
1859 SvNOK is true only if the NV value is accurate
1862 while converting from PV to NV, check to see if converting that NV to an
1863 IV(or UV) would lose accuracy over a direct conversion from PV to
1864 IV(or UV). If it would, cache both conversions, return NV, but mark
1865 SV as IOK NOKp (ie not NOK).
1867 While converting from PV to IV, check to see if converting that IV to an
1868 NV would lose accuracy over a direct conversion from PV to NV. If it
1869 would, cache both conversions, flag similarly.
1871 Before, the SV value "3.2" could become NV=3.2 IV=3 NOK, IOK quite
1872 correctly because if IV & NV were set NV *always* overruled.
1873 Now, "3.2" will become NV=3.2 IV=3 NOK, IOKp, because the flag's meaning
1874 changes - now IV and NV together means that the two are interchangeable:
1875 SvIVX == (IV) SvNVX && SvNVX == (NV) SvIVX;
1877 The benefit of this is that operations such as pp_add know that if
1878 SvIOK is true for both left and right operands, then integer addition
1879 can be used instead of floating point (for cases where the result won't
1880 overflow). Before, floating point was always used, which could lead to
1881 loss of precision compared with integer addition.
1883 * making IV and NV equal status should make maths accurate on 64 bit
1885 * may speed up maths somewhat if pp_add and friends start to use
1886 integers when possible instead of fp. (Hopefully the overhead in
1887 looking for SvIOK and checking for overflow will not outweigh the
1888 fp to integer speedup)
1889 * will slow down integer operations (callers of SvIV) on "inaccurate"
1890 values, as the change from SvIOK to SvIOKp will cause a call into
1891 sv_2iv each time rather than a macro access direct to the IV slot
1892 * should speed up number->string conversion on integers as IV is
1893 favoured when IV and NV are equally accurate
1895 ####################################################################
1896 You had better be using SvIOK_notUV if you want an IV for arithmetic:
1897 SvIOK is true if (IV or UV), so you might be getting (IV)SvUV.
1898 On the other hand, SvUOK is true iff UV.
1899 ####################################################################
1901 Your mileage will vary depending your CPU's relative fp to integer
1905 #ifndef NV_PRESERVES_UV
1906 # define IS_NUMBER_UNDERFLOW_IV 1
1907 # define IS_NUMBER_UNDERFLOW_UV 2
1908 # define IS_NUMBER_IV_AND_UV 2
1909 # define IS_NUMBER_OVERFLOW_IV 4
1910 # define IS_NUMBER_OVERFLOW_UV 5
1912 /* sv_2iuv_non_preserve(): private routine for use by sv_2iv() and sv_2uv() */
1914 /* For sv_2nv these three cases are "SvNOK and don't bother casting" */
1916 S_sv_2iuv_non_preserve(pTHX_ register SV *const sv
1924 PERL_ARGS_ASSERT_SV_2IUV_NON_PRESERVE;
1926 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));
1927 if (SvNVX(sv) < (NV)IV_MIN) {
1928 (void)SvIOKp_on(sv);
1930 SvIV_set(sv, IV_MIN);
1931 return IS_NUMBER_UNDERFLOW_IV;
1933 if (SvNVX(sv) > (NV)UV_MAX) {
1934 (void)SvIOKp_on(sv);
1937 SvUV_set(sv, UV_MAX);
1938 return IS_NUMBER_OVERFLOW_UV;
1940 (void)SvIOKp_on(sv);
1942 /* Can't use strtol etc to convert this string. (See truth table in
1944 if (SvNVX(sv) <= (UV)IV_MAX) {
1945 SvIV_set(sv, I_V(SvNVX(sv)));
1946 if ((NV)(SvIVX(sv)) == SvNVX(sv)) {
1947 SvIOK_on(sv); /* Integer is precise. NOK, IOK */
1949 /* Integer is imprecise. NOK, IOKp */
1951 return SvNVX(sv) < 0 ? IS_NUMBER_UNDERFLOW_UV : IS_NUMBER_IV_AND_UV;
1954 SvUV_set(sv, U_V(SvNVX(sv)));
1955 if ((NV)(SvUVX(sv)) == SvNVX(sv)) {
1956 if (SvUVX(sv) == UV_MAX) {
1957 /* As we know that NVs don't preserve UVs, UV_MAX cannot
1958 possibly be preserved by NV. Hence, it must be overflow.
1960 return IS_NUMBER_OVERFLOW_UV;
1962 SvIOK_on(sv); /* Integer is precise. NOK, UOK */
1964 /* Integer is imprecise. NOK, IOKp */
1966 return IS_NUMBER_OVERFLOW_IV;
1968 #endif /* !NV_PRESERVES_UV*/
1971 S_sv_2iuv_common(pTHX_ SV *const sv)
1975 PERL_ARGS_ASSERT_SV_2IUV_COMMON;
1978 /* erm. not sure. *should* never get NOKp (without NOK) from sv_2nv
1979 * without also getting a cached IV/UV from it at the same time
1980 * (ie PV->NV conversion should detect loss of accuracy and cache
1981 * IV or UV at same time to avoid this. */
1982 /* IV-over-UV optimisation - choose to cache IV if possible */
1984 if (SvTYPE(sv) == SVt_NV)
1985 sv_upgrade(sv, SVt_PVNV);
1987 (void)SvIOKp_on(sv); /* Must do this first, to clear any SvOOK */
1988 /* < not <= as for NV doesn't preserve UV, ((NV)IV_MAX+1) will almost
1989 certainly cast into the IV range at IV_MAX, whereas the correct
1990 answer is the UV IV_MAX +1. Hence < ensures that dodgy boundary
1992 #if defined(NAN_COMPARE_BROKEN) && defined(Perl_isnan)
1993 if (Perl_isnan(SvNVX(sv))) {
1999 if (SvNVX(sv) < (NV)IV_MAX + 0.5) {
2000 SvIV_set(sv, I_V(SvNVX(sv)));
2001 if (SvNVX(sv) == (NV) SvIVX(sv)
2002 #ifndef NV_PRESERVES_UV
2003 && (((UV)1 << NV_PRESERVES_UV_BITS) >
2004 (UV)(SvIVX(sv) > 0 ? SvIVX(sv) : -SvIVX(sv)))
2005 /* Don't flag it as "accurately an integer" if the number
2006 came from a (by definition imprecise) NV operation, and
2007 we're outside the range of NV integer precision */
2011 SvIOK_on(sv); /* Can this go wrong with rounding? NWC */
2013 /* scalar has trailing garbage, eg "42a" */
2015 DEBUG_c(PerlIO_printf(Perl_debug_log,
2016 "0x%"UVxf" iv(%"NVgf" => %"IVdf") (precise)\n",
2022 /* IV not precise. No need to convert from PV, as NV
2023 conversion would already have cached IV if it detected
2024 that PV->IV would be better than PV->NV->IV
2025 flags already correct - don't set public IOK. */
2026 DEBUG_c(PerlIO_printf(Perl_debug_log,
2027 "0x%"UVxf" iv(%"NVgf" => %"IVdf") (imprecise)\n",
2032 /* Can the above go wrong if SvIVX == IV_MIN and SvNVX < IV_MIN,
2033 but the cast (NV)IV_MIN rounds to a the value less (more
2034 negative) than IV_MIN which happens to be equal to SvNVX ??
2035 Analogous to 0xFFFFFFFFFFFFFFFF rounding up to NV (2**64) and
2036 NV rounding back to 0xFFFFFFFFFFFFFFFF, so UVX == UV(NVX) and
2037 (NV)UVX == NVX are both true, but the values differ. :-(
2038 Hopefully for 2s complement IV_MIN is something like
2039 0x8000000000000000 which will be exact. NWC */
2042 SvUV_set(sv, U_V(SvNVX(sv)));
2044 (SvNVX(sv) == (NV) SvUVX(sv))
2045 #ifndef NV_PRESERVES_UV
2046 /* Make sure it's not 0xFFFFFFFFFFFFFFFF */
2047 /*&& (SvUVX(sv) != UV_MAX) irrelevant with code below */
2048 && (((UV)1 << NV_PRESERVES_UV_BITS) > SvUVX(sv))
2049 /* Don't flag it as "accurately an integer" if the number
2050 came from a (by definition imprecise) NV operation, and
2051 we're outside the range of NV integer precision */
2057 DEBUG_c(PerlIO_printf(Perl_debug_log,
2058 "0x%"UVxf" 2iv(%"UVuf" => %"IVdf") (as unsigned)\n",
2064 else if (SvPOKp(sv) && SvLEN(sv)) {
2066 const int numtype = grok_number(SvPVX_const(sv), SvCUR(sv), &value);
2067 /* We want to avoid a possible problem when we cache an IV/ a UV which
2068 may be later translated to an NV, and the resulting NV is not
2069 the same as the direct translation of the initial string
2070 (eg 123.456 can shortcut to the IV 123 with atol(), but we must
2071 be careful to ensure that the value with the .456 is around if the
2072 NV value is requested in the future).
2074 This means that if we cache such an IV/a UV, we need to cache the
2075 NV as well. Moreover, we trade speed for space, and do not
2076 cache the NV if we are sure it's not needed.
2079 /* SVt_PVNV is one higher than SVt_PVIV, hence this order */
2080 if ((numtype & (IS_NUMBER_IN_UV | IS_NUMBER_NOT_INT))
2081 == IS_NUMBER_IN_UV) {
2082 /* It's definitely an integer, only upgrade to PVIV */
2083 if (SvTYPE(sv) < SVt_PVIV)
2084 sv_upgrade(sv, SVt_PVIV);
2086 } else if (SvTYPE(sv) < SVt_PVNV)
2087 sv_upgrade(sv, SVt_PVNV);
2089 /* If NVs preserve UVs then we only use the UV value if we know that
2090 we aren't going to call atof() below. If NVs don't preserve UVs
2091 then the value returned may have more precision than atof() will
2092 return, even though value isn't perfectly accurate. */
2093 if ((numtype & (IS_NUMBER_IN_UV
2094 #ifdef NV_PRESERVES_UV
2097 )) == IS_NUMBER_IN_UV) {
2098 /* This won't turn off the public IOK flag if it was set above */
2099 (void)SvIOKp_on(sv);
2101 if (!(numtype & IS_NUMBER_NEG)) {
2103 if (value <= (UV)IV_MAX) {
2104 SvIV_set(sv, (IV)value);
2106 /* it didn't overflow, and it was positive. */
2107 SvUV_set(sv, value);
2111 /* 2s complement assumption */
2112 if (value <= (UV)IV_MIN) {
2113 SvIV_set(sv, -(IV)value);
2115 /* Too negative for an IV. This is a double upgrade, but
2116 I'm assuming it will be rare. */
2117 if (SvTYPE(sv) < SVt_PVNV)
2118 sv_upgrade(sv, SVt_PVNV);
2122 SvNV_set(sv, -(NV)value);
2123 SvIV_set(sv, IV_MIN);
2127 /* For !NV_PRESERVES_UV and IS_NUMBER_IN_UV and IS_NUMBER_NOT_INT we
2128 will be in the previous block to set the IV slot, and the next
2129 block to set the NV slot. So no else here. */
2131 if ((numtype & (IS_NUMBER_IN_UV | IS_NUMBER_NOT_INT))
2132 != IS_NUMBER_IN_UV) {
2133 /* It wasn't an (integer that doesn't overflow the UV). */
2134 SvNV_set(sv, Atof(SvPVX_const(sv)));
2136 if (! numtype && ckWARN(WARN_NUMERIC))
2139 #if defined(USE_LONG_DOUBLE)
2140 DEBUG_c(PerlIO_printf(Perl_debug_log, "0x%"UVxf" 2iv(%" PERL_PRIgldbl ")\n",
2141 PTR2UV(sv), SvNVX(sv)));
2143 DEBUG_c(PerlIO_printf(Perl_debug_log, "0x%"UVxf" 2iv(%"NVgf")\n",
2144 PTR2UV(sv), SvNVX(sv)));
2147 #ifdef NV_PRESERVES_UV
2148 (void)SvIOKp_on(sv);
2150 if (SvNVX(sv) < (NV)IV_MAX + 0.5) {
2151 SvIV_set(sv, I_V(SvNVX(sv)));
2152 if ((NV)(SvIVX(sv)) == SvNVX(sv)) {
2155 NOOP; /* Integer is imprecise. NOK, IOKp */
2157 /* UV will not work better than IV */
2159 if (SvNVX(sv) > (NV)UV_MAX) {
2161 /* Integer is inaccurate. NOK, IOKp, is UV */
2162 SvUV_set(sv, UV_MAX);
2164 SvUV_set(sv, U_V(SvNVX(sv)));
2165 /* 0xFFFFFFFFFFFFFFFF not an issue in here, NVs
2166 NV preservse UV so can do correct comparison. */
2167 if ((NV)(SvUVX(sv)) == SvNVX(sv)) {
2170 NOOP; /* Integer is imprecise. NOK, IOKp, is UV */
2175 #else /* NV_PRESERVES_UV */
2176 if ((numtype & (IS_NUMBER_IN_UV | IS_NUMBER_NOT_INT))
2177 == (IS_NUMBER_IN_UV | IS_NUMBER_NOT_INT)) {
2178 /* The IV/UV slot will have been set from value returned by
2179 grok_number above. The NV slot has just been set using
2182 assert (SvIOKp(sv));
2184 if (((UV)1 << NV_PRESERVES_UV_BITS) >
2185 U_V(SvNVX(sv) > 0 ? SvNVX(sv) : -SvNVX(sv))) {
2186 /* Small enough to preserve all bits. */
2187 (void)SvIOKp_on(sv);
2189 SvIV_set(sv, I_V(SvNVX(sv)));
2190 if ((NV)(SvIVX(sv)) == SvNVX(sv))
2192 /* Assumption: first non-preserved integer is < IV_MAX,
2193 this NV is in the preserved range, therefore: */
2194 if (!(U_V(SvNVX(sv) > 0 ? SvNVX(sv) : -SvNVX(sv))
2196 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);
2200 0 0 already failed to read UV.
2201 0 1 already failed to read UV.
2202 1 0 you won't get here in this case. IV/UV
2203 slot set, public IOK, Atof() unneeded.
2204 1 1 already read UV.
2205 so there's no point in sv_2iuv_non_preserve() attempting
2206 to use atol, strtol, strtoul etc. */
2208 sv_2iuv_non_preserve (sv, numtype);
2210 sv_2iuv_non_preserve (sv);
2214 #endif /* NV_PRESERVES_UV */
2215 /* It might be more code efficient to go through the entire logic above
2216 and conditionally set with SvIOKp_on() rather than SvIOK(), but it
2217 gets complex and potentially buggy, so more programmer efficient
2218 to do it this way, by turning off the public flags: */
2220 SvFLAGS(sv) &= ~(SVf_IOK|SVf_NOK);
2224 if (isGV_with_GP(sv))
2225 return glob_2number(MUTABLE_GV(sv));
2227 if (!SvPADTMP(sv)) {
2228 if (!PL_localizing && ckWARN(WARN_UNINITIALIZED))
2231 if (SvTYPE(sv) < SVt_IV)
2232 /* Typically the caller expects that sv_any is not NULL now. */
2233 sv_upgrade(sv, SVt_IV);
2234 /* Return 0 from the caller. */
2241 =for apidoc sv_2iv_flags
2243 Return the integer value of an SV, doing any necessary string
2244 conversion. If flags includes SV_GMAGIC, does an mg_get() first.
2245 Normally used via the C<SvIV(sv)> and C<SvIVx(sv)> macros.
2251 Perl_sv_2iv_flags(pTHX_ register SV *const sv, const I32 flags)
2256 if (SvGMAGICAL(sv) || SvVALID(sv)) {
2257 /* FBMs use the space for SvIVX and SvNVX for other purposes, and use
2258 the same flag bit as SVf_IVisUV, so must not let them cache IVs.
2259 In practice they are extremely unlikely to actually get anywhere
2260 accessible by user Perl code - the only way that I'm aware of is when
2261 a constant subroutine which is used as the second argument to index.
2263 if (flags & SV_GMAGIC)
2268 return I_V(SvNVX(sv));
2270 if (SvPOKp(sv) && SvLEN(sv)) {
2273 = grok_number(SvPVX_const(sv), SvCUR(sv), &value);
2275 if ((numtype & (IS_NUMBER_IN_UV | IS_NUMBER_NOT_INT))
2276 == IS_NUMBER_IN_UV) {
2277 /* It's definitely an integer */
2278 if (numtype & IS_NUMBER_NEG) {
2279 if (value < (UV)IV_MIN)
2282 if (value < (UV)IV_MAX)
2287 if (ckWARN(WARN_NUMERIC))
2290 return I_V(Atof(SvPVX_const(sv)));
2295 assert(SvTYPE(sv) >= SVt_PVMG);
2296 /* This falls through to the report_uninit inside S_sv_2iuv_common. */
2297 } else if (SvTHINKFIRST(sv)) {
2302 if (flags & SV_SKIP_OVERLOAD)
2304 tmpstr = AMG_CALLunary(sv, numer_amg);
2305 if (tmpstr && (!SvROK(tmpstr) || (SvRV(tmpstr) != SvRV(sv)))) {
2306 return SvIV(tmpstr);
2309 return PTR2IV(SvRV(sv));
2312 sv_force_normal_flags(sv, 0);
2314 if (SvREADONLY(sv) && !SvOK(sv)) {
2315 if (ckWARN(WARN_UNINITIALIZED))
2321 if (S_sv_2iuv_common(aTHX_ sv))
2324 DEBUG_c(PerlIO_printf(Perl_debug_log, "0x%"UVxf" 2iv(%"IVdf")\n",
2325 PTR2UV(sv),SvIVX(sv)));
2326 return SvIsUV(sv) ? (IV)SvUVX(sv) : SvIVX(sv);
2330 =for apidoc sv_2uv_flags
2332 Return the unsigned integer value of an SV, doing any necessary string
2333 conversion. If flags includes SV_GMAGIC, does an mg_get() first.
2334 Normally used via the C<SvUV(sv)> and C<SvUVx(sv)> macros.
2340 Perl_sv_2uv_flags(pTHX_ register SV *const sv, const I32 flags)
2345 if (SvGMAGICAL(sv) || SvVALID(sv)) {
2346 /* FBMs use the space for SvIVX and SvNVX for other purposes, and use
2347 the same flag bit as SVf_IVisUV, so must not let them cache IVs. */
2348 if (flags & SV_GMAGIC)
2353 return U_V(SvNVX(sv));
2354 if (SvPOKp(sv) && SvLEN(sv)) {
2357 = grok_number(SvPVX_const(sv), SvCUR(sv), &value);
2359 if ((numtype & (IS_NUMBER_IN_UV | IS_NUMBER_NOT_INT))
2360 == IS_NUMBER_IN_UV) {
2361 /* It's definitely an integer */
2362 if (!(numtype & IS_NUMBER_NEG))
2366 if (ckWARN(WARN_NUMERIC))
2369 return U_V(Atof(SvPVX_const(sv)));
2374 assert(SvTYPE(sv) >= SVt_PVMG);
2375 /* This falls through to the report_uninit inside S_sv_2iuv_common. */
2376 } else if (SvTHINKFIRST(sv)) {
2381 if (flags & SV_SKIP_OVERLOAD)
2383 tmpstr = AMG_CALLunary(sv, numer_amg);
2384 if (tmpstr && (!SvROK(tmpstr) || (SvRV(tmpstr) != SvRV(sv)))) {
2385 return SvUV(tmpstr);
2388 return PTR2UV(SvRV(sv));
2391 sv_force_normal_flags(sv, 0);
2393 if (SvREADONLY(sv) && !SvOK(sv)) {
2394 if (ckWARN(WARN_UNINITIALIZED))
2400 if (S_sv_2iuv_common(aTHX_ sv))
2404 DEBUG_c(PerlIO_printf(Perl_debug_log, "0x%"UVxf" 2uv(%"UVuf")\n",
2405 PTR2UV(sv),SvUVX(sv)));
2406 return SvIsUV(sv) ? SvUVX(sv) : (UV)SvIVX(sv);
2410 =for apidoc sv_2nv_flags
2412 Return the num value of an SV, doing any necessary string or integer
2413 conversion. If flags includes SV_GMAGIC, does an mg_get() first.
2414 Normally used via the C<SvNV(sv)> and C<SvNVx(sv)> macros.
2420 Perl_sv_2nv_flags(pTHX_ register SV *const sv, const I32 flags)
2425 if (SvGMAGICAL(sv) || SvVALID(sv)) {
2426 /* FBMs use the space for SvIVX and SvNVX for other purposes, and use
2427 the same flag bit as SVf_IVisUV, so must not let them cache NVs. */
2428 if (flags & SV_GMAGIC)
2432 if ((SvPOKp(sv) && SvLEN(sv)) && !SvIOKp(sv)) {
2433 if (!SvIOKp(sv) && ckWARN(WARN_NUMERIC) &&
2434 !grok_number(SvPVX_const(sv), SvCUR(sv), NULL))
2436 return Atof(SvPVX_const(sv));
2440 return (NV)SvUVX(sv);
2442 return (NV)SvIVX(sv);
2447 assert(SvTYPE(sv) >= SVt_PVMG);
2448 /* This falls through to the report_uninit near the end of the
2450 } else if (SvTHINKFIRST(sv)) {
2455 if (flags & SV_SKIP_OVERLOAD)
2457 tmpstr = AMG_CALLunary(sv, numer_amg);
2458 if (tmpstr && (!SvROK(tmpstr) || (SvRV(tmpstr) != SvRV(sv)))) {
2459 return SvNV(tmpstr);
2462 return PTR2NV(SvRV(sv));
2465 sv_force_normal_flags(sv, 0);
2467 if (SvREADONLY(sv) && !SvOK(sv)) {
2468 if (ckWARN(WARN_UNINITIALIZED))
2473 if (SvTYPE(sv) < SVt_NV) {
2474 /* The logic to use SVt_PVNV if necessary is in sv_upgrade. */
2475 sv_upgrade(sv, SVt_NV);
2476 #ifdef USE_LONG_DOUBLE
2478 STORE_NUMERIC_LOCAL_SET_STANDARD();
2479 PerlIO_printf(Perl_debug_log,
2480 "0x%"UVxf" num(%" PERL_PRIgldbl ")\n",
2481 PTR2UV(sv), SvNVX(sv));
2482 RESTORE_NUMERIC_LOCAL();
2486 STORE_NUMERIC_LOCAL_SET_STANDARD();
2487 PerlIO_printf(Perl_debug_log, "0x%"UVxf" num(%"NVgf")\n",
2488 PTR2UV(sv), SvNVX(sv));
2489 RESTORE_NUMERIC_LOCAL();
2493 else if (SvTYPE(sv) < SVt_PVNV)
2494 sv_upgrade(sv, SVt_PVNV);
2499 SvNV_set(sv, SvIsUV(sv) ? (NV)SvUVX(sv) : (NV)SvIVX(sv));
2500 #ifdef NV_PRESERVES_UV
2506 /* Only set the public NV OK flag if this NV preserves the IV */
2507 /* Check it's not 0xFFFFFFFFFFFFFFFF */
2509 SvIsUV(sv) ? ((SvUVX(sv) != UV_MAX)&&(SvUVX(sv) == U_V(SvNVX(sv))))
2510 : (SvIVX(sv) == I_V(SvNVX(sv))))
2516 else if (SvPOKp(sv) && SvLEN(sv)) {
2518 const int numtype = grok_number(SvPVX_const(sv), SvCUR(sv), &value);
2519 if (!SvIOKp(sv) && !numtype && ckWARN(WARN_NUMERIC))
2521 #ifdef NV_PRESERVES_UV
2522 if ((numtype & (IS_NUMBER_IN_UV | IS_NUMBER_NOT_INT))
2523 == IS_NUMBER_IN_UV) {
2524 /* It's definitely an integer */
2525 SvNV_set(sv, (numtype & IS_NUMBER_NEG) ? -(NV)value : (NV)value);
2527 SvNV_set(sv, Atof(SvPVX_const(sv)));
2533 SvNV_set(sv, Atof(SvPVX_const(sv)));
2534 /* Only set the public NV OK flag if this NV preserves the value in
2535 the PV at least as well as an IV/UV would.
2536 Not sure how to do this 100% reliably. */
2537 /* if that shift count is out of range then Configure's test is
2538 wonky. We shouldn't be in here with NV_PRESERVES_UV_BITS ==
2540 if (((UV)1 << NV_PRESERVES_UV_BITS) >
2541 U_V(SvNVX(sv) > 0 ? SvNVX(sv) : -SvNVX(sv))) {
2542 SvNOK_on(sv); /* Definitely small enough to preserve all bits */
2543 } else if (!(numtype & IS_NUMBER_IN_UV)) {
2544 /* Can't use strtol etc to convert this string, so don't try.
2545 sv_2iv and sv_2uv will use the NV to convert, not the PV. */
2548 /* value has been set. It may not be precise. */
2549 if ((numtype & IS_NUMBER_NEG) && (value > (UV)IV_MIN)) {
2550 /* 2s complement assumption for (UV)IV_MIN */
2551 SvNOK_on(sv); /* Integer is too negative. */
2556 if (numtype & IS_NUMBER_NEG) {
2557 SvIV_set(sv, -(IV)value);
2558 } else if (value <= (UV)IV_MAX) {
2559 SvIV_set(sv, (IV)value);
2561 SvUV_set(sv, value);
2565 if (numtype & IS_NUMBER_NOT_INT) {
2566 /* I believe that even if the original PV had decimals,
2567 they are lost beyond the limit of the FP precision.
2568 However, neither is canonical, so both only get p
2569 flags. NWC, 2000/11/25 */
2570 /* Both already have p flags, so do nothing */
2572 const NV nv = SvNVX(sv);
2573 if (SvNVX(sv) < (NV)IV_MAX + 0.5) {
2574 if (SvIVX(sv) == I_V(nv)) {
2577 /* It had no "." so it must be integer. */
2581 /* between IV_MAX and NV(UV_MAX).
2582 Could be slightly > UV_MAX */
2584 if (numtype & IS_NUMBER_NOT_INT) {
2585 /* UV and NV both imprecise. */
2587 const UV nv_as_uv = U_V(nv);
2589 if (value == nv_as_uv && SvUVX(sv) != UV_MAX) {
2598 /* It might be more code efficient to go through the entire logic above
2599 and conditionally set with SvNOKp_on() rather than SvNOK(), but it
2600 gets complex and potentially buggy, so more programmer efficient
2601 to do it this way, by turning off the public flags: */
2603 SvFLAGS(sv) &= ~(SVf_IOK|SVf_NOK);
2604 #endif /* NV_PRESERVES_UV */
2607 if (isGV_with_GP(sv)) {
2608 glob_2number(MUTABLE_GV(sv));
2612 if (!PL_localizing && !SvPADTMP(sv) && ckWARN(WARN_UNINITIALIZED))
2614 assert (SvTYPE(sv) >= SVt_NV);
2615 /* Typically the caller expects that sv_any is not NULL now. */
2616 /* XXX Ilya implies that this is a bug in callers that assume this
2617 and ideally should be fixed. */
2620 #if defined(USE_LONG_DOUBLE)
2622 STORE_NUMERIC_LOCAL_SET_STANDARD();
2623 PerlIO_printf(Perl_debug_log, "0x%"UVxf" 2nv(%" PERL_PRIgldbl ")\n",
2624 PTR2UV(sv), SvNVX(sv));
2625 RESTORE_NUMERIC_LOCAL();
2629 STORE_NUMERIC_LOCAL_SET_STANDARD();
2630 PerlIO_printf(Perl_debug_log, "0x%"UVxf" 1nv(%"NVgf")\n",
2631 PTR2UV(sv), SvNVX(sv));
2632 RESTORE_NUMERIC_LOCAL();
2641 Return an SV with the numeric value of the source SV, doing any necessary
2642 reference or overload conversion. You must use the C<SvNUM(sv)> macro to
2643 access this function.
2649 Perl_sv_2num(pTHX_ register SV *const sv)
2651 PERL_ARGS_ASSERT_SV_2NUM;
2656 SV * const tmpsv = AMG_CALLunary(sv, numer_amg);
2657 TAINT_IF(tmpsv && SvTAINTED(tmpsv));
2658 if (tmpsv && (!SvROK(tmpsv) || (SvRV(tmpsv) != SvRV(sv))))
2659 return sv_2num(tmpsv);
2661 return sv_2mortal(newSVuv(PTR2UV(SvRV(sv))));
2664 /* uiv_2buf(): private routine for use by sv_2pv_flags(): print an IV or
2665 * UV as a string towards the end of buf, and return pointers to start and
2668 * We assume that buf is at least TYPE_CHARS(UV) long.
2672 S_uiv_2buf(char *const buf, const IV iv, UV uv, const int is_uv, char **const peob)
2674 char *ptr = buf + TYPE_CHARS(UV);
2675 char * const ebuf = ptr;
2678 PERL_ARGS_ASSERT_UIV_2BUF;
2690 *--ptr = '0' + (char)(uv % 10);
2699 =for apidoc sv_2pv_flags
2701 Returns a pointer to the string value of an SV, and sets *lp to its length.
2702 If flags includes SV_GMAGIC, does an mg_get() first. Coerces sv to a
2703 string if necessary. Normally invoked via the C<SvPV_flags> macro.
2704 C<sv_2pv()> and C<sv_2pv_nomg> usually end up here too.
2710 Perl_sv_2pv_flags(pTHX_ register SV *const sv, STRLEN *const lp, const I32 flags)
2720 if (SvGMAGICAL(sv)) {
2721 if (flags & SV_GMAGIC)
2726 if (flags & SV_MUTABLE_RETURN)
2727 return SvPVX_mutable(sv);
2728 if (flags & SV_CONST_RETURN)
2729 return (char *)SvPVX_const(sv);
2732 if (SvIOKp(sv) || SvNOKp(sv)) {
2733 char tbuf[64]; /* Must fit sprintf/Gconvert of longest IV/NV */
2738 ? my_snprintf(tbuf, sizeof(tbuf), "%"UVuf, (UV)SvUVX(sv))
2739 : my_snprintf(tbuf, sizeof(tbuf), "%"IVdf, (IV)SvIVX(sv));
2740 } else if(SvNVX(sv) == 0.0) {
2745 Gconvert(SvNVX(sv), NV_DIG, 0, tbuf);
2752 SvUPGRADE(sv, SVt_PV);
2755 s = SvGROW_mutable(sv, len + 1);
2758 return (char*)memcpy(s, tbuf, len + 1);
2764 assert(SvTYPE(sv) >= SVt_PVMG);
2765 /* This falls through to the report_uninit near the end of the
2767 } else if (SvTHINKFIRST(sv)) {
2772 if (flags & SV_SKIP_OVERLOAD)
2774 tmpstr = AMG_CALLunary(sv, string_amg);
2775 TAINT_IF(tmpstr && SvTAINTED(tmpstr));
2776 if (tmpstr && (!SvROK(tmpstr) || (SvRV(tmpstr) != SvRV(sv)))) {
2778 /* char *pv = lp ? SvPV(tmpstr, *lp) : SvPV_nolen(tmpstr);
2782 if ((SvFLAGS(tmpstr) & (SVf_POK)) == SVf_POK) {
2783 if (flags & SV_CONST_RETURN) {
2784 pv = (char *) SvPVX_const(tmpstr);
2786 pv = (flags & SV_MUTABLE_RETURN)
2787 ? SvPVX_mutable(tmpstr) : SvPVX(tmpstr);
2790 *lp = SvCUR(tmpstr);
2792 pv = sv_2pv_flags(tmpstr, lp, flags);
2805 SV *const referent = SvRV(sv);
2809 retval = buffer = savepvn("NULLREF", len);
2810 } else if (SvTYPE(referent) == SVt_REGEXP) {
2811 REGEXP * const re = (REGEXP *)MUTABLE_PTR(referent);
2816 /* If the regex is UTF-8 we want the containing scalar to
2817 have an UTF-8 flag too */
2823 if ((seen_evals = RX_SEEN_EVALS(re)))
2824 PL_reginterp_cnt += seen_evals;
2827 *lp = RX_WRAPLEN(re);
2829 return RX_WRAPPED(re);
2831 const char *const typestr = sv_reftype(referent, 0);
2832 const STRLEN typelen = strlen(typestr);
2833 UV addr = PTR2UV(referent);
2834 const char *stashname = NULL;
2835 STRLEN stashnamelen = 0; /* hush, gcc */
2836 const char *buffer_end;
2838 if (SvOBJECT(referent)) {
2839 const HEK *const name = HvNAME_HEK(SvSTASH(referent));
2842 stashname = HEK_KEY(name);
2843 stashnamelen = HEK_LEN(name);
2845 if (HEK_UTF8(name)) {
2851 stashname = "__ANON__";
2854 len = stashnamelen + 1 /* = */ + typelen + 3 /* (0x */
2855 + 2 * sizeof(UV) + 2 /* )\0 */;
2857 len = typelen + 3 /* (0x */
2858 + 2 * sizeof(UV) + 2 /* )\0 */;
2861 Newx(buffer, len, char);
2862 buffer_end = retval = buffer + len;
2864 /* Working backwards */
2868 *--retval = PL_hexdigit[addr & 15];
2869 } while (addr >>= 4);
2875 memcpy(retval, typestr, typelen);
2879 retval -= stashnamelen;
2880 memcpy(retval, stashname, stashnamelen);
2882 /* retval may not necessarily have reached the start of the
2884 assert (retval >= buffer);
2886 len = buffer_end - retval - 1; /* -1 for that \0 */
2894 if (SvREADONLY(sv) && !SvOK(sv)) {
2897 if (flags & SV_UNDEF_RETURNS_NULL)
2899 if (ckWARN(WARN_UNINITIALIZED))
2904 if (SvIOK(sv) || ((SvIOKp(sv) && !SvNOKp(sv)))) {
2905 /* I'm assuming that if both IV and NV are equally valid then
2906 converting the IV is going to be more efficient */
2907 const U32 isUIOK = SvIsUV(sv);
2908 char buf[TYPE_CHARS(UV)];
2912 if (SvTYPE(sv) < SVt_PVIV)
2913 sv_upgrade(sv, SVt_PVIV);
2914 ptr = uiv_2buf(buf, SvIVX(sv), SvUVX(sv), isUIOK, &ebuf);
2916 /* inlined from sv_setpvn */
2917 s = SvGROW_mutable(sv, len + 1);
2918 Move(ptr, s, len, char);
2922 else if (SvNOKp(sv)) {
2923 if (SvTYPE(sv) < SVt_PVNV)
2924 sv_upgrade(sv, SVt_PVNV);
2925 if (SvNVX(sv) == 0.0) {
2926 s = SvGROW_mutable(sv, 2);
2931 /* The +20 is pure guesswork. Configure test needed. --jhi */
2932 s = SvGROW_mutable(sv, NV_DIG + 20);
2933 /* some Xenix systems wipe out errno here */
2934 Gconvert(SvNVX(sv), NV_DIG, 0, s);
2944 if (isGV_with_GP(sv)) {
2945 GV *const gv = MUTABLE_GV(sv);
2946 SV *const buffer = sv_newmortal();
2948 gv_efullname3(buffer, gv, "*");
2950 assert(SvPOK(buffer));
2952 *lp = SvCUR(buffer);
2954 if ( SvUTF8(buffer) ) SvUTF8_on(sv);
2955 return SvPVX(buffer);
2960 if (flags & SV_UNDEF_RETURNS_NULL)
2962 if (!PL_localizing && !SvPADTMP(sv) && ckWARN(WARN_UNINITIALIZED))
2964 if (SvTYPE(sv) < SVt_PV)
2965 /* Typically the caller expects that sv_any is not NULL now. */
2966 sv_upgrade(sv, SVt_PV);
2970 const STRLEN len = s - SvPVX_const(sv);
2976 DEBUG_c(PerlIO_printf(Perl_debug_log, "0x%"UVxf" 2pv(%s)\n",
2977 PTR2UV(sv),SvPVX_const(sv)));
2978 if (flags & SV_CONST_RETURN)
2979 return (char *)SvPVX_const(sv);
2980 if (flags & SV_MUTABLE_RETURN)
2981 return SvPVX_mutable(sv);
2986 =for apidoc sv_copypv
2988 Copies a stringified representation of the source SV into the
2989 destination SV. Automatically performs any necessary mg_get and
2990 coercion of numeric values into strings. Guaranteed to preserve
2991 UTF8 flag even from overloaded objects. Similar in nature to
2992 sv_2pv[_flags] but operates directly on an SV instead of just the
2993 string. Mostly uses sv_2pv_flags to do its work, except when that
2994 would lose the UTF-8'ness of the PV.
3000 Perl_sv_copypv(pTHX_ SV *const dsv, register SV *const ssv)
3003 const char * const s = SvPV_const(ssv,len);
3005 PERL_ARGS_ASSERT_SV_COPYPV;
3007 sv_setpvn(dsv,s,len);
3015 =for apidoc sv_2pvbyte
3017 Return a pointer to the byte-encoded representation of the SV, and set *lp
3018 to its length. May cause the SV to be downgraded from UTF-8 as a
3021 Usually accessed via the C<SvPVbyte> macro.
3027 Perl_sv_2pvbyte(pTHX_ register SV *const sv, STRLEN *const lp)
3029 PERL_ARGS_ASSERT_SV_2PVBYTE;
3032 sv_utf8_downgrade(sv,0);
3033 return lp ? SvPV_nomg(sv,*lp) : SvPV_nomg_nolen(sv);
3037 =for apidoc sv_2pvutf8
3039 Return a pointer to the UTF-8-encoded representation of the SV, and set *lp
3040 to its length. May cause the SV to be upgraded to UTF-8 as a side-effect.
3042 Usually accessed via the C<SvPVutf8> macro.
3048 Perl_sv_2pvutf8(pTHX_ register SV *const sv, STRLEN *const lp)
3050 PERL_ARGS_ASSERT_SV_2PVUTF8;
3052 sv_utf8_upgrade(sv);
3053 return lp ? SvPV(sv,*lp) : SvPV_nolen(sv);
3058 =for apidoc sv_2bool
3060 This macro is only used by sv_true() or its macro equivalent, and only if
3061 the latter's argument is neither SvPOK, SvIOK nor SvNOK.
3062 It calls sv_2bool_flags with the SV_GMAGIC flag.
3064 =for apidoc sv_2bool_flags
3066 This function is only used by sv_true() and friends, and only if
3067 the latter's argument is neither SvPOK, SvIOK nor SvNOK. If the flags
3068 contain SV_GMAGIC, then it does an mg_get() first.
3075 Perl_sv_2bool_flags(pTHX_ register SV *const sv, const I32 flags)
3079 PERL_ARGS_ASSERT_SV_2BOOL_FLAGS;
3081 if(flags & SV_GMAGIC) SvGETMAGIC(sv);
3087 SV * const tmpsv = AMG_CALLunary(sv, bool__amg);
3088 if (tmpsv && (!SvROK(tmpsv) || (SvRV(tmpsv) != SvRV(sv))))
3089 return cBOOL(SvTRUE(tmpsv));
3091 return SvRV(sv) != 0;
3094 register XPV* const Xpvtmp = (XPV*)SvANY(sv);
3096 (*sv->sv_u.svu_pv > '0' ||
3097 Xpvtmp->xpv_cur > 1 ||
3098 (Xpvtmp->xpv_cur && *sv->sv_u.svu_pv != '0')))
3105 return SvIVX(sv) != 0;
3108 return SvNVX(sv) != 0.0;
3110 if (isGV_with_GP(sv))
3120 =for apidoc sv_utf8_upgrade
3122 Converts the PV of an SV to its UTF-8-encoded form.
3123 Forces the SV to string form if it is not already.
3124 Will C<mg_get> on C<sv> if appropriate.
3125 Always sets the SvUTF8 flag to avoid future validity checks even
3126 if the whole string is the same in UTF-8 as not.
3127 Returns the number of bytes in the converted string
3129 This is not as a general purpose byte encoding to Unicode interface:
3130 use the Encode extension for that.
3132 =for apidoc sv_utf8_upgrade_nomg
3134 Like sv_utf8_upgrade, but doesn't do magic on C<sv>.
3136 =for apidoc sv_utf8_upgrade_flags
3138 Converts the PV of an SV to its UTF-8-encoded form.
3139 Forces the SV to string form if it is not already.
3140 Always sets the SvUTF8 flag to avoid future validity checks even
3141 if all the bytes are invariant in UTF-8. If C<flags> has C<SV_GMAGIC> bit set,
3142 will C<mg_get> on C<sv> if appropriate, else not.
3143 Returns the number of bytes in the converted string
3144 C<sv_utf8_upgrade> and
3145 C<sv_utf8_upgrade_nomg> are implemented in terms of this function.
3147 This is not as a general purpose byte encoding to Unicode interface:
3148 use the Encode extension for that.
3152 The grow version is currently not externally documented. It adds a parameter,
3153 extra, which is the number of unused bytes the string of 'sv' is guaranteed to
3154 have free after it upon return. This allows the caller to reserve extra space
3155 that it intends to fill, to avoid extra grows.
3157 Also externally undocumented for the moment is the flag SV_FORCE_UTF8_UPGRADE,
3158 which can be used to tell this function to not first check to see if there are
3159 any characters that are different in UTF-8 (variant characters) which would
3160 force it to allocate a new string to sv, but to assume there are. Typically
3161 this flag is used by a routine that has already parsed the string to find that
3162 there are such characters, and passes this information on so that the work
3163 doesn't have to be repeated.
3165 (One might think that the calling routine could pass in the position of the
3166 first such variant, so it wouldn't have to be found again. But that is not the
3167 case, because typically when the caller is likely to use this flag, it won't be
3168 calling this routine unless it finds something that won't fit into a byte.
3169 Otherwise it tries to not upgrade and just use bytes. But some things that
3170 do fit into a byte are variants in utf8, and the caller may not have been
3171 keeping track of these.)
3173 If the routine itself changes the string, it adds a trailing NUL. Such a NUL
3174 isn't guaranteed due to having other routines do the work in some input cases,
3175 or if the input is already flagged as being in utf8.
3177 The speed of this could perhaps be improved for many cases if someone wanted to
3178 write a fast function that counts the number of variant characters in a string,
3179 especially if it could return the position of the first one.
3184 Perl_sv_utf8_upgrade_flags_grow(pTHX_ register SV *const sv, const I32 flags, STRLEN extra)
3188 PERL_ARGS_ASSERT_SV_UTF8_UPGRADE_FLAGS_GROW;
3190 if (sv == &PL_sv_undef)
3194 if (SvREADONLY(sv) && (SvPOKp(sv) || SvIOKp(sv) || SvNOKp(sv))) {
3195 (void) sv_2pv_flags(sv,&len, flags);
3197 if (extra) SvGROW(sv, SvCUR(sv) + extra);
3201 (void) SvPV_force_flags(sv,len,flags & SV_GMAGIC);
3206 if (extra) SvGROW(sv, SvCUR(sv) + extra);
3211 sv_force_normal_flags(sv, 0);
3214 if (PL_encoding && !(flags & SV_UTF8_NO_ENCODING)) {
3215 sv_recode_to_utf8(sv, PL_encoding);
3216 if (extra) SvGROW(sv, SvCUR(sv) + extra);
3220 if (SvCUR(sv) == 0) {
3221 if (extra) SvGROW(sv, extra);
3222 } else { /* Assume Latin-1/EBCDIC */
3223 /* This function could be much more efficient if we
3224 * had a FLAG in SVs to signal if there are any variant
3225 * chars in the PV. Given that there isn't such a flag
3226 * make the loop as fast as possible (although there are certainly ways
3227 * to speed this up, eg. through vectorization) */
3228 U8 * s = (U8 *) SvPVX_const(sv);
3229 U8 * e = (U8 *) SvEND(sv);
3231 STRLEN two_byte_count = 0;
3233 if (flags & SV_FORCE_UTF8_UPGRADE) goto must_be_utf8;
3235 /* See if really will need to convert to utf8. We mustn't rely on our
3236 * incoming SV being well formed and having a trailing '\0', as certain
3237 * code in pp_formline can send us partially built SVs. */
3241 if (NATIVE_IS_INVARIANT(ch)) continue;
3243 t--; /* t already incremented; re-point to first variant */
3248 /* utf8 conversion not needed because all are invariants. Mark as
3249 * UTF-8 even if no variant - saves scanning loop */
3251 if (extra) SvGROW(sv, SvCUR(sv) + extra);
3256 /* Here, the string should be converted to utf8, either because of an
3257 * input flag (two_byte_count = 0), or because a character that
3258 * requires 2 bytes was found (two_byte_count = 1). t points either to
3259 * the beginning of the string (if we didn't examine anything), or to
3260 * the first variant. In either case, everything from s to t - 1 will
3261 * occupy only 1 byte each on output.
3263 * There are two main ways to convert. One is to create a new string
3264 * and go through the input starting from the beginning, appending each
3265 * converted value onto the new string as we go along. It's probably
3266 * best to allocate enough space in the string for the worst possible
3267 * case rather than possibly running out of space and having to
3268 * reallocate and then copy what we've done so far. Since everything
3269 * from s to t - 1 is invariant, the destination can be initialized
3270 * with these using a fast memory copy
3272 * The other way is to figure out exactly how big the string should be
3273 * by parsing the entire input. Then you don't have to make it big
3274 * enough to handle the worst possible case, and more importantly, if
3275 * the string you already have is large enough, you don't have to
3276 * allocate a new string, you can copy the last character in the input
3277 * string to the final position(s) that will be occupied by the
3278 * converted string and go backwards, stopping at t, since everything
3279 * before that is invariant.
3281 * There are advantages and disadvantages to each method.
3283 * In the first method, we can allocate a new string, do the memory
3284 * copy from the s to t - 1, and then proceed through the rest of the
3285 * string byte-by-byte.
3287 * In the second method, we proceed through the rest of the input
3288 * string just calculating how big the converted string will be. Then
3289 * there are two cases:
3290 * 1) if the string has enough extra space to handle the converted
3291 * value. We go backwards through the string, converting until we
3292 * get to the position we are at now, and then stop. If this
3293 * position is far enough along in the string, this method is
3294 * faster than the other method. If the memory copy were the same
3295 * speed as the byte-by-byte loop, that position would be about
3296 * half-way, as at the half-way mark, parsing to the end and back
3297 * is one complete string's parse, the same amount as starting
3298 * over and going all the way through. Actually, it would be
3299 * somewhat less than half-way, as it's faster to just count bytes
3300 * than to also copy, and we don't have the overhead of allocating
3301 * a new string, changing the scalar to use it, and freeing the
3302 * existing one. But if the memory copy is fast, the break-even
3303 * point is somewhere after half way. The counting loop could be
3304 * sped up by vectorization, etc, to move the break-even point
3305 * further towards the beginning.
3306 * 2) if the string doesn't have enough space to handle the converted
3307 * value. A new string will have to be allocated, and one might
3308 * as well, given that, start from the beginning doing the first
3309 * method. We've spent extra time parsing the string and in
3310 * exchange all we've gotten is that we know precisely how big to
3311 * make the new one. Perl is more optimized for time than space,
3312 * so this case is a loser.
3313 * So what I've decided to do is not use the 2nd method unless it is
3314 * guaranteed that a new string won't have to be allocated, assuming
3315 * the worst case. I also decided not to put any more conditions on it
3316 * than this, for now. It seems likely that, since the worst case is
3317 * twice as big as the unknown portion of the string (plus 1), we won't
3318 * be guaranteed enough space, causing us to go to the first method,
3319 * unless the string is short, or the first variant character is near
3320 * the end of it. In either of these cases, it seems best to use the
3321 * 2nd method. The only circumstance I can think of where this would
3322 * be really slower is if the string had once had much more data in it
3323 * than it does now, but there is still a substantial amount in it */
3326 STRLEN invariant_head = t - s;
3327 STRLEN size = invariant_head + (e - t) * 2 + 1 + extra;
3328 if (SvLEN(sv) < size) {
3330 /* Here, have decided to allocate a new string */
3335 Newx(dst, size, U8);
3337 /* If no known invariants at the beginning of the input string,
3338 * set so starts from there. Otherwise, can use memory copy to
3339 * get up to where we are now, and then start from here */
3341 if (invariant_head <= 0) {
3344 Copy(s, dst, invariant_head, char);
3345 d = dst + invariant_head;
3349 const UV uv = NATIVE8_TO_UNI(*t++);
3350 if (UNI_IS_INVARIANT(uv))
3351 *d++ = (U8)UNI_TO_NATIVE(uv);
3353 *d++ = (U8)UTF8_EIGHT_BIT_HI(uv);
3354 *d++ = (U8)UTF8_EIGHT_BIT_LO(uv);
3358 SvPV_free(sv); /* No longer using pre-existing string */
3359 SvPV_set(sv, (char*)dst);
3360 SvCUR_set(sv, d - dst);
3361 SvLEN_set(sv, size);
3364 /* Here, have decided to get the exact size of the string.
3365 * Currently this happens only when we know that there is
3366 * guaranteed enough space to fit the converted string, so
3367 * don't have to worry about growing. If two_byte_count is 0,
3368 * then t points to the first byte of the string which hasn't
3369 * been examined yet. Otherwise two_byte_count is 1, and t
3370 * points to the first byte in the string that will expand to
3371 * two. Depending on this, start examining at t or 1 after t.
3374 U8 *d = t + two_byte_count;
3377 /* Count up the remaining bytes that expand to two */
3380 const U8 chr = *d++;
3381 if (! NATIVE_IS_INVARIANT(chr)) two_byte_count++;
3384 /* The string will expand by just the number of bytes that
3385 * occupy two positions. But we are one afterwards because of
3386 * the increment just above. This is the place to put the
3387 * trailing NUL, and to set the length before we decrement */
3389 d += two_byte_count;
3390 SvCUR_set(sv, d - s);
3394 /* Having decremented d, it points to the position to put the
3395 * very last byte of the expanded string. Go backwards through
3396 * the string, copying and expanding as we go, stopping when we
3397 * get to the part that is invariant the rest of the way down */
3401 const U8 ch = NATIVE8_TO_UNI(*e--);
3402 if (UNI_IS_INVARIANT(ch)) {
3403 *d-- = UNI_TO_NATIVE(ch);
3405 *d-- = (U8)UTF8_EIGHT_BIT_LO(ch);
3406 *d-- = (U8)UTF8_EIGHT_BIT_HI(ch);
3411 if (SvTYPE(sv) >= SVt_PVMG && SvMAGIC(sv)) {
3412 /* Update pos. We do it at the end rather than during
3413 * the upgrade, to avoid slowing down the common case
3414 * (upgrade without pos) */
3415 MAGIC * mg = mg_find(sv, PERL_MAGIC_regex_global);
3417 I32 pos = mg->mg_len;
3418 if (pos > 0 && (U32)pos > invariant_head) {
3419 U8 *d = (U8*) SvPVX(sv) + invariant_head;
3420 STRLEN n = (U32)pos - invariant_head;
3422 if (UTF8_IS_START(*d))
3427 mg->mg_len = d - (U8*)SvPVX(sv);
3430 if ((mg = mg_find(sv, PERL_MAGIC_utf8)))
3431 magic_setutf8(sv,mg); /* clear UTF8 cache */
3436 /* Mark as UTF-8 even if no variant - saves scanning loop */
3442 =for apidoc sv_utf8_downgrade
3444 Attempts to convert the PV of an SV from characters to bytes.
3445 If the PV contains a character that cannot fit
3446 in a byte, this conversion will fail;
3447 in this case, either returns false or, if C<fail_ok> is not
3450 This is not as a general purpose Unicode to byte encoding interface:
3451 use the Encode extension for that.
3457 Perl_sv_utf8_downgrade(pTHX_ register SV *const sv, const bool fail_ok)
3461 PERL_ARGS_ASSERT_SV_UTF8_DOWNGRADE;
3463 if (SvPOKp(sv) && SvUTF8(sv)) {
3467 int mg_flags = SV_GMAGIC;
3470 sv_force_normal_flags(sv, 0);
3472 if (SvTYPE(sv) >= SVt_PVMG && SvMAGIC(sv)) {
3474 MAGIC * mg = mg_find(sv, PERL_MAGIC_regex_global);
3476 I32 pos = mg->mg_len;
3478 sv_pos_b2u(sv, &pos);
3479 mg_flags = 0; /* sv_pos_b2u does get magic */
3483 if ((mg = mg_find(sv, PERL_MAGIC_utf8)))
3484 magic_setutf8(sv,mg); /* clear UTF8 cache */
3487 s = (U8 *) SvPV_flags(sv, len, mg_flags);
3489 if (!utf8_to_bytes(s, &len)) {
3494 Perl_croak(aTHX_ "Wide character in %s",
3497 Perl_croak(aTHX_ "Wide character");
3508 =for apidoc sv_utf8_encode
3510 Converts the PV of an SV to UTF-8, but then turns the C<SvUTF8>
3511 flag off so that it looks like octets again.
3517 Perl_sv_utf8_encode(pTHX_ register SV *const sv)
3519 PERL_ARGS_ASSERT_SV_UTF8_ENCODE;
3522 sv_force_normal_flags(sv, 0);
3524 if (SvREADONLY(sv)) {
3525 Perl_croak_no_modify(aTHX);
3527 (void) sv_utf8_upgrade(sv);
3532 =for apidoc sv_utf8_decode
3534 If the PV of the SV is an octet sequence in UTF-8
3535 and contains a multiple-byte character, the C<SvUTF8> flag is turned on
3536 so that it looks like a character. If the PV contains only single-byte
3537 characters, the C<SvUTF8> flag stays off.
3538 Scans PV for validity and returns false if the PV is invalid UTF-8.
3544 Perl_sv_utf8_decode(pTHX_ register SV *const sv)
3546 PERL_ARGS_ASSERT_SV_UTF8_DECODE;
3549 const U8 *start, *c;
3552 /* The octets may have got themselves encoded - get them back as
3555 if (!sv_utf8_downgrade(sv, TRUE))
3558 /* it is actually just a matter of turning the utf8 flag on, but
3559 * we want to make sure everything inside is valid utf8 first.
3561 c = start = (const U8 *) SvPVX_const(sv);
3562 if (!is_utf8_string(c, SvCUR(sv)+1))
3564 e = (const U8 *) SvEND(sv);
3567 if (!UTF8_IS_INVARIANT(ch)) {
3572 if (SvTYPE(sv) >= SVt_PVMG && SvMAGIC(sv)) {
3573 /* adjust pos to the start of a UTF8 char sequence */
3574 MAGIC * mg = mg_find(sv, PERL_MAGIC_regex_global);
3576 I32 pos = mg->mg_len;
3578 for (c = start + pos; c > start; c--) {
3579 if (UTF8_IS_START(*c))
3582 mg->mg_len = c - start;
3585 if ((mg = mg_find(sv, PERL_MAGIC_utf8)))
3586 magic_setutf8(sv,mg); /* clear UTF8 cache */
3593 =for apidoc sv_setsv
3595 Copies the contents of the source SV C<ssv> into the destination SV
3596 C<dsv>. The source SV may be destroyed if it is mortal, so don't use this
3597 function if the source SV needs to be reused. Does not handle 'set' magic.
3598 Loosely speaking, it performs a copy-by-value, obliterating any previous
3599 content of the destination.
3601 You probably want to use one of the assortment of wrappers, such as
3602 C<SvSetSV>, C<SvSetSV_nosteal>, C<SvSetMagicSV> and
3603 C<SvSetMagicSV_nosteal>.
3605 =for apidoc sv_setsv_flags
3607 Copies the contents of the source SV C<ssv> into the destination SV
3608 C<dsv>. The source SV may be destroyed if it is mortal, so don't use this
3609 function if the source SV needs to be reused. Does not handle 'set' magic.
3610 Loosely speaking, it performs a copy-by-value, obliterating any previous
3611 content of the destination.
3612 If the C<flags> parameter has the C<SV_GMAGIC> bit set, will C<mg_get> on
3613 C<ssv> if appropriate, else not. If the C<flags>
3614 parameter has the C<NOSTEAL> bit set then the
3615 buffers of temps will not be stolen. <sv_setsv>
3616 and C<sv_setsv_nomg> are implemented in terms of this function.
3618 You probably want to use one of the assortment of wrappers, such as
3619 C<SvSetSV>, C<SvSetSV_nosteal>, C<SvSetMagicSV> and
3620 C<SvSetMagicSV_nosteal>.
3622 This is the primary function for copying scalars, and most other
3623 copy-ish functions and macros use this underneath.
3629 S_glob_assign_glob(pTHX_ SV *const dstr, SV *const sstr, const int dtype)
3631 I32 mro_changes = 0; /* 1 = method, 2 = isa, 3 = recursive isa */
3632 HV *old_stash = NULL;
3634 PERL_ARGS_ASSERT_GLOB_ASSIGN_GLOB;
3636 if (dtype != SVt_PVGV && !isGV_with_GP(dstr)) {
3637 const char * const name = GvNAME(sstr);
3638 const STRLEN len = GvNAMELEN(sstr);
3640 if (dtype >= SVt_PV) {
3646 SvUPGRADE(dstr, SVt_PVGV);
3647 (void)SvOK_off(dstr);
3648 /* FIXME - why are we doing this, then turning it off and on again
3650 isGV_with_GP_on(dstr);
3652 GvSTASH(dstr) = GvSTASH(sstr);
3654 Perl_sv_add_backref(aTHX_ MUTABLE_SV(GvSTASH(dstr)), dstr);
3655 gv_name_set(MUTABLE_GV(dstr), name, len,
3656 GV_ADD | (GvNAMEUTF8(sstr) ? SVf_UTF8 : 0 ));
3657 SvFAKE_on(dstr); /* can coerce to non-glob */
3660 if(GvGP(MUTABLE_GV(sstr))) {
3661 /* If source has method cache entry, clear it */
3663 SvREFCNT_dec(GvCV(sstr));
3664 GvCV_set(sstr, NULL);
3667 /* If source has a real method, then a method is
3670 GvCV((const GV *)sstr) && GvSTASH(dstr) && HvENAME(GvSTASH(dstr))
3676 /* If dest already had a real method, that's a change as well */
3678 !mro_changes && GvGP(MUTABLE_GV(dstr)) && GvCVu((const GV *)dstr)
3679 && GvSTASH(dstr) && HvENAME(GvSTASH(dstr))
3684 /* We don't need to check the name of the destination if it was not a
3685 glob to begin with. */
3686 if(dtype == SVt_PVGV) {
3687 const char * const name = GvNAME((const GV *)dstr);
3690 /* The stash may have been detached from the symbol table, so
3692 && GvSTASH(dstr) && HvENAME(GvSTASH(dstr))
3693 && GvAV((const GV *)sstr)
3697 const STRLEN len = GvNAMELEN(dstr);
3698 if ((len > 1 && name[len-2] == ':' && name[len-1] == ':')
3699 || (len == 1 && name[0] == ':')) {
3702 /* Set aside the old stash, so we can reset isa caches on
3704 if((old_stash = GvHV(dstr)))
3705 /* Make sure we do not lose it early. */
3706 SvREFCNT_inc_simple_void_NN(
3707 sv_2mortal((SV *)old_stash)
3713 gp_free(MUTABLE_GV(dstr));
3714 isGV_with_GP_off(dstr);
3715 (void)SvOK_off(dstr);
3716 isGV_with_GP_on(dstr);
3717 GvINTRO_off(dstr); /* one-shot flag */
3718 GvGP_set(dstr, gp_ref(GvGP(sstr)));
3719 if (SvTAINTED(sstr))
3721 if (GvIMPORTED(dstr) != GVf_IMPORTED
3722 && CopSTASH_ne(PL_curcop, GvSTASH(dstr)))
3724 GvIMPORTED_on(dstr);
3727 if(mro_changes == 2) {
3729 SV * const sref = (SV *)GvAV((const GV *)dstr);
3730 if (SvSMAGICAL(sref) && (mg = mg_find(sref, PERL_MAGIC_isa))) {
3731 if (SvTYPE(mg->mg_obj) != SVt_PVAV) {
3732 AV * const ary = newAV();
3733 av_push(ary, mg->mg_obj); /* takes the refcount */
3734 mg->mg_obj = (SV *)ary;
3736 av_push((AV *)mg->mg_obj, SvREFCNT_inc_simple_NN(dstr));
3738 else sv_magic(sref, dstr, PERL_MAGIC_isa, NULL, 0);
3739 mro_isa_changed_in(GvSTASH(dstr));
3741 else if(mro_changes == 3) {
3742 HV * const stash = GvHV(dstr);
3743 if(old_stash ? (HV *)HvENAME_get(old_stash) : stash)
3749 else if(mro_changes) mro_method_changed_in(GvSTASH(dstr));
3754 S_glob_assign_ref(pTHX_ SV *const dstr, SV *const sstr)
3756 SV * const sref = SvREFCNT_inc(SvRV(sstr));
3758 const int intro = GvINTRO(dstr);
3761 const U32 stype = SvTYPE(sref);
3763 PERL_ARGS_ASSERT_GLOB_ASSIGN_REF;
3766 GvINTRO_off(dstr); /* one-shot flag */
3767 GvLINE(dstr) = CopLINE(PL_curcop);
3768 GvEGV(dstr) = MUTABLE_GV(dstr);
3773 location = (SV **) &(GvGP(dstr)->gp_cv); /* XXX bypassing GvCV_set */
3774 import_flag = GVf_IMPORTED_CV;
3777 location = (SV **) &GvHV(dstr);
3778 import_flag = GVf_IMPORTED_HV;
3781 location = (SV **) &GvAV(dstr);
3782 import_flag = GVf_IMPORTED_AV;
3785 location = (SV **) &GvIOp(dstr);
3788 location = (SV **) &GvFORM(dstr);
3791 location = &GvSV(dstr);
3792 import_flag = GVf_IMPORTED_SV;
3795 if (stype == SVt_PVCV) {
3796 /*if (GvCVGEN(dstr) && (GvCV(dstr) != (const CV *)sref || GvCVGEN(dstr))) {*/
3797 if (GvCVGEN(dstr)) {
3798 SvREFCNT_dec(GvCV(dstr));
3799 GvCV_set(dstr, NULL);
3800 GvCVGEN(dstr) = 0; /* Switch off cacheness. */
3803 SAVEGENERICSV(*location);
3807 if (stype == SVt_PVCV && (*location != sref || GvCVGEN(dstr))) {
3808 CV* const cv = MUTABLE_CV(*location);
3810 if (!GvCVGEN((const GV *)dstr) &&
3811 (CvROOT(cv) || CvXSUB(cv)) &&
3812 /* redundant check that avoids creating the extra SV
3813 most of the time: */
3814 (CvCONST(cv) || ckWARN(WARN_REDEFINE)))
3816 SV * const new_const_sv =
3817 CvCONST((const CV *)sref)
3818 ? cv_const_sv((const CV *)sref)
3820 report_redefined_cv(
3821 sv_2mortal(Perl_newSVpvf(aTHX_
3824 HvNAME_HEK(GvSTASH((const GV *)dstr))
3826 HEKfARG(GvENAME_HEK(MUTABLE_GV(dstr)))
3829 CvCONST((const CV *)sref) ? &new_const_sv : NULL
3833 cv_ckproto_len_flags(cv, (const GV *)dstr,
3834 SvPOK(sref) ? CvPROTO(sref) : NULL,
3835 SvPOK(sref) ? CvPROTOLEN(sref) : 0,
3836 SvPOK(sref) ? SvUTF8(sref) : 0);
3838 GvCVGEN(dstr) = 0; /* Switch off cacheness. */
3839 GvASSUMECV_on(dstr);
3840 if(GvSTASH(dstr)) mro_method_changed_in(GvSTASH(dstr)); /* sub foo { 1 } sub bar { 2 } *bar = \&foo */
3843 if (import_flag && !(GvFLAGS(dstr) & import_flag)
3844 && CopSTASH_ne(PL_curcop, GvSTASH(dstr))) {
3845 GvFLAGS(dstr) |= import_flag;
3847 if (stype == SVt_PVHV) {
3848 const char * const name = GvNAME((GV*)dstr);
3849 const STRLEN len = GvNAMELEN(dstr);
3852 (len > 1 && name[len-2] == ':' && name[len-1] == ':')
3853 || (len == 1 && name[0] == ':')
3855 && (!dref || HvENAME_get(dref))
3858 (HV *)sref, (HV *)dref,
3864 stype == SVt_PVAV && sref != dref
3865 && strEQ(GvNAME((GV*)dstr), "ISA")
3866 /* The stash may have been detached from the symbol table, so
3867 check its name before doing anything. */
3868 && GvSTASH(dstr) && HvENAME(GvSTASH(dstr))
3871 MAGIC * const omg = dref && SvSMAGICAL(dref)
3872 ? mg_find(dref, PERL_MAGIC_isa)
3874 if (SvSMAGICAL(sref) && (mg = mg_find(sref, PERL_MAGIC_isa))) {
3875 if (SvTYPE(mg->mg_obj) != SVt_PVAV) {
3876 AV * const ary = newAV();
3877 av_push(ary, mg->mg_obj); /* takes the refcount */
3878 mg->mg_obj = (SV *)ary;
3881 if (SvTYPE(omg->mg_obj) == SVt_PVAV) {
3882 SV **svp = AvARRAY((AV *)omg->mg_obj);
3883 I32 items = AvFILLp((AV *)omg->mg_obj) + 1;
3887 SvREFCNT_inc_simple_NN(*svp++)
3893 SvREFCNT_inc_simple_NN(omg->mg_obj)
3897 av_push((AV *)mg->mg_obj,SvREFCNT_inc_simple_NN(dstr));
3902 sref, omg ? omg->mg_obj : dstr, PERL_MAGIC_isa, NULL, 0
3904 mg = mg_find(sref, PERL_MAGIC_isa);
3906 /* Since the *ISA assignment could have affected more than
3907 one stash, don't call mro_isa_changed_in directly, but let
3908 magic_clearisa do it for us, as it already has the logic for
3909 dealing with globs vs arrays of globs. */
3911 Perl_magic_clearisa(aTHX_ NULL, mg);
3916 if (SvTAINTED(sstr))
3922 Perl_sv_setsv_flags(pTHX_ SV *dstr, register SV* sstr, const I32 flags)
3925 register U32 sflags;
3927 register svtype stype;
3929 PERL_ARGS_ASSERT_SV_SETSV_FLAGS;
3934 if (SvIS_FREED(dstr)) {
3935 Perl_croak(aTHX_ "panic: attempt to copy value %" SVf
3936 " to a freed scalar %p", SVfARG(sstr), (void *)dstr);
3938 SV_CHECK_THINKFIRST_COW_DROP(dstr);
3940 sstr = &PL_sv_undef;
3941 if (SvIS_FREED(sstr)) {
3942 Perl_croak(aTHX_ "panic: attempt to copy freed scalar %p to %p",
3943 (void*)sstr, (void*)dstr);
3945 stype = SvTYPE(sstr);
3946 dtype = SvTYPE(dstr);
3948 (void)SvAMAGIC_off(dstr);
3951 /* need to nuke the magic */
3955 /* There's a lot of redundancy below but we're going for speed here */
3960 if (dtype != SVt_PVGV && dtype != SVt_PVLV) {
3961 (void)SvOK_off(dstr);
3969 sv_upgrade(dstr, SVt_IV);
3973 sv_upgrade(dstr, SVt_PVIV);
3977 goto end_of_first_switch;
3979 (void)SvIOK_only(dstr);
3980 SvIV_set(dstr, SvIVX(sstr));
3983 /* SvTAINTED can only be true if the SV has taint magic, which in
3984 turn means that the SV type is PVMG (or greater). This is the
3985 case statement for SVt_IV, so this cannot be true (whatever gcov
3987 assert(!SvTAINTED(sstr));
3992 if (dtype < SVt_PV && dtype != SVt_IV)
3993 sv_upgrade(dstr, SVt_IV);
4001 sv_upgrade(dstr, SVt_NV);
4005 sv_upgrade(dstr, SVt_PVNV);
4009 goto end_of_first_switch;
4011 SvNV_set(dstr, SvNVX(sstr));
4012 (void)SvNOK_only(dstr);
4013 /* SvTAINTED can only be true if the SV has taint magic, which in
4014 turn means that the SV type is PVMG (or greater). This is the
4015 case statement for SVt_NV, so this cannot be true (whatever gcov
4017 assert(!SvTAINTED(sstr));
4023 #ifdef PERL_OLD_COPY_ON_WRITE
4024 if ((SvFLAGS(sstr) & CAN_COW_MASK) == CAN_COW_FLAGS) {
4025 if (dtype < SVt_PVIV)
4026 sv_upgrade(dstr, SVt_PVIV);
4033 sv_upgrade(dstr, SVt_PV);
4036 if (dtype < SVt_PVIV)
4037 sv_upgrade(dstr, SVt_PVIV);
4040 if (dtype < SVt_PVNV)
4041 sv_upgrade(dstr, SVt_PVNV);
4045 const char * const type = sv_reftype(sstr,0);
4047 Perl_croak(aTHX_ "Bizarre copy of %s in %s", type, OP_DESC(PL_op));
4049 Perl_croak(aTHX_ "Bizarre copy of %s", type);
4054 if (dtype < SVt_REGEXP)
4055 sv_upgrade(dstr, SVt_REGEXP);
4058 /* case SVt_BIND: */
4062 if (SvGMAGICAL(sstr) && (flags & SV_GMAGIC)) {
4064 if (SvTYPE(sstr) != stype)
4065 stype = SvTYPE(sstr);
4067 if (isGV_with_GP(sstr) && dtype <= SVt_PVLV) {
4068 glob_assign_glob(dstr, sstr, dtype);
4071 if (stype == SVt_PVLV)
4072 SvUPGRADE(dstr, SVt_PVNV);
4074 SvUPGRADE(dstr, (svtype)stype);
4076 end_of_first_switch:
4078 /* dstr may have been upgraded. */
4079 dtype = SvTYPE(dstr);
4080 sflags = SvFLAGS(sstr);
4082 if (dtype == SVt_PVCV || dtype == SVt_PVFM) {
4083 /* Assigning to a subroutine sets the prototype. */
4086 const char *const ptr = SvPV_const(sstr, len);
4088 SvGROW(dstr, len + 1);
4089 Copy(ptr, SvPVX(dstr), len + 1, char);
4090 SvCUR_set(dstr, len);
4092 SvFLAGS(dstr) |= sflags & SVf_UTF8;
4093 CvAUTOLOAD_off(dstr);
4097 } else if (dtype == SVt_PVAV || dtype == SVt_PVHV) {
4098 const char * const type = sv_reftype(dstr,0);
4100 Perl_croak(aTHX_ "Cannot copy to %s in %s", type, OP_DESC(PL_op));
4102 Perl_croak(aTHX_ "Cannot copy to %s", type);
4103 } else if (sflags & SVf_ROK) {
4104 if (isGV_with_GP(dstr)
4105 && SvTYPE(SvRV(sstr)) == SVt_PVGV && isGV_with_GP(SvRV(sstr))) {
4108 if (GvIMPORTED(dstr) != GVf_IMPORTED
4109 && CopSTASH_ne(PL_curcop, GvSTASH(dstr)))
4111 GvIMPORTED_on(dstr);
4116 glob_assign_glob(dstr, sstr, dtype);
4120 if (dtype >= SVt_PV) {
4121 if (isGV_with_GP(dstr)) {
4122 glob_assign_ref(dstr, sstr);
4125 if (SvPVX_const(dstr)) {
4131 (void)SvOK_off(dstr);
4132 SvRV_set(dstr, SvREFCNT_inc(SvRV(sstr)));
4133 SvFLAGS(dstr) |= sflags & SVf_ROK;
4134 assert(!(sflags & SVp_NOK));
4135 assert(!(sflags & SVp_IOK));
4136 assert(!(sflags & SVf_NOK));
4137 assert(!(sflags & SVf_IOK));
4139 else if (isGV_with_GP(dstr)) {
4140 if (!(sflags & SVf_OK)) {
4141 Perl_ck_warner(aTHX_ packWARN(WARN_MISC),
4142 "Undefined value assigned to typeglob");
4145 GV *gv = gv_fetchsv_nomg(sstr, GV_ADD, SVt_PVGV);
4146 if (dstr != (const SV *)gv) {
4147 const char * const name = GvNAME((const GV *)dstr);
4148 const STRLEN len = GvNAMELEN(dstr);
4149 HV *old_stash = NULL;
4150 bool reset_isa = FALSE;
4151 if ((len > 1 && name[len-2] == ':' && name[len-1] == ':')
4152 || (len == 1 && name[0] == ':')) {
4153 /* Set aside the old stash, so we can reset isa caches
4154 on its subclasses. */
4155 if((old_stash = GvHV(dstr))) {
4156 /* Make sure we do not lose it early. */
4157 SvREFCNT_inc_simple_void_NN(
4158 sv_2mortal((SV *)old_stash)
4165 gp_free(MUTABLE_GV(dstr));
4166 GvGP_set(dstr, gp_ref(GvGP(gv)));
4169 HV * const stash = GvHV(dstr);
4171 old_stash ? (HV *)HvENAME_get(old_stash) : stash
4181 else if (dtype == SVt_REGEXP && stype == SVt_REGEXP) {
4182 reg_temp_copy((REGEXP*)dstr, (REGEXP*)sstr);
4184 else if (sflags & SVp_POK) {
4188 * Check to see if we can just swipe the string. If so, it's a
4189 * possible small lose on short strings, but a big win on long ones.
4190 * It might even be a win on short strings if SvPVX_const(dstr)
4191 * has to be allocated and SvPVX_const(sstr) has to be freed.
4192 * Likewise if we can set up COW rather than doing an actual copy, we
4193 * drop to the else clause, as the swipe code and the COW setup code
4194 * have much in common.
4197 /* Whichever path we take through the next code, we want this true,
4198 and doing it now facilitates the COW check. */
4199 (void)SvPOK_only(dstr);
4202 /* If we're already COW then this clause is not true, and if COW
4203 is allowed then we drop down to the else and make dest COW
4204 with us. If caller hasn't said that we're allowed to COW
4205 shared hash keys then we don't do the COW setup, even if the
4206 source scalar is a shared hash key scalar. */
4207 (((flags & SV_COW_SHARED_HASH_KEYS)
4208 ? (sflags & (SVf_FAKE|SVf_READONLY)) != (SVf_FAKE|SVf_READONLY)
4209 : 1 /* If making a COW copy is forbidden then the behaviour we
4210 desire is as if the source SV isn't actually already
4211 COW, even if it is. So we act as if the source flags
4212 are not COW, rather than actually testing them. */
4214 #ifndef PERL_OLD_COPY_ON_WRITE
4215 /* The change that added SV_COW_SHARED_HASH_KEYS makes the logic
4216 when PERL_OLD_COPY_ON_WRITE is defined a little wrong.
4217 Conceptually PERL_OLD_COPY_ON_WRITE being defined should
4218 override SV_COW_SHARED_HASH_KEYS, because it means "always COW"
4219 but in turn, it's somewhat dead code, never expected to go
4220 live, but more kept as a placeholder on how to do it better
4221 in a newer implementation. */
4222 /* If we are COW and dstr is a suitable target then we drop down
4223 into the else and make dest a COW of us. */
4224 || (SvFLAGS(dstr) & CAN_COW_MASK) != CAN_COW_FLAGS
4229 (sflags & SVs_TEMP) && /* slated for free anyway? */
4230 !(sflags & SVf_OOK) && /* and not involved in OOK hack? */
4231 (!(flags & SV_NOSTEAL)) &&
4232 /* and we're allowed to steal temps */
4233 SvREFCNT(sstr) == 1 && /* and no other references to it? */
4234 SvLEN(sstr)) /* and really is a string */
4235 #ifdef PERL_OLD_COPY_ON_WRITE
4236 && ((flags & SV_COW_SHARED_HASH_KEYS)
4237 ? (!((sflags & CAN_COW_MASK) == CAN_COW_FLAGS
4238 && (SvFLAGS(dstr) & CAN_COW_MASK) == CAN_COW_FLAGS
4239 && SvTYPE(sstr) >= SVt_PVIV && SvTYPE(sstr) != SVt_PVFM))
4243 /* Failed the swipe test, and it's not a shared hash key either.
4244 Have to copy the string. */
4245 STRLEN len = SvCUR(sstr);
4246 SvGROW(dstr, len + 1); /* inlined from sv_setpvn */
4247 Move(SvPVX_const(sstr),SvPVX(dstr),len,char);
4248 SvCUR_set(dstr, len);
4249 *SvEND(dstr) = '\0';
4251 /* If PERL_OLD_COPY_ON_WRITE is not defined, then isSwipe will always
4253 /* Either it's a shared hash key, or it's suitable for
4254 copy-on-write or we can swipe the string. */
4256 PerlIO_printf(Perl_debug_log, "Copy on write: sstr --> dstr\n");
4260 #ifdef PERL_OLD_COPY_ON_WRITE
4262 if ((sflags & (SVf_FAKE | SVf_READONLY))
4263 != (SVf_FAKE | SVf_READONLY)) {
4264 SvREADONLY_on(sstr);
4266 /* Make the source SV into a loop of 1.
4267 (about to become 2) */
4268 SV_COW_NEXT_SV_SET(sstr, sstr);
4272 /* Initial code is common. */
4273 if (SvPVX_const(dstr)) { /* we know that dtype >= SVt_PV */
4278 /* making another shared SV. */
4279 STRLEN cur = SvCUR(sstr);
4280 STRLEN len = SvLEN(sstr);
4281 #ifdef PERL_OLD_COPY_ON_WRITE
4283 assert (SvTYPE(dstr) >= SVt_PVIV);
4284 /* SvIsCOW_normal */
4285 /* splice us in between source and next-after-source. */
4286 SV_COW_NEXT_SV_SET(dstr, SV_COW_NEXT_SV(sstr));
4287 SV_COW_NEXT_SV_SET(sstr, dstr);
4288 SvPV_set(dstr, SvPVX_mutable(sstr));
4292 /* SvIsCOW_shared_hash */
4293 DEBUG_C(PerlIO_printf(Perl_debug_log,
4294 "Copy on write: Sharing hash\n"));
4296 assert (SvTYPE(dstr) >= SVt_PV);
4298 HEK_KEY(share_hek_hek(SvSHARED_HEK_FROM_PV(SvPVX_const(sstr)))));
4300 SvLEN_set(dstr, len);
4301 SvCUR_set(dstr, cur);
4302 SvREADONLY_on(dstr);
4306 { /* Passes the swipe test. */
4307 SvPV_set(dstr, SvPVX_mutable(sstr));
4308 SvLEN_set(dstr, SvLEN(sstr));
4309 SvCUR_set(dstr, SvCUR(sstr));
4312 (void)SvOK_off(sstr); /* NOTE: nukes most SvFLAGS on sstr */
4313 SvPV_set(sstr, NULL);
4319 if (sflags & SVp_NOK) {
4320 SvNV_set(dstr, SvNVX(sstr));
4322 if (sflags & SVp_IOK) {
4323 SvIV_set(dstr, SvIVX(sstr));
4324 /* Must do this otherwise some other overloaded use of 0x80000000
4325 gets confused. I guess SVpbm_VALID */
4326 if (sflags & SVf_IVisUV)
4329 SvFLAGS(dstr) |= sflags & (SVf_IOK|SVp_IOK|SVf_NOK|SVp_NOK|SVf_UTF8);
4331 const MAGIC * const smg = SvVSTRING_mg(sstr);
4333 sv_magic(dstr, NULL, PERL_MAGIC_vstring,
4334 smg->mg_ptr, smg->mg_len);
4335 SvRMAGICAL_on(dstr);
4339 else if (sflags & (SVp_IOK|SVp_NOK)) {
4340 (void)SvOK_off(dstr);
4341 SvFLAGS(dstr) |= sflags & (SVf_IOK|SVp_IOK|SVf_IVisUV|SVf_NOK|SVp_NOK);
4342 if (sflags & SVp_IOK) {
4343 /* XXXX Do we want to set IsUV for IV(ROK)? Be extra safe... */
4344 SvIV_set(dstr, SvIVX(sstr));
4346 if (sflags & SVp_NOK) {
4347 SvNV_set(dstr, SvNVX(sstr));
4351 if (isGV_with_GP(sstr)) {
4352 gv_efullname3(dstr, MUTABLE_GV(sstr), "*");
4355 (void)SvOK_off(dstr);
4357 if (SvTAINTED(sstr))
4362 =for apidoc sv_setsv_mg
4364 Like C<sv_setsv>, but also handles 'set' magic.
4370 Perl_sv_setsv_mg(pTHX_ SV *const dstr, register SV *const sstr)
4372 PERL_ARGS_ASSERT_SV_SETSV_MG;
4374 sv_setsv(dstr,sstr);
4378 #ifdef PERL_OLD_COPY_ON_WRITE
4380 Perl_sv_setsv_cow(pTHX_ SV *dstr, SV *sstr)
4382 STRLEN cur = SvCUR(sstr);
4383 STRLEN len = SvLEN(sstr);
4384 register char *new_pv;
4386 PERL_ARGS_ASSERT_SV_SETSV_COW;
4389 PerlIO_printf(Perl_debug_log, "Fast copy on write: %p -> %p\n",
4390 (void*)sstr, (void*)dstr);
4397 if (SvTHINKFIRST(dstr))
4398 sv_force_normal_flags(dstr, SV_COW_DROP_PV);
4399 else if (SvPVX_const(dstr))
4400 Safefree(SvPVX_const(dstr));
4404 SvUPGRADE(dstr, SVt_PVIV);
4406 assert (SvPOK(sstr));
4407 assert (SvPOKp(sstr));
4408 assert (!SvIOK(sstr));
4409 assert (!SvIOKp(sstr));
4410 assert (!SvNOK(sstr));
4411 assert (!SvNOKp(sstr));
4413 if (SvIsCOW(sstr)) {
4415 if (SvLEN(sstr) == 0) {
4416 /* source is a COW shared hash key. */
4417 DEBUG_C(PerlIO_printf(Perl_debug_log,
4418 "Fast copy on write: Sharing hash\n"));
4419 new_pv = HEK_KEY(share_hek_hek(SvSHARED_HEK_FROM_PV(SvPVX_const(sstr))));
4422 SV_COW_NEXT_SV_SET(dstr, SV_COW_NEXT_SV(sstr));
4424 assert ((SvFLAGS(sstr) & CAN_COW_MASK) == CAN_COW_FLAGS);
4425 SvUPGRADE(sstr, SVt_PVIV);
4426 SvREADONLY_on(sstr);
4428 DEBUG_C(PerlIO_printf(Perl_debug_log,
4429 "Fast copy on write: Converting sstr to COW\n"));
4430 SV_COW_NEXT_SV_SET(dstr, sstr);
4432 SV_COW_NEXT_SV_SET(sstr, dstr);
4433 new_pv = SvPVX_mutable(sstr);
4436 SvPV_set(dstr, new_pv);
4437 SvFLAGS(dstr) = (SVt_PVIV|SVf_POK|SVp_POK|SVf_FAKE|SVf_READONLY);
4440 SvLEN_set(dstr, len);
4441 SvCUR_set(dstr, cur);
4450 =for apidoc sv_setpvn
4452 Copies a string into an SV. The C<len> parameter indicates the number of
4453 bytes to be copied. If the C<ptr> argument is NULL the SV will become
4454 undefined. Does not handle 'set' magic. See C<sv_setpvn_mg>.
4460 Perl_sv_setpvn(pTHX_ register SV *const sv, register const char *const ptr, register const STRLEN len)
4463 register char *dptr;
4465 PERL_ARGS_ASSERT_SV_SETPVN;
4467 SV_CHECK_THINKFIRST_COW_DROP(sv);
4473 /* len is STRLEN which is unsigned, need to copy to signed */
4476 Perl_croak(aTHX_ "panic: sv_setpvn called with negative strlen");
4478 SvUPGRADE(sv, SVt_PV);
4480 dptr = SvGROW(sv, len + 1);
4481 Move(ptr,dptr,len,char);
4484 (void)SvPOK_only_UTF8(sv); /* validate pointer */
4486 if (SvTYPE(sv) == SVt_PVCV) CvAUTOLOAD_off(sv);
4490 =for apidoc sv_setpvn_mg
4492 Like C<sv_setpvn>, but also handles 'set' magic.
4498 Perl_sv_setpvn_mg(pTHX_ register SV *const sv, register const char *const ptr, register const STRLEN len)
4500 PERL_ARGS_ASSERT_SV_SETPVN_MG;
4502 sv_setpvn(sv,ptr,len);
4507 =for apidoc sv_setpv
4509 Copies a string into an SV. The string must be null-terminated. Does not
4510 handle 'set' magic. See C<sv_setpv_mg>.
4516 Perl_sv_setpv(pTHX_ register SV *const sv, register const char *const ptr)
4519 register STRLEN len;
4521 PERL_ARGS_ASSERT_SV_SETPV;
4523 SV_CHECK_THINKFIRST_COW_DROP(sv);
4529 SvUPGRADE(sv, SVt_PV);
4531 SvGROW(sv, len + 1);
4532 Move(ptr,SvPVX(sv),len+1,char);
4534 (void)SvPOK_only_UTF8(sv); /* validate pointer */
4536 if (SvTYPE(sv) == SVt_PVCV) CvAUTOLOAD_off(sv);
4540 =for apidoc sv_setpv_mg
4542 Like C<sv_setpv>, but also handles 'set' magic.
4548 Perl_sv_setpv_mg(pTHX_ register SV *const sv, register const char *const ptr)
4550 PERL_ARGS_ASSERT_SV_SETPV_MG;
4557 Perl_sv_sethek(pTHX_ register SV *const sv, const HEK *const hek)
4561 PERL_ARGS_ASSERT_SV_SETHEK;
4567 if (HEK_LEN(hek) == HEf_SVKEY) {
4568 sv_setsv(sv, *(SV**)HEK_KEY(hek));
4571 const int flags = HEK_FLAGS(hek);
4572 if (flags & HVhek_WASUTF8) {
4573 STRLEN utf8_len = HEK_LEN(hek);
4574 char *as_utf8 = (char *)bytes_to_utf8((U8*)HEK_KEY(hek), &utf8_len);
4575 sv_usepvn_flags(sv, as_utf8, utf8_len, SV_HAS_TRAILING_NUL);
4578 } else if (flags & (HVhek_REHASH|HVhek_UNSHARED)) {
4579 sv_setpvn(sv, HEK_KEY(hek), HEK_LEN(hek));
4582 else SvUTF8_off(sv);
4586 SvUPGRADE(sv, SVt_PV);
4587 sv_usepvn_flags(sv, (char *)HEK_KEY(share_hek_hek(hek)), HEK_LEN(hek), SV_HAS_TRAILING_NUL);
4594 else SvUTF8_off(sv);
4602 =for apidoc sv_usepvn_flags
4604 Tells an SV to use C<ptr> to find its string value. Normally the
4605 string is stored inside the SV but sv_usepvn allows the SV to use an
4606 outside string. The C<ptr> should point to memory that was allocated
4607 by C<malloc>. The string length, C<len>, must be supplied. By default
4608 this function will realloc (i.e. move) the memory pointed to by C<ptr>,
4609 so that pointer should not be freed or used by the programmer after
4610 giving it to sv_usepvn, and neither should any pointers from "behind"
4611 that pointer (e.g. ptr + 1) be used.
4613 If C<flags> & SV_SMAGIC is true, will call SvSETMAGIC. If C<flags> &
4614 SV_HAS_TRAILING_NUL is true, then C<ptr[len]> must be NUL, and the realloc
4615 will be skipped (i.e. the buffer is actually at least 1 byte longer than
4616 C<len>, and already meets the requirements for storing in C<SvPVX>).
4622 Perl_sv_usepvn_flags(pTHX_ SV *const sv, char *ptr, const STRLEN len, const U32 flags)
4627 PERL_ARGS_ASSERT_SV_USEPVN_FLAGS;
4629 SV_CHECK_THINKFIRST_COW_DROP(sv);
4630 SvUPGRADE(sv, SVt_PV);
4633 if (flags & SV_SMAGIC)