xref: /openbsd/gnu/usr.bin/perl/sv.h (revision d89ec533)
1 /*    sv.h
2  *
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 and others
5  *
6  *    You may distribute under the terms of either the GNU General Public
7  *    License or the Artistic License, as specified in the README file.
8  *
9  */
10 
11 #ifdef sv_flags
12 #undef sv_flags		/* Convex has this in <signal.h> for sigvec() */
13 #endif
14 
15 /*
16 =head1 SV Flags
17 
18 =for apidoc AmnU||svtype
19 An enum of flags for Perl types.  These are found in the file F<sv.h>
20 in the C<svtype> enum.  Test these flags with the C<SvTYPE> macro.
21 
22 The types are:
23 
24     SVt_NULL
25     SVt_IV
26     SVt_NV
27     SVt_RV
28     SVt_PV
29     SVt_PVIV
30     SVt_PVNV
31     SVt_PVMG
32     SVt_INVLIST
33     SVt_REGEXP
34     SVt_PVGV
35     SVt_PVLV
36     SVt_PVAV
37     SVt_PVHV
38     SVt_PVCV
39     SVt_PVFM
40     SVt_PVIO
41 
42 These are most easily explained from the bottom up.
43 
44 C<SVt_PVIO> is for I/O objects, C<SVt_PVFM> for formats, C<SVt_PVCV> for
45 subroutines, C<SVt_PVHV> for hashes and C<SVt_PVAV> for arrays.
46 
47 All the others are scalar types, that is, things that can be bound to a
48 C<$> variable.  For these, the internal types are mostly orthogonal to
49 types in the Perl language.
50 
51 Hence, checking C<< SvTYPE(sv) < SVt_PVAV >> is the best way to see whether
52 something is a scalar.
53 
54 C<SVt_PVGV> represents a typeglob.  If C<!SvFAKE(sv)>, then it is a real,
55 incoercible typeglob.  If C<SvFAKE(sv)>, then it is a scalar to which a
56 typeglob has been assigned.  Assigning to it again will stop it from being
57 a typeglob.  C<SVt_PVLV> represents a scalar that delegates to another scalar
58 behind the scenes.  It is used, e.g., for the return value of C<substr> and
59 for tied hash and array elements.  It can hold any scalar value, including
60 a typeglob.  C<SVt_REGEXP> is for regular
61 expressions.  C<SVt_INVLIST> is for Perl
62 core internal use only.
63 
64 C<SVt_PVMG> represents a "normal" scalar (not a typeglob, regular expression,
65 or delegate).  Since most scalars do not need all the internal fields of a
66 PVMG, we save memory by allocating smaller structs when possible.  All the
67 other types are just simpler forms of C<SVt_PVMG>, with fewer internal fields.
68 C<SVt_NULL> can only hold undef.  C<SVt_IV> can hold undef, an integer, or a
69 reference.  (C<SVt_RV> is an alias for C<SVt_IV>, which exists for backward
70 compatibility.)  C<SVt_NV> can hold any of those or a double.  C<SVt_PV> can only
71 hold C<undef> or a string.  C<SVt_PVIV> is a superset of C<SVt_PV> and C<SVt_IV>.
72 C<SVt_PVNV> is similar.  C<SVt_PVMG> can hold anything C<SVt_PVNV> can hold, but it
73 can, but does not have to, be blessed or magical.
74 
75 =for apidoc AmnU||SVt_NULL
76 Type flag for scalars.  See L</svtype>.
77 
78 =for apidoc AmnU||SVt_IV
79 Type flag for scalars.  See L</svtype>.
80 
81 =for apidoc AmnU||SVt_NV
82 Type flag for scalars.  See L</svtype>.
83 
84 =for apidoc AmnU||SVt_PV
85 Type flag for scalars.  See L</svtype>.
86 
87 =for apidoc AmnU||SVt_PVIV
88 Type flag for scalars.  See L</svtype>.
89 
90 =for apidoc AmnU||SVt_PVNV
91 Type flag for scalars.  See L</svtype>.
92 
93 =for apidoc AmnU||SVt_PVMG
94 Type flag for scalars.  See L</svtype>.
95 
96 =for apidoc CmnU||SVt_INVLIST
97 Type flag for scalars.  See L<perlapi/svtype>.
98 
99 =for apidoc AmnU||SVt_REGEXP
100 Type flag for regular expressions.  See L</svtype>.
101 
102 =for apidoc AmnU||SVt_PVGV
103 Type flag for typeglobs.  See L</svtype>.
104 
105 =for apidoc AmnU||SVt_PVLV
106 Type flag for scalars.  See L</svtype>.
107 
108 =for apidoc AmnU||SVt_PVAV
109 Type flag for arrays.  See L</svtype>.
110 
111 =for apidoc AmnU||SVt_PVHV
112 Type flag for hashes.  See L</svtype>.
113 
114 =for apidoc AmnU||SVt_PVCV
115 Type flag for subroutines.  See L</svtype>.
116 
117 =for apidoc AmnU||SVt_PVFM
118 Type flag for formats.  See L</svtype>.
119 
120 =for apidoc AmnU||SVt_PVIO
121 Type flag for I/O objects.  See L</svtype>.
122 
123 =cut
124 
125   These are ordered so that the simpler types have a lower value; SvUPGRADE
126   doesn't allow you to upgrade from a higher numbered type to a lower numbered
127   one; also there is code that assumes that anything that has as a PV component
128   has a type numbered >= SVt_PV.
129 */
130 
131 
132 typedef enum {
133 	SVt_NULL,	/* 0 */
134 	/* BIND was here, before INVLIST replaced it.  */
135 	SVt_IV,		/* 1 */
136 	SVt_NV,		/* 2 */
137 	/* RV was here, before it was merged with IV.  */
138 	SVt_PV,		/* 3 */
139 	SVt_INVLIST,	/* 4, implemented as a PV */
140 	SVt_PVIV,	/* 5 */
141 	SVt_PVNV,	/* 6 */
142 	SVt_PVMG,	/* 7 */
143 	SVt_REGEXP,	/* 8 */
144 	/* PVBM was here, before BIND replaced it.  */
145 	SVt_PVGV,	/* 9 */
146 	SVt_PVLV,	/* 10 */
147 	SVt_PVAV,	/* 11 */
148 	SVt_PVHV,	/* 12 */
149 	SVt_PVCV,	/* 13 */
150 	SVt_PVFM,	/* 14 */
151 	SVt_PVIO,	/* 15 */
152                         /* 16-31: Unused, though one should be reserved for a
153                          * freed sv, if the other 3 bits below the flags ones
154                          * get allocated */
155 	SVt_LAST	/* keep last in enum. used to size arrays */
156 } svtype;
157 
158 /* *** any alterations to the SV types above need to be reflected in
159  * SVt_MASK and the various PL_valid_types_* tables.  As of this writing those
160  * tables are in perl.h.  There are also two affected names tables in dump.c,
161  * one in B.xs, and 'bodies_by_type[]' in sv.c.
162  *
163  * The bits that match 0xe0 are CURRENTLY UNUSED
164  * The bits above that are for flags, like SVf_IOK */
165 
166 #define SVt_MASK 0x1f	/* smallest bitmask that covers all types */
167 
168 #ifndef PERL_CORE
169 /* Fast Boyer Moore tables are now stored in magic attached to PVMGs */
170 #  define SVt_PVBM	SVt_PVMG
171 /* Anything wanting to create a reference from clean should ensure that it has
172    a scalar of type SVt_IV now:  */
173 #  define SVt_RV	SVt_IV
174 #endif
175 
176 /* There is collusion here with sv_clear - sv_clear exits early for SVt_NULL
177    so never reaches the clause at the end that uses sv_type_details->body_size
178    to determine whether to call safefree(). Hence body_size can be set
179    non-zero to record the size of HEs, without fear of bogus frees.  */
180 #if defined(PERL_IN_HV_C) || defined(PERL_IN_XS_APITEST)
181 #define HE_SVSLOT	SVt_NULL
182 #endif
183 #ifdef PERL_IN_SV_C
184 #  define SVt_FIRST SVt_NULL	/* the type of SV that new_SV() in sv.c returns */
185 #endif
186 
187 #define PERL_ARENA_ROOTS_SIZE	(SVt_LAST)
188 
189 /* typedefs to eliminate some typing */
190 typedef struct he HE;
191 typedef struct hek HEK;
192 
193 /* Using C's structural equivalence to help emulate C++ inheritance here... */
194 
195 /* start with 2 sv-head building blocks */
196 #define _SV_HEAD(ptrtype) \
197     ptrtype	sv_any;		/* pointer to body */	\
198     U32		sv_refcnt;	/* how many references to us */	\
199     U32		sv_flags	/* what we are */
200 
201 #if NVSIZE <= IVSIZE
202 #  define _NV_BODYLESS_UNION NV svu_nv;
203 #else
204 #  define _NV_BODYLESS_UNION
205 #endif
206 
207 #define _SV_HEAD_UNION \
208     union {				\
209 	char*   svu_pv;		/* pointer to malloced string */	\
210 	IV      svu_iv;			\
211 	UV      svu_uv;			\
212 	_NV_BODYLESS_UNION		\
213 	SV*     svu_rv;		/* pointer to another SV */		\
214 	SV**    svu_array;		\
215 	HE**	svu_hash;		\
216 	GP*	svu_gp;			\
217 	PerlIO *svu_fp;			\
218     }	sv_u				\
219     _SV_HEAD_DEBUG
220 
221 #ifdef DEBUG_LEAKING_SCALARS
222 #define _SV_HEAD_DEBUG ;\
223     PERL_BITFIELD32 sv_debug_optype:9;	/* the type of OP that allocated us */ \
224     PERL_BITFIELD32 sv_debug_inpad:1;	/* was allocated in a pad for an OP */ \
225     PERL_BITFIELD32 sv_debug_line:16;	/* the line where we were allocated */ \
226     UV		    sv_debug_serial;	/* serial number of sv allocation   */ \
227     char *	    sv_debug_file;	/* the file where we were allocated */ \
228     SV *	    sv_debug_parent	/* what we were cloned from (ithreads)*/
229 #else
230 #define _SV_HEAD_DEBUG
231 #endif
232 
233 struct STRUCT_SV {		/* struct sv { */
234     _SV_HEAD(void*);
235     _SV_HEAD_UNION;
236 };
237 
238 struct gv {
239     _SV_HEAD(XPVGV*);		/* pointer to xpvgv body */
240     _SV_HEAD_UNION;
241 };
242 
243 struct cv {
244     _SV_HEAD(XPVCV*);		/* pointer to xpvcv body */
245     _SV_HEAD_UNION;
246 };
247 
248 struct av {
249     _SV_HEAD(XPVAV*);		/* pointer to xpvav body */
250     _SV_HEAD_UNION;
251 };
252 
253 struct hv {
254     _SV_HEAD(XPVHV*);		/* pointer to xpvhv body */
255     _SV_HEAD_UNION;
256 };
257 
258 struct io {
259     _SV_HEAD(XPVIO*);		/* pointer to xpvio body */
260     _SV_HEAD_UNION;
261 };
262 
263 struct p5rx {
264     _SV_HEAD(struct regexp*);	/* pointer to regexp body */
265     _SV_HEAD_UNION;
266 };
267 
268 #undef _SV_HEAD
269 #undef _SV_HEAD_UNION		/* ensure no pollution */
270 
271 /*
272 =head1 SV Manipulation Functions
273 
274 =for apidoc Am|U32|SvREFCNT|SV* sv
275 Returns the value of the object's reference count. Exposed
276 to perl code via Internals::SvREFCNT().
277 
278 =for apidoc SvREFCNT_inc
279 Increments the reference count of the given SV, returning the SV.
280 
281 All of the following C<SvREFCNT_inc>* are optimized versions of
282 C<SvREFCNT_inc>, and can be replaced with C<SvREFCNT_inc>.
283 
284 =for apidoc SvREFCNT_inc_NN
285 Same as C<SvREFCNT_inc>, but can only be used if you know C<sv>
286 is not C<NULL>.  Since we don't have to check the NULLness, it's faster
287 and smaller.
288 
289 =for apidoc SvREFCNT_inc_void
290 Same as C<SvREFCNT_inc>, but can only be used if you don't need the
291 return value.  The macro doesn't need to return a meaningful value.
292 
293 =for apidoc Am|void|SvREFCNT_inc_void_NN|SV* sv
294 Same as C<SvREFCNT_inc>, but can only be used if you don't need the return
295 value, and you know that C<sv> is not C<NULL>.  The macro doesn't need
296 to return a meaningful value, or check for NULLness, so it's smaller
297 and faster.
298 
299 =for apidoc Am|SV*|SvREFCNT_inc_simple|SV* sv
300 Same as C<SvREFCNT_inc>, but can only be used with expressions without side
301 effects.  Since we don't have to store a temporary value, it's faster.
302 
303 =for apidoc Am|SV*|SvREFCNT_inc_simple_NN|SV* sv
304 Same as C<SvREFCNT_inc_simple>, but can only be used if you know C<sv>
305 is not C<NULL>.  Since we don't have to check the NULLness, it's faster
306 and smaller.
307 
308 =for apidoc Am|void|SvREFCNT_inc_simple_void|SV* sv
309 Same as C<SvREFCNT_inc_simple>, but can only be used if you don't need the
310 return value.  The macro doesn't need to return a meaningful value.
311 
312 =for apidoc Am|void|SvREFCNT_inc_simple_void_NN|SV* sv
313 Same as C<SvREFCNT_inc>, but can only be used if you don't need the return
314 value, and you know that C<sv> is not C<NULL>.  The macro doesn't need
315 to return a meaningful value, or check for NULLness, so it's smaller
316 and faster.
317 
318 =for apidoc SvREFCNT_dec
319 Decrements the reference count of the given SV.  C<sv> may be C<NULL>.
320 
321 =for apidoc SvREFCNT_dec_NN
322 Same as C<SvREFCNT_dec>, but can only be used if you know C<sv>
323 is not C<NULL>.  Since we don't have to check the NULLness, it's faster
324 and smaller.
325 
326 =for apidoc Am|svtype|SvTYPE|SV* sv
327 Returns the type of the SV.  See C<L</svtype>>.
328 
329 =for apidoc Am|void|SvUPGRADE|SV* sv|svtype type
330 Used to upgrade an SV to a more complex form.  Uses C<sv_upgrade> to
331 perform the upgrade if necessary.  See C<L</svtype>>.
332 
333 =cut
334 */
335 
336 #define SvANY(sv)	(sv)->sv_any
337 #define SvFLAGS(sv)	(sv)->sv_flags
338 #define SvREFCNT(sv)	(sv)->sv_refcnt
339 
340 #define SvREFCNT_inc(sv)		Perl_SvREFCNT_inc(MUTABLE_SV(sv))
341 #define SvREFCNT_inc_simple(sv)		SvREFCNT_inc(sv)
342 #define SvREFCNT_inc_NN(sv)		Perl_SvREFCNT_inc_NN(MUTABLE_SV(sv))
343 #define SvREFCNT_inc_void(sv)		Perl_SvREFCNT_inc_void(MUTABLE_SV(sv))
344 
345 /* These guys don't need the curly blocks */
346 #define SvREFCNT_inc_simple_void(sv)	STMT_START { if (sv) SvREFCNT(sv)++; } STMT_END
347 #define SvREFCNT_inc_simple_NN(sv)	(++(SvREFCNT(sv)),MUTABLE_SV(sv))
348 #define SvREFCNT_inc_void_NN(sv)	(void)(++SvREFCNT(MUTABLE_SV(sv)))
349 #define SvREFCNT_inc_simple_void_NN(sv)	(void)(++SvREFCNT(MUTABLE_SV(sv)))
350 
351 #define SvREFCNT_dec(sv)	Perl_SvREFCNT_dec(aTHX_ MUTABLE_SV(sv))
352 #define SvREFCNT_dec_NN(sv)	Perl_SvREFCNT_dec_NN(aTHX_ MUTABLE_SV(sv))
353 
354 #define SVTYPEMASK	0xff
355 #define SvTYPE(sv)	((svtype)((sv)->sv_flags & SVTYPEMASK))
356 
357 /* Sadly there are some parts of the core that have pointers to already-freed
358    SV heads, and rely on being able to tell that they are now free. So mark
359    them all by using a consistent macro.  */
360 #define SvIS_FREED(sv)	UNLIKELY(((sv)->sv_flags == SVTYPEMASK))
361 
362 /* this is defined in this peculiar way to avoid compiler warnings.
363  * See the <20121213131428.GD1842@iabyn.com> thread in p5p */
364 #define SvUPGRADE(sv, mt) \
365     ((void)(SvTYPE(sv) >= (mt) || (sv_upgrade(sv, mt),1)))
366 
367 #define SVf_IOK		0x00000100  /* has valid public integer value */
368 #define SVf_NOK		0x00000200  /* has valid public numeric value */
369 #define SVf_POK		0x00000400  /* has valid public pointer value */
370 #define SVf_ROK		0x00000800  /* has a valid reference pointer */
371 
372 #define SVp_IOK		0x00001000  /* has valid non-public integer value */
373 #define SVp_NOK		0x00002000  /* has valid non-public numeric value */
374 #define SVp_POK		0x00004000  /* has valid non-public pointer value */
375 #define SVp_SCREAM	0x00008000  /* currently unused on plain scalars */
376 #define SVphv_CLONEABLE	SVp_SCREAM  /* PVHV (stashes) clone its objects */
377 #define SVpgv_GP	SVp_SCREAM  /* GV has a valid GP */
378 #define SVprv_PCS_IMPORTED  SVp_SCREAM  /* RV is a proxy for a constant
379 				       subroutine in another package. Set the
380 				       GvIMPORTED_CV_on() if it needs to be
381 				       expanded to a real GV */
382 
383 /* SVf_PROTECT is what SVf_READONLY should have been: i.e. modifying
384  * this SV is completely illegal. However, SVf_READONLY (via
385  * Internals::SvREADONLY()) has come to be seen as a flag that can be
386  * temporarily set and unset by the user to indicate e.g. whether a hash
387  * is "locked". Now, Hash::Util et al only set SVf_READONLY, while core
388  * sets both (SVf_READONLY|SVf_PROTECT) to indicate both to core and user
389  * code that this SV should not be messed with.
390  */
391 #define SVf_PROTECT	0x00010000  /* very read-only */
392 #define SVs_PADTMP	0x00020000  /* in use as tmp */
393 #define SVs_PADSTALE	0x00040000  /* lexical has gone out of scope;
394 					only used when !PADTMP */
395 #define SVs_TEMP	0x00080000  /* mortal (implies string is stealable) */
396 #define SVs_OBJECT	0x00100000  /* is "blessed" */
397 #define SVs_GMG		0x00200000  /* has magical get method */
398 #define SVs_SMG		0x00400000  /* has magical set method */
399 #define SVs_RMG		0x00800000  /* has random magical methods */
400 
401 #define SVf_FAKE	0x01000000  /* 0: glob is just a copy
402 				       1: SV head arena wasn't malloc()ed
403 				       2: For PVCV, whether CvUNIQUE(cv)
404 					  refers to an eval or once only
405 					  [CvEVAL(cv), CvSPECIAL(cv)]
406                                        3: HV: informally reserved by DAPM
407                                           for vtables
408                                        4: Together with other flags (or
409                                            lack thereof) indicates a regex,
410                                            including PVLV-as-regex. See
411                                            isREGEXP().
412                                        */
413 #define SVf_OOK		0x02000000  /* has valid offset value. For a PVHV this
414 				       means that a hv_aux struct is present
415 				       after the main array */
416 #define SVf_BREAK	0x04000000  /* refcnt is artificially low - used by
417 				       SVs in final arena cleanup.
418 				       Set in S_regtry on PL_reg_curpm, so that
419 				       perl_destruct will skip it.
420                                        Used for mark and sweep by OP_AASSIGN
421                                        */
422 #define SVf_READONLY	0x08000000  /* may not be modified */
423 
424 
425 
426 
427 #define SVf_THINKFIRST	(SVf_READONLY|SVf_PROTECT|SVf_ROK|SVf_FAKE \
428 			|SVs_RMG|SVf_IsCOW)
429 
430 #define SVf_OK		(SVf_IOK|SVf_NOK|SVf_POK|SVf_ROK| \
431 			 SVp_IOK|SVp_NOK|SVp_POK|SVpgv_GP)
432 
433 #define PRIVSHIFT 4	/* (SVp_?OK >> PRIVSHIFT) == SVf_?OK */
434 
435 /* SVf_AMAGIC means that the stash *may* have overload methods. It's
436  * set each time a function is compiled into a stash, and is reset by the
437  * overload code when called for the first time and finds that there are
438  * no overload methods. Note that this used to be set on the object; but
439  * is now only set on stashes.
440  */
441 #define SVf_AMAGIC	0x10000000  /* has magical overloaded methods */
442 #define SVf_IsCOW	0x10000000  /* copy on write (shared hash key if
443 				       SvLEN == 0) */
444 
445 /* Ensure this value does not clash with the GV_ADD* flags in gv.h, or the
446    CV_CKPROTO_* flags in op.c, or the padadd_* flags in pad.h: */
447 #define SVf_UTF8        0x20000000  /* SvPV is UTF-8 encoded
448 				       This is also set on RVs whose overloaded
449 				       stringification is UTF-8. This might
450 				       only happen as a side effect of SvPV() */
451 /* PVHV */
452 #define SVphv_SHAREKEYS 0x20000000  /* PVHV keys live on shared string table */
453 
454 /* PVAV could probably use 0x2000000 without conflict. I assume that PVFM can
455    be UTF-8 encoded, and PVCVs could well have UTF-8 prototypes. PVIOs haven't
456    been restructured, so sometimes get used as string buffers.  */
457 
458 
459 /* Some private flags. */
460 
461 
462 /* PVAV */
463 #define SVpav_REAL	0x40000000  /* free old entries */
464 /* PVHV */
465 #define SVphv_LAZYDEL	0x40000000  /* entry in xhv_eiter must be deleted */
466 
467 /* IV, PVIV, PVNV, PVMG, PVGV and (I assume) PVLV  */
468 #define SVf_IVisUV	0x80000000  /* use XPVUV instead of XPVIV */
469 /* PVAV */
470 #define SVpav_REIFY 	0x80000000  /* can become real */
471 /* PVHV */
472 #define SVphv_HASKFLAGS	0x80000000  /* keys have flag byte after hash */
473 /* RV upwards. However, SVf_ROK and SVp_IOK are exclusive  */
474 #define SVprv_WEAKREF   0x80000000  /* Weak reference */
475 /* pad name vars only */
476 
477 #define _XPV_HEAD							\
478     HV*		xmg_stash;	/* class package */			\
479     union _xmgu	xmg_u;							\
480     STRLEN	xpv_cur;	/* length of svu_pv as a C string */    \
481     union {								\
482 	STRLEN	xpvlenu_len; 	/* allocated size */			\
483         struct regexp* xpvlenu_rx; /* regex when SV body is XPVLV */    \
484     } xpv_len_u
485 
486 #define xpv_len	xpv_len_u.xpvlenu_len
487 
488 union _xnvu {
489     NV	    xnv_nv;		/* numeric value, if any */
490     HV *    xgv_stash;
491     line_t  xnv_lines;           /* used internally by S_scan_subst() */
492     bool    xnv_bm_tail;        /* an SvVALID (BM) SV has an implicit "\n" */
493 };
494 
495 union _xivu {
496     IV	    xivu_iv;		/* integer value */
497     UV	    xivu_uv;
498     HEK *   xivu_namehek;	/* xpvlv, xpvgv: GvNAME */
499     bool    xivu_eval_seen;     /* used internally by S_scan_subst() */
500 
501 };
502 
503 union _xmgu {
504     MAGIC*  xmg_magic;		/* linked list of magicalness */
505     STRLEN  xmg_hash_index;	/* used while freeing hash entries */
506 };
507 
508 struct xpv {
509     _XPV_HEAD;
510 };
511 
512 struct xpviv {
513     _XPV_HEAD;
514     union _xivu xiv_u;
515 };
516 
517 #define xiv_iv xiv_u.xivu_iv
518 
519 struct xpvuv {
520     _XPV_HEAD;
521     union _xivu xuv_u;
522 };
523 
524 #define xuv_uv xuv_u.xivu_uv
525 
526 struct xpvnv {
527     _XPV_HEAD;
528     union _xivu xiv_u;
529     union _xnvu xnv_u;
530 };
531 
532 /* This structure must match the beginning of struct xpvhv in hv.h. */
533 struct xpvmg {
534     _XPV_HEAD;
535     union _xivu xiv_u;
536     union _xnvu xnv_u;
537 };
538 
539 struct xpvlv {
540     _XPV_HEAD;
541     union _xivu xiv_u;
542     union _xnvu xnv_u;
543     union {
544 	STRLEN	xlvu_targoff;
545 	SSize_t xlvu_stargoff;
546     } xlv_targoff_u;
547     STRLEN	xlv_targlen;
548     SV*		xlv_targ;
549     char	xlv_type;	/* k=keys .=pos x=substr v=vec /=join/re
550 				 * y=alem/helem/iter t=tie T=tied HE */
551     char	xlv_flags;	/* 1 = negative offset  2 = negative len
552                                    4 = out of range (vec) */
553 };
554 
555 #define xlv_targoff xlv_targoff_u.xlvu_targoff
556 
557 struct xpvinvlist {
558     _XPV_HEAD;
559     IV          prev_index;     /* caches result of previous invlist_search() */
560     STRLEN	iterator;       /* Stores where we are in iterating */
561     bool	is_offset;	/* The data structure for all inversion lists
562                                    begins with an element for code point U+0000.
563                                    If this bool is set, the actual list contains
564                                    that 0; otherwise, the list actually begins
565                                    with the following element.  Thus to invert
566                                    the list, merely toggle this flag  */
567 };
568 
569 /* This structure works in 2 ways - regular scalar, or GV with GP */
570 
571 struct xpvgv {
572     _XPV_HEAD;
573     union _xivu xiv_u;
574     union _xnvu xnv_u;
575 };
576 
577 typedef U32 cv_flags_t;
578 
579 #define _XPVCV_COMMON								\
580     HV *	xcv_stash;							\
581     union {									\
582 	OP *	xcv_start;							\
583 	ANY	xcv_xsubany;							\
584     }		xcv_start_u;					    		\
585     union {									\
586 	OP *	xcv_root;							\
587 	void	(*xcv_xsub) (pTHX_ CV*);					\
588     }		xcv_root_u;							\
589     union {								\
590 	GV *	xcv_gv;							\
591 	HEK *	xcv_hek;						\
592     }		xcv_gv_u;						\
593     char *	xcv_file;							\
594     union {									\
595 	PADLIST *	xcv_padlist;						\
596 	void *		xcv_hscxt;						\
597     }		xcv_padlist_u;							\
598     CV *	xcv_outside;							\
599     U32		xcv_outside_seq; /* the COP sequence (at the point of our	\
600 				  * compilation) in the lexically enclosing	\
601 				  * sub */					\
602     cv_flags_t	xcv_flags;						\
603     I32	xcv_depth	/* >= 2 indicates recursive call */
604 
605 /* This structure must match XPVCV in cv.h */
606 
607 struct xpvfm {
608     _XPV_HEAD;
609     _XPVCV_COMMON;
610 };
611 
612 
613 struct xpvio {
614     _XPV_HEAD;
615     union _xivu xiv_u;
616     /* ifp and ofp are normally the same, but sockets need separate streams */
617     PerlIO *	xio_ofp;
618     /* Cray addresses everything by word boundaries (64 bits) and
619      * code and data pointers cannot be mixed (which is exactly what
620      * Perl_filter_add() tries to do with the dirp), hence the
621      *  following union trick (as suggested by Gurusamy Sarathy).
622      * For further information see Geir Johansen's problem report
623      * titled [ID 20000612.002 (#3366)] Perl problem on Cray system
624      * The any pointer (known as IoANY()) will also be a good place
625      * to hang any IO disciplines to.
626      */
627     union {
628 	DIR *	xiou_dirp;	/* for opendir, readdir, etc */
629 	void *	xiou_any;	/* for alignment */
630     } xio_dirpu;
631     /* IV xio_lines is now in IVX  $. */
632     IV		xio_page;	/* $% */
633     IV		xio_page_len;	/* $= */
634     IV		xio_lines_left;	/* $- */
635     char *	xio_top_name;	/* $^ */
636     GV *	xio_top_gv;	/* $^ */
637     char *	xio_fmt_name;	/* $~ */
638     GV *	xio_fmt_gv;	/* $~ */
639     char *	xio_bottom_name;/* $^B */
640     GV *	xio_bottom_gv;	/* $^B */
641     char	xio_type;
642     U8		xio_flags;
643 };
644 
645 #define xio_dirp	xio_dirpu.xiou_dirp
646 #define xio_any		xio_dirpu.xiou_any
647 
648 #define IOf_ARGV	1	/* this fp iterates over ARGV */
649 #define IOf_START	2	/* check for null ARGV and substitute '-' */
650 #define IOf_FLUSH	4	/* this fp wants a flush after write op */
651 #define IOf_DIDTOP	8	/* just did top of form */
652 #define IOf_UNTAINT	16	/* consider this fp (and its data) "safe" */
653 #define IOf_NOLINE	32	/* slurped a pseudo-line from empty file */
654 #define IOf_FAKE_DIRP	64	/* xio_dirp is fake (source filters kludge)
655 				   Also, when this is set, SvPVX() is valid */
656 
657 /* The following macros define implementation-independent predicates on SVs. */
658 
659 /*
660 =for apidoc Am|U32|SvNIOK|SV* sv
661 Returns a U32 value indicating whether the SV contains a number, integer or
662 double.
663 
664 =for apidoc Am|U32|SvNIOKp|SV* sv
665 Returns a U32 value indicating whether the SV contains a number, integer or
666 double.  Checks the B<private> setting.  Use C<SvNIOK> instead.
667 
668 =for apidoc Am|void|SvNIOK_off|SV* sv
669 Unsets the NV/IV status of an SV.
670 
671 =for apidoc Am|U32|SvOK|SV* sv
672 Returns a U32 value indicating whether the value is defined.  This is
673 only meaningful for scalars.
674 
675 =for apidoc Am|U32|SvIOKp|SV* sv
676 Returns a U32 value indicating whether the SV contains an integer.  Checks
677 the B<private> setting.  Use C<SvIOK> instead.
678 
679 =for apidoc Am|U32|SvNOKp|SV* sv
680 Returns a U32 value indicating whether the SV contains a double.  Checks the
681 B<private> setting.  Use C<SvNOK> instead.
682 
683 =for apidoc Am|U32|SvPOKp|SV* sv
684 Returns a U32 value indicating whether the SV contains a character string.
685 Checks the B<private> setting.  Use C<SvPOK> instead.
686 
687 =for apidoc Am|U32|SvIOK|SV* sv
688 Returns a U32 value indicating whether the SV contains an integer.
689 
690 =for apidoc Am|void|SvIOK_on|SV* sv
691 Tells an SV that it is an integer.
692 
693 =for apidoc Am|void|SvIOK_off|SV* sv
694 Unsets the IV status of an SV.
695 
696 =for apidoc Am|void|SvIOK_only|SV* sv
697 Tells an SV that it is an integer and disables all other C<OK> bits.
698 
699 =for apidoc Am|void|SvIOK_only_UV|SV* sv
700 Tells an SV that it is an unsigned integer and disables all other C<OK> bits.
701 
702 =for apidoc Am|bool|SvIOK_UV|SV* sv
703 Returns a boolean indicating whether the SV contains an integer that must be
704 interpreted as unsigned.  A non-negative integer whose value is within the
705 range of both an IV and a UV may be flagged as either C<SvUOK> or C<SvIOK>.
706 
707 =for apidoc Am|bool|SvUOK|SV* sv
708 Returns a boolean indicating whether the SV contains an integer that must be
709 interpreted as unsigned.  A non-negative integer whose value is within the
710 range of both an IV and a UV may be flagged as either C<SvUOK> or C<SvIOK>.
711 
712 =for apidoc Am|bool|SvIOK_notUV|SV* sv
713 Returns a boolean indicating whether the SV contains a signed integer.
714 
715 =for apidoc Am|U32|SvNOK|SV* sv
716 Returns a U32 value indicating whether the SV contains a double.
717 
718 =for apidoc Am|void|SvNOK_on|SV* sv
719 Tells an SV that it is a double.
720 
721 =for apidoc Am|void|SvNOK_off|SV* sv
722 Unsets the NV status of an SV.
723 
724 =for apidoc Am|void|SvNOK_only|SV* sv
725 Tells an SV that it is a double and disables all other OK bits.
726 
727 =for apidoc Am|U32|SvPOK|SV* sv
728 Returns a U32 value indicating whether the SV contains a character
729 string.
730 
731 =for apidoc Am|void|SvPOK_on|SV* sv
732 Tells an SV that it is a string.
733 
734 =for apidoc Am|void|SvPOK_off|SV* sv
735 Unsets the PV status of an SV.
736 
737 =for apidoc Am|void|SvPOK_only|SV* sv
738 Tells an SV that it is a string and disables all other C<OK> bits.
739 Will also turn off the UTF-8 status.
740 
741 =for apidoc Am|bool|SvVOK|SV* sv
742 Returns a boolean indicating whether the SV contains a v-string.
743 
744 =for apidoc Am|U32|SvOOK|SV* sv
745 Returns a U32 indicating whether the pointer to the string buffer is offset.
746 This hack is used internally to speed up removal of characters from the
747 beginning of a C<SvPV>.  When C<SvOOK> is true, then the start of the
748 allocated string buffer is actually C<SvOOK_offset()> bytes before C<SvPVX>.
749 This offset used to be stored in C<SvIVX>, but is now stored within the spare
750 part of the buffer.
751 
752 =for apidoc Am|U32|SvROK|SV* sv
753 Tests if the SV is an RV.
754 
755 =for apidoc Am|void|SvROK_on|SV* sv
756 Tells an SV that it is an RV.
757 
758 =for apidoc Am|void|SvROK_off|SV* sv
759 Unsets the RV status of an SV.
760 
761 =for apidoc Am|SV*|SvRV|SV* sv
762 Dereferences an RV to return the SV.
763 
764 =for apidoc Am|IV|SvIVX|SV* sv
765 Returns the raw value in the SV's IV slot, without checks or conversions.
766 Only use when you are sure C<SvIOK> is true.  See also C<L</SvIV>>.
767 
768 =for apidoc Am|UV|SvUVX|SV* sv
769 Returns the raw value in the SV's UV slot, without checks or conversions.
770 Only use when you are sure C<SvIOK> is true.  See also C<L</SvUV>>.
771 
772 =for apidoc AmD|UV|SvUVXx|SV* sv
773 This is an unnecessary synonym for L</SvUVX>
774 
775 =for apidoc Am|NV|SvNVX|SV* sv
776 Returns the raw value in the SV's NV slot, without checks or conversions.
777 Only use when you are sure C<SvNOK> is true.  See also C<L</SvNV>>.
778 
779 =for apidoc Am|char*|SvPVX|SV* sv
780 Returns a pointer to the physical string in the SV.  The SV must contain a
781 string.  Prior to 5.9.3 it is not safe
782 to execute this macro unless the SV's
783 type >= C<SVt_PV>.
784 
785 This is also used to store the name of an autoloaded subroutine in an XS
786 AUTOLOAD routine.  See L<perlguts/Autoloading with XSUBs>.
787 
788 =for apidoc Am|STRLEN|SvCUR|SV* sv
789 Returns the length of the string which is in the SV.  See C<L</SvLEN>>.
790 
791 =for apidoc Am|STRLEN|SvLEN|SV* sv
792 Returns the size of the string buffer in the SV, not including any part
793 attributable to C<SvOOK>.  See C<L</SvCUR>>.
794 
795 =for apidoc Am|char*|SvEND|SV* sv
796 Returns a pointer to the spot just after the last character in
797 the string which is in the SV, where there is usually a trailing
798 C<NUL> character (even though Perl scalars do not strictly require it).
799 See C<L</SvCUR>>.  Access the character as C<*(SvEND(sv))>.
800 
801 Warning: If C<SvCUR> is equal to C<SvLEN>, then C<SvEND> points to
802 unallocated memory.
803 
804 =for apidoc Am|HV*|SvSTASH|SV* sv
805 Returns the stash of the SV.
806 
807 =for apidoc Am|void|SvIV_set|SV* sv|IV val
808 Set the value of the IV pointer in sv to val.  It is possible to perform
809 the same function of this macro with an lvalue assignment to C<SvIVX>.
810 With future Perls, however, it will be more efficient to use
811 C<SvIV_set> instead of the lvalue assignment to C<SvIVX>.
812 
813 =for apidoc Am|void|SvNV_set|SV* sv|NV val
814 Set the value of the NV pointer in C<sv> to val.  See C<L</SvIV_set>>.
815 
816 =for apidoc Am|void|SvPV_set|SV* sv|char* val
817 This is probably not what you want to use, you probably wanted
818 L</sv_usepvn_flags> or L</sv_setpvn> or L</sv_setpvs>.
819 
820 Set the value of the PV pointer in C<sv> to the Perl allocated
821 C<NUL>-terminated string C<val>.  See also C<L</SvIV_set>>.
822 
823 Remember to free the previous PV buffer. There are many things to check.
824 Beware that the existing pointer may be involved in copy-on-write or other
825 mischief, so do C<SvOOK_off(sv)> and use C<sv_force_normal> or
826 C<SvPV_force> (or check the C<SvIsCOW> flag) first to make sure this
827 modification is safe. Then finally, if it is not a COW, call C<SvPV_free> to
828 free the previous PV buffer.
829 
830 =for apidoc Am|void|SvUV_set|SV* sv|UV val
831 Set the value of the UV pointer in C<sv> to val.  See C<L</SvIV_set>>.
832 
833 =for apidoc Am|void|SvRV_set|SV* sv|SV* val
834 Set the value of the RV pointer in C<sv> to val.  See C<L</SvIV_set>>.
835 
836 =for apidoc Am|void|SvMAGIC_set|SV* sv|MAGIC* val
837 Set the value of the MAGIC pointer in C<sv> to val.  See C<L</SvIV_set>>.
838 
839 =for apidoc Am|void|SvSTASH_set|SV* sv|HV* val
840 Set the value of the STASH pointer in C<sv> to val.  See C<L</SvIV_set>>.
841 
842 =for apidoc Am|void|SvCUR_set|SV* sv|STRLEN len
843 Set the current length of the string which is in the SV.  See C<L</SvCUR>>
844 and C<SvIV_set>>.
845 
846 =for apidoc Am|void|SvLEN_set|SV* sv|STRLEN len
847 Set the size of the string buffer for the SV. See C<L</SvLEN>>.
848 
849 =cut
850 */
851 
852 #define SvNIOK(sv)		(SvFLAGS(sv) & (SVf_IOK|SVf_NOK))
853 #define SvNIOKp(sv)		(SvFLAGS(sv) & (SVp_IOK|SVp_NOK))
854 #define SvNIOK_off(sv)		(SvFLAGS(sv) &= ~(SVf_IOK|SVf_NOK| \
855 						  SVp_IOK|SVp_NOK|SVf_IVisUV))
856 
857 #define assert_not_ROK(sv)	assert_(!SvROK(sv) || !SvRV(sv))
858 #define assert_not_glob(sv)	assert_(!isGV_with_GP(sv))
859 
860 #define SvOK(sv)		(SvFLAGS(sv) & SVf_OK)
861 #define SvOK_off(sv)		(assert_not_ROK(sv) assert_not_glob(sv)	\
862 				 SvFLAGS(sv) &=	~(SVf_OK|		\
863 						  SVf_IVisUV|SVf_UTF8),	\
864 							SvOOK_off(sv))
865 #define SvOK_off_exc_UV(sv)	(assert_not_ROK(sv)			\
866 				 SvFLAGS(sv) &=	~(SVf_OK|		\
867 						  SVf_UTF8),		\
868 							SvOOK_off(sv))
869 
870 #define SvOKp(sv)		(SvFLAGS(sv) & (SVp_IOK|SVp_NOK|SVp_POK))
871 #define SvIOKp(sv)		(SvFLAGS(sv) & SVp_IOK)
872 #define SvIOKp_on(sv)		(assert_not_glob(sv)	\
873 				    SvFLAGS(sv) |= SVp_IOK)
874 #define SvNOKp(sv)		(SvFLAGS(sv) & SVp_NOK)
875 #define SvNOKp_on(sv)		(assert_not_glob(sv) SvFLAGS(sv) |= SVp_NOK)
876 #define SvPOKp(sv)		(SvFLAGS(sv) & SVp_POK)
877 #define SvPOKp_on(sv)		(assert_not_ROK(sv) assert_not_glob(sv)	\
878 				 SvFLAGS(sv) |= SVp_POK)
879 
880 #define SvIOK(sv)		(SvFLAGS(sv) & SVf_IOK)
881 #define SvIOK_on(sv)		(assert_not_glob(sv)	\
882 				    SvFLAGS(sv) |= (SVf_IOK|SVp_IOK))
883 #define SvIOK_off(sv)		(SvFLAGS(sv) &= ~(SVf_IOK|SVp_IOK|SVf_IVisUV))
884 #define SvIOK_only(sv)		(SvOK_off(sv), \
885 				    SvFLAGS(sv) |= (SVf_IOK|SVp_IOK))
886 #define SvIOK_only_UV(sv)	(assert_not_glob(sv) SvOK_off_exc_UV(sv), \
887 				    SvFLAGS(sv) |= (SVf_IOK|SVp_IOK))
888 
889 #define SvIOK_UV(sv)		((SvFLAGS(sv) & (SVf_IOK|SVf_IVisUV))	\
890 				 == (SVf_IOK|SVf_IVisUV))
891 #define SvUOK(sv)		SvIOK_UV(sv)
892 #define SvIOK_notUV(sv)		((SvFLAGS(sv) & (SVf_IOK|SVf_IVisUV))	\
893 				 == SVf_IOK)
894 
895 #define SvIsUV(sv)		(SvFLAGS(sv) & SVf_IVisUV)
896 #define SvIsUV_on(sv)		(SvFLAGS(sv) |= SVf_IVisUV)
897 #define SvIsUV_off(sv)		(SvFLAGS(sv) &= ~SVf_IVisUV)
898 
899 #define SvNOK(sv)		(SvFLAGS(sv) & SVf_NOK)
900 #define SvNOK_on(sv)		(assert_not_glob(sv) \
901 				 SvFLAGS(sv) |= (SVf_NOK|SVp_NOK))
902 #define SvNOK_off(sv)		(SvFLAGS(sv) &= ~(SVf_NOK|SVp_NOK))
903 #define SvNOK_only(sv)		(SvOK_off(sv), \
904 				    SvFLAGS(sv) |= (SVf_NOK|SVp_NOK))
905 
906 /*
907 =for apidoc Am|U32|SvUTF8|SV* sv
908 Returns a U32 value indicating the UTF-8 status of an SV.  If things are set-up
909 properly, this indicates whether or not the SV contains UTF-8 encoded data.
910 You should use this I<after> a call to C<SvPV()> or one of its variants, in
911 case any call to string overloading updates the internal flag.
912 
913 If you want to take into account the L<bytes> pragma, use C<L</DO_UTF8>>
914 instead.
915 
916 =for apidoc Am|void|SvUTF8_on|SV *sv
917 Turn on the UTF-8 status of an SV (the data is not changed, just the flag).
918 Do not use frivolously.
919 
920 =for apidoc Am|void|SvUTF8_off|SV *sv
921 Unsets the UTF-8 status of an SV (the data is not changed, just the flag).
922 Do not use frivolously.
923 
924 =for apidoc Am|void|SvPOK_only_UTF8|SV* sv
925 Tells an SV that it is a string and disables all other C<OK> bits,
926 and leaves the UTF-8 status as it was.
927 
928 =cut
929  */
930 
931 /* Ensure the return value of this macro does not clash with the GV_ADD* flags
932 in gv.h: */
933 #define SvUTF8(sv)		(SvFLAGS(sv) & SVf_UTF8)
934 #define SvUTF8_on(sv)		(SvFLAGS(sv) |= (SVf_UTF8))
935 #define SvUTF8_off(sv)		(SvFLAGS(sv) &= ~(SVf_UTF8))
936 
937 #define SvPOK(sv)		(SvFLAGS(sv) & SVf_POK)
938 #define SvPOK_on(sv)		(assert_not_ROK(sv) assert_not_glob(sv)	\
939 				 SvFLAGS(sv) |= (SVf_POK|SVp_POK))
940 #define SvPOK_off(sv)		(SvFLAGS(sv) &= ~(SVf_POK|SVp_POK))
941 #define SvPOK_only(sv)		(assert_not_ROK(sv) assert_not_glob(sv)	\
942 				 SvFLAGS(sv) &= ~(SVf_OK|		\
943 						  SVf_IVisUV|SVf_UTF8),	\
944 				    SvFLAGS(sv) |= (SVf_POK|SVp_POK))
945 #define SvPOK_only_UTF8(sv)	(assert_not_ROK(sv) assert_not_glob(sv)	\
946 				 SvFLAGS(sv) &= ~(SVf_OK|		\
947 						  SVf_IVisUV),		\
948 				    SvFLAGS(sv) |= (SVf_POK|SVp_POK))
949 
950 #define SvVOK(sv)		(SvMAGICAL(sv)				\
951 				 && mg_find(sv,PERL_MAGIC_vstring))
952 /* returns the vstring magic, if any */
953 #define SvVSTRING_mg(sv)	(SvMAGICAL(sv) \
954 				 ? mg_find(sv,PERL_MAGIC_vstring) : NULL)
955 
956 #define SvOOK(sv)		(SvFLAGS(sv) & SVf_OOK)
957 #define SvOOK_on(sv)		(SvFLAGS(sv) |= SVf_OOK)
958 #define SvOOK_off(sv)		((void)(SvOOK(sv) && (sv_backoff(sv),0)))
959 
960 #define SvFAKE(sv)		(SvFLAGS(sv) & SVf_FAKE)
961 #define SvFAKE_on(sv)		(SvFLAGS(sv) |= SVf_FAKE)
962 #define SvFAKE_off(sv)		(SvFLAGS(sv) &= ~SVf_FAKE)
963 
964 #define SvROK(sv)		(SvFLAGS(sv) & SVf_ROK)
965 #define SvROK_on(sv)		(SvFLAGS(sv) |= SVf_ROK)
966 #define SvROK_off(sv)		(SvFLAGS(sv) &= ~(SVf_ROK))
967 
968 #define SvMAGICAL(sv)		(SvFLAGS(sv) & (SVs_GMG|SVs_SMG|SVs_RMG))
969 #define SvMAGICAL_on(sv)	(SvFLAGS(sv) |= (SVs_GMG|SVs_SMG|SVs_RMG))
970 #define SvMAGICAL_off(sv)	(SvFLAGS(sv) &= ~(SVs_GMG|SVs_SMG|SVs_RMG))
971 
972 #define SvGMAGICAL(sv)		(SvFLAGS(sv) & SVs_GMG)
973 #define SvGMAGICAL_on(sv)	(SvFLAGS(sv) |= SVs_GMG)
974 #define SvGMAGICAL_off(sv)	(SvFLAGS(sv) &= ~SVs_GMG)
975 
976 #define SvSMAGICAL(sv)		(SvFLAGS(sv) & SVs_SMG)
977 #define SvSMAGICAL_on(sv)	(SvFLAGS(sv) |= SVs_SMG)
978 #define SvSMAGICAL_off(sv)	(SvFLAGS(sv) &= ~SVs_SMG)
979 
980 #define SvRMAGICAL(sv)		(SvFLAGS(sv) & SVs_RMG)
981 #define SvRMAGICAL_on(sv)	(SvFLAGS(sv) |= SVs_RMG)
982 #define SvRMAGICAL_off(sv)	(SvFLAGS(sv) &= ~SVs_RMG)
983 
984 #define SvAMAGIC(sv)		(SvROK(sv) && SvOBJECT(SvRV(sv)) &&	\
985 				 HvAMAGIC(SvSTASH(SvRV(sv))))
986 
987 /* To be used on the stashes themselves: */
988 #define HvAMAGIC(hv)		(SvFLAGS(hv) & SVf_AMAGIC)
989 #define HvAMAGIC_on(hv)		(SvFLAGS(hv) |= SVf_AMAGIC)
990 #define HvAMAGIC_off(hv)	(SvFLAGS(hv) &=~ SVf_AMAGIC)
991 
992 
993 /* "nog" means "doesn't have get magic" */
994 #define SvPOK_nog(sv)		((SvFLAGS(sv) & (SVf_POK|SVs_GMG)) == SVf_POK)
995 #define SvIOK_nog(sv)		((SvFLAGS(sv) & (SVf_IOK|SVs_GMG)) == SVf_IOK)
996 #define SvUOK_nog(sv)		((SvFLAGS(sv) & (SVf_IOK|SVf_IVisUV|SVs_GMG)) == (SVf_IOK|SVf_IVisUV))
997 #define SvNOK_nog(sv)		((SvFLAGS(sv) & (SVf_NOK|SVs_GMG)) == SVf_NOK)
998 #define SvNIOK_nog(sv)		(SvNIOK(sv) && !(SvFLAGS(sv) & SVs_GMG))
999 
1000 #define SvPOK_nogthink(sv)	((SvFLAGS(sv) & (SVf_POK|SVf_THINKFIRST|SVs_GMG)) == SVf_POK)
1001 #define SvIOK_nogthink(sv)	((SvFLAGS(sv) & (SVf_IOK|SVf_THINKFIRST|SVs_GMG)) == SVf_IOK)
1002 #define SvUOK_nogthink(sv)	((SvFLAGS(sv) & (SVf_IOK|SVf_IVisUV|SVf_THINKFIRST|SVs_GMG)) == (SVf_IOK|SVf_IVisUV))
1003 #define SvNOK_nogthink(sv)	((SvFLAGS(sv) & (SVf_NOK|SVf_THINKFIRST|SVs_GMG)) == SVf_NOK)
1004 #define SvNIOK_nogthink(sv)	(SvNIOK(sv) && !(SvFLAGS(sv) & (SVf_THINKFIRST|SVs_GMG)))
1005 
1006 #define SvPOK_utf8_nog(sv)	((SvFLAGS(sv) & (SVf_POK|SVf_UTF8|SVs_GMG)) == (SVf_POK|SVf_UTF8))
1007 #define SvPOK_utf8_nogthink(sv)	((SvFLAGS(sv) & (SVf_POK|SVf_UTF8|SVf_THINKFIRST|SVs_GMG)) == (SVf_POK|SVf_UTF8))
1008 
1009 #define SvPOK_byte_nog(sv)	((SvFLAGS(sv) & (SVf_POK|SVf_UTF8|SVs_GMG)) == SVf_POK)
1010 #define SvPOK_byte_nogthink(sv)	((SvFLAGS(sv) & (SVf_POK|SVf_UTF8|SVf_THINKFIRST|SVs_GMG)) == SVf_POK)
1011 
1012 #define SvPOK_pure_nogthink(sv) \
1013     ((SvFLAGS(sv) & (SVf_POK|SVf_IOK|SVf_NOK|SVf_ROK|SVpgv_GP|SVf_THINKFIRST|SVs_GMG)) == SVf_POK)
1014 #define SvPOK_utf8_pure_nogthink(sv) \
1015     ((SvFLAGS(sv) & (SVf_POK|SVf_UTF8|SVf_IOK|SVf_NOK|SVf_ROK|SVpgv_GP|SVf_THINKFIRST|SVs_GMG)) == (SVf_POK|SVf_UTF8))
1016 #define SvPOK_byte_pure_nogthink(sv) \
1017     ((SvFLAGS(sv) & (SVf_POK|SVf_UTF8|SVf_IOK|SVf_NOK|SVf_ROK|SVpgv_GP|SVf_THINKFIRST|SVs_GMG)) == SVf_POK)
1018 
1019 /*
1020 =for apidoc Am|U32|SvGAMAGIC|SV* sv
1021 
1022 Returns true if the SV has get magic or
1023 overloading.  If either is true then
1024 the scalar is active data, and has the potential to return a new value every
1025 time it is accessed.  Hence you must be careful to
1026 only read it once per user logical operation and work
1027 with that returned value.  If neither is true then
1028 the scalar's value cannot change unless written to.
1029 
1030 =cut
1031 */
1032 
1033 #define SvGAMAGIC(sv)           (SvGMAGICAL(sv) || SvAMAGIC(sv))
1034 
1035 #define Gv_AMG(stash) \
1036 	(HvNAME(stash) && Gv_AMupdate(stash,FALSE) \
1037 	    ? 1					    \
1038 	    : (HvAMAGIC_off(stash), 0))
1039 
1040 #define SvWEAKREF(sv)		((SvFLAGS(sv) & (SVf_ROK|SVprv_WEAKREF)) \
1041 				  == (SVf_ROK|SVprv_WEAKREF))
1042 #define SvWEAKREF_on(sv)	(SvFLAGS(sv) |=  (SVf_ROK|SVprv_WEAKREF))
1043 #define SvWEAKREF_off(sv)	(SvFLAGS(sv) &= ~(SVf_ROK|SVprv_WEAKREF))
1044 
1045 #define SvPCS_IMPORTED(sv)	((SvFLAGS(sv) & (SVf_ROK|SVprv_PCS_IMPORTED)) \
1046 				 == (SVf_ROK|SVprv_PCS_IMPORTED))
1047 #define SvPCS_IMPORTED_on(sv)	(SvFLAGS(sv) |=  (SVf_ROK|SVprv_PCS_IMPORTED))
1048 #define SvPCS_IMPORTED_off(sv)	(SvFLAGS(sv) &= ~(SVf_ROK|SVprv_PCS_IMPORTED))
1049 
1050 /*
1051 =for apidoc m|U32|SvTHINKFIRST|SV *sv
1052 
1053 A quick flag check to see whether an C<sv> should be passed to C<sv_force_normal>
1054 to be "downgraded" before C<SvIVX> or C<SvPVX> can be modified directly.
1055 
1056 For example, if your scalar is a reference and you want to modify the C<SvIVX>
1057 slot, you can't just do C<SvROK_off>, as that will leak the referent.
1058 
1059 This is used internally by various sv-modifying functions, such as
1060 C<sv_setsv>, C<sv_setiv> and C<sv_pvn_force>.
1061 
1062 One case that this does not handle is a gv without SvFAKE set.  After
1063 
1064     if (SvTHINKFIRST(gv)) sv_force_normal(gv);
1065 
1066 it will still be a gv.
1067 
1068 C<SvTHINKFIRST> sometimes produces false positives.  In those cases
1069 C<sv_force_normal> does nothing.
1070 
1071 =cut
1072 */
1073 
1074 #define SvTHINKFIRST(sv)	(SvFLAGS(sv) & SVf_THINKFIRST)
1075 
1076 #define SVs_PADMY		0
1077 #define SvPADMY(sv)		!(SvFLAGS(sv) & SVs_PADTMP)
1078 #ifndef PERL_CORE
1079 # define SvPADMY_on(sv)		SvPADTMP_off(sv)
1080 #endif
1081 
1082 #define SvPADTMP(sv)		(SvFLAGS(sv) & (SVs_PADTMP))
1083 #define SvPADSTALE(sv)		(SvFLAGS(sv) & (SVs_PADSTALE))
1084 
1085 #define SvPADTMP_on(sv)		(SvFLAGS(sv) |= SVs_PADTMP)
1086 #define SvPADTMP_off(sv)	(SvFLAGS(sv) &= ~SVs_PADTMP)
1087 #define SvPADSTALE_on(sv)	Perl_SvPADSTALE_on(MUTABLE_SV(sv))
1088 #define SvPADSTALE_off(sv)	Perl_SvPADSTALE_off(MUTABLE_SV(sv))
1089 
1090 #define SvTEMP(sv)		(SvFLAGS(sv) & SVs_TEMP)
1091 #define SvTEMP_on(sv)		(SvFLAGS(sv) |= SVs_TEMP)
1092 #define SvTEMP_off(sv)		(SvFLAGS(sv) &= ~SVs_TEMP)
1093 
1094 #define SvOBJECT(sv)		(SvFLAGS(sv) & SVs_OBJECT)
1095 #define SvOBJECT_on(sv)		(SvFLAGS(sv) |= SVs_OBJECT)
1096 #define SvOBJECT_off(sv)	(SvFLAGS(sv) &= ~SVs_OBJECT)
1097 
1098 /*
1099 =for apidoc Am|U32|SvREADONLY|SV* sv
1100 Returns true if the argument is readonly, otherwise returns false.
1101 Exposed to perl code via Internals::SvREADONLY().
1102 
1103 =for apidoc Am|U32|SvREADONLY_on|SV* sv
1104 Mark an object as readonly. Exactly what this means depends on the object
1105 type. Exposed to perl code via Internals::SvREADONLY().
1106 
1107 =for apidoc Am|U32|SvREADONLY_off|SV* sv
1108 Mark an object as not-readonly. Exactly what this mean depends on the
1109 object type. Exposed to perl code via Internals::SvREADONLY().
1110 
1111 =cut
1112 */
1113 
1114 #define SvREADONLY(sv)		(SvFLAGS(sv) & (SVf_READONLY|SVf_PROTECT))
1115 #ifdef PERL_CORE
1116 # define SvREADONLY_on(sv)	(SvFLAGS(sv) |= (SVf_READONLY|SVf_PROTECT))
1117 # define SvREADONLY_off(sv)	(SvFLAGS(sv) &=~(SVf_READONLY|SVf_PROTECT))
1118 #else
1119 # define SvREADONLY_on(sv)	(SvFLAGS(sv) |= SVf_READONLY)
1120 # define SvREADONLY_off(sv)	(SvFLAGS(sv) &= ~SVf_READONLY)
1121 #endif
1122 
1123 #define SvSCREAM(sv) ((SvFLAGS(sv) & (SVp_SCREAM|SVp_POK)) == (SVp_SCREAM|SVp_POK))
1124 #define SvSCREAM_on(sv)		(SvFLAGS(sv) |= SVp_SCREAM)
1125 #define SvSCREAM_off(sv)	(SvFLAGS(sv) &= ~SVp_SCREAM)
1126 
1127 #ifndef PERL_CORE
1128 #  define SvCOMPILED(sv)	0
1129 #  define SvCOMPILED_on(sv)
1130 #  define SvCOMPILED_off(sv)
1131 #endif
1132 
1133 
1134 #if defined (DEBUGGING) && defined(__GNUC__) && !defined(PERL_GCC_BRACE_GROUPS_FORBIDDEN)
1135 #  define SvTAIL(sv)	({ const SV *const _svtail = (const SV *)(sv);	\
1136 			    assert(SvTYPE(_svtail) != SVt_PVAV);	\
1137 			    assert(SvTYPE(_svtail) != SVt_PVHV);	\
1138 			    assert(!(SvFLAGS(_svtail) & (SVf_NOK|SVp_NOK))); \
1139 			    assert(SvVALID(_svtail));                        \
1140                             ((XPVNV*)SvANY(_svtail))->xnv_u.xnv_bm_tail;     \
1141 			})
1142 #else
1143 #  define SvTAIL(_svtail)  (((XPVNV*)SvANY(_svtail))->xnv_u.xnv_bm_tail)
1144 #endif
1145 
1146 /* Does the SV have a Boyer-Moore table attached as magic?
1147  * 'VALID' is a poor name, but is kept for historical reasons.  */
1148 #define SvVALID(_svvalid) (                                  \
1149                SvPOKp(_svvalid)                              \
1150             && SvSMAGICAL(_svvalid)                          \
1151             && SvMAGIC(_svvalid)                             \
1152             && (SvMAGIC(_svvalid)->mg_type == PERL_MAGIC_bm  \
1153                 || mg_find(_svvalid, PERL_MAGIC_bm))         \
1154         )
1155 
1156 #define SvRVx(sv) SvRV(sv)
1157 
1158 #ifdef PERL_DEBUG_COW
1159 /* Need -0.0 for SvNVX to preserve IEEE FP "negative zero" because
1160    +0.0 + -0.0 => +0.0 but -0.0 + -0.0 => -0.0 */
1161 #  define SvIVX(sv) (0 + ((XPVIV*) SvANY(sv))->xiv_iv)
1162 #  define SvUVX(sv) (0 + ((XPVUV*) SvANY(sv))->xuv_uv)
1163 #  define SvNVX(sv) (-0.0 + ((XPVNV*) SvANY(sv))->xnv_u.xnv_nv)
1164 #  define SvRV(sv) (0 + (sv)->sv_u.svu_rv)
1165 #  define SvRV_const(sv) (0 + (sv)->sv_u.svu_rv)
1166 /* Don't test the core XS code yet.  */
1167 #  if defined (PERL_CORE) && PERL_DEBUG_COW > 1
1168 #    define SvPVX(sv) (0 + (assert_(!SvREADONLY(sv)) (sv)->sv_u.svu_pv))
1169 #  else
1170 #  define SvPVX(sv) SvPVX_mutable(sv)
1171 #  endif
1172 #  define SvCUR(sv) (0 + ((XPV*) SvANY(sv))->xpv_cur)
1173 #  define SvLEN(sv) (0 + ((XPV*) SvANY(sv))->xpv_len)
1174 #  define SvEND(sv) ((sv)->sv_u.svu_pv + ((XPV*)SvANY(sv))->xpv_cur)
1175 
1176 #  define SvMAGIC(sv)	(0 + *(assert_(SvTYPE(sv) >= SVt_PVMG) &((XPVMG*)  SvANY(sv))->xmg_u.xmg_magic))
1177 #  define SvSTASH(sv)	(0 + *(assert_(SvTYPE(sv) >= SVt_PVMG) &((XPVMG*)  SvANY(sv))->xmg_stash))
1178 #else
1179 # ifdef PERL_CORE
1180 #  define SvLEN(sv) (0 + ((XPV*) SvANY(sv))->xpv_len)
1181 # else
1182 #  define SvLEN(sv) ((XPV*) SvANY(sv))->xpv_len
1183 # endif
1184 #  define SvEND(sv) ((sv)->sv_u.svu_pv + ((XPV*)SvANY(sv))->xpv_cur)
1185 
1186 #  if defined (DEBUGGING) && defined(__GNUC__) && !defined(PERL_GCC_BRACE_GROUPS_FORBIDDEN)
1187 /* These get expanded inside other macros that already use a variable _sv  */
1188 #    define SvPVX(sv)							\
1189 	(*({ SV *const _svpvx = MUTABLE_SV(sv);				\
1190 	    assert(PL_valid_types_PVX[SvTYPE(_svpvx) & SVt_MASK]);	\
1191 	    assert(!isGV_with_GP(_svpvx));				\
1192 	    assert(!(SvTYPE(_svpvx) == SVt_PVIO				\
1193 		     && !(IoFLAGS(_svpvx) & IOf_FAKE_DIRP)));		\
1194 	    &((_svpvx)->sv_u.svu_pv);					\
1195 	 }))
1196 #   ifdef PERL_CORE
1197 #    define SvCUR(sv)							\
1198 	({ const SV *const _svcur = (const SV *)(sv);			\
1199 	    assert(PL_valid_types_PVX[SvTYPE(_svcur) & SVt_MASK]);	\
1200 	    assert(!isGV_with_GP(_svcur));				\
1201 	    assert(!(SvTYPE(_svcur) == SVt_PVIO				\
1202 		     && !(IoFLAGS(_svcur) & IOf_FAKE_DIRP)));		\
1203 	    (((XPV*) MUTABLE_PTR(SvANY(_svcur)))->xpv_cur);		\
1204 	 })
1205 #   else
1206 #    define SvCUR(sv)							\
1207 	(*({ const SV *const _svcur = (const SV *)(sv);			\
1208 	    assert(PL_valid_types_PVX[SvTYPE(_svcur) & SVt_MASK]);	\
1209 	    assert(!isGV_with_GP(_svcur));				\
1210 	    assert(!(SvTYPE(_svcur) == SVt_PVIO				\
1211 		     && !(IoFLAGS(_svcur) & IOf_FAKE_DIRP)));		\
1212 	    &(((XPV*) MUTABLE_PTR(SvANY(_svcur)))->xpv_cur);		\
1213 	 }))
1214 #   endif
1215 #    define SvIVX(sv)							\
1216 	(*({ const SV *const _svivx = (const SV *)(sv);			\
1217 	    assert(PL_valid_types_IVX[SvTYPE(_svivx) & SVt_MASK]);	\
1218 	    assert(!isGV_with_GP(_svivx));				\
1219 	    &(((XPVIV*) MUTABLE_PTR(SvANY(_svivx)))->xiv_iv);		\
1220 	 }))
1221 #    define SvUVX(sv)							\
1222 	(*({ const SV *const _svuvx = (const SV *)(sv);			\
1223 	    assert(PL_valid_types_IVX[SvTYPE(_svuvx) & SVt_MASK]);	\
1224 	    assert(!isGV_with_GP(_svuvx));				\
1225 	    &(((XPVUV*) MUTABLE_PTR(SvANY(_svuvx)))->xuv_uv);		\
1226 	 }))
1227 #    define SvNVX(sv)							\
1228 	(*({ const SV *const _svnvx = (const SV *)(sv);			\
1229 	    assert(PL_valid_types_NVX[SvTYPE(_svnvx) & SVt_MASK]);	\
1230 	    assert(!isGV_with_GP(_svnvx));				\
1231 	    &(((XPVNV*) MUTABLE_PTR(SvANY(_svnvx)))->xnv_u.xnv_nv);	\
1232 	 }))
1233 #    define SvRV(sv)							\
1234 	(*({ SV *const _svrv = MUTABLE_SV(sv);				\
1235 	    assert(PL_valid_types_RV[SvTYPE(_svrv) & SVt_MASK]);	\
1236 	    assert(!isGV_with_GP(_svrv));				\
1237 	    assert(!(SvTYPE(_svrv) == SVt_PVIO				\
1238 		     && !(IoFLAGS(_svrv) & IOf_FAKE_DIRP)));		\
1239 	    &((_svrv)->sv_u.svu_rv);					\
1240 	 }))
1241 #    define SvRV_const(sv)						\
1242 	({ const SV *const _svrv = (const SV *)(sv);			\
1243 	    assert(PL_valid_types_RV[SvTYPE(_svrv) & SVt_MASK]);	\
1244 	    assert(!isGV_with_GP(_svrv));				\
1245 	    assert(!(SvTYPE(_svrv) == SVt_PVIO				\
1246 		     && !(IoFLAGS(_svrv) & IOf_FAKE_DIRP)));		\
1247 	    (_svrv)->sv_u.svu_rv;					\
1248 	 })
1249 #    define SvMAGIC(sv)							\
1250 	(*({ const SV *const _svmagic = (const SV *)(sv);		\
1251 	    assert(SvTYPE(_svmagic) >= SVt_PVMG);			\
1252 	    &(((XPVMG*) MUTABLE_PTR(SvANY(_svmagic)))->xmg_u.xmg_magic); \
1253 	  }))
1254 #    define SvSTASH(sv)							\
1255 	(*({ const SV *const _svstash = (const SV *)(sv);		\
1256 	    assert(SvTYPE(_svstash) >= SVt_PVMG);			\
1257 	    &(((XPVMG*) MUTABLE_PTR(SvANY(_svstash)))->xmg_stash);	\
1258 	  }))
1259 #  else
1260 #    define SvPVX(sv) ((sv)->sv_u.svu_pv)
1261 #    define SvCUR(sv) ((XPV*) SvANY(sv))->xpv_cur
1262 #    define SvIVX(sv) ((XPVIV*) SvANY(sv))->xiv_iv
1263 #    define SvUVX(sv) ((XPVUV*) SvANY(sv))->xuv_uv
1264 #    define SvNVX(sv) ((XPVNV*) SvANY(sv))->xnv_u.xnv_nv
1265 #    define SvRV(sv) ((sv)->sv_u.svu_rv)
1266 #    define SvRV_const(sv) (0 + (sv)->sv_u.svu_rv)
1267 #    define SvMAGIC(sv)	((XPVMG*)  SvANY(sv))->xmg_u.xmg_magic
1268 #    define SvSTASH(sv)	((XPVMG*)  SvANY(sv))->xmg_stash
1269 #  endif
1270 #endif
1271 
1272 #ifndef PERL_POISON
1273 /* Given that these two are new, there can't be any existing code using them
1274  *  as LVALUEs  */
1275 #  define SvPVX_mutable(sv)	(0 + (sv)->sv_u.svu_pv)
1276 #  define SvPVX_const(sv)	((const char*)(0 + (sv)->sv_u.svu_pv))
1277 #else
1278 /* Except for the poison code, which uses & to scribble over the pointer after
1279    free() is called.  */
1280 #  define SvPVX_mutable(sv)	((sv)->sv_u.svu_pv)
1281 #  define SvPVX_const(sv)	((const char*)((sv)->sv_u.svu_pv))
1282 #endif
1283 
1284 #define SvIVXx(sv) SvIVX(sv)
1285 #define SvUVXx(sv) SvUVX(sv)
1286 #define SvNVXx(sv) SvNVX(sv)
1287 #define SvPVXx(sv) SvPVX(sv)
1288 #define SvLENx(sv) SvLEN(sv)
1289 #define SvENDx(sv) ((PL_Sv = (sv)), SvEND(PL_Sv))
1290 
1291 
1292 /* Ask a scalar nicely to try to become an IV, if possible.
1293    Not guaranteed to stay returning void */
1294 /* Macro won't actually call sv_2iv if already IOK */
1295 #define SvIV_please(sv) \
1296 	STMT_START {if (!SvIOKp(sv) && (SvFLAGS(sv) & (SVf_NOK|SVf_POK))) \
1297 		(void) SvIV(sv); } STMT_END
1298 #define SvIV_please_nomg(sv) \
1299 	(!(SvFLAGS(sv) & (SVf_IOK|SVp_IOK)) && (SvFLAGS(sv) & (SVf_NOK|SVf_POK)) \
1300 	    ? (sv_2iv_flags(sv, 0), SvIOK(sv))	  \
1301 	    : SvIOK(sv))
1302 #define SvIV_set(sv, val) \
1303 	STMT_START { \
1304 		assert(PL_valid_types_IV_set[SvTYPE(sv) & SVt_MASK]);	\
1305 		assert(!isGV_with_GP(sv));		\
1306 		(((XPVIV*)  SvANY(sv))->xiv_iv = (val)); } STMT_END
1307 #define SvNV_set(sv, val) \
1308 	STMT_START { \
1309 		assert(PL_valid_types_NV_set[SvTYPE(sv) & SVt_MASK]);	\
1310 		assert(!isGV_with_GP(sv));		\
1311 		(((XPVNV*)SvANY(sv))->xnv_u.xnv_nv = (val)); } STMT_END
1312 #define SvPV_set(sv, val) \
1313 	STMT_START { \
1314 		assert(PL_valid_types_PVX[SvTYPE(sv) & SVt_MASK]);	\
1315 		assert(!isGV_with_GP(sv));		\
1316 		assert(!(SvTYPE(sv) == SVt_PVIO		\
1317 		     && !(IoFLAGS(sv) & IOf_FAKE_DIRP))); \
1318 		((sv)->sv_u.svu_pv = (val)); } STMT_END
1319 #define SvUV_set(sv, val) \
1320 	STMT_START { \
1321 		assert(PL_valid_types_IV_set[SvTYPE(sv) & SVt_MASK]);	\
1322 		assert(!isGV_with_GP(sv));		\
1323 		(((XPVUV*)SvANY(sv))->xuv_uv = (val)); } STMT_END
1324 #define SvRV_set(sv, val) \
1325         STMT_START { \
1326 		assert(PL_valid_types_RV[SvTYPE(sv) & SVt_MASK]);	\
1327 		assert(!isGV_with_GP(sv));		\
1328 		assert(!(SvTYPE(sv) == SVt_PVIO		\
1329 		     && !(IoFLAGS(sv) & IOf_FAKE_DIRP))); \
1330                 ((sv)->sv_u.svu_rv = (val)); } STMT_END
1331 #define SvMAGIC_set(sv, val) \
1332         STMT_START { assert(SvTYPE(sv) >= SVt_PVMG); \
1333                 (((XPVMG*)SvANY(sv))->xmg_u.xmg_magic = (val)); } STMT_END
1334 #define SvSTASH_set(sv, val) \
1335         STMT_START { assert(SvTYPE(sv) >= SVt_PVMG); \
1336                 (((XPVMG*)  SvANY(sv))->xmg_stash = (val)); } STMT_END
1337 #define SvCUR_set(sv, val) \
1338 	STMT_START { \
1339 		assert(PL_valid_types_PVX[SvTYPE(sv) & SVt_MASK]);	\
1340 		assert(!isGV_with_GP(sv));		\
1341 		assert(!(SvTYPE(sv) == SVt_PVIO		\
1342 		     && !(IoFLAGS(sv) & IOf_FAKE_DIRP))); \
1343 		(((XPV*)  SvANY(sv))->xpv_cur = (val)); } STMT_END
1344 #define SvLEN_set(sv, val) \
1345 	STMT_START { \
1346 		assert(PL_valid_types_PVX[SvTYPE(sv) & SVt_MASK]);	\
1347 		assert(!isGV_with_GP(sv));	\
1348 		assert(!(SvTYPE(sv) == SVt_PVIO		\
1349 		     && !(IoFLAGS(sv) & IOf_FAKE_DIRP))); \
1350 		(((XPV*)  SvANY(sv))->xpv_len = (val)); } STMT_END
1351 #define SvEND_set(sv, val) \
1352 	STMT_START { assert(SvTYPE(sv) >= SVt_PV); \
1353 		SvCUR_set(sv, (val) - SvPVX(sv)); } STMT_END
1354 
1355 #define SvPV_renew(sv,n) \
1356 	STMT_START { SvLEN_set(sv, n); \
1357 		SvPV_set((sv), (MEM_WRAP_CHECK_(n,char)			\
1358 				(char*)saferealloc((Malloc_t)SvPVX(sv), \
1359 						   (MEM_SIZE)((n)))));  \
1360 		 } STMT_END
1361 
1362 #define SvPV_shrink_to_cur(sv) STMT_START { \
1363 		   const STRLEN _lEnGtH = SvCUR(sv) + 1; \
1364 		   SvPV_renew(sv, _lEnGtH); \
1365 		 } STMT_END
1366 
1367 #define SvPV_free(sv)							\
1368     STMT_START {							\
1369 		     assert(SvTYPE(sv) >= SVt_PV);			\
1370 		     if (SvLEN(sv)) {					\
1371 			 assert(!SvROK(sv));				\
1372 			 if(UNLIKELY(SvOOK(sv))) {			\
1373 			     STRLEN zok; 				\
1374 			     SvOOK_offset(sv, zok);			\
1375 			     SvPV_set(sv, SvPVX_mutable(sv) - zok);	\
1376 			     SvFLAGS(sv) &= ~SVf_OOK;			\
1377 			 }						\
1378 			 Safefree(SvPVX(sv));				\
1379 		     }							\
1380 		 } STMT_END
1381 
1382 #ifdef PERL_CORE
1383 /* Code that crops up in three places to take a scalar and ready it to hold
1384    a reference */
1385 #  define prepare_SV_for_RV(sv)						\
1386     STMT_START {							\
1387 		    if (SvTYPE(sv) < SVt_PV && SvTYPE(sv) != SVt_IV)	\
1388 			sv_upgrade(sv, SVt_IV);				\
1389 		    else if (SvTYPE(sv) >= SVt_PV) {			\
1390 			SvPV_free(sv);					\
1391 			SvLEN_set(sv, 0);				\
1392                         SvCUR_set(sv, 0);				\
1393 		    }							\
1394 		 } STMT_END
1395 #endif
1396 
1397 #ifndef PERL_CORE
1398 #  define BmFLAGS(sv)		(SvTAIL(sv) ? FBMcf_TAIL : 0)
1399 #endif
1400 
1401 #if defined (DEBUGGING) && defined(__GNUC__) && !defined(PERL_GCC_BRACE_GROUPS_FORBIDDEN)
1402 #  define BmUSEFUL(sv)							\
1403 	(*({ SV *const _bmuseful = MUTABLE_SV(sv);			\
1404 	    assert(SvTYPE(_bmuseful) >= SVt_PVIV);			\
1405 	    assert(SvVALID(_bmuseful));					\
1406 	    assert(!SvIOK(_bmuseful));					\
1407 	    &(((XPVIV*) SvANY(_bmuseful))->xiv_u.xivu_iv);              \
1408 	 }))
1409 #else
1410 #  define BmUSEFUL(sv)          ((XPVIV*) SvANY(sv))->xiv_u.xivu_iv
1411 
1412 #endif
1413 
1414 #ifndef PERL_CORE
1415 # define BmRARE(sv)	0
1416 # define BmPREVIOUS(sv)	0
1417 #endif
1418 
1419 #define FmLINES(sv)	((XPVIV*)  SvANY(sv))->xiv_iv
1420 
1421 #define LvTYPE(sv)	((XPVLV*)  SvANY(sv))->xlv_type
1422 #define LvTARG(sv)	((XPVLV*)  SvANY(sv))->xlv_targ
1423 #define LvTARGOFF(sv)	((XPVLV*)  SvANY(sv))->xlv_targoff
1424 #define LvSTARGOFF(sv)	((XPVLV*)  SvANY(sv))->xlv_targoff_u.xlvu_stargoff
1425 #define LvTARGLEN(sv)	((XPVLV*)  SvANY(sv))->xlv_targlen
1426 #define LvFLAGS(sv)	((XPVLV*)  SvANY(sv))->xlv_flags
1427 
1428 #define LVf_NEG_OFF      0x1
1429 #define LVf_NEG_LEN      0x2
1430 #define LVf_OUT_OF_RANGE 0x4
1431 
1432 #define IoIFP(sv)	(sv)->sv_u.svu_fp
1433 #define IoOFP(sv)	((XPVIO*)  SvANY(sv))->xio_ofp
1434 #define IoDIRP(sv)	((XPVIO*)  SvANY(sv))->xio_dirp
1435 #define IoANY(sv)	((XPVIO*)  SvANY(sv))->xio_any
1436 #define IoLINES(sv)	((XPVIO*)  SvANY(sv))->xiv_u.xivu_iv
1437 #define IoPAGE(sv)	((XPVIO*)  SvANY(sv))->xio_page
1438 #define IoPAGE_LEN(sv)	((XPVIO*)  SvANY(sv))->xio_page_len
1439 #define IoLINES_LEFT(sv)((XPVIO*)  SvANY(sv))->xio_lines_left
1440 #define IoTOP_NAME(sv)	((XPVIO*)  SvANY(sv))->xio_top_name
1441 #define IoTOP_GV(sv)	((XPVIO*)  SvANY(sv))->xio_top_gv
1442 #define IoFMT_NAME(sv)	((XPVIO*)  SvANY(sv))->xio_fmt_name
1443 #define IoFMT_GV(sv)	((XPVIO*)  SvANY(sv))->xio_fmt_gv
1444 #define IoBOTTOM_NAME(sv)((XPVIO*) SvANY(sv))->xio_bottom_name
1445 #define IoBOTTOM_GV(sv)	((XPVIO*)  SvANY(sv))->xio_bottom_gv
1446 #define IoTYPE(sv)	((XPVIO*)  SvANY(sv))->xio_type
1447 #define IoFLAGS(sv)	((XPVIO*)  SvANY(sv))->xio_flags
1448 
1449 /* IoTYPE(sv) is a single character telling the type of I/O connection. */
1450 #define IoTYPE_RDONLY		'<'
1451 #define IoTYPE_WRONLY		'>'
1452 #define IoTYPE_RDWR		'+'
1453 #define IoTYPE_APPEND 		'a'
1454 #define IoTYPE_PIPE		'|'
1455 #define IoTYPE_STD		'-'	/* stdin or stdout */
1456 #define IoTYPE_SOCKET		's'
1457 #define IoTYPE_CLOSED		' '
1458 #define IoTYPE_IMPLICIT		'I'	/* stdin or stdout or stderr */
1459 #define IoTYPE_NUMERIC		'#'	/* fdopen */
1460 
1461 /*
1462 =for apidoc Am|bool|SvTAINTED|SV* sv
1463 Checks to see if an SV is tainted.  Returns TRUE if it is, FALSE if
1464 not.
1465 
1466 =for apidoc Am|void|SvTAINTED_on|SV* sv
1467 Marks an SV as tainted if tainting is enabled.
1468 
1469 =for apidoc Am|void|SvTAINTED_off|SV* sv
1470 Untaints an SV.  Be I<very> careful with this routine, as it short-circuits
1471 some of Perl's fundamental security features.  XS module authors should not
1472 use this function unless they fully understand all the implications of
1473 unconditionally untainting the value.  Untainting should be done in the
1474 standard perl fashion, via a carefully crafted regexp, rather than directly
1475 untainting variables.
1476 
1477 =for apidoc Am|void|SvTAINT|SV* sv
1478 Taints an SV if tainting is enabled, and if some input to the current
1479 expression is tainted--usually a variable, but possibly also implicit
1480 inputs such as locale settings.  C<SvTAINT> propagates that taintedness to
1481 the outputs of an expression in a pessimistic fashion; i.e., without paying
1482 attention to precisely which outputs are influenced by which inputs.
1483 
1484 =cut
1485 */
1486 
1487 #define sv_taint(sv)	  sv_magic((sv), NULL, PERL_MAGIC_taint, NULL, 0)
1488 
1489 #ifdef NO_TAINT_SUPPORT
1490 #   define SvTAINTED(sv) 0
1491 #else
1492 #   define SvTAINTED(sv)	  (SvMAGICAL(sv) && sv_tainted(sv))
1493 #endif
1494 #define SvTAINTED_on(sv)  STMT_START{ if(UNLIKELY(TAINTING_get)){sv_taint(sv);}   }STMT_END
1495 #define SvTAINTED_off(sv) STMT_START{ if(UNLIKELY(TAINTING_get)){sv_untaint(sv);} }STMT_END
1496 
1497 #define SvTAINT(sv)			\
1498     STMT_START {			\
1499         assert(TAINTING_get || !TAINT_get); \
1500         if (UNLIKELY(TAINT_get))	\
1501             SvTAINTED_on(sv);	        \
1502     } STMT_END
1503 
1504 /*
1505 =for apidoc Am|char*|SvPV_force|SV* sv|STRLEN len
1506 Like C<SvPV> but will force the SV into containing a string (C<SvPOK>), and
1507 only a string (C<SvPOK_only>), by hook or by crook.  You need force if you are
1508 going to update the C<SvPVX> directly.  Processes get magic.
1509 
1510 Note that coercing an arbitrary scalar into a plain PV will potentially
1511 strip useful data from it.  For example if the SV was C<SvROK>, then the
1512 referent will have its reference count decremented, and the SV itself may
1513 be converted to an C<SvPOK> scalar with a string buffer containing a value
1514 such as C<"ARRAY(0x1234)">.
1515 
1516 =for apidoc Am|char*|SvPV_force_nomg|SV* sv|STRLEN len
1517 Like C<SvPV_force>, but doesn't process get magic.
1518 
1519 =for apidoc Am|char*|SvPV|SV* sv|STRLEN len
1520 Returns a pointer to the string in the SV, or a stringified form of
1521 the SV if the SV does not contain a string.  The SV may cache the
1522 stringified version becoming C<SvPOK>.  Handles 'get' magic.  The
1523 C<len> variable will be set to the length of the string (this is a macro, so
1524 don't use C<&len>).  See also C<L</SvPVx>> for a version which guarantees to
1525 evaluate C<sv> only once.
1526 
1527 Note that there is no guarantee that the return value of C<SvPV()> is
1528 equal to C<SvPVX(sv)>, or that C<SvPVX(sv)> contains valid data, or that
1529 successive calls to C<SvPV(sv)> will return the same pointer value each
1530 time.  This is due to the way that things like overloading and
1531 Copy-On-Write are handled.  In these cases, the return value may point to
1532 a temporary buffer or similar.  If you absolutely need the C<SvPVX> field to
1533 be valid (for example, if you intend to write to it), then see
1534 C<L</SvPV_force>>.
1535 
1536 =for apidoc Am|char*|SvPVx|SV* sv|STRLEN len
1537 A version of C<SvPV> which guarantees to evaluate C<sv> only once.
1538 Only use this if C<sv> is an expression with side effects, otherwise use the
1539 more efficient C<SvPV>.
1540 
1541 =for apidoc Am|char*|SvPV_nomg|SV* sv|STRLEN len
1542 Like C<SvPV> but doesn't process magic.
1543 
1544 =for apidoc Am|char*|SvPV_nolen|SV* sv
1545 Like C<SvPV> but doesn't set a length variable.
1546 
1547 =for apidoc Am|char*|SvPV_nomg_nolen|SV* sv
1548 Like C<SvPV_nolen> but doesn't process magic.
1549 
1550 =for apidoc Am|IV|SvIV|SV* sv
1551 Coerces the given SV to IV and returns it.  The returned value in many
1552 circumstances will get stored in C<sv>'s IV slot, but not in all cases.  (Use
1553 C<L</sv_setiv>> to make sure it does).
1554 
1555 See C<L</SvIVx>> for a version which guarantees to evaluate C<sv> only once.
1556 
1557 =for apidoc Am|IV|SvIV_nomg|SV* sv
1558 Like C<SvIV> but doesn't process magic.
1559 
1560 =for apidoc Am|IV|SvIVx|SV* sv
1561 Coerces the given SV to IV and returns it.  The returned value in many
1562 circumstances will get stored in C<sv>'s IV slot, but not in all cases.  (Use
1563 C<L</sv_setiv>> to make sure it does).
1564 
1565 This form guarantees to evaluate C<sv> only once.  Only use this if C<sv> is an
1566 expression with side effects, otherwise use the more efficient C<SvIV>.
1567 
1568 =for apidoc Am|NV|SvNV|SV* sv
1569 Coerces the given SV to NV and returns it.  The returned value in many
1570 circumstances will get stored in C<sv>'s NV slot, but not in all cases.  (Use
1571 C<L</sv_setnv>> to make sure it does).
1572 
1573 See C<L</SvNVx>> for a version which guarantees to evaluate C<sv> only once.
1574 
1575 =for apidoc Am|NV|SvNV_nomg|SV* sv
1576 Like C<SvNV> but doesn't process magic.
1577 
1578 =for apidoc Am|NV|SvNVx|SV* sv
1579 Coerces the given SV to NV and returns it.  The returned value in many
1580 circumstances will get stored in C<sv>'s NV slot, but not in all cases.  (Use
1581 C<L</sv_setnv>> to make sure it does).
1582 
1583 This form guarantees to evaluate C<sv> only once.  Only use this if C<sv> is an
1584 expression with side effects, otherwise use the more efficient C<SvNV>.
1585 
1586 =for apidoc Am|UV|SvUV|SV* sv
1587 Coerces the given SV to UV and returns it.  The returned value in many
1588 circumstances will get stored in C<sv>'s UV slot, but not in all cases.  (Use
1589 C<L</sv_setuv>> to make sure it does).
1590 
1591 See C<L</SvUVx>> for a version which guarantees to evaluate C<sv> only once.
1592 
1593 =for apidoc Am|UV|SvUV_nomg|SV* sv
1594 Like C<SvUV> but doesn't process magic.
1595 
1596 =for apidoc Am|UV|SvUVx|SV* sv
1597 Coerces the given SV to UV and returns it.  The returned value in many
1598 circumstances will get stored in C<sv>'s UV slot, but not in all cases.  (Use
1599 C<L</sv_setuv>> to make sure it does).
1600 
1601 This form guarantees to evaluate C<sv> only once.  Only use this if C<sv> is an
1602 expression with side effects, otherwise use the more efficient C<SvUV>.
1603 
1604 =for apidoc Am|bool|SvTRUE|SV* sv
1605 Returns a boolean indicating whether Perl would evaluate the SV as true or
1606 false.  See C<L</SvOK>> for a defined/undefined test.  Handles 'get' magic
1607 unless the scalar is already C<SvPOK>, C<SvIOK> or C<SvNOK> (the public, not the
1608 private flags).
1609 
1610 See C<L</SvTRUEx>> for a version which guarantees to evaluate C<sv> only once.
1611 
1612 =for apidoc Am|bool|SvTRUE_nomg|SV* sv
1613 Returns a boolean indicating whether Perl would evaluate the SV as true or
1614 false.  See C<L</SvOK>> for a defined/undefined test.  Does not handle 'get' magic.
1615 
1616 =for apidoc Am|bool|SvTRUEx|SV* sv
1617 Returns a boolean indicating whether Perl would evaluate the SV as true or
1618 false.  See C<L</SvOK>> for a defined/undefined test.  Handles 'get' magic
1619 unless the scalar is already C<SvPOK>, C<SvIOK> or C<SvNOK> (the public, not the
1620 private flags).
1621 
1622 This form guarantees to evaluate C<sv> only once.  Only use this if C<sv> is an
1623 expression with side effects, otherwise use the more efficient C<SvTRUE>.
1624 
1625 =for apidoc Am|char*|SvPVutf8_force|SV* sv|STRLEN len
1626 Like C<SvPV_force>, but converts C<sv> to UTF-8 first if necessary.
1627 
1628 =for apidoc Am|char*|SvPVutf8|SV* sv|STRLEN len
1629 Like C<SvPV>, but converts C<sv> to UTF-8 first if necessary.
1630 
1631 =for apidoc Am|char*|SvPVutf8_nomg|SV* sv|STRLEN len
1632 Like C<SvPVutf8>, but does not process get magic.
1633 
1634 =for apidoc Am|char*|SvPVutf8_or_null|SV* sv|STRLEN len
1635 Like C<SvPVutf8>, but when C<sv> is undef, returns C<NULL>.
1636 
1637 =for apidoc Am|char*|SvPVutf8_or_null_nomg|SV* sv|STRLEN len
1638 Like C<SvPVutf8_or_null>, but does not process get magic.
1639 
1640 =for apidoc Am|char*|SvPVutf8_nolen|SV* sv
1641 Like C<SvPV_nolen>, but converts C<sv> to UTF-8 first if necessary.
1642 
1643 =for apidoc Am|char*|SvPVbyte_force|SV* sv|STRLEN len
1644 Like C<SvPV_force>, but converts C<sv> to byte representation first if
1645 necessary.  If the SV cannot be downgraded from UTF-8, this croaks.
1646 
1647 =for apidoc Am|char*|SvPVbyte|SV* sv|STRLEN len
1648 Like C<SvPV>, but converts C<sv> to byte representation first if necessary.  If
1649 the SV cannot be downgraded from UTF-8, this croaks.
1650 
1651 =for apidoc Am|char*|SvPVbyte_nomg|SV* sv|STRLEN len
1652 Like C<SvPVbyte>, but does not process get magic.
1653 
1654 =for apidoc Am|char*|SvPVbyte_or_null|SV* sv|STRLEN len
1655 Like C<SvPVbyte>, but when C<sv> is undef, returns C<NULL>.
1656 
1657 =for apidoc Am|char*|SvPVbyte_or_null_nomg|SV* sv|STRLEN len
1658 Like C<SvPVbyte_or_null>, but does not process get magic.
1659 
1660 =for apidoc Am|char*|SvPVbyte_nolen|SV* sv
1661 Like C<SvPV_nolen>, but converts C<sv> to byte representation first if
1662 necessary.  If the SV cannot be downgraded from UTF-8, this croaks.
1663 
1664 =for apidoc Am|char*|SvPVutf8x_force|SV* sv|STRLEN len
1665 Like C<SvPV_force>, but converts C<sv> to UTF-8 first if necessary.
1666 Guarantees to evaluate C<sv> only once; use the more efficient C<SvPVutf8_force>
1667 otherwise.
1668 
1669 =for apidoc Am|char*|SvPVutf8x|SV* sv|STRLEN len
1670 Like C<SvPV>, but converts C<sv> to UTF-8 first if necessary.
1671 Guarantees to evaluate C<sv> only once; use the more efficient C<SvPVutf8>
1672 otherwise.
1673 
1674 =for apidoc Am|char*|SvPVbytex_force|SV* sv|STRLEN len
1675 Like C<SvPV_force>, but converts C<sv> to byte representation first if necessary.
1676 Guarantees to evaluate C<sv> only once; use the more efficient C<SvPVbyte_force>
1677 otherwise.  If the SV cannot be downgraded from UTF-8, this croaks.
1678 
1679 =for apidoc Am|char*|SvPVbytex|SV* sv|STRLEN len
1680 Like C<SvPV>, but converts C<sv> to byte representation first if necessary.
1681 Guarantees to evaluate C<sv> only once; use the more efficient C<SvPVbyte>
1682 otherwise.  If the SV cannot be downgraded from UTF-8, this croaks.
1683 
1684 =for apidoc Am|U32|SvIsCOW|SV* sv
1685 Returns a U32 value indicating whether the SV is Copy-On-Write (either shared
1686 hash key scalars, or full Copy On Write scalars if 5.9.0 is configured for
1687 COW).
1688 
1689 =for apidoc Am|bool|SvIsCOW_shared_hash|SV* sv
1690 Returns a boolean indicating whether the SV is Copy-On-Write shared hash key
1691 scalar.
1692 
1693 =for apidoc Am|void|sv_catpvn_nomg|SV* sv|const char* ptr|STRLEN len
1694 Like C<sv_catpvn> but doesn't process magic.
1695 
1696 =for apidoc Am|void|sv_catpv_nomg|SV* sv|const char* ptr
1697 Like C<sv_catpv> but doesn't process magic.
1698 
1699 =for apidoc Am|void|sv_setsv_nomg|SV* dsv|SV* ssv
1700 Like C<sv_setsv> but doesn't process magic.
1701 
1702 =for apidoc Am|void|sv_catsv_nomg|SV* dsv|SV* ssv
1703 Like C<sv_catsv> but doesn't process magic.
1704 
1705 =cut
1706 */
1707 
1708 /* Let us hope that bitmaps for UV and IV are the same */
1709 #define SvIV(sv) (SvIOK_nog(sv) ? SvIVX(sv) : sv_2iv(sv))
1710 #define SvUV(sv) (SvUOK_nog(sv) ? SvUVX(sv) : sv_2uv(sv))
1711 #define SvNV(sv) (SvNOK_nog(sv) ? SvNVX(sv) : sv_2nv(sv))
1712 
1713 #define SvIV_nomg(sv) (SvIOK(sv) ? SvIVX(sv) : sv_2iv_flags(sv, 0))
1714 #define SvUV_nomg(sv) (SvIOK(sv) ? SvUVX(sv) : sv_2uv_flags(sv, 0))
1715 #define SvNV_nomg(sv) (SvNOK(sv) ? SvNVX(sv) : sv_2nv_flags(sv, 0))
1716 
1717 /* ----*/
1718 
1719 #define SvPV(sv, lp)         SvPV_flags(sv, lp, SV_GMAGIC)
1720 #define SvPV_const(sv, lp)   SvPV_flags_const(sv, lp, SV_GMAGIC)
1721 #define SvPV_mutable(sv, lp) SvPV_flags_mutable(sv, lp, SV_GMAGIC)
1722 
1723 #define SvPV_flags(sv, lp, flags) \
1724     (SvPOK_nog(sv) \
1725      ? ((lp = SvCUR(sv)), SvPVX(sv)) : sv_2pv_flags(sv, &lp, flags))
1726 #define SvPV_flags_const(sv, lp, flags) \
1727     (SvPOK_nog(sv) \
1728      ? ((lp = SvCUR(sv)), SvPVX_const(sv)) : \
1729      (const char*) sv_2pv_flags(sv, &lp, (flags|SV_CONST_RETURN)))
1730 #define SvPV_flags_const_nolen(sv, flags) \
1731     (SvPOK_nog(sv) \
1732      ? SvPVX_const(sv) : \
1733      (const char*) sv_2pv_flags(sv, 0, (flags|SV_CONST_RETURN)))
1734 #define SvPV_flags_mutable(sv, lp, flags) \
1735     (SvPOK_nog(sv) \
1736      ? ((lp = SvCUR(sv)), SvPVX_mutable(sv)) : \
1737      sv_2pv_flags(sv, &lp, (flags|SV_MUTABLE_RETURN)))
1738 
1739 #define SvPV_force(sv, lp) SvPV_force_flags(sv, lp, SV_GMAGIC)
1740 #define SvPV_force_nolen(sv) SvPV_force_flags_nolen(sv, SV_GMAGIC)
1741 #define SvPV_force_mutable(sv, lp) SvPV_force_flags_mutable(sv, lp, SV_GMAGIC)
1742 
1743 #define SvPV_force_nomg(sv, lp) SvPV_force_flags(sv, lp, 0)
1744 #define SvPV_force_nomg_nolen(sv) SvPV_force_flags_nolen(sv, 0)
1745 
1746 #define SvPV_force_flags(sv, lp, flags) \
1747     (SvPOK_pure_nogthink(sv) \
1748      ? ((lp = SvCUR(sv)), SvPVX(sv)) : sv_pvn_force_flags(sv, &lp, flags))
1749 
1750 #define SvPV_force_flags_nolen(sv, flags) \
1751     (SvPOK_pure_nogthink(sv) \
1752      ? SvPVX(sv) : sv_pvn_force_flags(sv, 0, flags))
1753 
1754 #define SvPV_force_flags_mutable(sv, lp, flags) \
1755     (SvPOK_pure_nogthink(sv) \
1756      ? ((lp = SvCUR(sv)), SvPVX_mutable(sv)) \
1757      : sv_pvn_force_flags(sv, &lp, flags|SV_MUTABLE_RETURN))
1758 
1759 #define SvPV_nolen(sv) \
1760     (SvPOK_nog(sv) \
1761      ? SvPVX(sv) : sv_2pv_flags(sv, 0, SV_GMAGIC))
1762 
1763 /* "_nomg" in these defines means no mg_get() */
1764 #define SvPV_nomg_nolen(sv) \
1765     (SvPOK_nog(sv) \
1766      ? SvPVX(sv) : sv_2pv_flags(sv, 0, 0))
1767 
1768 #define SvPV_nolen_const(sv) \
1769     (SvPOK_nog(sv) \
1770      ? SvPVX_const(sv) : sv_2pv_flags(sv, 0, SV_GMAGIC|SV_CONST_RETURN))
1771 
1772 #define SvPV_nomg(sv, lp) SvPV_flags(sv, lp, 0)
1773 #define SvPV_nomg_const(sv, lp) SvPV_flags_const(sv, lp, 0)
1774 #define SvPV_nomg_const_nolen(sv) SvPV_flags_const_nolen(sv, 0)
1775 
1776 /* ----*/
1777 
1778 #define SvPVutf8(sv, lp) \
1779     (SvPOK_utf8_nog(sv) \
1780      ? ((lp = SvCUR(sv)), SvPVX(sv)) : sv_2pvutf8(sv, &lp))
1781 
1782 #define SvPVutf8_or_null(sv, lp) \
1783     (SvPOK_utf8_nog(sv) \
1784      ? ((lp = SvCUR(sv)), SvPVX(sv)) : (SvGETMAGIC(sv), SvOK(sv)) \
1785      ? sv_2pvutf8_flags(sv, &lp, 0) : ((lp = 0), NULL))
1786 
1787 #define SvPVutf8_nomg(sv, lp) \
1788     (SvPOK_utf8_nog(sv) \
1789      ? ((lp = SvCUR(sv)), SvPVX(sv)) : sv_2pvutf8_flags(sv, &lp, 0))
1790 
1791 #define SvPVutf8_or_null_nomg(sv, lp) \
1792     (SvPOK_utf8_nog(sv) \
1793      ? ((lp = SvCUR(sv)), SvPVX(sv)) : SvOK(sv) \
1794      ? sv_2pvutf8_flags(sv, &lp, 0) : ((lp = 0), NULL))
1795 
1796 #define SvPVutf8_force(sv, lp) \
1797     (SvPOK_utf8_pure_nogthink(sv) \
1798      ? ((lp = SvCUR(sv)), SvPVX(sv)) : sv_pvutf8n_force(sv, &lp))
1799 
1800 #define SvPVutf8_nolen(sv) \
1801     (SvPOK_utf8_nog(sv) \
1802      ? SvPVX(sv) : sv_2pvutf8(sv, 0))
1803 
1804 /* ----*/
1805 
1806 #define SvPVbyte(sv, lp) \
1807     (SvPOK_byte_nog(sv) \
1808      ? ((lp = SvCUR(sv)), SvPVX(sv)) : sv_2pvbyte(sv, &lp))
1809 
1810 #define SvPVbyte_or_null(sv, lp) \
1811     (SvPOK_byte_nog(sv) \
1812      ? ((lp = SvCUR(sv)), SvPVX(sv)) : (SvGETMAGIC(sv), SvOK(sv)) \
1813      ? sv_2pvbyte_flags(sv, &lp, 0) : ((lp = 0), NULL))
1814 
1815 #define SvPVbyte_nomg(sv, lp) \
1816     (SvPOK_byte_nog(sv) \
1817      ? ((lp = SvCUR(sv)), SvPVX(sv)) : sv_2pvbyte_flags(sv, &lp, 0))
1818 
1819 #define SvPVbyte_or_null_nomg(sv, lp) \
1820     (SvPOK_utf8_nog(sv) \
1821      ? ((lp = SvCUR(sv)), SvPVX(sv)) : SvOK(sv) \
1822      ? sv_2pvbyte_flags(sv, &lp, 0) : ((lp = 0), NULL))
1823 
1824 #define SvPVbyte_force(sv, lp) \
1825     (SvPOK_byte_pure_nogthink(sv) \
1826      ? ((lp = SvCUR(sv)), SvPVX(sv)) : sv_pvbyten_force(sv, &lp))
1827 
1828 #define SvPVbyte_nolen(sv) \
1829     (SvPOK_byte_nog(sv) \
1830      ? SvPVX(sv) : sv_2pvbyte(sv, 0))
1831 
1832 
1833 /* define FOOx(): idempotent versions of FOO(). If possible, use a local
1834  * var to evaluate the arg once; failing that, use a global if possible;
1835  * failing that, call a function to do the work
1836  */
1837 
1838 #define SvPVx_force(sv, lp) sv_pvn_force(sv, &lp)
1839 #define SvPVutf8x_force(sv, lp) sv_pvutf8n_force(sv, &lp)
1840 #define SvPVbytex_force(sv, lp) sv_pvbyten_force(sv, &lp)
1841 
1842 #define SvTRUE(sv)         Perl_SvTRUE(aTHX_ sv)
1843 #define SvTRUE_nomg(sv)    (LIKELY(sv) && SvTRUE_nomg_NN(sv))
1844 #define SvTRUE_NN(sv)      (SvGETMAGIC(sv), SvTRUE_nomg_NN(sv))
1845 #define SvTRUE_nomg_NN(sv) (SvTRUE_common(sv, sv_2bool_nomg(sv)))
1846 
1847 #define SvTRUE_common(sv,fallback) (			\
1848       SvIMMORTAL_INTERP(sv)                             \
1849         ? SvIMMORTAL_TRUE(sv)                           \
1850     : !SvOK(sv)						\
1851 	? 0						\
1852     : SvPOK(sv)						\
1853 	? SvPVXtrue(sv)					\
1854     : SvIOK(sv)                			        \
1855         ? (SvIVX(sv) != 0 /* cast to bool */)           \
1856     : (SvROK(sv) && !(   SvOBJECT(SvRV(sv))             \
1857                       && HvAMAGIC(SvSTASH(SvRV(sv)))))  \
1858         ? TRUE                                          \
1859     : (fallback))
1860 
1861 #if defined(__GNUC__) && !defined(PERL_GCC_BRACE_GROUPS_FORBIDDEN)
1862 
1863 #  define SvIVx(sv) ({SV *_sv = MUTABLE_SV(sv); SvIV(_sv); })
1864 #  define SvUVx(sv) ({SV *_sv = MUTABLE_SV(sv); SvUV(_sv); })
1865 #  define SvNVx(sv) ({SV *_sv = MUTABLE_SV(sv); SvNV(_sv); })
1866 #  define SvPVx(sv, lp) ({SV *_sv = (sv); SvPV(_sv, lp); })
1867 #  define SvPVx_const(sv, lp) ({SV *_sv = (sv); SvPV_const(_sv, lp); })
1868 #  define SvPVx_nolen(sv) ({SV *_sv = (sv); SvPV_nolen(_sv); })
1869 #  define SvPVx_nolen_const(sv) ({SV *_sv = (sv); SvPV_nolen_const(_sv); })
1870 #  define SvPVutf8x(sv, lp) ({SV *_sv = (sv); SvPVutf8(_sv, lp); })
1871 #  define SvPVbytex(sv, lp) ({SV *_sv = (sv); SvPVbyte(_sv, lp); })
1872 #  define SvPVbytex_nolen(sv) ({SV *_sv = (sv); SvPVbyte_nolen(_sv); })
1873 #  define SvTRUEx(sv)      ({SV *_sv = (sv); SvTRUE(_sv); })
1874 #  define SvTRUEx_nomg(sv) ({SV *_sv = (sv); SvTRUE_nomg(_sv); })
1875 
1876 #else /* __GNUC__ */
1877 
1878 /* These inlined macros use globals, which will require a thread
1879  * declaration in user code, so we avoid them under threads */
1880 
1881 #  define SvIVx(sv) ((PL_Sv = (sv)), SvIV(PL_Sv))
1882 #  define SvUVx(sv) ((PL_Sv = (sv)), SvUV(PL_Sv))
1883 #  define SvNVx(sv) ((PL_Sv = (sv)), SvNV(PL_Sv))
1884 #  define SvPVx(sv, lp) ((PL_Sv = (sv)), SvPV(PL_Sv, lp))
1885 #  define SvPVx_const(sv, lp) ((PL_Sv = (sv)), SvPV_const(PL_Sv, lp))
1886 #  define SvPVx_nolen(sv) ((PL_Sv = (sv)), SvPV_nolen(PL_Sv))
1887 #  define SvPVx_nolen_const(sv) ((PL_Sv = (sv)), SvPV_nolen_const(PL_Sv))
1888 #  define SvPVutf8x(sv, lp) ((PL_Sv = (sv)), SvPVutf8(PL_Sv, lp))
1889 #  define SvPVbytex(sv, lp) ((PL_Sv = (sv)), SvPVbyte(PL_Sv, lp))
1890 #  define SvPVbytex_nolen(sv) ((PL_Sv = (sv)), SvPVbyte_nolen(PL_Sv))
1891 #  define SvTRUEx(sv)      ((PL_Sv = (sv)), SvTRUE(PL_Sv))
1892 #  define SvTRUEx_nomg(sv) ((PL_Sv = (sv)), SvTRUE_nomg(PL_Sv))
1893 #endif /* __GNU__ */
1894 
1895 #define SvPVXtrue(sv)	(					\
1896     ((XPV*)SvANY((sv))) 					\
1897      && (							\
1898 	((XPV*)SvANY((sv)))->xpv_cur > 1			\
1899 	|| (							\
1900 	    ((XPV*)SvANY((sv)))->xpv_cur			\
1901 	    && *(sv)->sv_u.svu_pv != '0'				\
1902 	)							\
1903     )								\
1904 )
1905 
1906 #define SvIsCOW(sv)		(SvFLAGS(sv) & SVf_IsCOW)
1907 #define SvIsCOW_on(sv)		(SvFLAGS(sv) |= SVf_IsCOW)
1908 #define SvIsCOW_off(sv)		(SvFLAGS(sv) &= ~SVf_IsCOW)
1909 #define SvIsCOW_shared_hash(sv)	(SvIsCOW(sv) && SvLEN(sv) == 0)
1910 
1911 #define SvSHARED_HEK_FROM_PV(pvx) \
1912 	((struct hek*)(pvx - STRUCT_OFFSET(struct hek, hek_key)))
1913 #define SvSHARED_HASH(sv) (0 + SvSHARED_HEK_FROM_PV(SvPVX_const(sv))->hek_hash)
1914 
1915 /* flag values for sv_*_flags functions */
1916 #define SV_UTF8_NO_ENCODING	0       /* No longer used */
1917 #define SV_IMMEDIATE_UNREF	1
1918 #define SV_GMAGIC		2
1919 #define SV_COW_DROP_PV		4
1920 #define SV_NOSTEAL		16
1921 #define SV_CONST_RETURN		32
1922 #define SV_MUTABLE_RETURN	64
1923 #define SV_SMAGIC		128
1924 #define SV_HAS_TRAILING_NUL	256
1925 #define SV_COW_SHARED_HASH_KEYS	512
1926 /* This one is only enabled for PERL_OLD_COPY_ON_WRITE */
1927 /* XXX This flag actually enabled for any COW.  But it appears not to do
1928        anything.  Can we just remove it?  Or will it serve some future
1929        purpose.  */
1930 #define SV_COW_OTHER_PVS	1024
1931 /* Make sv_2pv_flags return NULL if something is undefined.  */
1932 #define SV_UNDEF_RETURNS_NULL	2048
1933 /* Tell sv_utf8_upgrade() to not check to see if an upgrade is really needed.
1934  * This is used when the caller has already determined it is, and avoids
1935  * redundant work */
1936 #define SV_FORCE_UTF8_UPGRADE	4096
1937 /* if (after resolving magic etc), the SV is found to be overloaded,
1938  * don't call the overload magic, just return as-is */
1939 #define SV_SKIP_OVERLOAD	8192
1940 #define SV_CATBYTES		16384
1941 #define SV_CATUTF8		32768
1942 
1943 /* The core is safe for this COW optimisation. XS code on CPAN may not be.
1944    So only default to doing the COW setup if we're in the core.
1945  */
1946 #ifdef PERL_CORE
1947 #  ifndef SV_DO_COW_SVSETSV
1948 #    define SV_DO_COW_SVSETSV	SV_COW_SHARED_HASH_KEYS|SV_COW_OTHER_PVS
1949 #  endif
1950 #endif
1951 
1952 #ifndef SV_DO_COW_SVSETSV
1953 #  define SV_DO_COW_SVSETSV	0
1954 #endif
1955 
1956 
1957 #define sv_unref(sv)    	sv_unref_flags(sv, 0)
1958 #define sv_force_normal(sv)	sv_force_normal_flags(sv, 0)
1959 #define sv_usepvn(sv, p, l)	sv_usepvn_flags(sv, p, l, 0)
1960 #define sv_usepvn_mg(sv, p, l)	sv_usepvn_flags(sv, p, l, SV_SMAGIC)
1961 
1962 /* We are about to replace the SV's current value. So if it's copy on write
1963    we need to normalise it. Use the SV_COW_DROP_PV flag hint to say that
1964    the value is about to get thrown away, so drop the PV rather than go to
1965    the effort of making a read-write copy only for it to get immediately
1966    discarded.  */
1967 
1968 #define SV_CHECK_THINKFIRST_COW_DROP(sv) if (SvTHINKFIRST(sv)) \
1969 				    sv_force_normal_flags(sv, SV_COW_DROP_PV)
1970 
1971 #ifdef PERL_COPY_ON_WRITE
1972 #   define SvCANCOW(sv)					    \
1973 	(SvIsCOW(sv)					     \
1974 	 ? SvLEN(sv) ? CowREFCNT(sv) != SV_COW_REFCNT_MAX : 1 \
1975 	 : (SvFLAGS(sv) & CAN_COW_MASK) == CAN_COW_FLAGS       \
1976 			    && SvCUR(sv)+1 < SvLEN(sv))
1977    /* Note: To allow 256 COW "copies", a refcnt of 0 means 1. */
1978 #   define CowREFCNT(sv)	(*(U8 *)(SvPVX(sv)+SvLEN(sv)-1))
1979 #   define SV_COW_REFCNT_MAX	((1 << sizeof(U8)*8) - 1)
1980 #   define CAN_COW_MASK	(SVf_POK|SVf_ROK|SVp_POK|SVf_FAKE| \
1981 			 SVf_OOK|SVf_BREAK|SVf_READONLY|SVf_PROTECT)
1982 #endif
1983 
1984 #define CAN_COW_FLAGS	(SVp_POK|SVf_POK)
1985 
1986 #define SV_CHECK_THINKFIRST(sv) if (SvTHINKFIRST(sv)) \
1987 				    sv_force_normal_flags(sv, 0)
1988 
1989 
1990 /* all these 'functions' are now just macros */
1991 
1992 #define sv_pv(sv) SvPV_nolen(sv)
1993 #define sv_pvutf8(sv) SvPVutf8_nolen(sv)
1994 #define sv_pvbyte(sv) SvPVbyte_nolen(sv)
1995 
1996 #define sv_pvn_force_nomg(sv, lp) sv_pvn_force_flags(sv, lp, 0)
1997 #define sv_utf8_upgrade_flags(sv, flags) sv_utf8_upgrade_flags_grow(sv, flags, 0)
1998 #define sv_utf8_upgrade_nomg(sv) sv_utf8_upgrade_flags(sv, 0)
1999 #define sv_utf8_downgrade(sv, fail_ok) sv_utf8_downgrade_flags(sv, fail_ok, SV_GMAGIC)
2000 #define sv_utf8_downgrade_nomg(sv, fail_ok) sv_utf8_downgrade_flags(sv, fail_ok, 0)
2001 #define sv_catpvn_nomg(dsv, sstr, slen) sv_catpvn_flags(dsv, sstr, slen, 0)
2002 #define sv_catpv_nomg(dsv, sstr) sv_catpv_flags(dsv, sstr, 0)
2003 #define sv_setsv(dsv, ssv) \
2004 	sv_setsv_flags(dsv, ssv, SV_GMAGIC|SV_DO_COW_SVSETSV)
2005 #define sv_setsv_nomg(dsv, ssv) sv_setsv_flags(dsv, ssv, SV_DO_COW_SVSETSV)
2006 #define sv_catsv(dsv, ssv) sv_catsv_flags(dsv, ssv, SV_GMAGIC)
2007 #define sv_catsv_nomg(dsv, ssv) sv_catsv_flags(dsv, ssv, 0)
2008 #define sv_catsv_mg(dsv, ssv) sv_catsv_flags(dsv, ssv, SV_GMAGIC|SV_SMAGIC)
2009 #define sv_catpvn(dsv, sstr, slen) sv_catpvn_flags(dsv, sstr, slen, SV_GMAGIC)
2010 #define sv_catpvn_mg(sv, sstr, slen) sv_catpvn_flags(sv, sstr, slen, SV_GMAGIC|SV_SMAGIC);
2011 #define sv_copypv(dsv, ssv) sv_copypv_flags(dsv, ssv, SV_GMAGIC)
2012 #define sv_copypv_nomg(dsv, ssv) sv_copypv_flags(dsv, ssv, 0)
2013 #define sv_2pv(sv, lp) sv_2pv_flags(sv, lp, SV_GMAGIC)
2014 #define sv_2pv_nolen(sv) sv_2pv(sv, 0)
2015 #define sv_2pvbyte(sv, lp) sv_2pvbyte_flags(sv, lp, SV_GMAGIC)
2016 #define sv_2pvbyte_nolen(sv) sv_2pvbyte(sv, 0)
2017 #define sv_2pvutf8(sv, lp) sv_2pvutf8_flags(sv, lp, SV_GMAGIC)
2018 #define sv_2pvutf8_nolen(sv) sv_2pvutf8(sv, 0)
2019 #define sv_2pv_nomg(sv, lp) sv_2pv_flags(sv, lp, 0)
2020 #define sv_pvn_force(sv, lp) sv_pvn_force_flags(sv, lp, SV_GMAGIC)
2021 #define sv_utf8_upgrade(sv) sv_utf8_upgrade_flags(sv, SV_GMAGIC)
2022 #define sv_2iv(sv) sv_2iv_flags(sv, SV_GMAGIC)
2023 #define sv_2uv(sv) sv_2uv_flags(sv, SV_GMAGIC)
2024 #define sv_2nv(sv) sv_2nv_flags(sv, SV_GMAGIC)
2025 #define sv_eq(sv1, sv2) sv_eq_flags(sv1, sv2, SV_GMAGIC)
2026 #define sv_cmp(sv1, sv2) sv_cmp_flags(sv1, sv2, SV_GMAGIC)
2027 #define sv_cmp_locale(sv1, sv2) sv_cmp_locale_flags(sv1, sv2, SV_GMAGIC)
2028 #define sv_collxfrm(sv, nxp) sv_cmp_flags(sv, nxp, SV_GMAGIC)
2029 #define sv_2bool(sv) sv_2bool_flags(sv, SV_GMAGIC)
2030 #define sv_2bool_nomg(sv) sv_2bool_flags(sv, 0)
2031 #define sv_insert(bigstr, offset, len, little, littlelen)		\
2032 	Perl_sv_insert_flags(aTHX_ (bigstr),(offset), (len), (little),	\
2033 			     (littlelen), SV_GMAGIC)
2034 #define sv_mortalcopy(sv) \
2035 	Perl_sv_mortalcopy_flags(aTHX_ sv, SV_GMAGIC|SV_DO_COW_SVSETSV)
2036 #define sv_cathek(sv,hek)					    \
2037 	STMT_START {						     \
2038 	    HEK * const bmxk = hek;				      \
2039 	    sv_catpvn_flags(sv, HEK_KEY(bmxk), HEK_LEN(bmxk),	       \
2040 			    HEK_UTF8(bmxk) ? SV_CATUTF8 : SV_CATBYTES); \
2041 	} STMT_END
2042 
2043 /* Should be named SvCatPVN_utf8_upgrade? */
2044 #define sv_catpvn_nomg_utf8_upgrade(dsv, sstr, slen, nsv)	\
2045 	STMT_START {					\
2046 	    if (!(nsv))					\
2047 		nsv = newSVpvn_flags(sstr, slen, SVs_TEMP);	\
2048 	    else					\
2049 		sv_setpvn(nsv, sstr, slen);		\
2050 	    SvUTF8_off(nsv);				\
2051 	    sv_utf8_upgrade(nsv);			\
2052 	    sv_catsv_nomg(dsv, nsv);			\
2053 	} STMT_END
2054 #define sv_catpvn_nomg_maybeutf8(dsv, sstr, slen, is_utf8) \
2055 	sv_catpvn_flags(dsv, sstr, slen, (is_utf8)?SV_CATUTF8:SV_CATBYTES)
2056 
2057 #if defined(PERL_CORE) || defined(PERL_EXT)
2058 # define sv_or_pv_len_utf8(sv, pv, bytelen)	      \
2059     (SvGAMAGIC(sv)				       \
2060 	? utf8_length((U8 *)(pv), (U8 *)(pv)+(bytelen))	\
2061 	: sv_len_utf8(sv))
2062 #endif
2063 
2064 /*
2065 =for apidoc Am|SV*|newRV_inc|SV* sv
2066 
2067 Creates an RV wrapper for an SV.  The reference count for the original SV is
2068 incremented.
2069 
2070 =cut
2071 */
2072 
2073 #define newRV_inc(sv)	newRV(sv)
2074 
2075 /* the following macros update any magic values this C<sv> is associated with */
2076 
2077 /*
2078 =head1 Magical Functions
2079 
2080 =for apidoc Am|void|SvGETMAGIC|SV* sv
2081 Invokes C<mg_get> on an SV if it has 'get' magic.  For example, this
2082 will call C<FETCH> on a tied variable.  This macro evaluates its
2083 argument more than once.
2084 
2085 =for apidoc Am|void|SvSETMAGIC|SV* sv
2086 Invokes C<mg_set> on an SV if it has 'set' magic.  This is necessary
2087 after modifying a scalar, in case it is a magical variable like C<$|>
2088 or a tied variable (it calls C<STORE>).  This macro evaluates its
2089 argument more than once.
2090 
2091 =for apidoc Am|void|SvSetSV|SV* dsv|SV* ssv
2092 Calls C<sv_setsv> if C<dsv> is not the same as C<ssv>.  May evaluate arguments
2093 more than once.  Does not handle 'set' magic on the destination SV.
2094 
2095 =for apidoc Am|void|SvSetSV_nosteal|SV* dsv|SV* ssv
2096 Calls a non-destructive version of C<sv_setsv> if C<dsv> is not the same as
2097 C<ssv>.  May evaluate arguments more than once.
2098 
2099 =for apidoc Am|void|SvSetMagicSV|SV* dsv|SV* ssv
2100 Like C<SvSetSV>, but does any set magic required afterwards.
2101 
2102 =for apidoc Am|void|SvSetMagicSV_nosteal|SV* dsv|SV* ssv
2103 Like C<SvSetSV_nosteal>, but does any set magic required afterwards.
2104 
2105 =for apidoc Am|void|SvSHARE|SV* sv
2106 Arranges for C<sv> to be shared between threads if a suitable module
2107 has been loaded.
2108 
2109 =for apidoc Am|void|SvLOCK|SV* sv
2110 Arranges for a mutual exclusion lock to be obtained on C<sv> if a suitable module
2111 has been loaded.
2112 
2113 =for apidoc Am|void|SvUNLOCK|SV* sv
2114 Releases a mutual exclusion lock on C<sv> if a suitable module
2115 has been loaded.
2116 
2117 =head1 SV Manipulation Functions
2118 
2119 =for apidoc Am|char *|SvGROW|SV* sv|STRLEN len
2120 Expands the character buffer in the SV so that it has room for the
2121 indicated number of bytes (remember to reserve space for an extra trailing
2122 C<NUL> character).  Calls C<sv_grow> to perform the expansion if necessary.
2123 Returns a pointer to the character
2124 buffer.  SV must be of type >= C<SVt_PV>.  One
2125 alternative is to call C<sv_grow> if you are not sure of the type of SV.
2126 
2127 You might mistakenly think that C<len> is the number of bytes to add to the
2128 existing size, but instead it is the total size C<sv> should be.
2129 
2130 =for apidoc Am|char *|SvPVCLEAR|SV* sv
2131 Ensures that sv is a SVt_PV and that its SvCUR is 0, and that it is
2132 properly null terminated. Equivalent to sv_setpvs(""), but more efficient.
2133 
2134 =cut
2135 */
2136 
2137 #define SvPVCLEAR(sv) sv_setpv_bufsize(sv,0,0)
2138 #define SvSHARE(sv) PL_sharehook(aTHX_ sv)
2139 #define SvLOCK(sv) PL_lockhook(aTHX_ sv)
2140 #define SvUNLOCK(sv) PL_unlockhook(aTHX_ sv)
2141 #define SvDESTROYABLE(sv) PL_destroyhook(aTHX_ sv)
2142 
2143 #define SvGETMAGIC(x) ((void)(UNLIKELY(SvGMAGICAL(x)) && mg_get(x)))
2144 #define SvSETMAGIC(x) STMT_START { if (UNLIKELY(SvSMAGICAL(x))) mg_set(x); } STMT_END
2145 
2146 #define SvSetSV_and(dst,src,finally) \
2147 	STMT_START {					\
2148 	    if (LIKELY((dst) != (src))) {		\
2149 		sv_setsv(dst, src);			\
2150 		finally;				\
2151 	    }						\
2152 	} STMT_END
2153 #define SvSetSV_nosteal_and(dst,src,finally) \
2154 	STMT_START {					\
2155 	    if (LIKELY((dst) != (src))) {			\
2156 		sv_setsv_flags(dst, src, SV_GMAGIC | SV_NOSTEAL | SV_DO_COW_SVSETSV);	\
2157 		finally;				\
2158 	    }						\
2159 	} STMT_END
2160 
2161 #define SvSetSV(dst,src) \
2162 		SvSetSV_and(dst,src,/*nothing*/;)
2163 #define SvSetSV_nosteal(dst,src) \
2164 		SvSetSV_nosteal_and(dst,src,/*nothing*/;)
2165 
2166 #define SvSetMagicSV(dst,src) \
2167 		SvSetSV_and(dst,src,SvSETMAGIC(dst))
2168 #define SvSetMagicSV_nosteal(dst,src) \
2169 		SvSetSV_nosteal_and(dst,src,SvSETMAGIC(dst))
2170 
2171 
2172 #if !defined(SKIP_DEBUGGING)
2173 #define SvPEEK(sv) sv_peek(sv)
2174 #else
2175 #define SvPEEK(sv) ""
2176 #endif
2177 
2178 /* Is this a per-interpreter immortal SV (rather than global)?
2179  * These should either occupy adjacent entries in the interpreter struct
2180  * (MULTIPLICITY) or adjacent elements of PL_sv_immortals[] otherwise.
2181  * The unsigned (Size_t) cast avoids the need for a second < 0 condition.
2182  */
2183 #define SvIMMORTAL_INTERP(sv) ((Size_t)((sv) - &PL_sv_yes) < 4)
2184 
2185 /* Does this immortal have a true value? Currently only PL_sv_yes does. */
2186 #define SvIMMORTAL_TRUE(sv)   ((sv) == &PL_sv_yes)
2187 
2188 /* the SvREADONLY() test is to quickly reject most SVs */
2189 #define SvIMMORTAL(sv) \
2190                 (  SvREADONLY(sv) \
2191                 && (SvIMMORTAL_INTERP(sv) || (sv) == &PL_sv_placeholder))
2192 
2193 #ifdef DEBUGGING
2194    /* exercise the immortal resurrection code in sv_free2() */
2195 #  define SvREFCNT_IMMORTAL 1000
2196 #else
2197 #  define SvREFCNT_IMMORTAL ((~(U32)0)/2)
2198 #endif
2199 
2200 /*
2201 =for apidoc Am|SV *|boolSV|bool b
2202 
2203 Returns a true SV if C<b> is a true value, or a false SV if C<b> is 0.
2204 
2205 See also C<L</PL_sv_yes>> and C<L</PL_sv_no>>.
2206 
2207 =cut
2208 */
2209 
2210 #define boolSV(b) ((b) ? &PL_sv_yes : &PL_sv_no)
2211 
2212 #define isGV(sv) (SvTYPE(sv) == SVt_PVGV)
2213 /* If I give every macro argument a different name, then there won't be bugs
2214    where nested macros get confused. Been there, done that.  */
2215 #define isGV_with_GP(pwadak) \
2216 	(((SvFLAGS(pwadak) & (SVp_POK|SVpgv_GP)) == SVpgv_GP)	\
2217 	&& (SvTYPE(pwadak) == SVt_PVGV || SvTYPE(pwadak) == SVt_PVLV))
2218 #define isGV_with_GP_on(sv)	STMT_START {			       \
2219 	assert (SvTYPE(sv) == SVt_PVGV || SvTYPE(sv) == SVt_PVLV); \
2220 	assert (!SvPOKp(sv));					       \
2221 	assert (!SvIOKp(sv));					       \
2222 	(SvFLAGS(sv) |= SVpgv_GP);				       \
2223     } STMT_END
2224 #define isGV_with_GP_off(sv)	STMT_START {			       \
2225 	assert (SvTYPE(sv) == SVt_PVGV || SvTYPE(sv) == SVt_PVLV); \
2226 	assert (!SvPOKp(sv));					       \
2227 	assert (!SvIOKp(sv));					       \
2228 	(SvFLAGS(sv) &= ~SVpgv_GP);				       \
2229     } STMT_END
2230 #ifdef PERL_CORE
2231 # define isGV_or_RVCV(kadawp) \
2232     (isGV(kadawp) || (SvROK(kadawp) && SvTYPE(SvRV(kadawp)) == SVt_PVCV))
2233 #endif
2234 #define isREGEXP(sv) \
2235     (SvTYPE(sv) == SVt_REGEXP				      \
2236      || (SvFLAGS(sv) & (SVTYPEMASK|SVpgv_GP|SVf_FAKE))        \
2237 	 == (SVt_PVLV|SVf_FAKE))
2238 
2239 
2240 #ifdef PERL_ANY_COW
2241 # define SvGROW(sv,len) \
2242 	(SvIsCOW(sv) || SvLEN(sv) < (len) ? sv_grow(sv,len) : SvPVX(sv))
2243 #else
2244 # define SvGROW(sv,len) (SvLEN(sv) < (len) ? sv_grow(sv,len) : SvPVX(sv))
2245 #endif
2246 #define SvGROW_mutable(sv,len) \
2247     (SvLEN(sv) < (len) ? sv_grow(sv,len) : SvPVX_mutable(sv))
2248 #define Sv_Grow sv_grow
2249 
2250 #define CLONEf_COPY_STACKS 1
2251 #define CLONEf_KEEP_PTR_TABLE 2
2252 #define CLONEf_CLONE_HOST 4
2253 #define CLONEf_JOIN_IN 8
2254 
2255 struct clone_params {
2256   AV* stashes;
2257   UV  flags;
2258   PerlInterpreter *proto_perl;
2259   PerlInterpreter *new_perl;
2260   AV *unreferenced;
2261 };
2262 
2263 /* SV_NOSTEAL prevents TEMP buffers being, well, stolen, and saves games
2264    with SvTEMP_off and SvTEMP_on round a call to sv_setsv.  */
2265 #define newSVsv(sv) newSVsv_flags((sv), SV_GMAGIC|SV_NOSTEAL)
2266 #define newSVsv_nomg(sv) newSVsv_flags((sv), SV_NOSTEAL)
2267 
2268 /*
2269 =for apidoc Am|SV*|newSVpvn_utf8|const char* s|STRLEN len|U32 utf8
2270 
2271 Creates a new SV and copies a string (which may contain C<NUL> (C<\0>)
2272 characters) into it.  If C<utf8> is true, calls
2273 C<SvUTF8_on> on the new SV.  Implemented as a wrapper around C<newSVpvn_flags>.
2274 
2275 =cut
2276 */
2277 
2278 #define newSVpvn_utf8(s, len, u) newSVpvn_flags((s), (len), (u) ? SVf_UTF8 : 0)
2279 
2280 /*
2281 =for apidoc Amx|SV*|newSVpadname|PADNAME *pn
2282 
2283 Creates a new SV containing the pad name.
2284 
2285 =cut
2286 */
2287 
2288 #define newSVpadname(pn) newSVpvn_utf8(PadnamePV(pn), PadnameLEN(pn), TRUE)
2289 
2290 /*
2291 =for apidoc Am|void|SvOOK_offset|SV*sv|STRLEN len
2292 
2293 Reads into C<len> the offset from C<SvPVX> back to the true start of the
2294 allocated buffer, which will be non-zero if C<sv_chop> has been used to
2295 efficiently remove characters from start of the buffer.  Implemented as a
2296 macro, which takes the address of C<len>, which must be of type C<STRLEN>.
2297 Evaluates C<sv> more than once.  Sets C<len> to 0 if C<SvOOK(sv)> is false.
2298 
2299 =cut
2300 */
2301 
2302 #ifdef DEBUGGING
2303 /* Does the bot know something I don't?
2304 10:28 <@Nicholas> metabatman
2305 10:28 <+meta> Nicholas: crash
2306 */
2307 #  define SvOOK_offset(sv, offset) STMT_START {				\
2308 	assert(sizeof(offset) == sizeof(STRLEN));			\
2309 	if (SvOOK(sv)) {						\
2310 	    const U8 *_crash = (U8*)SvPVX_const(sv);			\
2311 	    (offset) = *--_crash;					\
2312 	    if (!(offset)) {						\
2313 		_crash -= sizeof(STRLEN);				\
2314 		Copy(_crash, (U8 *)&(offset), sizeof(STRLEN), U8);	\
2315 	    }								\
2316 	    {								\
2317 		/* Validate the preceding buffer's sentinels to		\
2318 		   verify that no-one is using it.  */			\
2319 		const U8 *const _bonk = (U8*)SvPVX_const(sv) - (offset);\
2320 		while (_crash > _bonk) {				\
2321 		    --_crash;						\
2322 		    assert (*_crash == (U8)PTR2UV(_crash));		\
2323 		}							\
2324 	    }								\
2325 	} else {							\
2326 	    (offset) = 0;						\
2327 	}								\
2328     } STMT_END
2329 #else
2330     /* This is the same code, but avoids using any temporary variables:  */
2331 #  define SvOOK_offset(sv, offset) STMT_START {				\
2332 	assert(sizeof(offset) == sizeof(STRLEN));			\
2333 	if (SvOOK(sv)) {						\
2334 	    (offset) = ((U8*)SvPVX_const(sv))[-1];			\
2335 	    if (!(offset)) {						\
2336 		Copy(SvPVX_const(sv) - 1 - sizeof(STRLEN),		\
2337 		     (U8*)&(offset), sizeof(STRLEN), U8);		\
2338 	    }								\
2339 	} else {							\
2340 	    (offset) = 0;						\
2341 	}								\
2342     } STMT_END
2343 #endif
2344 
2345 #define newIO()	MUTABLE_IO(newSV_type(SVt_PVIO))
2346 
2347 #define SV_CONST(name) \
2348 	PL_sv_consts[SV_CONST_##name] \
2349 		? PL_sv_consts[SV_CONST_##name] \
2350 		: (PL_sv_consts[SV_CONST_##name] = newSVpv_share(#name, 0))
2351 
2352 #define SV_CONST_TIESCALAR 0
2353 #define SV_CONST_TIEARRAY 1
2354 #define SV_CONST_TIEHASH 2
2355 #define SV_CONST_TIEHANDLE 3
2356 
2357 #define SV_CONST_FETCH 4
2358 #define SV_CONST_FETCHSIZE 5
2359 #define SV_CONST_STORE 6
2360 #define SV_CONST_STORESIZE 7
2361 #define SV_CONST_EXISTS 8
2362 
2363 #define SV_CONST_PUSH 9
2364 #define SV_CONST_POP 10
2365 #define SV_CONST_SHIFT 11
2366 #define SV_CONST_UNSHIFT 12
2367 #define SV_CONST_SPLICE 13
2368 #define SV_CONST_EXTEND 14
2369 
2370 #define SV_CONST_FIRSTKEY 15
2371 #define SV_CONST_NEXTKEY 16
2372 #define SV_CONST_SCALAR 17
2373 
2374 #define SV_CONST_OPEN 18
2375 #define SV_CONST_WRITE 19
2376 #define SV_CONST_PRINT 20
2377 #define SV_CONST_PRINTF 21
2378 #define SV_CONST_READ 22
2379 #define SV_CONST_READLINE 23
2380 #define SV_CONST_GETC 24
2381 #define SV_CONST_SEEK 25
2382 #define SV_CONST_TELL 26
2383 #define SV_CONST_EOF 27
2384 #define SV_CONST_BINMODE 28
2385 #define SV_CONST_FILENO 29
2386 #define SV_CONST_CLOSE 30
2387 
2388 #define SV_CONST_DELETE 31
2389 #define SV_CONST_CLEAR 32
2390 #define SV_CONST_UNTIE 33
2391 #define SV_CONST_DESTROY 34
2392 
2393 #define SV_CONSTS_COUNT 35
2394 
2395 /*
2396  * Bodyless IVs and NVs!
2397  *
2398  * Since 5.9.2, we can avoid allocating a body for SVt_IV-type SVs.
2399  * Since the larger IV-holding variants of SVs store their integer
2400  * values in their respective bodies, the family of SvIV() accessor
2401  * macros would  naively have to branch on the SV type to find the
2402  * integer value either in the HEAD or BODY. In order to avoid this
2403  * expensive branch, a clever soul has deployed a great hack:
2404  * We set up the SvANY pointer such that instead of pointing to a
2405  * real body, it points into the memory before the location of the
2406  * head. We compute this pointer such that the location of
2407  * the integer member of the hypothetical body struct happens to
2408  * be the same as the location of the integer member of the bodyless
2409  * SV head. This now means that the SvIV() family of accessors can
2410  * always read from the (hypothetical or real) body via SvANY.
2411  *
2412  * Since the 5.21 dev series, we employ the same trick for NVs
2413  * if the architecture can support it (NVSIZE <= IVSIZE).
2414  */
2415 
2416 /* The following two macros compute the necessary offsets for the above
2417  * trick and store them in SvANY for SvIV() (and friends) to use. */
2418 
2419 #ifdef PERL_CORE
2420 #  define SET_SVANY_FOR_BODYLESS_IV(sv) \
2421 	SvANY(sv) =   (XPVIV*)((char*)&(sv->sv_u.svu_iv) \
2422                     - STRUCT_OFFSET(XPVIV, xiv_iv))
2423 
2424 #  define SET_SVANY_FOR_BODYLESS_NV(sv) \
2425 	SvANY(sv) =   (XPVNV*)((char*)&(sv->sv_u.svu_nv) \
2426                     - STRUCT_OFFSET(XPVNV, xnv_u.xnv_nv))
2427 #endif
2428 
2429 /*
2430  * ex: set ts=8 sts=4 sw=4 et:
2431  */
2432