xref: /openbsd-src/gnu/usr.bin/perl/hv.c (revision 50b7afb2c2c0993b0894d4e34bf857cb13ed9c80)
1 /*    hv.c
2  *
3  *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
4  *    2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 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 /*
12  *      I sit beside the fire and think
13  *          of all that I have seen.
14  *                         --Bilbo
15  *
16  *     [p.278 of _The Lord of the Rings_, II/iii: "The Ring Goes South"]
17  */
18 
19 /*
20 =head1 Hash Manipulation Functions
21 
22 A HV structure represents a Perl hash.  It consists mainly of an array
23 of pointers, each of which points to a linked list of HE structures.  The
24 array is indexed by the hash function of the key, so each linked list
25 represents all the hash entries with the same hash value.  Each HE contains
26 a pointer to the actual value, plus a pointer to a HEK structure which
27 holds the key and hash value.
28 
29 =cut
30 
31 */
32 
33 #include "EXTERN.h"
34 #define PERL_IN_HV_C
35 #define PERL_HASH_INTERNAL_ACCESS
36 #include "perl.h"
37 
38 #define DO_HSPLIT(xhv) ((xhv)->xhv_keys > (xhv)->xhv_max) /* HvTOTALKEYS(hv) > HvMAX(hv) */
39 
40 static const char S_strtab_error[]
41     = "Cannot modify shared string table in hv_%s";
42 
43 #ifdef PURIFY
44 
45 #define new_HE() (HE*)safemalloc(sizeof(HE))
46 #define del_HE(p) safefree((char*)p)
47 
48 #else
49 
50 STATIC HE*
51 S_new_he(pTHX)
52 {
53     dVAR;
54     HE* he;
55     void ** const root = &PL_body_roots[HE_SVSLOT];
56 
57     if (!*root)
58 	Perl_more_bodies(aTHX_ HE_SVSLOT, sizeof(HE), PERL_ARENA_SIZE);
59     he = (HE*) *root;
60     assert(he);
61     *root = HeNEXT(he);
62     return he;
63 }
64 
65 #define new_HE() new_he()
66 #define del_HE(p) \
67     STMT_START { \
68 	HeNEXT(p) = (HE*)(PL_body_roots[HE_SVSLOT]);	\
69 	PL_body_roots[HE_SVSLOT] = p; \
70     } STMT_END
71 
72 
73 
74 #endif
75 
76 STATIC HEK *
77 S_save_hek_flags(const char *str, I32 len, U32 hash, int flags)
78 {
79     const int flags_masked = flags & HVhek_MASK;
80     char *k;
81     HEK *hek;
82 
83     PERL_ARGS_ASSERT_SAVE_HEK_FLAGS;
84 
85     Newx(k, HEK_BASESIZE + len + 2, char);
86     hek = (HEK*)k;
87     Copy(str, HEK_KEY(hek), len, char);
88     HEK_KEY(hek)[len] = 0;
89     HEK_LEN(hek) = len;
90     HEK_HASH(hek) = hash;
91     HEK_FLAGS(hek) = (unsigned char)flags_masked | HVhek_UNSHARED;
92 
93     if (flags & HVhek_FREEKEY)
94 	Safefree(str);
95     return hek;
96 }
97 
98 /* free the pool of temporary HE/HEK pairs returned by hv_fetch_ent
99  * for tied hashes */
100 
101 void
102 Perl_free_tied_hv_pool(pTHX)
103 {
104     dVAR;
105     HE *he = PL_hv_fetch_ent_mh;
106     while (he) {
107 	HE * const ohe = he;
108 	Safefree(HeKEY_hek(he));
109 	he = HeNEXT(he);
110 	del_HE(ohe);
111     }
112     PL_hv_fetch_ent_mh = NULL;
113 }
114 
115 #if defined(USE_ITHREADS)
116 HEK *
117 Perl_hek_dup(pTHX_ HEK *source, CLONE_PARAMS* param)
118 {
119     HEK *shared;
120 
121     PERL_ARGS_ASSERT_HEK_DUP;
122     PERL_UNUSED_ARG(param);
123 
124     if (!source)
125 	return NULL;
126 
127     shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
128     if (shared) {
129 	/* We already shared this hash key.  */
130 	(void)share_hek_hek(shared);
131     }
132     else {
133 	shared
134 	    = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
135 			      HEK_HASH(source), HEK_FLAGS(source));
136 	ptr_table_store(PL_ptr_table, source, shared);
137     }
138     return shared;
139 }
140 
141 HE *
142 Perl_he_dup(pTHX_ const HE *e, bool shared, CLONE_PARAMS* param)
143 {
144     HE *ret;
145 
146     PERL_ARGS_ASSERT_HE_DUP;
147 
148     if (!e)
149 	return NULL;
150     /* look for it in the table first */
151     ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
152     if (ret)
153 	return ret;
154 
155     /* create anew and remember what it is */
156     ret = new_HE();
157     ptr_table_store(PL_ptr_table, e, ret);
158 
159     HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
160     if (HeKLEN(e) == HEf_SVKEY) {
161 	char *k;
162 	Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
163 	HeKEY_hek(ret) = (HEK*)k;
164 	HeKEY_sv(ret) = sv_dup_inc(HeKEY_sv(e), param);
165     }
166     else if (shared) {
167 	/* This is hek_dup inlined, which seems to be important for speed
168 	   reasons.  */
169 	HEK * const source = HeKEY_hek(e);
170 	HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
171 
172 	if (shared) {
173 	    /* We already shared this hash key.  */
174 	    (void)share_hek_hek(shared);
175 	}
176 	else {
177 	    shared
178 		= share_hek_flags(HEK_KEY(source), HEK_LEN(source),
179 				  HEK_HASH(source), HEK_FLAGS(source));
180 	    ptr_table_store(PL_ptr_table, source, shared);
181 	}
182 	HeKEY_hek(ret) = shared;
183     }
184     else
185 	HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
186                                         HeKFLAGS(e));
187     HeVAL(ret) = sv_dup_inc(HeVAL(e), param);
188     return ret;
189 }
190 #endif	/* USE_ITHREADS */
191 
192 static void
193 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
194 		const char *msg)
195 {
196     SV * const sv = sv_newmortal();
197 
198     PERL_ARGS_ASSERT_HV_NOTALLOWED;
199 
200     if (!(flags & HVhek_FREEKEY)) {
201 	sv_setpvn(sv, key, klen);
202     }
203     else {
204 	/* Need to free saved eventually assign to mortal SV */
205 	/* XXX is this line an error ???:  SV *sv = sv_newmortal(); */
206 	sv_usepvn(sv, (char *) key, klen);
207     }
208     if (flags & HVhek_UTF8) {
209 	SvUTF8_on(sv);
210     }
211     Perl_croak(aTHX_ msg, SVfARG(sv));
212 }
213 
214 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
215  * contains an SV* */
216 
217 /*
218 =for apidoc hv_store
219 
220 Stores an SV in a hash.  The hash key is specified as C<key> and the
221 absolute value of C<klen> is the length of the key.  If C<klen> is
222 negative the key is assumed to be in UTF-8-encoded Unicode.  The
223 C<hash> parameter is the precomputed hash value; if it is zero then
224 Perl will compute it.
225 
226 The return value will be
227 NULL if the operation failed or if the value did not need to be actually
228 stored within the hash (as in the case of tied hashes).  Otherwise it can
229 be dereferenced to get the original C<SV*>.  Note that the caller is
230 responsible for suitably incrementing the reference count of C<val> before
231 the call, and decrementing it if the function returned NULL.  Effectively
232 a successful hv_store takes ownership of one reference to C<val>.  This is
233 usually what you want; a newly created SV has a reference count of one, so
234 if all your code does is create SVs then store them in a hash, hv_store
235 will own the only reference to the new SV, and your code doesn't need to do
236 anything further to tidy up.  hv_store is not implemented as a call to
237 hv_store_ent, and does not create a temporary SV for the key, so if your
238 key data is not already in SV form then use hv_store in preference to
239 hv_store_ent.
240 
241 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
242 information on how to use this function on tied hashes.
243 
244 =for apidoc hv_store_ent
245 
246 Stores C<val> in a hash.  The hash key is specified as C<key>.  The C<hash>
247 parameter is the precomputed hash value; if it is zero then Perl will
248 compute it.  The return value is the new hash entry so created.  It will be
249 NULL if the operation failed or if the value did not need to be actually
250 stored within the hash (as in the case of tied hashes).  Otherwise the
251 contents of the return value can be accessed using the C<He?> macros
252 described here.  Note that the caller is responsible for suitably
253 incrementing the reference count of C<val> before the call, and
254 decrementing it if the function returned NULL.  Effectively a successful
255 hv_store_ent takes ownership of one reference to C<val>.  This is
256 usually what you want; a newly created SV has a reference count of one, so
257 if all your code does is create SVs then store them in a hash, hv_store
258 will own the only reference to the new SV, and your code doesn't need to do
259 anything further to tidy up.  Note that hv_store_ent only reads the C<key>;
260 unlike C<val> it does not take ownership of it, so maintaining the correct
261 reference count on C<key> is entirely the caller's responsibility.  hv_store
262 is not implemented as a call to hv_store_ent, and does not create a temporary
263 SV for the key, so if your key data is not already in SV form then use
264 hv_store in preference to hv_store_ent.
265 
266 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
267 information on how to use this function on tied hashes.
268 
269 =for apidoc hv_exists
270 
271 Returns a boolean indicating whether the specified hash key exists.  The
272 absolute value of C<klen> is the length of the key.  If C<klen> is
273 negative the key is assumed to be in UTF-8-encoded Unicode.
274 
275 =for apidoc hv_fetch
276 
277 Returns the SV which corresponds to the specified key in the hash.
278 The absolute value of C<klen> is the length of the key.  If C<klen> is
279 negative the key is assumed to be in UTF-8-encoded Unicode.  If
280 C<lval> is set then the fetch will be part of a store.  This means that if
281 there is no value in the hash associated with the given key, then one is
282 created and a pointer to it is returned.  The C<SV*> it points to can be
283 assigned to.  But always check that the
284 return value is non-null before dereferencing it to an C<SV*>.
285 
286 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
287 information on how to use this function on tied hashes.
288 
289 =for apidoc hv_exists_ent
290 
291 Returns a boolean indicating whether
292 the specified hash key exists.  C<hash>
293 can be a valid precomputed hash value, or 0 to ask for it to be
294 computed.
295 
296 =cut
297 */
298 
299 /* returns an HE * structure with the all fields set */
300 /* note that hent_val will be a mortal sv for MAGICAL hashes */
301 /*
302 =for apidoc hv_fetch_ent
303 
304 Returns the hash entry which corresponds to the specified key in the hash.
305 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
306 if you want the function to compute it.  IF C<lval> is set then the fetch
307 will be part of a store.  Make sure the return value is non-null before
308 accessing it.  The return value when C<hv> is a tied hash is a pointer to a
309 static location, so be sure to make a copy of the structure if you need to
310 store it somewhere.
311 
312 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
313 information on how to use this function on tied hashes.
314 
315 =cut
316 */
317 
318 /* Common code for hv_delete()/hv_exists()/hv_fetch()/hv_store()  */
319 void *
320 Perl_hv_common_key_len(pTHX_ HV *hv, const char *key, I32 klen_i32,
321 		       const int action, SV *val, const U32 hash)
322 {
323     STRLEN klen;
324     int flags;
325 
326     PERL_ARGS_ASSERT_HV_COMMON_KEY_LEN;
327 
328     if (klen_i32 < 0) {
329 	klen = -klen_i32;
330 	flags = HVhek_UTF8;
331     } else {
332 	klen = klen_i32;
333 	flags = 0;
334     }
335     return hv_common(hv, NULL, key, klen, flags, action, val, hash);
336 }
337 
338 void *
339 Perl_hv_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
340 	       int flags, int action, SV *val, U32 hash)
341 {
342     dVAR;
343     XPVHV* xhv;
344     HE *entry;
345     HE **oentry;
346     SV *sv;
347     bool is_utf8;
348     int masked_flags;
349     const int return_svp = action & HV_FETCH_JUST_SV;
350 
351     if (!hv)
352 	return NULL;
353     if (SvTYPE(hv) == (svtype)SVTYPEMASK)
354 	return NULL;
355 
356     assert(SvTYPE(hv) == SVt_PVHV);
357 
358     if (SvSMAGICAL(hv) && SvGMAGICAL(hv) && !(action & HV_DISABLE_UVAR_XKEY)) {
359 	MAGIC* mg;
360 	if ((mg = mg_find((const SV *)hv, PERL_MAGIC_uvar))) {
361 	    struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
362 	    if (uf->uf_set == NULL) {
363 		SV* obj = mg->mg_obj;
364 
365 		if (!keysv) {
366 		    keysv = newSVpvn_flags(key, klen, SVs_TEMP |
367 					   ((flags & HVhek_UTF8)
368 					    ? SVf_UTF8 : 0));
369 		}
370 
371 		mg->mg_obj = keysv;         /* pass key */
372 		uf->uf_index = action;      /* pass action */
373 		magic_getuvar(MUTABLE_SV(hv), mg);
374 		keysv = mg->mg_obj;         /* may have changed */
375 		mg->mg_obj = obj;
376 
377 		/* If the key may have changed, then we need to invalidate
378 		   any passed-in computed hash value.  */
379 		hash = 0;
380 	    }
381 	}
382     }
383     if (keysv) {
384 	if (flags & HVhek_FREEKEY)
385 	    Safefree(key);
386 	key = SvPV_const(keysv, klen);
387 	is_utf8 = (SvUTF8(keysv) != 0);
388 	if (SvIsCOW_shared_hash(keysv)) {
389 	    flags = HVhek_KEYCANONICAL | (is_utf8 ? HVhek_UTF8 : 0);
390 	} else {
391 	    flags = is_utf8 ? HVhek_UTF8 : 0;
392 	}
393     } else {
394 	is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
395     }
396 
397     if (action & HV_DELETE) {
398 	return (void *) hv_delete_common(hv, keysv, key, klen,
399 					 flags, action, hash);
400     }
401 
402     xhv = (XPVHV*)SvANY(hv);
403     if (SvMAGICAL(hv)) {
404 	if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
405 	    if (mg_find((const SV *)hv, PERL_MAGIC_tied)
406 		|| SvGMAGICAL((const SV *)hv))
407 	    {
408 		/* FIXME should be able to skimp on the HE/HEK here when
409 		   HV_FETCH_JUST_SV is true.  */
410 		if (!keysv) {
411 		    keysv = newSVpvn_utf8(key, klen, is_utf8);
412   		} else {
413 		    keysv = newSVsv(keysv);
414 		}
415                 sv = sv_newmortal();
416                 mg_copy(MUTABLE_SV(hv), sv, (char *)keysv, HEf_SVKEY);
417 
418 		/* grab a fake HE/HEK pair from the pool or make a new one */
419 		entry = PL_hv_fetch_ent_mh;
420 		if (entry)
421 		    PL_hv_fetch_ent_mh = HeNEXT(entry);
422 		else {
423 		    char *k;
424 		    entry = new_HE();
425 		    Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
426 		    HeKEY_hek(entry) = (HEK*)k;
427 		}
428 		HeNEXT(entry) = NULL;
429 		HeSVKEY_set(entry, keysv);
430 		HeVAL(entry) = sv;
431 		sv_upgrade(sv, SVt_PVLV);
432 		LvTYPE(sv) = 'T';
433 		 /* so we can free entry when freeing sv */
434 		LvTARG(sv) = MUTABLE_SV(entry);
435 
436 		/* XXX remove at some point? */
437 		if (flags & HVhek_FREEKEY)
438 		    Safefree(key);
439 
440 		if (return_svp) {
441 		    return entry ? (void *) &HeVAL(entry) : NULL;
442 		}
443 		return (void *) entry;
444 	    }
445 #ifdef ENV_IS_CASELESS
446 	    else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
447 		U32 i;
448 		for (i = 0; i < klen; ++i)
449 		    if (isLOWER(key[i])) {
450 			/* Would be nice if we had a routine to do the
451 			   copy and upercase in a single pass through.  */
452 			const char * const nkey = strupr(savepvn(key,klen));
453 			/* Note that this fetch is for nkey (the uppercased
454 			   key) whereas the store is for key (the original)  */
455 			void *result = hv_common(hv, NULL, nkey, klen,
456 						 HVhek_FREEKEY, /* free nkey */
457 						 0 /* non-LVAL fetch */
458 						 | HV_DISABLE_UVAR_XKEY
459 						 | return_svp,
460 						 NULL /* no value */,
461 						 0 /* compute hash */);
462 			if (!result && (action & HV_FETCH_LVALUE)) {
463 			    /* This call will free key if necessary.
464 			       Do it this way to encourage compiler to tail
465 			       call optimise.  */
466 			    result = hv_common(hv, keysv, key, klen, flags,
467 					       HV_FETCH_ISSTORE
468 					       | HV_DISABLE_UVAR_XKEY
469 					       | return_svp,
470 					       newSV(0), hash);
471 			} else {
472 			    if (flags & HVhek_FREEKEY)
473 				Safefree(key);
474 			}
475 			return result;
476 		    }
477 	    }
478 #endif
479 	} /* ISFETCH */
480 	else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
481 	    if (mg_find((const SV *)hv, PERL_MAGIC_tied)
482 		|| SvGMAGICAL((const SV *)hv)) {
483 		/* I don't understand why hv_exists_ent has svret and sv,
484 		   whereas hv_exists only had one.  */
485 		SV * const svret = sv_newmortal();
486 		sv = sv_newmortal();
487 
488 		if (keysv || is_utf8) {
489 		    if (!keysv) {
490 			keysv = newSVpvn_utf8(key, klen, TRUE);
491 		    } else {
492 			keysv = newSVsv(keysv);
493 		    }
494 		    mg_copy(MUTABLE_SV(hv), sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
495 		} else {
496 		    mg_copy(MUTABLE_SV(hv), sv, key, klen);
497 		}
498 		if (flags & HVhek_FREEKEY)
499 		    Safefree(key);
500 		magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
501 		/* This cast somewhat evil, but I'm merely using NULL/
502 		   not NULL to return the boolean exists.
503 		   And I know hv is not NULL.  */
504 		return SvTRUE(svret) ? (void *)hv : NULL;
505 		}
506 #ifdef ENV_IS_CASELESS
507 	    else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
508 		/* XXX This code isn't UTF8 clean.  */
509 		char * const keysave = (char * const)key;
510 		/* Will need to free this, so set FREEKEY flag.  */
511 		key = savepvn(key,klen);
512 		key = (const char*)strupr((char*)key);
513 		is_utf8 = FALSE;
514 		hash = 0;
515 		keysv = 0;
516 
517 		if (flags & HVhek_FREEKEY) {
518 		    Safefree(keysave);
519 		}
520 		flags |= HVhek_FREEKEY;
521 	    }
522 #endif
523 	} /* ISEXISTS */
524 	else if (action & HV_FETCH_ISSTORE) {
525 	    bool needs_copy;
526 	    bool needs_store;
527 	    hv_magic_check (hv, &needs_copy, &needs_store);
528 	    if (needs_copy) {
529 		const bool save_taint = TAINT_get;
530 		if (keysv || is_utf8) {
531 		    if (!keysv) {
532 			keysv = newSVpvn_utf8(key, klen, TRUE);
533 		    }
534 		    if (TAINTING_get)
535 			TAINT_set(SvTAINTED(keysv));
536 		    keysv = sv_2mortal(newSVsv(keysv));
537 		    mg_copy(MUTABLE_SV(hv), val, (char*)keysv, HEf_SVKEY);
538 		} else {
539 		    mg_copy(MUTABLE_SV(hv), val, key, klen);
540 		}
541 
542 		TAINT_IF(save_taint);
543 #ifdef NO_TAINT_SUPPORT
544                 PERL_UNUSED_VAR(save_taint);
545 #endif
546 		if (!needs_store) {
547 		    if (flags & HVhek_FREEKEY)
548 			Safefree(key);
549 		    return NULL;
550 		}
551 #ifdef ENV_IS_CASELESS
552 		else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
553 		    /* XXX This code isn't UTF8 clean.  */
554 		    const char *keysave = key;
555 		    /* Will need to free this, so set FREEKEY flag.  */
556 		    key = savepvn(key,klen);
557 		    key = (const char*)strupr((char*)key);
558 		    is_utf8 = FALSE;
559 		    hash = 0;
560 		    keysv = 0;
561 
562 		    if (flags & HVhek_FREEKEY) {
563 			Safefree(keysave);
564 		    }
565 		    flags |= HVhek_FREEKEY;
566 		}
567 #endif
568 	    }
569 	} /* ISSTORE */
570     } /* SvMAGICAL */
571 
572     if (!HvARRAY(hv)) {
573 	if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
574 #ifdef DYNAMIC_ENV_FETCH  /* if it's an %ENV lookup, we may get it on the fly */
575 		 || (SvRMAGICAL((const SV *)hv)
576 		     && mg_find((const SV *)hv, PERL_MAGIC_env))
577 #endif
578 								  ) {
579 	    char *array;
580 	    Newxz(array,
581 		 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
582 		 char);
583 	    HvARRAY(hv) = (HE**)array;
584 	}
585 #ifdef DYNAMIC_ENV_FETCH
586 	else if (action & HV_FETCH_ISEXISTS) {
587 	    /* for an %ENV exists, if we do an insert it's by a recursive
588 	       store call, so avoid creating HvARRAY(hv) right now.  */
589 	}
590 #endif
591 	else {
592 	    /* XXX remove at some point? */
593             if (flags & HVhek_FREEKEY)
594                 Safefree(key);
595 
596 	    return NULL;
597 	}
598     }
599 
600     if (is_utf8 && !(flags & HVhek_KEYCANONICAL)) {
601 	char * const keysave = (char *)key;
602 	key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
603         if (is_utf8)
604 	    flags |= HVhek_UTF8;
605 	else
606 	    flags &= ~HVhek_UTF8;
607         if (key != keysave) {
608 	    if (flags & HVhek_FREEKEY)
609 		Safefree(keysave);
610             flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
611 	    /* If the caller calculated a hash, it was on the sequence of
612 	       octets that are the UTF-8 form. We've now changed the sequence
613 	       of octets stored to that of the equivalent byte representation,
614 	       so the hash we need is different.  */
615 	    hash = 0;
616 	}
617     }
618 
619     if (!hash) {
620         if (keysv && (SvIsCOW_shared_hash(keysv)))
621             hash = SvSHARED_HASH(keysv);
622         else
623             PERL_HASH(hash, key, klen);
624     }
625 
626     masked_flags = (flags & HVhek_MASK);
627 
628 #ifdef DYNAMIC_ENV_FETCH
629     if (!HvARRAY(hv)) entry = NULL;
630     else
631 #endif
632     {
633 	entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
634     }
635     for (; entry; entry = HeNEXT(entry)) {
636 	if (HeHASH(entry) != hash)		/* strings can't be equal */
637 	    continue;
638 	if (HeKLEN(entry) != (I32)klen)
639 	    continue;
640 	if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen))	/* is this it? */
641 	    continue;
642 	if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
643 	    continue;
644 
645         if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
646 	    if (HeKFLAGS(entry) != masked_flags) {
647 		/* We match if HVhek_UTF8 bit in our flags and hash key's
648 		   match.  But if entry was set previously with HVhek_WASUTF8
649 		   and key now doesn't (or vice versa) then we should change
650 		   the key's flag, as this is assignment.  */
651 		if (HvSHAREKEYS(hv)) {
652 		    /* Need to swap the key we have for a key with the flags we
653 		       need. As keys are shared we can't just write to the
654 		       flag, so we share the new one, unshare the old one.  */
655 		    HEK * const new_hek = share_hek_flags(key, klen, hash,
656 						   masked_flags);
657 		    unshare_hek (HeKEY_hek(entry));
658 		    HeKEY_hek(entry) = new_hek;
659 		}
660 		else if (hv == PL_strtab) {
661 		    /* PL_strtab is usually the only hash without HvSHAREKEYS,
662 		       so putting this test here is cheap  */
663 		    if (flags & HVhek_FREEKEY)
664 			Safefree(key);
665 		    Perl_croak(aTHX_ S_strtab_error,
666 			       action & HV_FETCH_LVALUE ? "fetch" : "store");
667 		}
668 		else
669 		    HeKFLAGS(entry) = masked_flags;
670 		if (masked_flags & HVhek_ENABLEHVKFLAGS)
671 		    HvHASKFLAGS_on(hv);
672 	    }
673 	    if (HeVAL(entry) == &PL_sv_placeholder) {
674 		/* yes, can store into placeholder slot */
675 		if (action & HV_FETCH_LVALUE) {
676 		    if (SvMAGICAL(hv)) {
677 			/* This preserves behaviour with the old hv_fetch
678 			   implementation which at this point would bail out
679 			   with a break; (at "if we find a placeholder, we
680 			   pretend we haven't found anything")
681 
682 			   That break mean that if a placeholder were found, it
683 			   caused a call into hv_store, which in turn would
684 			   check magic, and if there is no magic end up pretty
685 			   much back at this point (in hv_store's code).  */
686 			break;
687 		    }
688 		    /* LVAL fetch which actually needs a store.  */
689 		    val = newSV(0);
690 		    HvPLACEHOLDERS(hv)--;
691 		} else {
692 		    /* store */
693 		    if (val != &PL_sv_placeholder)
694 			HvPLACEHOLDERS(hv)--;
695 		}
696 		HeVAL(entry) = val;
697 	    } else if (action & HV_FETCH_ISSTORE) {
698 		SvREFCNT_dec(HeVAL(entry));
699 		HeVAL(entry) = val;
700 	    }
701 	} else if (HeVAL(entry) == &PL_sv_placeholder) {
702 	    /* if we find a placeholder, we pretend we haven't found
703 	       anything */
704 	    break;
705 	}
706 	if (flags & HVhek_FREEKEY)
707 	    Safefree(key);
708 	if (return_svp) {
709 	    return entry ? (void *) &HeVAL(entry) : NULL;
710 	}
711 	return entry;
712     }
713 #ifdef DYNAMIC_ENV_FETCH  /* %ENV lookup?  If so, try to fetch the value now */
714     if (!(action & HV_FETCH_ISSTORE)
715 	&& SvRMAGICAL((const SV *)hv)
716 	&& mg_find((const SV *)hv, PERL_MAGIC_env)) {
717 	unsigned long len;
718 	const char * const env = PerlEnv_ENVgetenv_len(key,&len);
719 	if (env) {
720 	    sv = newSVpvn(env,len);
721 	    SvTAINTED_on(sv);
722 	    return hv_common(hv, keysv, key, klen, flags,
723 			     HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
724 			     sv, hash);
725 	}
726     }
727 #endif
728 
729     if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
730 	hv_notallowed(flags, key, klen,
731 			"Attempt to access disallowed key '%"SVf"' in"
732 			" a restricted hash");
733     }
734     if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
735 	/* Not doing some form of store, so return failure.  */
736 	if (flags & HVhek_FREEKEY)
737 	    Safefree(key);
738 	return NULL;
739     }
740     if (action & HV_FETCH_LVALUE) {
741 	val = action & HV_FETCH_EMPTY_HE ? NULL : newSV(0);
742 	if (SvMAGICAL(hv)) {
743 	    /* At this point the old hv_fetch code would call to hv_store,
744 	       which in turn might do some tied magic. So we need to make that
745 	       magic check happen.  */
746 	    /* gonna assign to this, so it better be there */
747 	    /* If a fetch-as-store fails on the fetch, then the action is to
748 	       recurse once into "hv_store". If we didn't do this, then that
749 	       recursive call would call the key conversion routine again.
750 	       However, as we replace the original key with the converted
751 	       key, this would result in a double conversion, which would show
752 	       up as a bug if the conversion routine is not idempotent.  */
753 	    return hv_common(hv, keysv, key, klen, flags,
754 			     HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
755 			     val, hash);
756 	    /* XXX Surely that could leak if the fetch-was-store fails?
757 	       Just like the hv_fetch.  */
758 	}
759     }
760 
761     /* Welcome to hv_store...  */
762 
763     if (!HvARRAY(hv)) {
764 	/* Not sure if we can get here.  I think the only case of oentry being
765 	   NULL is for %ENV with dynamic env fetch.  But that should disappear
766 	   with magic in the previous code.  */
767 	char *array;
768 	Newxz(array,
769 	     PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
770 	     char);
771 	HvARRAY(hv) = (HE**)array;
772     }
773 
774     oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
775 
776     entry = new_HE();
777     /* share_hek_flags will do the free for us.  This might be considered
778        bad API design.  */
779     if (HvSHAREKEYS(hv))
780 	HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
781     else if (hv == PL_strtab) {
782 	/* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
783 	   this test here is cheap  */
784 	if (flags & HVhek_FREEKEY)
785 	    Safefree(key);
786 	Perl_croak(aTHX_ S_strtab_error,
787 		   action & HV_FETCH_LVALUE ? "fetch" : "store");
788     }
789     else                                       /* gotta do the real thing */
790 	HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
791     HeVAL(entry) = val;
792 
793 #ifdef PERL_HASH_RANDOMIZE_KEYS
794     /* This logic semi-randomizes the insert order in a bucket.
795      * Either we insert into the top, or the slot below the top,
796      * making it harder to see if there is a collision. We also
797      * reset the iterator randomizer if there is one.
798      */
799     if ( *oentry && PL_HASH_RAND_BITS_ENABLED) {
800         PL_hash_rand_bits++;
801         PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
802         if ( PL_hash_rand_bits & 1 ) {
803             HeNEXT(entry) = HeNEXT(*oentry);
804             HeNEXT(*oentry) = entry;
805         } else {
806             HeNEXT(entry) = *oentry;
807             *oentry = entry;
808         }
809     } else
810 #endif
811     {
812         HeNEXT(entry) = *oentry;
813         *oentry = entry;
814     }
815 #ifdef PERL_HASH_RANDOMIZE_KEYS
816     if (SvOOK(hv)) {
817         /* Currently this makes various tests warn in annoying ways.
818          * So Silenced for now. - Yves | bogus end of comment =>* /
819         if (HvAUX(hv)->xhv_riter != -1) {
820             Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
821                              "[TESTING] Inserting into a hash during each() traversal results in undefined behavior"
822                              pTHX__FORMAT
823                              pTHX__VALUE);
824         }
825         */
826         if (PL_HASH_RAND_BITS_ENABLED) {
827             if (PL_HASH_RAND_BITS_ENABLED == 1)
828                 PL_hash_rand_bits += (PTRV)entry + 1;  /* we don't bother to use ptr_hash here */
829             PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
830         }
831         HvAUX(hv)->xhv_rand= (U32)PL_hash_rand_bits;
832     }
833 #endif
834 
835     if (val == &PL_sv_placeholder)
836 	HvPLACEHOLDERS(hv)++;
837     if (masked_flags & HVhek_ENABLEHVKFLAGS)
838 	HvHASKFLAGS_on(hv);
839 
840     xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
841     if ( DO_HSPLIT(xhv) ) {
842         const STRLEN oldsize = xhv->xhv_max + 1;
843         const U32 items = (U32)HvPLACEHOLDERS_get(hv);
844 
845         if (items /* hash has placeholders  */
846             && !SvREADONLY(hv) /* but is not a restricted hash */) {
847             /* If this hash previously was a "restricted hash" and had
848                placeholders, but the "restricted" flag has been turned off,
849                then the placeholders no longer serve any useful purpose.
850                However, they have the downsides of taking up RAM, and adding
851                extra steps when finding used values. It's safe to clear them
852                at this point, even though Storable rebuilds restricted hashes by
853                putting in all the placeholders (first) before turning on the
854                readonly flag, because Storable always pre-splits the hash.
855                If we're lucky, then we may clear sufficient placeholders to
856                avoid needing to split the hash at all.  */
857             clear_placeholders(hv, items);
858             if (DO_HSPLIT(xhv))
859                 hsplit(hv, oldsize, oldsize * 2);
860         } else
861             hsplit(hv, oldsize, oldsize * 2);
862     }
863 
864     if (return_svp) {
865 	return entry ? (void *) &HeVAL(entry) : NULL;
866     }
867     return (void *) entry;
868 }
869 
870 STATIC void
871 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
872 {
873     const MAGIC *mg = SvMAGIC(hv);
874 
875     PERL_ARGS_ASSERT_HV_MAGIC_CHECK;
876 
877     *needs_copy = FALSE;
878     *needs_store = TRUE;
879     while (mg) {
880 	if (isUPPER(mg->mg_type)) {
881 	    *needs_copy = TRUE;
882 	    if (mg->mg_type == PERL_MAGIC_tied) {
883 		*needs_store = FALSE;
884 		return; /* We've set all there is to set. */
885 	    }
886 	}
887 	mg = mg->mg_moremagic;
888     }
889 }
890 
891 /*
892 =for apidoc hv_scalar
893 
894 Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
895 
896 =cut
897 */
898 
899 SV *
900 Perl_hv_scalar(pTHX_ HV *hv)
901 {
902     SV *sv;
903 
904     PERL_ARGS_ASSERT_HV_SCALAR;
905 
906     if (SvRMAGICAL(hv)) {
907 	MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_tied);
908 	if (mg)
909 	    return magic_scalarpack(hv, mg);
910     }
911 
912     sv = sv_newmortal();
913     if (HvTOTALKEYS((const HV *)hv))
914         Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
915                 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
916     else
917         sv_setiv(sv, 0);
918 
919     return sv;
920 }
921 
922 /*
923 =for apidoc hv_delete
924 
925 Deletes a key/value pair in the hash.  The value's SV is removed from
926 the hash, made mortal, and returned to the caller.  The absolute
927 value of C<klen> is the length of the key.  If C<klen> is negative the
928 key is assumed to be in UTF-8-encoded Unicode.  The C<flags> value
929 will normally be zero; if set to G_DISCARD then NULL will be returned.
930 NULL will also be returned if the key is not found.
931 
932 =for apidoc hv_delete_ent
933 
934 Deletes a key/value pair in the hash.  The value SV is removed from the hash,
935 made mortal, and returned to the caller.  The C<flags> value will normally be
936 zero; if set to G_DISCARD then NULL will be returned.  NULL will also be
937 returned if the key is not found.  C<hash> can be a valid precomputed hash
938 value, or 0 to ask for it to be computed.
939 
940 =cut
941 */
942 
943 STATIC SV *
944 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
945 		   int k_flags, I32 d_flags, U32 hash)
946 {
947     dVAR;
948     XPVHV* xhv;
949     HE *entry;
950     HE **oentry;
951     bool is_utf8 = (k_flags & HVhek_UTF8) ? TRUE : FALSE;
952     int masked_flags;
953 
954     if (SvRMAGICAL(hv)) {
955 	bool needs_copy;
956 	bool needs_store;
957 	hv_magic_check (hv, &needs_copy, &needs_store);
958 
959 	if (needs_copy) {
960 	    SV *sv;
961 	    entry = (HE *) hv_common(hv, keysv, key, klen,
962 				     k_flags & ~HVhek_FREEKEY,
963 				     HV_FETCH_LVALUE|HV_DISABLE_UVAR_XKEY,
964 				     NULL, hash);
965 	    sv = entry ? HeVAL(entry) : NULL;
966 	    if (sv) {
967 		if (SvMAGICAL(sv)) {
968 		    mg_clear(sv);
969 		}
970 		if (!needs_store) {
971 		    if (mg_find(sv, PERL_MAGIC_tiedelem)) {
972 			/* No longer an element */
973 			sv_unmagic(sv, PERL_MAGIC_tiedelem);
974 			return sv;
975 		    }
976 		    return NULL;		/* element cannot be deleted */
977 		}
978 #ifdef ENV_IS_CASELESS
979 		else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
980 		    /* XXX This code isn't UTF8 clean.  */
981 		    keysv = newSVpvn_flags(key, klen, SVs_TEMP);
982 		    if (k_flags & HVhek_FREEKEY) {
983 			Safefree(key);
984 		    }
985 		    key = strupr(SvPVX(keysv));
986 		    is_utf8 = 0;
987 		    k_flags = 0;
988 		    hash = 0;
989 		}
990 #endif
991 	    }
992 	}
993     }
994     xhv = (XPVHV*)SvANY(hv);
995     if (!HvARRAY(hv))
996 	return NULL;
997 
998     if (is_utf8 && !(k_flags & HVhek_KEYCANONICAL)) {
999 	const char * const keysave = key;
1000 	key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
1001 
1002         if (is_utf8)
1003             k_flags |= HVhek_UTF8;
1004 	else
1005             k_flags &= ~HVhek_UTF8;
1006         if (key != keysave) {
1007 	    if (k_flags & HVhek_FREEKEY) {
1008 		/* This shouldn't happen if our caller does what we expect,
1009 		   but strictly the API allows it.  */
1010 		Safefree(keysave);
1011 	    }
1012 	    k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
1013 	}
1014         HvHASKFLAGS_on(MUTABLE_SV(hv));
1015     }
1016 
1017     if (!hash) {
1018         if (keysv && (SvIsCOW_shared_hash(keysv)))
1019             hash = SvSHARED_HASH(keysv);
1020         else
1021             PERL_HASH(hash, key, klen);
1022     }
1023 
1024     masked_flags = (k_flags & HVhek_MASK);
1025 
1026     oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
1027     entry = *oentry;
1028     for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1029 	SV *sv;
1030 	U8 mro_changes = 0; /* 1 = isa; 2 = package moved */
1031 	GV *gv = NULL;
1032 	HV *stash = NULL;
1033 
1034 	if (HeHASH(entry) != hash)		/* strings can't be equal */
1035 	    continue;
1036 	if (HeKLEN(entry) != (I32)klen)
1037 	    continue;
1038 	if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen))	/* is this it? */
1039 	    continue;
1040 	if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
1041 	    continue;
1042 
1043 	if (hv == PL_strtab) {
1044 	    if (k_flags & HVhek_FREEKEY)
1045 		Safefree(key);
1046 	    Perl_croak(aTHX_ S_strtab_error, "delete");
1047 	}
1048 
1049 	/* if placeholder is here, it's already been deleted.... */
1050 	if (HeVAL(entry) == &PL_sv_placeholder) {
1051 	    if (k_flags & HVhek_FREEKEY)
1052 		Safefree(key);
1053 	    return NULL;
1054 	}
1055 	if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))
1056 	 && !SvIsCOW(HeVAL(entry))) {
1057 	    hv_notallowed(k_flags, key, klen,
1058 			    "Attempt to delete readonly key '%"SVf"' from"
1059 			    " a restricted hash");
1060 	}
1061         if (k_flags & HVhek_FREEKEY)
1062             Safefree(key);
1063 
1064 	/* If this is a stash and the key ends with ::, then someone is
1065 	 * deleting a package.
1066 	 */
1067 	if (HeVAL(entry) && HvENAME_get(hv)) {
1068 		gv = (GV *)HeVAL(entry);
1069 		if (keysv) key = SvPV(keysv, klen);
1070 		if ((
1071 		     (klen > 1 && key[klen-2] == ':' && key[klen-1] == ':')
1072 		      ||
1073 		     (klen == 1 && key[0] == ':')
1074 		    )
1075 		 && (klen != 6 || hv!=PL_defstash || memNE(key,"main::",6))
1076 		 && SvTYPE(gv) == SVt_PVGV && (stash = GvHV((GV *)gv))
1077 		 && HvENAME_get(stash)) {
1078 			/* A previous version of this code checked that the
1079 			 * GV was still in the symbol table by fetching the
1080 			 * GV with its name. That is not necessary (and
1081 			 * sometimes incorrect), as HvENAME cannot be set
1082 			 * on hv if it is not in the symtab. */
1083 			mro_changes = 2;
1084 			/* Hang on to it for a bit. */
1085 			SvREFCNT_inc_simple_void_NN(
1086 			 sv_2mortal((SV *)gv)
1087 			);
1088 		}
1089 		else if (klen == 3 && strnEQ(key, "ISA", 3))
1090 		    mro_changes = 1;
1091 	}
1092 
1093 	sv = d_flags & G_DISCARD ? HeVAL(entry) : sv_2mortal(HeVAL(entry));
1094 	HeVAL(entry) = &PL_sv_placeholder;
1095 	if (sv) {
1096 	    /* deletion of method from stash */
1097 	    if (isGV(sv) && isGV_with_GP(sv) && GvCVu(sv)
1098 	     && HvENAME_get(hv))
1099 		mro_method_changed_in(hv);
1100 	}
1101 
1102 	/*
1103 	 * If a restricted hash, rather than really deleting the entry, put
1104 	 * a placeholder there. This marks the key as being "approved", so
1105 	 * we can still access via not-really-existing key without raising
1106 	 * an error.
1107 	 */
1108 	if (SvREADONLY(hv))
1109 	    /* We'll be saving this slot, so the number of allocated keys
1110 	     * doesn't go down, but the number placeholders goes up */
1111 	    HvPLACEHOLDERS(hv)++;
1112 	else {
1113 	    *oentry = HeNEXT(entry);
1114 	    if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */)
1115 		HvLAZYDEL_on(hv);
1116 	    else {
1117 		if (SvOOK(hv) && HvLAZYDEL(hv) &&
1118 		    entry == HeNEXT(HvAUX(hv)->xhv_eiter))
1119 		    HeNEXT(HvAUX(hv)->xhv_eiter) = HeNEXT(entry);
1120 		hv_free_ent(hv, entry);
1121 	    }
1122 	    xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1123 	    if (xhv->xhv_keys == 0)
1124 	        HvHASKFLAGS_off(hv);
1125 	}
1126 
1127 	if (d_flags & G_DISCARD) {
1128 	    SvREFCNT_dec(sv);
1129 	    sv = NULL;
1130 	}
1131 
1132 	if (mro_changes == 1) mro_isa_changed_in(hv);
1133 	else if (mro_changes == 2)
1134 	    mro_package_moved(NULL, stash, gv, 1);
1135 
1136 	return sv;
1137     }
1138     if (SvREADONLY(hv)) {
1139 	hv_notallowed(k_flags, key, klen,
1140 			"Attempt to delete disallowed key '%"SVf"' from"
1141 			" a restricted hash");
1142     }
1143 
1144     if (k_flags & HVhek_FREEKEY)
1145 	Safefree(key);
1146     return NULL;
1147 }
1148 
1149 STATIC void
1150 S_hsplit(pTHX_ HV *hv, STRLEN const oldsize, STRLEN newsize)
1151 {
1152     dVAR;
1153     STRLEN i = 0;
1154     char *a = (char*) HvARRAY(hv);
1155     HE **aep;
1156 
1157     PERL_ARGS_ASSERT_HSPLIT;
1158 
1159     /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1160       (void*)hv, (int) oldsize);*/
1161 
1162     PL_nomemok = TRUE;
1163     Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1164 	  + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1165     if (!a) {
1166       PL_nomemok = FALSE;
1167       return;
1168     }
1169 #ifdef PERL_HASH_RANDOMIZE_KEYS
1170     /* the idea of this is that we create a "random" value by hashing the address of
1171      * the array, we then use the low bit to decide if we insert at the top, or insert
1172      * second from top. After each such insert we rotate the hashed value. So we can
1173      * use the same hashed value over and over, and in normal build environments use
1174      * very few ops to do so. ROTL32() should produce a single machine operation. */
1175     if (PL_HASH_RAND_BITS_ENABLED) {
1176         if (PL_HASH_RAND_BITS_ENABLED == 1)
1177             PL_hash_rand_bits += ptr_hash((PTRV)a);
1178         PL_hash_rand_bits = ROTL_UV(PL_hash_rand_bits,1);
1179     }
1180 #endif
1181 
1182     if (SvOOK(hv)) {
1183         struct xpvhv_aux *const dest
1184             = (struct xpvhv_aux*) &a[newsize * sizeof(HE*)];
1185         Move(&a[oldsize * sizeof(HE*)], dest, 1, struct xpvhv_aux);
1186         /* we reset the iterator's xhv_rand as well, so they get a totally new ordering */
1187 #ifdef PERL_HASH_RANDOMIZE_KEYS
1188         dest->xhv_rand = (U32)PL_hash_rand_bits;
1189 #endif
1190     }
1191 
1192     PL_nomemok = FALSE;
1193     Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char);	/* zero 2nd half*/
1194     HvMAX(hv) = --newsize;
1195     HvARRAY(hv) = (HE**) a;
1196 
1197     if (!HvTOTALKEYS(hv))       /* skip rest if no entries */
1198         return;
1199 
1200     aep = (HE**)a;
1201     do {
1202 	HE **oentry = aep + i;
1203 	HE *entry = aep[i];
1204 
1205 	if (!entry)				/* non-existent */
1206 	    continue;
1207 	do {
1208             U32 j = (HeHASH(entry) & newsize);
1209 	    if (j != (U32)i) {
1210 		*oentry = HeNEXT(entry);
1211 #ifdef PERL_HASH_RANDOMIZE_KEYS
1212                 /* if the target cell is empty or PL_HASH_RAND_BITS_ENABLED is false
1213                  * insert to top, otherwise rotate the bucket rand 1 bit,
1214                  * and use the new low bit to decide if we insert at top,
1215                  * or next from top. IOW, we only rotate on a collision.*/
1216                 if (aep[j] && PL_HASH_RAND_BITS_ENABLED) {
1217                     PL_hash_rand_bits+= ROTL_UV(HeHASH(entry), 17);
1218                     PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
1219                     if (PL_hash_rand_bits & 1) {
1220                         HeNEXT(entry)= HeNEXT(aep[j]);
1221                         HeNEXT(aep[j])= entry;
1222                     } else {
1223                         /* Note, this is structured in such a way as the optimizer
1224                         * should eliminate the duplicated code here and below without
1225                         * us needing to explicitly use a goto. */
1226                         HeNEXT(entry) = aep[j];
1227                         aep[j] = entry;
1228                     }
1229                 } else
1230 #endif
1231                 {
1232                     /* see comment above about duplicated code */
1233                     HeNEXT(entry) = aep[j];
1234                     aep[j] = entry;
1235                 }
1236 	    }
1237 	    else {
1238 		oentry = &HeNEXT(entry);
1239 	    }
1240 	    entry = *oentry;
1241 	} while (entry);
1242     } while (i++ < oldsize);
1243 }
1244 
1245 void
1246 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1247 {
1248     dVAR;
1249     XPVHV* xhv = (XPVHV*)SvANY(hv);
1250     const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1251     I32 newsize;
1252     char *a;
1253 
1254     PERL_ARGS_ASSERT_HV_KSPLIT;
1255 
1256     newsize = (I32) newmax;			/* possible truncation here */
1257     if (newsize != newmax || newmax <= oldsize)
1258 	return;
1259     while ((newsize & (1 + ~newsize)) != newsize) {
1260 	newsize &= ~(newsize & (1 + ~newsize));	/* get proper power of 2 */
1261     }
1262     if (newsize < newmax)
1263 	newsize *= 2;
1264     if (newsize < newmax)
1265 	return;					/* overflow detection */
1266 
1267     a = (char *) HvARRAY(hv);
1268     if (a) {
1269         hsplit(hv, oldsize, newsize);
1270     } else {
1271         Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1272         xhv->xhv_max = --newsize;
1273         HvARRAY(hv) = (HE **) a;
1274     }
1275 }
1276 
1277 /* IMO this should also handle cases where hv_max is smaller than hv_keys
1278  * as tied hashes could play silly buggers and mess us around. We will
1279  * do the right thing during hv_store() afterwards, but still - Yves */
1280 #define HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys) STMT_START {\
1281     /* Can we use fewer buckets? (hv_max is always 2^n-1) */        \
1282     if (hv_max < PERL_HASH_DEFAULT_HvMAX) {                         \
1283         hv_max = PERL_HASH_DEFAULT_HvMAX;                           \
1284     } else {                                                        \
1285         while (hv_max > PERL_HASH_DEFAULT_HvMAX && hv_max + 1 >= hv_keys * 2) \
1286             hv_max = hv_max / 2;                                    \
1287     }                                                               \
1288     HvMAX(hv) = hv_max;                                             \
1289 } STMT_END
1290 
1291 
1292 HV *
1293 Perl_newHVhv(pTHX_ HV *ohv)
1294 {
1295     dVAR;
1296     HV * const hv = newHV();
1297     STRLEN hv_max;
1298 
1299     if (!ohv || (!HvTOTALKEYS(ohv) && !SvMAGICAL((const SV *)ohv)))
1300 	return hv;
1301     hv_max = HvMAX(ohv);
1302 
1303     if (!SvMAGICAL((const SV *)ohv)) {
1304 	/* It's an ordinary hash, so copy it fast. AMS 20010804 */
1305 	STRLEN i;
1306 	const bool shared = !!HvSHAREKEYS(ohv);
1307 	HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1308 	char *a;
1309 	Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1310 	ents = (HE**)a;
1311 
1312 	/* In each bucket... */
1313 	for (i = 0; i <= hv_max; i++) {
1314 	    HE *prev = NULL;
1315 	    HE *oent = oents[i];
1316 
1317 	    if (!oent) {
1318 		ents[i] = NULL;
1319 		continue;
1320 	    }
1321 
1322 	    /* Copy the linked list of entries. */
1323 	    for (; oent; oent = HeNEXT(oent)) {
1324 		const U32 hash   = HeHASH(oent);
1325 		const char * const key = HeKEY(oent);
1326 		const STRLEN len = HeKLEN(oent);
1327 		const int flags  = HeKFLAGS(oent);
1328 		HE * const ent   = new_HE();
1329 		SV *const val    = HeVAL(oent);
1330 
1331 		HeVAL(ent) = SvIMMORTAL(val) ? val : newSVsv(val);
1332 		HeKEY_hek(ent)
1333                     = shared ? share_hek_flags(key, len, hash, flags)
1334                              :  save_hek_flags(key, len, hash, flags);
1335 		if (prev)
1336 		    HeNEXT(prev) = ent;
1337 		else
1338 		    ents[i] = ent;
1339 		prev = ent;
1340 		HeNEXT(ent) = NULL;
1341 	    }
1342 	}
1343 
1344 	HvMAX(hv)   = hv_max;
1345 	HvTOTALKEYS(hv)  = HvTOTALKEYS(ohv);
1346 	HvARRAY(hv) = ents;
1347     } /* not magical */
1348     else {
1349 	/* Iterate over ohv, copying keys and values one at a time. */
1350 	HE *entry;
1351 	const I32 riter = HvRITER_get(ohv);
1352 	HE * const eiter = HvEITER_get(ohv);
1353         STRLEN hv_keys = HvTOTALKEYS(ohv);
1354 
1355         HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys);
1356 
1357 	hv_iterinit(ohv);
1358 	while ((entry = hv_iternext_flags(ohv, 0))) {
1359 	    SV *val = hv_iterval(ohv,entry);
1360 	    SV * const keysv = HeSVKEY(entry);
1361 	    val = SvIMMORTAL(val) ? val : newSVsv(val);
1362 	    if (keysv)
1363 		(void)hv_store_ent(hv, keysv, val, 0);
1364 	    else
1365 	        (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry), val,
1366 				 HeHASH(entry), HeKFLAGS(entry));
1367 	}
1368 	HvRITER_set(ohv, riter);
1369 	HvEITER_set(ohv, eiter);
1370     }
1371 
1372     return hv;
1373 }
1374 
1375 /*
1376 =for apidoc Am|HV *|hv_copy_hints_hv|HV *ohv
1377 
1378 A specialised version of L</newHVhv> for copying C<%^H>.  I<ohv> must be
1379 a pointer to a hash (which may have C<%^H> magic, but should be generally
1380 non-magical), or C<NULL> (interpreted as an empty hash).  The content
1381 of I<ohv> is copied to a new hash, which has the C<%^H>-specific magic
1382 added to it.  A pointer to the new hash is returned.
1383 
1384 =cut
1385 */
1386 
1387 HV *
1388 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1389 {
1390     HV * const hv = newHV();
1391 
1392     if (ohv) {
1393 	STRLEN hv_max = HvMAX(ohv);
1394         STRLEN hv_keys = HvTOTALKEYS(ohv);
1395 	HE *entry;
1396 	const I32 riter = HvRITER_get(ohv);
1397 	HE * const eiter = HvEITER_get(ohv);
1398 
1399 	ENTER;
1400 	SAVEFREESV(hv);
1401 
1402         HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys);
1403 
1404 	hv_iterinit(ohv);
1405 	while ((entry = hv_iternext_flags(ohv, 0))) {
1406 	    SV *const sv = newSVsv(hv_iterval(ohv,entry));
1407 	    SV *heksv = HeSVKEY(entry);
1408 	    if (!heksv && sv) heksv = newSVhek(HeKEY_hek(entry));
1409 	    if (sv) sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1410 		     (char *)heksv, HEf_SVKEY);
1411 	    if (heksv == HeSVKEY(entry))
1412 		(void)hv_store_ent(hv, heksv, sv, 0);
1413 	    else {
1414 		(void)hv_common(hv, heksv, HeKEY(entry), HeKLEN(entry),
1415 				 HeKFLAGS(entry), HV_FETCH_ISSTORE|HV_FETCH_JUST_SV, sv, HeHASH(entry));
1416 		SvREFCNT_dec_NN(heksv);
1417 	    }
1418 	}
1419 	HvRITER_set(ohv, riter);
1420 	HvEITER_set(ohv, eiter);
1421 
1422 	SvREFCNT_inc_simple_void_NN(hv);
1423 	LEAVE;
1424     }
1425     hv_magic(hv, NULL, PERL_MAGIC_hints);
1426     return hv;
1427 }
1428 #undef HV_SET_MAX_ADJUSTED_FOR_KEYS
1429 
1430 /* like hv_free_ent, but returns the SV rather than freeing it */
1431 STATIC SV*
1432 S_hv_free_ent_ret(pTHX_ HV *hv, HE *entry)
1433 {
1434     dVAR;
1435     SV *val;
1436 
1437     PERL_ARGS_ASSERT_HV_FREE_ENT_RET;
1438 
1439     val = HeVAL(entry);
1440     if (HeKLEN(entry) == HEf_SVKEY) {
1441 	SvREFCNT_dec(HeKEY_sv(entry));
1442 	Safefree(HeKEY_hek(entry));
1443     }
1444     else if (HvSHAREKEYS(hv))
1445 	unshare_hek(HeKEY_hek(entry));
1446     else
1447 	Safefree(HeKEY_hek(entry));
1448     del_HE(entry);
1449     return val;
1450 }
1451 
1452 
1453 void
1454 Perl_hv_free_ent(pTHX_ HV *hv, HE *entry)
1455 {
1456     dVAR;
1457     SV *val;
1458 
1459     PERL_ARGS_ASSERT_HV_FREE_ENT;
1460 
1461     if (!entry)
1462 	return;
1463     val = hv_free_ent_ret(hv, entry);
1464     SvREFCNT_dec(val);
1465 }
1466 
1467 
1468 void
1469 Perl_hv_delayfree_ent(pTHX_ HV *hv, HE *entry)
1470 {
1471     dVAR;
1472 
1473     PERL_ARGS_ASSERT_HV_DELAYFREE_ENT;
1474 
1475     if (!entry)
1476 	return;
1477     /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent  */
1478     sv_2mortal(SvREFCNT_inc(HeVAL(entry)));	/* free between statements */
1479     if (HeKLEN(entry) == HEf_SVKEY) {
1480 	sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1481     }
1482     hv_free_ent(hv, entry);
1483 }
1484 
1485 /*
1486 =for apidoc hv_clear
1487 
1488 Frees the all the elements of a hash, leaving it empty.
1489 The XS equivalent of C<%hash = ()>.  See also L</hv_undef>.
1490 
1491 If any destructors are triggered as a result, the hv itself may
1492 be freed.
1493 
1494 =cut
1495 */
1496 
1497 void
1498 Perl_hv_clear(pTHX_ HV *hv)
1499 {
1500     dVAR;
1501     XPVHV* xhv;
1502     if (!hv)
1503 	return;
1504 
1505     DEBUG_A(Perl_hv_assert(aTHX_ hv));
1506 
1507     xhv = (XPVHV*)SvANY(hv);
1508 
1509     ENTER;
1510     SAVEFREESV(SvREFCNT_inc_simple_NN(hv));
1511     if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1512 	/* restricted hash: convert all keys to placeholders */
1513 	STRLEN i;
1514 	for (i = 0; i <= xhv->xhv_max; i++) {
1515 	    HE *entry = (HvARRAY(hv))[i];
1516 	    for (; entry; entry = HeNEXT(entry)) {
1517 		/* not already placeholder */
1518 		if (HeVAL(entry) != &PL_sv_placeholder) {
1519 		    if (HeVAL(entry)) {
1520 			if (SvREADONLY(HeVAL(entry)) && !SvIsCOW(HeVAL(entry))) {
1521 			    SV* const keysv = hv_iterkeysv(entry);
1522 			    Perl_croak_nocontext(
1523 				"Attempt to delete readonly key '%"SVf"' from a restricted hash",
1524 				(void*)keysv);
1525 			}
1526 			SvREFCNT_dec_NN(HeVAL(entry));
1527 		    }
1528 		    HeVAL(entry) = &PL_sv_placeholder;
1529 		    HvPLACEHOLDERS(hv)++;
1530 		}
1531 	    }
1532 	}
1533     }
1534     else {
1535 	hfreeentries(hv);
1536 	HvPLACEHOLDERS_set(hv, 0);
1537 
1538 	if (SvRMAGICAL(hv))
1539 	    mg_clear(MUTABLE_SV(hv));
1540 
1541 	HvHASKFLAGS_off(hv);
1542     }
1543     if (SvOOK(hv)) {
1544         if(HvENAME_get(hv))
1545             mro_isa_changed_in(hv);
1546 	HvEITER_set(hv, NULL);
1547     }
1548     LEAVE;
1549 }
1550 
1551 /*
1552 =for apidoc hv_clear_placeholders
1553 
1554 Clears any placeholders from a hash.  If a restricted hash has any of its keys
1555 marked as readonly and the key is subsequently deleted, the key is not actually
1556 deleted but is marked by assigning it a value of &PL_sv_placeholder.  This tags
1557 it so it will be ignored by future operations such as iterating over the hash,
1558 but will still allow the hash to have a value reassigned to the key at some
1559 future point.  This function clears any such placeholder keys from the hash.
1560 See Hash::Util::lock_keys() for an example of its use.
1561 
1562 =cut
1563 */
1564 
1565 void
1566 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1567 {
1568     dVAR;
1569     const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1570 
1571     PERL_ARGS_ASSERT_HV_CLEAR_PLACEHOLDERS;
1572 
1573     if (items)
1574 	clear_placeholders(hv, items);
1575 }
1576 
1577 static void
1578 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1579 {
1580     dVAR;
1581     I32 i;
1582 
1583     PERL_ARGS_ASSERT_CLEAR_PLACEHOLDERS;
1584 
1585     if (items == 0)
1586 	return;
1587 
1588     i = HvMAX(hv);
1589     do {
1590 	/* Loop down the linked list heads  */
1591 	HE **oentry = &(HvARRAY(hv))[i];
1592 	HE *entry;
1593 
1594 	while ((entry = *oentry)) {
1595 	    if (HeVAL(entry) == &PL_sv_placeholder) {
1596 		*oentry = HeNEXT(entry);
1597 		if (entry == HvEITER_get(hv))
1598 		    HvLAZYDEL_on(hv);
1599 		else {
1600 		    if (SvOOK(hv) && HvLAZYDEL(hv) &&
1601 			entry == HeNEXT(HvAUX(hv)->xhv_eiter))
1602 			HeNEXT(HvAUX(hv)->xhv_eiter) = HeNEXT(entry);
1603 		    hv_free_ent(hv, entry);
1604 		}
1605 
1606 		if (--items == 0) {
1607 		    /* Finished.  */
1608 		    HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS_get(hv);
1609 		    if (HvUSEDKEYS(hv) == 0)
1610 			HvHASKFLAGS_off(hv);
1611 		    HvPLACEHOLDERS_set(hv, 0);
1612 		    return;
1613 		}
1614 	    } else {
1615 		oentry = &HeNEXT(entry);
1616 	    }
1617 	}
1618     } while (--i >= 0);
1619     /* You can't get here, hence assertion should always fail.  */
1620     assert (items == 0);
1621     assert (0);
1622 }
1623 
1624 STATIC void
1625 S_hfreeentries(pTHX_ HV *hv)
1626 {
1627     STRLEN index = 0;
1628     XPVHV * const xhv = (XPVHV*)SvANY(hv);
1629     SV *sv;
1630 
1631     PERL_ARGS_ASSERT_HFREEENTRIES;
1632 
1633     while ((sv = Perl_hfree_next_entry(aTHX_ hv, &index))||xhv->xhv_keys) {
1634 	SvREFCNT_dec(sv);
1635     }
1636 }
1637 
1638 
1639 /* hfree_next_entry()
1640  * For use only by S_hfreeentries() and sv_clear().
1641  * Delete the next available HE from hv and return the associated SV.
1642  * Returns null on empty hash. Nevertheless null is not a reliable
1643  * indicator that the hash is empty, as the deleted entry may have a
1644  * null value.
1645  * indexp is a pointer to the current index into HvARRAY. The index should
1646  * initially be set to 0. hfree_next_entry() may update it.  */
1647 
1648 SV*
1649 Perl_hfree_next_entry(pTHX_ HV *hv, STRLEN *indexp)
1650 {
1651     struct xpvhv_aux *iter;
1652     HE *entry;
1653     HE ** array;
1654 #ifdef DEBUGGING
1655     STRLEN orig_index = *indexp;
1656 #endif
1657 
1658     PERL_ARGS_ASSERT_HFREE_NEXT_ENTRY;
1659 
1660     if (SvOOK(hv) && ((iter = HvAUX(hv)))
1661 	&& ((entry = iter->xhv_eiter)) )
1662     {
1663 	/* the iterator may get resurrected after each
1664 	 * destructor call, so check each time */
1665 	if (entry && HvLAZYDEL(hv)) {	/* was deleted earlier? */
1666 	    HvLAZYDEL_off(hv);
1667 	    hv_free_ent(hv, entry);
1668 	    /* warning: at this point HvARRAY may have been
1669 	     * re-allocated, HvMAX changed etc */
1670 	}
1671 	iter->xhv_riter = -1; 	/* HvRITER(hv) = -1 */
1672 	iter->xhv_eiter = NULL;	/* HvEITER(hv) = NULL */
1673 #ifdef PERL_HASH_RANDOMIZE_KEYS
1674         iter->xhv_last_rand = iter->xhv_rand;
1675 #endif
1676     }
1677 
1678     if (!((XPVHV*)SvANY(hv))->xhv_keys)
1679 	return NULL;
1680 
1681     array = HvARRAY(hv);
1682     assert(array);
1683     while ( ! ((entry = array[*indexp])) ) {
1684 	if ((*indexp)++ >= HvMAX(hv))
1685 	    *indexp = 0;
1686 	assert(*indexp != orig_index);
1687     }
1688     array[*indexp] = HeNEXT(entry);
1689     ((XPVHV*) SvANY(hv))->xhv_keys--;
1690 
1691     if (   PL_phase != PERL_PHASE_DESTRUCT && HvENAME(hv)
1692 	&& HeVAL(entry) && isGV(HeVAL(entry))
1693 	&& GvHV(HeVAL(entry)) && HvENAME(GvHV(HeVAL(entry)))
1694     ) {
1695 	STRLEN klen;
1696 	const char * const key = HePV(entry,klen);
1697 	if ((klen > 1 && key[klen-1]==':' && key[klen-2]==':')
1698 	 || (klen == 1 && key[0] == ':')) {
1699 	    mro_package_moved(
1700 	     NULL, GvHV(HeVAL(entry)),
1701 	     (GV *)HeVAL(entry), 0
1702 	    );
1703 	}
1704     }
1705     return hv_free_ent_ret(hv, entry);
1706 }
1707 
1708 
1709 /*
1710 =for apidoc hv_undef
1711 
1712 Undefines the hash.  The XS equivalent of C<undef(%hash)>.
1713 
1714 As well as freeing all the elements of the hash (like hv_clear()), this
1715 also frees any auxiliary data and storage associated with the hash.
1716 
1717 If any destructors are triggered as a result, the hv itself may
1718 be freed.
1719 
1720 See also L</hv_clear>.
1721 
1722 =cut
1723 */
1724 
1725 void
1726 Perl_hv_undef_flags(pTHX_ HV *hv, U32 flags)
1727 {
1728     dVAR;
1729     XPVHV* xhv;
1730     const char *name;
1731     bool save;
1732 
1733     if (!hv)
1734 	return;
1735     DEBUG_A(Perl_hv_assert(aTHX_ hv));
1736     xhv = (XPVHV*)SvANY(hv);
1737     save = !!SvREFCNT(hv);
1738 
1739     /* The name must be deleted before the call to hfreeeeentries so that
1740        CVs are anonymised properly. But the effective name must be pre-
1741        served until after that call (and only deleted afterwards if the
1742        call originated from sv_clear). For stashes with one name that is
1743        both the canonical name and the effective name, hv_name_set has to
1744        allocate an array for storing the effective name. We can skip that
1745        during global destruction, as it does not matter where the CVs point
1746        if they will be freed anyway. */
1747     /* note that the code following prior to hfreeentries is duplicated
1748      * in sv_clear(), and changes here should be done there too */
1749     if (PL_phase != PERL_PHASE_DESTRUCT && (name = HvNAME(hv))) {
1750         if (PL_stashcache) {
1751             DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for '%"
1752                              HEKf"'\n", HvNAME_HEK(hv)));
1753 	    (void)hv_delete(PL_stashcache, name,
1754                             HEK_UTF8(HvNAME_HEK(hv)) ? -HvNAMELEN_get(hv) : HvNAMELEN_get(hv),
1755                             G_DISCARD
1756                            );
1757         }
1758 	hv_name_set(hv, NULL, 0, 0);
1759     }
1760     if (save) {
1761 	ENTER;
1762 	SAVEFREESV(SvREFCNT_inc_simple_NN(hv));
1763     }
1764     hfreeentries(hv);
1765     if (SvOOK(hv)) {
1766       struct xpvhv_aux * const aux = HvAUX(hv);
1767       struct mro_meta *meta;
1768 
1769       if ((name = HvENAME_get(hv))) {
1770 	if (PL_phase != PERL_PHASE_DESTRUCT)
1771 	    mro_isa_changed_in(hv);
1772         if (PL_stashcache) {
1773             DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for effective name '%"
1774                              HEKf"'\n", HvENAME_HEK(hv)));
1775 	    (void)hv_delete(
1776 	            PL_stashcache, name,
1777                     HEK_UTF8(HvENAME_HEK(hv)) ? -HvENAMELEN_get(hv) : HvENAMELEN_get(hv),
1778                     G_DISCARD
1779 	          );
1780         }
1781       }
1782 
1783       /* If this call originated from sv_clear, then we must check for
1784        * effective names that need freeing, as well as the usual name. */
1785       name = HvNAME(hv);
1786       if (flags & HV_NAME_SETALL ? !!aux->xhv_name_u.xhvnameu_name : !!name) {
1787         if (name && PL_stashcache) {
1788             DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for name '%"
1789                              HEKf"'\n", HvNAME_HEK(hv)));
1790 	    (void)hv_delete(PL_stashcache, name, (HEK_UTF8(HvNAME_HEK(hv)) ? -HvNAMELEN_get(hv) : HvNAMELEN_get(hv)), G_DISCARD);
1791         }
1792 	hv_name_set(hv, NULL, 0, flags);
1793       }
1794       if((meta = aux->xhv_mro_meta)) {
1795 	if (meta->mro_linear_all) {
1796 	    SvREFCNT_dec_NN(meta->mro_linear_all);
1797 	    /* mro_linear_current is just acting as a shortcut pointer,
1798 	       hence the else.  */
1799 	}
1800 	else
1801 	    /* Only the current MRO is stored, so this owns the data.
1802 	     */
1803 	    SvREFCNT_dec(meta->mro_linear_current);
1804 	SvREFCNT_dec(meta->mro_nextmethod);
1805 	SvREFCNT_dec(meta->isa);
1806 	Safefree(meta);
1807 	aux->xhv_mro_meta = NULL;
1808       }
1809       SvREFCNT_dec(aux->xhv_super);
1810       if (!aux->xhv_name_u.xhvnameu_name && ! aux->xhv_backreferences)
1811 	SvFLAGS(hv) &= ~SVf_OOK;
1812     }
1813     if (!SvOOK(hv)) {
1814 	Safefree(HvARRAY(hv));
1815         xhv->xhv_max = PERL_HASH_DEFAULT_HvMAX;        /* HvMAX(hv) = 7 (it's a normal hash) */
1816 	HvARRAY(hv) = 0;
1817     }
1818     /* if we're freeing the HV, the SvMAGIC field has been reused for
1819      * other purposes, and so there can't be any placeholder magic */
1820     if (SvREFCNT(hv))
1821 	HvPLACEHOLDERS_set(hv, 0);
1822 
1823     if (SvRMAGICAL(hv))
1824 	mg_clear(MUTABLE_SV(hv));
1825     if (save) LEAVE;
1826 }
1827 
1828 /*
1829 =for apidoc hv_fill
1830 
1831 Returns the number of hash buckets that happen to be in use. This function is
1832 wrapped by the macro C<HvFILL>.
1833 
1834 Previously this value was stored in the HV structure, rather than being
1835 calculated on demand.
1836 
1837 =cut
1838 */
1839 
1840 STRLEN
1841 Perl_hv_fill(pTHX_ HV const *const hv)
1842 {
1843     STRLEN count = 0;
1844     HE **ents = HvARRAY(hv);
1845 
1846     PERL_ARGS_ASSERT_HV_FILL;
1847 
1848     if (ents) {
1849 	HE *const *const last = ents + HvMAX(hv);
1850 	count = last + 1 - ents;
1851 
1852 	do {
1853 	    if (!*ents)
1854 		--count;
1855 	} while (++ents <= last);
1856     }
1857     return count;
1858 }
1859 
1860 /* hash a pointer to a U32 - Used in the hash traversal randomization
1861  * and bucket order randomization code
1862  *
1863  * this code was derived from Sereal, which was derived from autobox.
1864  */
1865 
1866 PERL_STATIC_INLINE U32 S_ptr_hash(PTRV u) {
1867 #if PTRSIZE == 8
1868     /*
1869      * This is one of Thomas Wang's hash functions for 64-bit integers from:
1870      * http://www.concentric.net/~Ttwang/tech/inthash.htm
1871      */
1872     u = (~u) + (u << 18);
1873     u = u ^ (u >> 31);
1874     u = u * 21;
1875     u = u ^ (u >> 11);
1876     u = u + (u << 6);
1877     u = u ^ (u >> 22);
1878 #else
1879     /*
1880      * This is one of Bob Jenkins' hash functions for 32-bit integers
1881      * from: http://burtleburtle.net/bob/hash/integer.html
1882      */
1883     u = (u + 0x7ed55d16) + (u << 12);
1884     u = (u ^ 0xc761c23c) ^ (u >> 19);
1885     u = (u + 0x165667b1) + (u << 5);
1886     u = (u + 0xd3a2646c) ^ (u << 9);
1887     u = (u + 0xfd7046c5) + (u << 3);
1888     u = (u ^ 0xb55a4f09) ^ (u >> 16);
1889 #endif
1890     return (U32)u;
1891 }
1892 
1893 
1894 static struct xpvhv_aux*
1895 S_hv_auxinit(pTHX_ HV *hv) {
1896     struct xpvhv_aux *iter;
1897     char *array;
1898 
1899     PERL_ARGS_ASSERT_HV_AUXINIT;
1900 
1901     if (!SvOOK(hv)) {
1902         if (!HvARRAY(hv)) {
1903             Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1904                 + sizeof(struct xpvhv_aux), char);
1905         } else {
1906             array = (char *) HvARRAY(hv);
1907             Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1908                   + sizeof(struct xpvhv_aux), char);
1909         }
1910         HvARRAY(hv) = (HE**)array;
1911         SvOOK_on(hv);
1912         iter = HvAUX(hv);
1913 #ifdef PERL_HASH_RANDOMIZE_KEYS
1914         if (PL_HASH_RAND_BITS_ENABLED) {
1915             /* mix in some new state to PL_hash_rand_bits to "randomize" the traversal order*/
1916             if (PL_HASH_RAND_BITS_ENABLED == 1)
1917                 PL_hash_rand_bits += ptr_hash((PTRV)array);
1918             PL_hash_rand_bits = ROTL_UV(PL_hash_rand_bits,1);
1919         }
1920         iter->xhv_rand = (U32)PL_hash_rand_bits;
1921 #endif
1922     } else {
1923         iter = HvAUX(hv);
1924     }
1925 
1926     iter->xhv_riter = -1; 	/* HvRITER(hv) = -1 */
1927     iter->xhv_eiter = NULL;	/* HvEITER(hv) = NULL */
1928 #ifdef PERL_HASH_RANDOMIZE_KEYS
1929     iter->xhv_last_rand = iter->xhv_rand;
1930 #endif
1931     iter->xhv_name_u.xhvnameu_name = 0;
1932     iter->xhv_name_count = 0;
1933     iter->xhv_backreferences = 0;
1934     iter->xhv_mro_meta = NULL;
1935     iter->xhv_super = NULL;
1936     return iter;
1937 }
1938 
1939 /*
1940 =for apidoc hv_iterinit
1941 
1942 Prepares a starting point to traverse a hash table.  Returns the number of
1943 keys in the hash (i.e. the same as C<HvUSEDKEYS(hv)>).  The return value is
1944 currently only meaningful for hashes without tie magic.
1945 
1946 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1947 hash buckets that happen to be in use.  If you still need that esoteric
1948 value, you can get it through the macro C<HvFILL(hv)>.
1949 
1950 
1951 =cut
1952 */
1953 
1954 I32
1955 Perl_hv_iterinit(pTHX_ HV *hv)
1956 {
1957     PERL_ARGS_ASSERT_HV_ITERINIT;
1958 
1959     /* FIXME: Are we not NULL, or do we croak? Place bets now! */
1960 
1961     if (!hv)
1962 	Perl_croak(aTHX_ "Bad hash");
1963 
1964     if (SvOOK(hv)) {
1965 	struct xpvhv_aux * const iter = HvAUX(hv);
1966 	HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
1967 	if (entry && HvLAZYDEL(hv)) {	/* was deleted earlier? */
1968 	    HvLAZYDEL_off(hv);
1969 	    hv_free_ent(hv, entry);
1970 	}
1971 	iter->xhv_riter = -1; 	/* HvRITER(hv) = -1 */
1972 	iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1973 #ifdef PERL_HASH_RANDOMIZE_KEYS
1974         iter->xhv_last_rand = iter->xhv_rand;
1975 #endif
1976     } else {
1977 	hv_auxinit(hv);
1978     }
1979 
1980     /* used to be xhv->xhv_fill before 5.004_65 */
1981     return HvTOTALKEYS(hv);
1982 }
1983 
1984 I32 *
1985 Perl_hv_riter_p(pTHX_ HV *hv) {
1986     struct xpvhv_aux *iter;
1987 
1988     PERL_ARGS_ASSERT_HV_RITER_P;
1989 
1990     if (!hv)
1991 	Perl_croak(aTHX_ "Bad hash");
1992 
1993     iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1994     return &(iter->xhv_riter);
1995 }
1996 
1997 HE **
1998 Perl_hv_eiter_p(pTHX_ HV *hv) {
1999     struct xpvhv_aux *iter;
2000 
2001     PERL_ARGS_ASSERT_HV_EITER_P;
2002 
2003     if (!hv)
2004 	Perl_croak(aTHX_ "Bad hash");
2005 
2006     iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2007     return &(iter->xhv_eiter);
2008 }
2009 
2010 void
2011 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
2012     struct xpvhv_aux *iter;
2013 
2014     PERL_ARGS_ASSERT_HV_RITER_SET;
2015 
2016     if (!hv)
2017 	Perl_croak(aTHX_ "Bad hash");
2018 
2019     if (SvOOK(hv)) {
2020 	iter = HvAUX(hv);
2021     } else {
2022 	if (riter == -1)
2023 	    return;
2024 
2025 	iter = hv_auxinit(hv);
2026     }
2027     iter->xhv_riter = riter;
2028 }
2029 
2030 void
2031 Perl_hv_rand_set(pTHX_ HV *hv, U32 new_xhv_rand) {
2032     struct xpvhv_aux *iter;
2033 
2034     PERL_ARGS_ASSERT_HV_RAND_SET;
2035 
2036 #ifdef PERL_HASH_RANDOMIZE_KEYS
2037     if (!hv)
2038         Perl_croak(aTHX_ "Bad hash");
2039 
2040     if (SvOOK(hv)) {
2041         iter = HvAUX(hv);
2042     } else {
2043         iter = hv_auxinit(hv);
2044     }
2045     iter->xhv_rand = new_xhv_rand;
2046 #else
2047     Perl_croak(aTHX_ "This Perl has not been built with support for randomized hash key traversal but something called Perl_hv_rand_set().");
2048 #endif
2049 }
2050 
2051 void
2052 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
2053     struct xpvhv_aux *iter;
2054 
2055     PERL_ARGS_ASSERT_HV_EITER_SET;
2056 
2057     if (!hv)
2058 	Perl_croak(aTHX_ "Bad hash");
2059 
2060     if (SvOOK(hv)) {
2061 	iter = HvAUX(hv);
2062     } else {
2063 	/* 0 is the default so don't go malloc()ing a new structure just to
2064 	   hold 0.  */
2065 	if (!eiter)
2066 	    return;
2067 
2068 	iter = hv_auxinit(hv);
2069     }
2070     iter->xhv_eiter = eiter;
2071 }
2072 
2073 void
2074 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2075 {
2076     dVAR;
2077     struct xpvhv_aux *iter;
2078     U32 hash;
2079     HEK **spot;
2080 
2081     PERL_ARGS_ASSERT_HV_NAME_SET;
2082 
2083     if (len > I32_MAX)
2084 	Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2085 
2086     if (SvOOK(hv)) {
2087 	iter = HvAUX(hv);
2088 	if (iter->xhv_name_u.xhvnameu_name) {
2089 	    if(iter->xhv_name_count) {
2090 	      if(flags & HV_NAME_SETALL) {
2091 		HEK ** const name = HvAUX(hv)->xhv_name_u.xhvnameu_names;
2092 		HEK **hekp = name + (
2093 		    iter->xhv_name_count < 0
2094 		     ? -iter->xhv_name_count
2095 		     :  iter->xhv_name_count
2096 		   );
2097 		while(hekp-- > name+1)
2098 		    unshare_hek_or_pvn(*hekp, 0, 0, 0);
2099 		/* The first elem may be null. */
2100 		if(*name) unshare_hek_or_pvn(*name, 0, 0, 0);
2101 		Safefree(name);
2102 		spot = &iter->xhv_name_u.xhvnameu_name;
2103 		iter->xhv_name_count = 0;
2104 	      }
2105 	      else {
2106 		if(iter->xhv_name_count > 0) {
2107 		    /* shift some things over */
2108 		    Renew(
2109 		     iter->xhv_name_u.xhvnameu_names, iter->xhv_name_count + 1, HEK *
2110 		    );
2111 		    spot = iter->xhv_name_u.xhvnameu_names;
2112 		    spot[iter->xhv_name_count] = spot[1];
2113 		    spot[1] = spot[0];
2114 		    iter->xhv_name_count = -(iter->xhv_name_count + 1);
2115 		}
2116 		else if(*(spot = iter->xhv_name_u.xhvnameu_names)) {
2117 		    unshare_hek_or_pvn(*spot, 0, 0, 0);
2118 		}
2119 	      }
2120 	    }
2121 	    else if (flags & HV_NAME_SETALL) {
2122 		unshare_hek_or_pvn(iter->xhv_name_u.xhvnameu_name, 0, 0, 0);
2123 		spot = &iter->xhv_name_u.xhvnameu_name;
2124 	    }
2125 	    else {
2126 		HEK * const existing_name = iter->xhv_name_u.xhvnameu_name;
2127 		Newx(iter->xhv_name_u.xhvnameu_names, 2, HEK *);
2128 		iter->xhv_name_count = -2;
2129 		spot = iter->xhv_name_u.xhvnameu_names;
2130 		spot[1] = existing_name;
2131 	    }
2132 	}
2133 	else { spot = &iter->xhv_name_u.xhvnameu_name; iter->xhv_name_count = 0; }
2134     } else {
2135 	if (name == 0)
2136 	    return;
2137 
2138 	iter = hv_auxinit(hv);
2139 	spot = &iter->xhv_name_u.xhvnameu_name;
2140     }
2141     PERL_HASH(hash, name, len);
2142     *spot = name ? share_hek(name, flags & SVf_UTF8 ? -(I32)len : (I32)len, hash) : NULL;
2143 }
2144 
2145 /*
2146 This is basically sv_eq_flags() in sv.c, but we avoid the magic
2147 and bytes checking.
2148 */
2149 
2150 STATIC I32
2151 hek_eq_pvn_flags(pTHX_ const HEK *hek, const char* pv, const I32 pvlen, const U32 flags) {
2152     if ( (HEK_UTF8(hek) ? 1 : 0) != (flags & SVf_UTF8 ? 1 : 0) ) {
2153         if (flags & SVf_UTF8)
2154             return (bytes_cmp_utf8(
2155                         (const U8*)HEK_KEY(hek), HEK_LEN(hek),
2156 		        (const U8*)pv, pvlen) == 0);
2157         else
2158             return (bytes_cmp_utf8(
2159                         (const U8*)pv, pvlen,
2160 		        (const U8*)HEK_KEY(hek), HEK_LEN(hek)) == 0);
2161     }
2162     else
2163         return HEK_LEN(hek) == pvlen && ((HEK_KEY(hek) == pv)
2164                     || memEQ(HEK_KEY(hek), pv, pvlen));
2165 }
2166 
2167 /*
2168 =for apidoc hv_ename_add
2169 
2170 Adds a name to a stash's internal list of effective names.  See
2171 C<hv_ename_delete>.
2172 
2173 This is called when a stash is assigned to a new location in the symbol
2174 table.
2175 
2176 =cut
2177 */
2178 
2179 void
2180 Perl_hv_ename_add(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2181 {
2182     dVAR;
2183     struct xpvhv_aux *aux = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2184     U32 hash;
2185 
2186     PERL_ARGS_ASSERT_HV_ENAME_ADD;
2187 
2188     if (len > I32_MAX)
2189 	Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2190 
2191     PERL_HASH(hash, name, len);
2192 
2193     if (aux->xhv_name_count) {
2194 	HEK ** const xhv_name = aux->xhv_name_u.xhvnameu_names;
2195 	I32 count = aux->xhv_name_count;
2196 	HEK **hekp = xhv_name + (count < 0 ? -count : count);
2197 	while (hekp-- > xhv_name)
2198 	    if (
2199                  (HEK_UTF8(*hekp) || (flags & SVf_UTF8))
2200                     ? hek_eq_pvn_flags(aTHX_ *hekp, name, (I32)len, flags)
2201 	            : (HEK_LEN(*hekp) == (I32)len && memEQ(HEK_KEY(*hekp), name, len))
2202                ) {
2203 		if (hekp == xhv_name && count < 0)
2204 		    aux->xhv_name_count = -count;
2205 		return;
2206 	    }
2207 	if (count < 0) aux->xhv_name_count--, count = -count;
2208 	else aux->xhv_name_count++;
2209 	Renew(aux->xhv_name_u.xhvnameu_names, count + 1, HEK *);
2210 	(aux->xhv_name_u.xhvnameu_names)[count] = share_hek(name, (flags & SVf_UTF8 ? -(I32)len : (I32)len), hash);
2211     }
2212     else {
2213 	HEK *existing_name = aux->xhv_name_u.xhvnameu_name;
2214 	if (
2215 	    existing_name && (
2216              (HEK_UTF8(existing_name) || (flags & SVf_UTF8))
2217                 ? hek_eq_pvn_flags(aTHX_ existing_name, name, (I32)len, flags)
2218 	        : (HEK_LEN(existing_name) == (I32)len && memEQ(HEK_KEY(existing_name), name, len))
2219 	    )
2220 	) return;
2221 	Newx(aux->xhv_name_u.xhvnameu_names, 2, HEK *);
2222 	aux->xhv_name_count = existing_name ? 2 : -2;
2223 	*aux->xhv_name_u.xhvnameu_names = existing_name;
2224 	(aux->xhv_name_u.xhvnameu_names)[1] = share_hek(name, (flags & SVf_UTF8 ? -(I32)len : (I32)len), hash);
2225     }
2226 }
2227 
2228 /*
2229 =for apidoc hv_ename_delete
2230 
2231 Removes a name from a stash's internal list of effective names.  If this is
2232 the name returned by C<HvENAME>, then another name in the list will take
2233 its place (C<HvENAME> will use it).
2234 
2235 This is called when a stash is deleted from the symbol table.
2236 
2237 =cut
2238 */
2239 
2240 void
2241 Perl_hv_ename_delete(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2242 {
2243     dVAR;
2244     struct xpvhv_aux *aux;
2245 
2246     PERL_ARGS_ASSERT_HV_ENAME_DELETE;
2247 
2248     if (len > I32_MAX)
2249 	Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2250 
2251     if (!SvOOK(hv)) return;
2252 
2253     aux = HvAUX(hv);
2254     if (!aux->xhv_name_u.xhvnameu_name) return;
2255 
2256     if (aux->xhv_name_count) {
2257 	HEK ** const namep = aux->xhv_name_u.xhvnameu_names;
2258 	I32 const count = aux->xhv_name_count;
2259 	HEK **victim = namep + (count < 0 ? -count : count);
2260 	while (victim-- > namep + 1)
2261 	    if (
2262              (HEK_UTF8(*victim) || (flags & SVf_UTF8))
2263                 ? hek_eq_pvn_flags(aTHX_ *victim, name, (I32)len, flags)
2264 	        : (HEK_LEN(*victim) == (I32)len && memEQ(HEK_KEY(*victim), name, len))
2265 	    ) {
2266 		unshare_hek_or_pvn(*victim, 0, 0, 0);
2267 		if (count < 0) ++aux->xhv_name_count;
2268 		else --aux->xhv_name_count;
2269 		if (
2270 		    (aux->xhv_name_count == 1 || aux->xhv_name_count == -1)
2271 		 && !*namep
2272 		) {  /* if there are none left */
2273 		    Safefree(namep);
2274 		    aux->xhv_name_u.xhvnameu_names = NULL;
2275 		    aux->xhv_name_count = 0;
2276 		}
2277 		else {
2278 		    /* Move the last one back to fill the empty slot. It
2279 		       does not matter what order they are in. */
2280 		    *victim = *(namep + (count < 0 ? -count : count) - 1);
2281 		}
2282 		return;
2283 	    }
2284 	if (
2285 	    count > 0 && (HEK_UTF8(*namep) || (flags & SVf_UTF8))
2286                 ? hek_eq_pvn_flags(aTHX_ *namep, name, (I32)len, flags)
2287 	        : (HEK_LEN(*namep) == (I32)len && memEQ(HEK_KEY(*namep), name, len))
2288 	) {
2289 	    aux->xhv_name_count = -count;
2290 	}
2291     }
2292     else if(
2293         (HEK_UTF8(aux->xhv_name_u.xhvnameu_name) || (flags & SVf_UTF8))
2294                 ? hek_eq_pvn_flags(aTHX_ aux->xhv_name_u.xhvnameu_name, name, (I32)len, flags)
2295 	        : (HEK_LEN(aux->xhv_name_u.xhvnameu_name) == (I32)len &&
2296                             memEQ(HEK_KEY(aux->xhv_name_u.xhvnameu_name), name, len))
2297     ) {
2298 	HEK * const namehek = aux->xhv_name_u.xhvnameu_name;
2299 	Newx(aux->xhv_name_u.xhvnameu_names, 1, HEK *);
2300 	*aux->xhv_name_u.xhvnameu_names = namehek;
2301 	aux->xhv_name_count = -1;
2302     }
2303 }
2304 
2305 AV **
2306 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2307     struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2308 
2309     PERL_ARGS_ASSERT_HV_BACKREFERENCES_P;
2310     PERL_UNUSED_CONTEXT;
2311 
2312     return &(iter->xhv_backreferences);
2313 }
2314 
2315 void
2316 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2317     AV *av;
2318 
2319     PERL_ARGS_ASSERT_HV_KILL_BACKREFS;
2320 
2321     if (!SvOOK(hv))
2322 	return;
2323 
2324     av = HvAUX(hv)->xhv_backreferences;
2325 
2326     if (av) {
2327 	HvAUX(hv)->xhv_backreferences = 0;
2328 	Perl_sv_kill_backrefs(aTHX_ MUTABLE_SV(hv), av);
2329 	if (SvTYPE(av) == SVt_PVAV)
2330 	    SvREFCNT_dec_NN(av);
2331     }
2332 }
2333 
2334 /*
2335 hv_iternext is implemented as a macro in hv.h
2336 
2337 =for apidoc hv_iternext
2338 
2339 Returns entries from a hash iterator.  See C<hv_iterinit>.
2340 
2341 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2342 iterator currently points to, without losing your place or invalidating your
2343 iterator.  Note that in this case the current entry is deleted from the hash
2344 with your iterator holding the last reference to it.  Your iterator is flagged
2345 to free the entry on the next call to C<hv_iternext>, so you must not discard
2346 your iterator immediately else the entry will leak - call C<hv_iternext> to
2347 trigger the resource deallocation.
2348 
2349 =for apidoc hv_iternext_flags
2350 
2351 Returns entries from a hash iterator.  See C<hv_iterinit> and C<hv_iternext>.
2352 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2353 set the placeholders keys (for restricted hashes) will be returned in addition
2354 to normal keys. By default placeholders are automatically skipped over.
2355 Currently a placeholder is implemented with a value that is
2356 C<&PL_sv_placeholder>.  Note that the implementation of placeholders and
2357 restricted hashes may change, and the implementation currently is
2358 insufficiently abstracted for any change to be tidy.
2359 
2360 =cut
2361 */
2362 
2363 HE *
2364 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2365 {
2366     dVAR;
2367     XPVHV* xhv;
2368     HE *entry;
2369     HE *oldentry;
2370     MAGIC* mg;
2371     struct xpvhv_aux *iter;
2372 
2373     PERL_ARGS_ASSERT_HV_ITERNEXT_FLAGS;
2374 
2375     if (!hv)
2376 	Perl_croak(aTHX_ "Bad hash");
2377 
2378     xhv = (XPVHV*)SvANY(hv);
2379 
2380     if (!SvOOK(hv)) {
2381 	/* Too many things (well, pp_each at least) merrily assume that you can
2382 	   call hv_iternext without calling hv_iterinit, so we'll have to deal
2383 	   with it.  */
2384 	hv_iterinit(hv);
2385     }
2386     iter = HvAUX(hv);
2387 
2388     oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2389     if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2390 	if ( ( mg = mg_find((const SV *)hv, PERL_MAGIC_tied) ) ) {
2391             SV * const key = sv_newmortal();
2392             if (entry) {
2393                 sv_setsv(key, HeSVKEY_force(entry));
2394                 SvREFCNT_dec(HeSVKEY(entry));       /* get rid of previous key */
2395 		HeSVKEY_set(entry, NULL);
2396             }
2397             else {
2398                 char *k;
2399                 HEK *hek;
2400 
2401                 /* one HE per MAGICAL hash */
2402                 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2403 		HvLAZYDEL_on(hv); /* make sure entry gets freed */
2404                 Zero(entry, 1, HE);
2405                 Newxz(k, HEK_BASESIZE + sizeof(const SV *), char);
2406                 hek = (HEK*)k;
2407                 HeKEY_hek(entry) = hek;
2408                 HeKLEN(entry) = HEf_SVKEY;
2409             }
2410             magic_nextpack(MUTABLE_SV(hv),mg,key);
2411             if (SvOK(key)) {
2412                 /* force key to stay around until next time */
2413                 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2414                 return entry;               /* beware, hent_val is not set */
2415             }
2416             SvREFCNT_dec(HeVAL(entry));
2417             Safefree(HeKEY_hek(entry));
2418             del_HE(entry);
2419             iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2420 	    HvLAZYDEL_off(hv);
2421             return NULL;
2422         }
2423     }
2424 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__)  /* set up %ENV for iteration */
2425     if (!entry && SvRMAGICAL((const SV *)hv)
2426 	&& mg_find((const SV *)hv, PERL_MAGIC_env)) {
2427 	prime_env_iter();
2428 #ifdef VMS
2429 	/* The prime_env_iter() on VMS just loaded up new hash values
2430 	 * so the iteration count needs to be reset back to the beginning
2431 	 */
2432 	hv_iterinit(hv);
2433 	iter = HvAUX(hv);
2434 	oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2435 #endif
2436     }
2437 #endif
2438 
2439     /* hv_iterinit now ensures this.  */
2440     assert (HvARRAY(hv));
2441 
2442     /* At start of hash, entry is NULL.  */
2443     if (entry)
2444     {
2445 	entry = HeNEXT(entry);
2446         if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2447             /*
2448              * Skip past any placeholders -- don't want to include them in
2449              * any iteration.
2450              */
2451             while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2452                 entry = HeNEXT(entry);
2453             }
2454 	}
2455     }
2456 
2457 #ifdef PERL_HASH_RANDOMIZE_KEYS
2458     if (iter->xhv_last_rand != iter->xhv_rand) {
2459         if (iter->xhv_riter != -1) {
2460             Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
2461                              "Use of each() on hash after insertion without resetting hash iterator results in undefined behavior"
2462                              pTHX__FORMAT
2463                              pTHX__VALUE);
2464         }
2465         iter->xhv_last_rand = iter->xhv_rand;
2466     }
2467 #endif
2468 
2469     /* Skip the entire loop if the hash is empty.   */
2470     if ((flags & HV_ITERNEXT_WANTPLACEHOLDERS)
2471 	? HvTOTALKEYS(hv) : HvUSEDKEYS(hv)) {
2472 	while (!entry) {
2473 	    /* OK. Come to the end of the current list.  Grab the next one.  */
2474 
2475 	    iter->xhv_riter++; /* HvRITER(hv)++ */
2476 	    if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2477 		/* There is no next one.  End of the hash.  */
2478 		iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2479 #ifdef PERL_HASH_RANDOMIZE_KEYS
2480                 iter->xhv_last_rand = iter->xhv_rand; /* reset xhv_last_rand so we can detect inserts during traversal */
2481 #endif
2482 		break;
2483 	    }
2484             entry = (HvARRAY(hv))[ PERL_HASH_ITER_BUCKET(iter) & xhv->xhv_max ];
2485 
2486 	    if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2487 		/* If we have an entry, but it's a placeholder, don't count it.
2488 		   Try the next.  */
2489 		while (entry && HeVAL(entry) == &PL_sv_placeholder)
2490 		    entry = HeNEXT(entry);
2491 	    }
2492 	    /* Will loop again if this linked list starts NULL
2493 	       (for HV_ITERNEXT_WANTPLACEHOLDERS)
2494 	       or if we run through it and find only placeholders.  */
2495 	}
2496     }
2497     else {
2498         iter->xhv_riter = -1;
2499 #ifdef PERL_HASH_RANDOMIZE_KEYS
2500         iter->xhv_last_rand = iter->xhv_rand;
2501 #endif
2502     }
2503 
2504     if (oldentry && HvLAZYDEL(hv)) {		/* was deleted earlier? */
2505 	HvLAZYDEL_off(hv);
2506 	hv_free_ent(hv, oldentry);
2507     }
2508 
2509     iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2510     return entry;
2511 }
2512 
2513 /*
2514 =for apidoc hv_iterkey
2515 
2516 Returns the key from the current position of the hash iterator.  See
2517 C<hv_iterinit>.
2518 
2519 =cut
2520 */
2521 
2522 char *
2523 Perl_hv_iterkey(pTHX_ HE *entry, I32 *retlen)
2524 {
2525     PERL_ARGS_ASSERT_HV_ITERKEY;
2526 
2527     if (HeKLEN(entry) == HEf_SVKEY) {
2528 	STRLEN len;
2529 	char * const p = SvPV(HeKEY_sv(entry), len);
2530 	*retlen = len;
2531 	return p;
2532     }
2533     else {
2534 	*retlen = HeKLEN(entry);
2535 	return HeKEY(entry);
2536     }
2537 }
2538 
2539 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2540 /*
2541 =for apidoc hv_iterkeysv
2542 
2543 Returns the key as an C<SV*> from the current position of the hash
2544 iterator.  The return value will always be a mortal copy of the key.  Also
2545 see C<hv_iterinit>.
2546 
2547 =cut
2548 */
2549 
2550 SV *
2551 Perl_hv_iterkeysv(pTHX_ HE *entry)
2552 {
2553     PERL_ARGS_ASSERT_HV_ITERKEYSV;
2554 
2555     return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2556 }
2557 
2558 /*
2559 =for apidoc hv_iterval
2560 
2561 Returns the value from the current position of the hash iterator.  See
2562 C<hv_iterkey>.
2563 
2564 =cut
2565 */
2566 
2567 SV *
2568 Perl_hv_iterval(pTHX_ HV *hv, HE *entry)
2569 {
2570     PERL_ARGS_ASSERT_HV_ITERVAL;
2571 
2572     if (SvRMAGICAL(hv)) {
2573 	if (mg_find((const SV *)hv, PERL_MAGIC_tied)) {
2574 	    SV* const sv = sv_newmortal();
2575 	    if (HeKLEN(entry) == HEf_SVKEY)
2576 		mg_copy(MUTABLE_SV(hv), sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2577 	    else
2578 		mg_copy(MUTABLE_SV(hv), sv, HeKEY(entry), HeKLEN(entry));
2579 	    return sv;
2580 	}
2581     }
2582     return HeVAL(entry);
2583 }
2584 
2585 /*
2586 =for apidoc hv_iternextsv
2587 
2588 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2589 operation.
2590 
2591 =cut
2592 */
2593 
2594 SV *
2595 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2596 {
2597     HE * const he = hv_iternext_flags(hv, 0);
2598 
2599     PERL_ARGS_ASSERT_HV_ITERNEXTSV;
2600 
2601     if (!he)
2602 	return NULL;
2603     *key = hv_iterkey(he, retlen);
2604     return hv_iterval(hv, he);
2605 }
2606 
2607 /*
2608 
2609 Now a macro in hv.h
2610 
2611 =for apidoc hv_magic
2612 
2613 Adds magic to a hash.  See C<sv_magic>.
2614 
2615 =cut
2616 */
2617 
2618 /* possibly free a shared string if no one has access to it
2619  * len and hash must both be valid for str.
2620  */
2621 void
2622 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2623 {
2624     unshare_hek_or_pvn (NULL, str, len, hash);
2625 }
2626 
2627 
2628 void
2629 Perl_unshare_hek(pTHX_ HEK *hek)
2630 {
2631     assert(hek);
2632     unshare_hek_or_pvn(hek, NULL, 0, 0);
2633 }
2634 
2635 /* possibly free a shared string if no one has access to it
2636    hek if non-NULL takes priority over the other 3, else str, len and hash
2637    are used.  If so, len and hash must both be valid for str.
2638  */
2639 STATIC void
2640 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2641 {
2642     dVAR;
2643     XPVHV* xhv;
2644     HE *entry;
2645     HE **oentry;
2646     bool is_utf8 = FALSE;
2647     int k_flags = 0;
2648     const char * const save = str;
2649     struct shared_he *he = NULL;
2650 
2651     if (hek) {
2652 	/* Find the shared he which is just before us in memory.  */
2653 	he = (struct shared_he *)(((char *)hek)
2654 				  - STRUCT_OFFSET(struct shared_he,
2655 						  shared_he_hek));
2656 
2657 	/* Assert that the caller passed us a genuine (or at least consistent)
2658 	   shared hek  */
2659 	assert (he->shared_he_he.hent_hek == hek);
2660 
2661 	if (he->shared_he_he.he_valu.hent_refcount - 1) {
2662 	    --he->shared_he_he.he_valu.hent_refcount;
2663 	    return;
2664 	}
2665 
2666         hash = HEK_HASH(hek);
2667     } else if (len < 0) {
2668         STRLEN tmplen = -len;
2669         is_utf8 = TRUE;
2670         /* See the note in hv_fetch(). --jhi */
2671         str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2672         len = tmplen;
2673         if (is_utf8)
2674             k_flags = HVhek_UTF8;
2675         if (str != save)
2676             k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2677     }
2678 
2679     /* what follows was the moral equivalent of:
2680     if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2681 	if (--*Svp == NULL)
2682 	    hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2683     } */
2684     xhv = (XPVHV*)SvANY(PL_strtab);
2685     /* assert(xhv_array != 0) */
2686     oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2687     if (he) {
2688 	const HE *const he_he = &(he->shared_he_he);
2689         for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2690             if (entry == he_he)
2691                 break;
2692         }
2693     } else {
2694         const int flags_masked = k_flags & HVhek_MASK;
2695         for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2696             if (HeHASH(entry) != hash)		/* strings can't be equal */
2697                 continue;
2698             if (HeKLEN(entry) != len)
2699                 continue;
2700             if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len))	/* is this it? */
2701                 continue;
2702             if (HeKFLAGS(entry) != flags_masked)
2703                 continue;
2704             break;
2705         }
2706     }
2707 
2708     if (entry) {
2709         if (--entry->he_valu.hent_refcount == 0) {
2710             *oentry = HeNEXT(entry);
2711             Safefree(entry);
2712             xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2713         }
2714     }
2715 
2716     if (!entry)
2717 	Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
2718 			 "Attempt to free nonexistent shared string '%s'%s"
2719 			 pTHX__FORMAT,
2720 			 hek ? HEK_KEY(hek) : str,
2721 			 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2722     if (k_flags & HVhek_FREEKEY)
2723 	Safefree(str);
2724 }
2725 
2726 /* get a (constant) string ptr from the global string table
2727  * string will get added if it is not already there.
2728  * len and hash must both be valid for str.
2729  */
2730 HEK *
2731 Perl_share_hek(pTHX_ const char *str, I32 len, U32 hash)
2732 {
2733     bool is_utf8 = FALSE;
2734     int flags = 0;
2735     const char * const save = str;
2736 
2737     PERL_ARGS_ASSERT_SHARE_HEK;
2738 
2739     if (len < 0) {
2740       STRLEN tmplen = -len;
2741       is_utf8 = TRUE;
2742       /* See the note in hv_fetch(). --jhi */
2743       str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2744       len = tmplen;
2745       /* If we were able to downgrade here, then than means that we were passed
2746          in a key which only had chars 0-255, but was utf8 encoded.  */
2747       if (is_utf8)
2748           flags = HVhek_UTF8;
2749       /* If we found we were able to downgrade the string to bytes, then
2750          we should flag that it needs upgrading on keys or each.  Also flag
2751          that we need share_hek_flags to free the string.  */
2752       if (str != save) {
2753           dVAR;
2754           PERL_HASH(hash, str, len);
2755           flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2756       }
2757     }
2758 
2759     return share_hek_flags (str, len, hash, flags);
2760 }
2761 
2762 STATIC HEK *
2763 S_share_hek_flags(pTHX_ const char *str, I32 len, U32 hash, int flags)
2764 {
2765     dVAR;
2766     HE *entry;
2767     const int flags_masked = flags & HVhek_MASK;
2768     const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2769     XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2770 
2771     PERL_ARGS_ASSERT_SHARE_HEK_FLAGS;
2772 
2773     /* what follows is the moral equivalent of:
2774 
2775     if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2776 	hv_store(PL_strtab, str, len, NULL, hash);
2777 
2778 	Can't rehash the shared string table, so not sure if it's worth
2779 	counting the number of entries in the linked list
2780     */
2781 
2782     /* assert(xhv_array != 0) */
2783     entry = (HvARRAY(PL_strtab))[hindex];
2784     for (;entry; entry = HeNEXT(entry)) {
2785 	if (HeHASH(entry) != hash)		/* strings can't be equal */
2786 	    continue;
2787 	if (HeKLEN(entry) != len)
2788 	    continue;
2789 	if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len))	/* is this it? */
2790 	    continue;
2791 	if (HeKFLAGS(entry) != flags_masked)
2792 	    continue;
2793 	break;
2794     }
2795 
2796     if (!entry) {
2797 	/* What used to be head of the list.
2798 	   If this is NULL, then we're the first entry for this slot, which
2799 	   means we need to increate fill.  */
2800 	struct shared_he *new_entry;
2801 	HEK *hek;
2802 	char *k;
2803 	HE **const head = &HvARRAY(PL_strtab)[hindex];
2804 	HE *const next = *head;
2805 
2806 	/* We don't actually store a HE from the arena and a regular HEK.
2807 	   Instead we allocate one chunk of memory big enough for both,
2808 	   and put the HEK straight after the HE. This way we can find the
2809 	   HE directly from the HEK.
2810 	*/
2811 
2812 	Newx(k, STRUCT_OFFSET(struct shared_he,
2813 				shared_he_hek.hek_key[0]) + len + 2, char);
2814 	new_entry = (struct shared_he *)k;
2815 	entry = &(new_entry->shared_he_he);
2816 	hek = &(new_entry->shared_he_hek);
2817 
2818 	Copy(str, HEK_KEY(hek), len, char);
2819 	HEK_KEY(hek)[len] = 0;
2820 	HEK_LEN(hek) = len;
2821 	HEK_HASH(hek) = hash;
2822 	HEK_FLAGS(hek) = (unsigned char)flags_masked;
2823 
2824 	/* Still "point" to the HEK, so that other code need not know what
2825 	   we're up to.  */
2826 	HeKEY_hek(entry) = hek;
2827 	entry->he_valu.hent_refcount = 0;
2828 	HeNEXT(entry) = next;
2829 	*head = entry;
2830 
2831 	xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2832 	if (!next) {			/* initial entry? */
2833 	} else if ( DO_HSPLIT(xhv) ) {
2834             const STRLEN oldsize = xhv->xhv_max + 1;
2835             hsplit(PL_strtab, oldsize, oldsize * 2);
2836 	}
2837     }
2838 
2839     ++entry->he_valu.hent_refcount;
2840 
2841     if (flags & HVhek_FREEKEY)
2842 	Safefree(str);
2843 
2844     return HeKEY_hek(entry);
2845 }
2846 
2847 I32 *
2848 Perl_hv_placeholders_p(pTHX_ HV *hv)
2849 {
2850     dVAR;
2851     MAGIC *mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2852 
2853     PERL_ARGS_ASSERT_HV_PLACEHOLDERS_P;
2854 
2855     if (!mg) {
2856 	mg = sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, 0);
2857 
2858 	if (!mg) {
2859 	    Perl_die(aTHX_ "panic: hv_placeholders_p");
2860 	}
2861     }
2862     return &(mg->mg_len);
2863 }
2864 
2865 
2866 I32
2867 Perl_hv_placeholders_get(pTHX_ const HV *hv)
2868 {
2869     dVAR;
2870     MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2871 
2872     PERL_ARGS_ASSERT_HV_PLACEHOLDERS_GET;
2873 
2874     return mg ? mg->mg_len : 0;
2875 }
2876 
2877 void
2878 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2879 {
2880     dVAR;
2881     MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2882 
2883     PERL_ARGS_ASSERT_HV_PLACEHOLDERS_SET;
2884 
2885     if (mg) {
2886 	mg->mg_len = ph;
2887     } else if (ph) {
2888 	if (!sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, ph))
2889 	    Perl_die(aTHX_ "panic: hv_placeholders_set");
2890     }
2891     /* else we don't need to add magic to record 0 placeholders.  */
2892 }
2893 
2894 STATIC SV *
2895 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2896 {
2897     dVAR;
2898     SV *value;
2899 
2900     PERL_ARGS_ASSERT_REFCOUNTED_HE_VALUE;
2901 
2902     switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2903     case HVrhek_undef:
2904 	value = newSV(0);
2905 	break;
2906     case HVrhek_delete:
2907 	value = &PL_sv_placeholder;
2908 	break;
2909     case HVrhek_IV:
2910 	value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
2911 	break;
2912     case HVrhek_UV:
2913 	value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
2914 	break;
2915     case HVrhek_PV:
2916     case HVrhek_PV_UTF8:
2917 	/* Create a string SV that directly points to the bytes in our
2918 	   structure.  */
2919 	value = newSV_type(SVt_PV);
2920 	SvPV_set(value, (char *) he->refcounted_he_data + 1);
2921 	SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
2922 	/* This stops anything trying to free it  */
2923 	SvLEN_set(value, 0);
2924 	SvPOK_on(value);
2925 	SvREADONLY_on(value);
2926 	if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
2927 	    SvUTF8_on(value);
2928 	break;
2929     default:
2930 	Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %"UVxf,
2931 		   (UV)he->refcounted_he_data[0]);
2932     }
2933     return value;
2934 }
2935 
2936 /*
2937 =for apidoc m|HV *|refcounted_he_chain_2hv|const struct refcounted_he *c|U32 flags
2938 
2939 Generates and returns a C<HV *> representing the content of a
2940 C<refcounted_he> chain.
2941 I<flags> is currently unused and must be zero.
2942 
2943 =cut
2944 */
2945 HV *
2946 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain, U32 flags)
2947 {
2948     dVAR;
2949     HV *hv;
2950     U32 placeholders, max;
2951 
2952     if (flags)
2953 	Perl_croak(aTHX_ "panic: refcounted_he_chain_2hv bad flags %"UVxf,
2954 	    (UV)flags);
2955 
2956     /* We could chase the chain once to get an idea of the number of keys,
2957        and call ksplit.  But for now we'll make a potentially inefficient
2958        hash with only 8 entries in its array.  */
2959     hv = newHV();
2960     max = HvMAX(hv);
2961     if (!HvARRAY(hv)) {
2962 	char *array;
2963 	Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
2964 	HvARRAY(hv) = (HE**)array;
2965     }
2966 
2967     placeholders = 0;
2968     while (chain) {
2969 #ifdef USE_ITHREADS
2970 	U32 hash = chain->refcounted_he_hash;
2971 #else
2972 	U32 hash = HEK_HASH(chain->refcounted_he_hek);
2973 #endif
2974 	HE **oentry = &((HvARRAY(hv))[hash & max]);
2975 	HE *entry = *oentry;
2976 	SV *value;
2977 
2978 	for (; entry; entry = HeNEXT(entry)) {
2979 	    if (HeHASH(entry) == hash) {
2980 		/* We might have a duplicate key here.  If so, entry is older
2981 		   than the key we've already put in the hash, so if they are
2982 		   the same, skip adding entry.  */
2983 #ifdef USE_ITHREADS
2984 		const STRLEN klen = HeKLEN(entry);
2985 		const char *const key = HeKEY(entry);
2986 		if (klen == chain->refcounted_he_keylen
2987 		    && (!!HeKUTF8(entry)
2988 			== !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2989 		    && memEQ(key, REF_HE_KEY(chain), klen))
2990 		    goto next_please;
2991 #else
2992 		if (HeKEY_hek(entry) == chain->refcounted_he_hek)
2993 		    goto next_please;
2994 		if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
2995 		    && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
2996 		    && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
2997 			     HeKLEN(entry)))
2998 		    goto next_please;
2999 #endif
3000 	    }
3001 	}
3002 	assert (!entry);
3003 	entry = new_HE();
3004 
3005 #ifdef USE_ITHREADS
3006 	HeKEY_hek(entry)
3007 	    = share_hek_flags(REF_HE_KEY(chain),
3008 			      chain->refcounted_he_keylen,
3009 			      chain->refcounted_he_hash,
3010 			      (chain->refcounted_he_data[0]
3011 			       & (HVhek_UTF8|HVhek_WASUTF8)));
3012 #else
3013 	HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
3014 #endif
3015 	value = refcounted_he_value(chain);
3016 	if (value == &PL_sv_placeholder)
3017 	    placeholders++;
3018 	HeVAL(entry) = value;
3019 
3020 	/* Link it into the chain.  */
3021 	HeNEXT(entry) = *oentry;
3022 	*oentry = entry;
3023 
3024 	HvTOTALKEYS(hv)++;
3025 
3026     next_please:
3027 	chain = chain->refcounted_he_next;
3028     }
3029 
3030     if (placeholders) {
3031 	clear_placeholders(hv, placeholders);
3032 	HvTOTALKEYS(hv) -= placeholders;
3033     }
3034 
3035     /* We could check in the loop to see if we encounter any keys with key
3036        flags, but it's probably not worth it, as this per-hash flag is only
3037        really meant as an optimisation for things like Storable.  */
3038     HvHASKFLAGS_on(hv);
3039     DEBUG_A(Perl_hv_assert(aTHX_ hv));
3040 
3041     return hv;
3042 }
3043 
3044 /*
3045 =for apidoc m|SV *|refcounted_he_fetch_pvn|const struct refcounted_he *chain|const char *keypv|STRLEN keylen|U32 hash|U32 flags
3046 
3047 Search along a C<refcounted_he> chain for an entry with the key specified
3048 by I<keypv> and I<keylen>.  If I<flags> has the C<REFCOUNTED_HE_KEY_UTF8>
3049 bit set, the key octets are interpreted as UTF-8, otherwise they
3050 are interpreted as Latin-1.  I<hash> is a precomputed hash of the key
3051 string, or zero if it has not been precomputed.  Returns a mortal scalar
3052 representing the value associated with the key, or C<&PL_sv_placeholder>
3053 if there is no value associated with the key.
3054 
3055 =cut
3056 */
3057 
3058 SV *
3059 Perl_refcounted_he_fetch_pvn(pTHX_ const struct refcounted_he *chain,
3060 			 const char *keypv, STRLEN keylen, U32 hash, U32 flags)
3061 {
3062     dVAR;
3063     U8 utf8_flag;
3064     PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_PVN;
3065 
3066     if (flags & ~(REFCOUNTED_HE_KEY_UTF8|REFCOUNTED_HE_EXISTS))
3067 	Perl_croak(aTHX_ "panic: refcounted_he_fetch_pvn bad flags %"UVxf,
3068 	    (UV)flags);
3069     if (!chain)
3070 	return &PL_sv_placeholder;
3071     if (flags & REFCOUNTED_HE_KEY_UTF8) {
3072 	/* For searching purposes, canonicalise to Latin-1 where possible. */
3073 	const char *keyend = keypv + keylen, *p;
3074 	STRLEN nonascii_count = 0;
3075 	for (p = keypv; p != keyend; p++) {
3076 	    U8 c = (U8)*p;
3077 	    if (c & 0x80) {
3078 		if (!((c & 0xfe) == 0xc2 && ++p != keyend &&
3079 			    (((U8)*p) & 0xc0) == 0x80))
3080 		    goto canonicalised_key;
3081 		nonascii_count++;
3082 	    }
3083 	}
3084 	if (nonascii_count) {
3085 	    char *q;
3086 	    const char *p = keypv, *keyend = keypv + keylen;
3087 	    keylen -= nonascii_count;
3088 	    Newx(q, keylen, char);
3089 	    SAVEFREEPV(q);
3090 	    keypv = q;
3091 	    for (; p != keyend; p++, q++) {
3092 		U8 c = (U8)*p;
3093 		*q = (char)
3094 		    ((c & 0x80) ? ((c & 0x03) << 6) | (((U8)*++p) & 0x3f) : c);
3095 	    }
3096 	}
3097 	flags &= ~REFCOUNTED_HE_KEY_UTF8;
3098 	canonicalised_key: ;
3099     }
3100     utf8_flag = (flags & REFCOUNTED_HE_KEY_UTF8) ? HVhek_UTF8 : 0;
3101     if (!hash)
3102 	PERL_HASH(hash, keypv, keylen);
3103 
3104     for (; chain; chain = chain->refcounted_he_next) {
3105 	if (
3106 #ifdef USE_ITHREADS
3107 	    hash == chain->refcounted_he_hash &&
3108 	    keylen == chain->refcounted_he_keylen &&
3109 	    memEQ(REF_HE_KEY(chain), keypv, keylen) &&
3110 	    utf8_flag == (chain->refcounted_he_data[0] & HVhek_UTF8)
3111 #else
3112 	    hash == HEK_HASH(chain->refcounted_he_hek) &&
3113 	    keylen == (STRLEN)HEK_LEN(chain->refcounted_he_hek) &&
3114 	    memEQ(HEK_KEY(chain->refcounted_he_hek), keypv, keylen) &&
3115 	    utf8_flag == (HEK_FLAGS(chain->refcounted_he_hek) & HVhek_UTF8)
3116 #endif
3117 	) {
3118 	    if (flags & REFCOUNTED_HE_EXISTS)
3119 		return (chain->refcounted_he_data[0] & HVrhek_typemask)
3120 		    == HVrhek_delete
3121 		    ? NULL : &PL_sv_yes;
3122 	    return sv_2mortal(refcounted_he_value(chain));
3123 	}
3124     }
3125     return flags & REFCOUNTED_HE_EXISTS ? NULL : &PL_sv_placeholder;
3126 }
3127 
3128 /*
3129 =for apidoc m|SV *|refcounted_he_fetch_pv|const struct refcounted_he *chain|const char *key|U32 hash|U32 flags
3130 
3131 Like L</refcounted_he_fetch_pvn>, but takes a nul-terminated string
3132 instead of a string/length pair.
3133 
3134 =cut
3135 */
3136 
3137 SV *
3138 Perl_refcounted_he_fetch_pv(pTHX_ const struct refcounted_he *chain,
3139 			 const char *key, U32 hash, U32 flags)
3140 {
3141     PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_PV;
3142     return refcounted_he_fetch_pvn(chain, key, strlen(key), hash, flags);
3143 }
3144 
3145 /*
3146 =for apidoc m|SV *|refcounted_he_fetch_sv|const struct refcounted_he *chain|SV *key|U32 hash|U32 flags
3147 
3148 Like L</refcounted_he_fetch_pvn>, but takes a Perl scalar instead of a
3149 string/length pair.
3150 
3151 =cut
3152 */
3153 
3154 SV *
3155 Perl_refcounted_he_fetch_sv(pTHX_ const struct refcounted_he *chain,
3156 			 SV *key, U32 hash, U32 flags)
3157 {
3158     const char *keypv;
3159     STRLEN keylen;
3160     PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_SV;
3161     if (flags & REFCOUNTED_HE_KEY_UTF8)
3162 	Perl_croak(aTHX_ "panic: refcounted_he_fetch_sv bad flags %"UVxf,
3163 	    (UV)flags);
3164     keypv = SvPV_const(key, keylen);
3165     if (SvUTF8(key))
3166 	flags |= REFCOUNTED_HE_KEY_UTF8;
3167     if (!hash && SvIsCOW_shared_hash(key))
3168 	hash = SvSHARED_HASH(key);
3169     return refcounted_he_fetch_pvn(chain, keypv, keylen, hash, flags);
3170 }
3171 
3172 /*
3173 =for apidoc m|struct refcounted_he *|refcounted_he_new_pvn|struct refcounted_he *parent|const char *keypv|STRLEN keylen|U32 hash|SV *value|U32 flags
3174 
3175 Creates a new C<refcounted_he>.  This consists of a single key/value
3176 pair and a reference to an existing C<refcounted_he> chain (which may
3177 be empty), and thus forms a longer chain.  When using the longer chain,
3178 the new key/value pair takes precedence over any entry for the same key
3179 further along the chain.
3180 
3181 The new key is specified by I<keypv> and I<keylen>.  If I<flags> has
3182 the C<REFCOUNTED_HE_KEY_UTF8> bit set, the key octets are interpreted
3183 as UTF-8, otherwise they are interpreted as Latin-1.  I<hash> is
3184 a precomputed hash of the key string, or zero if it has not been
3185 precomputed.
3186 
3187 I<value> is the scalar value to store for this key.  I<value> is copied
3188 by this function, which thus does not take ownership of any reference
3189 to it, and later changes to the scalar will not be reflected in the
3190 value visible in the C<refcounted_he>.  Complex types of scalar will not
3191 be stored with referential integrity, but will be coerced to strings.
3192 I<value> may be either null or C<&PL_sv_placeholder> to indicate that no
3193 value is to be associated with the key; this, as with any non-null value,
3194 takes precedence over the existence of a value for the key further along
3195 the chain.
3196 
3197 I<parent> points to the rest of the C<refcounted_he> chain to be
3198 attached to the new C<refcounted_he>.  This function takes ownership
3199 of one reference to I<parent>, and returns one reference to the new
3200 C<refcounted_he>.
3201 
3202 =cut
3203 */
3204 
3205 struct refcounted_he *
3206 Perl_refcounted_he_new_pvn(pTHX_ struct refcounted_he *parent,
3207 	const char *keypv, STRLEN keylen, U32 hash, SV *value, U32 flags)
3208 {
3209     dVAR;
3210     STRLEN value_len = 0;
3211     const char *value_p = NULL;
3212     bool is_pv;
3213     char value_type;
3214     char hekflags;
3215     STRLEN key_offset = 1;
3216     struct refcounted_he *he;
3217     PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_PVN;
3218 
3219     if (!value || value == &PL_sv_placeholder) {
3220 	value_type = HVrhek_delete;
3221     } else if (SvPOK(value)) {
3222 	value_type = HVrhek_PV;
3223     } else if (SvIOK(value)) {
3224 	value_type = SvUOK((const SV *)value) ? HVrhek_UV : HVrhek_IV;
3225     } else if (!SvOK(value)) {
3226 	value_type = HVrhek_undef;
3227     } else {
3228 	value_type = HVrhek_PV;
3229     }
3230     is_pv = value_type == HVrhek_PV;
3231     if (is_pv) {
3232 	/* Do it this way so that the SvUTF8() test is after the SvPV, in case
3233 	   the value is overloaded, and doesn't yet have the UTF-8flag set.  */
3234 	value_p = SvPV_const(value, value_len);
3235 	if (SvUTF8(value))
3236 	    value_type = HVrhek_PV_UTF8;
3237 	key_offset = value_len + 2;
3238     }
3239     hekflags = value_type;
3240 
3241     if (flags & REFCOUNTED_HE_KEY_UTF8) {
3242 	/* Canonicalise to Latin-1 where possible. */
3243 	const char *keyend = keypv + keylen, *p;
3244 	STRLEN nonascii_count = 0;
3245 	for (p = keypv; p != keyend; p++) {
3246 	    U8 c = (U8)*p;
3247 	    if (c & 0x80) {
3248 		if (!((c & 0xfe) == 0xc2 && ++p != keyend &&
3249 			    (((U8)*p) & 0xc0) == 0x80))
3250 		    goto canonicalised_key;
3251 		nonascii_count++;
3252 	    }
3253 	}
3254 	if (nonascii_count) {
3255 	    char *q;
3256 	    const char *p = keypv, *keyend = keypv + keylen;
3257 	    keylen -= nonascii_count;
3258 	    Newx(q, keylen, char);
3259 	    SAVEFREEPV(q);
3260 	    keypv = q;
3261 	    for (; p != keyend; p++, q++) {
3262 		U8 c = (U8)*p;
3263 		*q = (char)
3264 		    ((c & 0x80) ? ((c & 0x03) << 6) | (((U8)*++p) & 0x3f) : c);
3265 	    }
3266 	}
3267 	flags &= ~REFCOUNTED_HE_KEY_UTF8;
3268 	canonicalised_key: ;
3269     }
3270     if (flags & REFCOUNTED_HE_KEY_UTF8)
3271 	hekflags |= HVhek_UTF8;
3272     if (!hash)
3273 	PERL_HASH(hash, keypv, keylen);
3274 
3275 #ifdef USE_ITHREADS
3276     he = (struct refcounted_he*)
3277 	PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
3278 			     + keylen
3279 			     + key_offset);
3280 #else
3281     he = (struct refcounted_he*)
3282 	PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
3283 			     + key_offset);
3284 #endif
3285 
3286     he->refcounted_he_next = parent;
3287 
3288     if (is_pv) {
3289 	Copy(value_p, he->refcounted_he_data + 1, value_len + 1, char);
3290 	he->refcounted_he_val.refcounted_he_u_len = value_len;
3291     } else if (value_type == HVrhek_IV) {
3292 	he->refcounted_he_val.refcounted_he_u_iv = SvIVX(value);
3293     } else if (value_type == HVrhek_UV) {
3294 	he->refcounted_he_val.refcounted_he_u_uv = SvUVX(value);
3295     }
3296 
3297 #ifdef USE_ITHREADS
3298     he->refcounted_he_hash = hash;
3299     he->refcounted_he_keylen = keylen;
3300     Copy(keypv, he->refcounted_he_data + key_offset, keylen, char);
3301 #else
3302     he->refcounted_he_hek = share_hek_flags(keypv, keylen, hash, hekflags);
3303 #endif
3304 
3305     he->refcounted_he_data[0] = hekflags;
3306     he->refcounted_he_refcnt = 1;
3307 
3308     return he;
3309 }
3310 
3311 /*
3312 =for apidoc m|struct refcounted_he *|refcounted_he_new_pv|struct refcounted_he *parent|const char *key|U32 hash|SV *value|U32 flags
3313 
3314 Like L</refcounted_he_new_pvn>, but takes a nul-terminated string instead
3315 of a string/length pair.
3316 
3317 =cut
3318 */
3319 
3320 struct refcounted_he *
3321 Perl_refcounted_he_new_pv(pTHX_ struct refcounted_he *parent,
3322 	const char *key, U32 hash, SV *value, U32 flags)
3323 {
3324     PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_PV;
3325     return refcounted_he_new_pvn(parent, key, strlen(key), hash, value, flags);
3326 }
3327 
3328 /*
3329 =for apidoc m|struct refcounted_he *|refcounted_he_new_sv|struct refcounted_he *parent|SV *key|U32 hash|SV *value|U32 flags
3330 
3331 Like L</refcounted_he_new_pvn>, but takes a Perl scalar instead of a
3332 string/length pair.
3333 
3334 =cut
3335 */
3336 
3337 struct refcounted_he *
3338 Perl_refcounted_he_new_sv(pTHX_ struct refcounted_he *parent,
3339 	SV *key, U32 hash, SV *value, U32 flags)
3340 {
3341     const char *keypv;
3342     STRLEN keylen;
3343     PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_SV;
3344     if (flags & REFCOUNTED_HE_KEY_UTF8)
3345 	Perl_croak(aTHX_ "panic: refcounted_he_new_sv bad flags %"UVxf,
3346 	    (UV)flags);
3347     keypv = SvPV_const(key, keylen);
3348     if (SvUTF8(key))
3349 	flags |= REFCOUNTED_HE_KEY_UTF8;
3350     if (!hash && SvIsCOW_shared_hash(key))
3351 	hash = SvSHARED_HASH(key);
3352     return refcounted_he_new_pvn(parent, keypv, keylen, hash, value, flags);
3353 }
3354 
3355 /*
3356 =for apidoc m|void|refcounted_he_free|struct refcounted_he *he
3357 
3358 Decrements the reference count of a C<refcounted_he> by one.  If the
3359 reference count reaches zero the structure's memory is freed, which
3360 (recursively) causes a reduction of its parent C<refcounted_he>'s
3361 reference count.  It is safe to pass a null pointer to this function:
3362 no action occurs in this case.
3363 
3364 =cut
3365 */
3366 
3367 void
3368 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
3369     dVAR;
3370     PERL_UNUSED_CONTEXT;
3371 
3372     while (he) {
3373 	struct refcounted_he *copy;
3374 	U32 new_count;
3375 
3376 	HINTS_REFCNT_LOCK;
3377 	new_count = --he->refcounted_he_refcnt;
3378 	HINTS_REFCNT_UNLOCK;
3379 
3380 	if (new_count) {
3381 	    return;
3382 	}
3383 
3384 #ifndef USE_ITHREADS
3385 	unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
3386 #endif
3387 	copy = he;
3388 	he = he->refcounted_he_next;
3389 	PerlMemShared_free(copy);
3390     }
3391 }
3392 
3393 /*
3394 =for apidoc m|struct refcounted_he *|refcounted_he_inc|struct refcounted_he *he
3395 
3396 Increment the reference count of a C<refcounted_he>.  The pointer to the
3397 C<refcounted_he> is also returned.  It is safe to pass a null pointer
3398 to this function: no action occurs and a null pointer is returned.
3399 
3400 =cut
3401 */
3402 
3403 struct refcounted_he *
3404 Perl_refcounted_he_inc(pTHX_ struct refcounted_he *he)
3405 {
3406     dVAR;
3407     if (he) {
3408 	HINTS_REFCNT_LOCK;
3409 	he->refcounted_he_refcnt++;
3410 	HINTS_REFCNT_UNLOCK;
3411     }
3412     return he;
3413 }
3414 
3415 /*
3416 =for apidoc cop_fetch_label
3417 
3418 Returns the label attached to a cop.
3419 The flags pointer may be set to C<SVf_UTF8> or 0.
3420 
3421 =cut
3422 */
3423 
3424 /* pp_entereval is aware that labels are stored with a key ':' at the top of
3425    the linked list.  */
3426 const char *
3427 Perl_cop_fetch_label(pTHX_ COP *const cop, STRLEN *len, U32 *flags) {
3428     struct refcounted_he *const chain = cop->cop_hints_hash;
3429 
3430     PERL_ARGS_ASSERT_COP_FETCH_LABEL;
3431 
3432     if (!chain)
3433 	return NULL;
3434 #ifdef USE_ITHREADS
3435     if (chain->refcounted_he_keylen != 1)
3436 	return NULL;
3437     if (*REF_HE_KEY(chain) != ':')
3438 	return NULL;
3439 #else
3440     if ((STRLEN)HEK_LEN(chain->refcounted_he_hek) != 1)
3441 	return NULL;
3442     if (*HEK_KEY(chain->refcounted_he_hek) != ':')
3443 	return NULL;
3444 #endif
3445     /* Stop anyone trying to really mess us up by adding their own value for
3446        ':' into %^H  */
3447     if ((chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV
3448 	&& (chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV_UTF8)
3449 	return NULL;
3450 
3451     if (len)
3452 	*len = chain->refcounted_he_val.refcounted_he_u_len;
3453     if (flags) {
3454 	*flags = ((chain->refcounted_he_data[0] & HVrhek_typemask)
3455 		  == HVrhek_PV_UTF8) ? SVf_UTF8 : 0;
3456     }
3457     return chain->refcounted_he_data + 1;
3458 }
3459 
3460 /*
3461 =for apidoc cop_store_label
3462 
3463 Save a label into a C<cop_hints_hash>. You need to set flags to C<SVf_UTF8>
3464 for a utf-8 label.
3465 
3466 =cut
3467 */
3468 
3469 void
3470 Perl_cop_store_label(pTHX_ COP *const cop, const char *label, STRLEN len,
3471 		     U32 flags)
3472 {
3473     SV *labelsv;
3474     PERL_ARGS_ASSERT_COP_STORE_LABEL;
3475 
3476     if (flags & ~(SVf_UTF8))
3477 	Perl_croak(aTHX_ "panic: cop_store_label illegal flag bits 0x%" UVxf,
3478 		   (UV)flags);
3479     labelsv = newSVpvn_flags(label, len, SVs_TEMP);
3480     if (flags & SVf_UTF8)
3481 	SvUTF8_on(labelsv);
3482     cop->cop_hints_hash
3483 	= refcounted_he_new_pvs(cop->cop_hints_hash, ":", labelsv, 0);
3484 }
3485 
3486 /*
3487 =for apidoc hv_assert
3488 
3489 Check that a hash is in an internally consistent state.
3490 
3491 =cut
3492 */
3493 
3494 #ifdef DEBUGGING
3495 
3496 void
3497 Perl_hv_assert(pTHX_ HV *hv)
3498 {
3499     dVAR;
3500     HE* entry;
3501     int withflags = 0;
3502     int placeholders = 0;
3503     int real = 0;
3504     int bad = 0;
3505     const I32 riter = HvRITER_get(hv);
3506     HE *eiter = HvEITER_get(hv);
3507 
3508     PERL_ARGS_ASSERT_HV_ASSERT;
3509 
3510     (void)hv_iterinit(hv);
3511 
3512     while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
3513 	/* sanity check the values */
3514 	if (HeVAL(entry) == &PL_sv_placeholder)
3515 	    placeholders++;
3516 	else
3517 	    real++;
3518 	/* sanity check the keys */
3519 	if (HeSVKEY(entry)) {
3520 	    NOOP;   /* Don't know what to check on SV keys.  */
3521 	} else if (HeKUTF8(entry)) {
3522 	    withflags++;
3523 	    if (HeKWASUTF8(entry)) {
3524 		PerlIO_printf(Perl_debug_log,
3525 			    "hash key has both WASUTF8 and UTF8: '%.*s'\n",
3526 			    (int) HeKLEN(entry),  HeKEY(entry));
3527 		bad = 1;
3528 	    }
3529 	} else if (HeKWASUTF8(entry))
3530 	    withflags++;
3531     }
3532     if (!SvTIED_mg((const SV *)hv, PERL_MAGIC_tied)) {
3533 	static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
3534 	const int nhashkeys = HvUSEDKEYS(hv);
3535 	const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
3536 
3537 	if (nhashkeys != real) {
3538 	    PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
3539 	    bad = 1;
3540 	}
3541 	if (nhashplaceholders != placeholders) {
3542 	    PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
3543 	    bad = 1;
3544 	}
3545     }
3546     if (withflags && ! HvHASKFLAGS(hv)) {
3547 	PerlIO_printf(Perl_debug_log,
3548 		    "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
3549 		    withflags);
3550 	bad = 1;
3551     }
3552     if (bad) {
3553 	sv_dump(MUTABLE_SV(hv));
3554     }
3555     HvRITER_set(hv, riter);		/* Restore hash iterator state */
3556     HvEITER_set(hv, eiter);
3557 }
3558 
3559 #endif
3560 
3561 /*
3562  * Local variables:
3563  * c-indentation-style: bsd
3564  * c-basic-offset: 4
3565  * indent-tabs-mode: nil
3566  * End:
3567  *
3568  * ex: set ts=8 sts=4 sw=4 et:
3569  */
3570