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author | HackBot |
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date | Sat, 14 May 2016 14:54:38 +0000 |
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1 /* mro_core.c | |
2 * | |
3 * Copyright (c) 2007 Brandon L Black | |
4 * Copyright (c) 2007, 2008, 2009, 2010, 2011 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 * This was 'mro.c', but changed because there is another mro.c in /ext, and | |
10 * the os390 loader can't cope with this situation (which involves the two | |
11 * files calling functions defined in the other) | |
12 */ | |
13 | |
14 /* | |
15 * 'Which order shall we go in?' said Frodo. 'Eldest first, or quickest first? | |
16 * You'll be last either way, Master Peregrin.' | |
17 * | |
18 * [p.101 of _The Lord of the Rings_, I/iii: "A Conspiracy Unmasked"] | |
19 */ | |
20 | |
21 /* | |
22 =head1 MRO Functions | |
23 These functions are related to the method resolution order of perl classes | |
24 | |
25 =cut | |
26 */ | |
27 | |
28 #include "EXTERN.h" | |
29 #define PERL_IN_MRO_C | |
30 #include "perl.h" | |
31 | |
32 static const struct mro_alg dfs_alg = | |
33 {S_mro_get_linear_isa_dfs, "dfs", 3, 0, 0}; | |
34 | |
35 SV * | |
36 Perl_mro_get_private_data(pTHX_ struct mro_meta *const smeta, | |
37 const struct mro_alg *const which) | |
38 { | |
39 SV **data; | |
40 PERL_ARGS_ASSERT_MRO_GET_PRIVATE_DATA; | |
41 | |
42 data = (SV **)Perl_hv_common(aTHX_ smeta->mro_linear_all, NULL, | |
43 which->name, which->length, which->kflags, | |
44 HV_FETCH_JUST_SV, NULL, which->hash); | |
45 if (!data) | |
46 return NULL; | |
47 | |
48 /* If we've been asked to look up the private data for the current MRO, then | |
49 cache it. */ | |
50 if (smeta->mro_which == which) | |
51 smeta->mro_linear_current = *data; | |
52 | |
53 return *data; | |
54 } | |
55 | |
56 SV * | |
57 Perl_mro_set_private_data(pTHX_ struct mro_meta *const smeta, | |
58 const struct mro_alg *const which, SV *const data) | |
59 { | |
60 PERL_ARGS_ASSERT_MRO_SET_PRIVATE_DATA; | |
61 | |
62 if (!smeta->mro_linear_all) { | |
63 if (smeta->mro_which == which) { | |
64 /* If all we need to store is the current MRO's data, then don't use | |
65 memory on a hash with 1 element - store it direct, and signal | |
66 this by leaving the would-be-hash NULL. */ | |
67 smeta->mro_linear_current = data; | |
68 return data; | |
69 } else { | |
70 HV *const hv = newHV(); | |
71 /* Start with 2 buckets. It's unlikely we'll need more. */ | |
72 HvMAX(hv) = 1; | |
73 smeta->mro_linear_all = hv; | |
74 | |
75 if (smeta->mro_linear_current) { | |
76 /* If we were storing something directly, put it in the hash | |
77 before we lose it. */ | |
78 Perl_mro_set_private_data(aTHX_ smeta, smeta->mro_which, | |
79 smeta->mro_linear_current); | |
80 } | |
81 } | |
82 } | |
83 | |
84 /* We get here if we're storing more than one linearisation for this stash, | |
85 or the linearisation we are storing is not that if its current MRO. */ | |
86 | |
87 if (smeta->mro_which == which) { | |
88 /* If we've been asked to store the private data for the current MRO, | |
89 then cache it. */ | |
90 smeta->mro_linear_current = data; | |
91 } | |
92 | |
93 if (!Perl_hv_common(aTHX_ smeta->mro_linear_all, NULL, | |
94 which->name, which->length, which->kflags, | |
95 HV_FETCH_ISSTORE, data, which->hash)) { | |
96 Perl_croak(aTHX_ "panic: hv_store() failed in set_mro_private_data() " | |
97 "for '%.*s' %d", (int) which->length, which->name, | |
98 which->kflags); | |
99 } | |
100 | |
101 return data; | |
102 } | |
103 | |
104 const struct mro_alg * | |
105 Perl_mro_get_from_name(pTHX_ SV *name) { | |
106 SV **data; | |
107 | |
108 PERL_ARGS_ASSERT_MRO_GET_FROM_NAME; | |
109 | |
110 data = (SV **)Perl_hv_common(aTHX_ PL_registered_mros, name, NULL, 0, 0, | |
111 HV_FETCH_JUST_SV, NULL, 0); | |
112 if (!data) | |
113 return NULL; | |
114 assert(SvTYPE(*data) == SVt_IV); | |
115 assert(SvIOK(*data)); | |
116 return INT2PTR(const struct mro_alg *, SvUVX(*data)); | |
117 } | |
118 | |
119 /* | |
120 =for apidoc mro_register | |
121 Registers a custom mro plugin. See L<perlmroapi> for details. | |
122 | |
123 =cut | |
124 */ | |
125 | |
126 void | |
127 Perl_mro_register(pTHX_ const struct mro_alg *mro) { | |
128 SV *wrapper = newSVuv(PTR2UV(mro)); | |
129 | |
130 PERL_ARGS_ASSERT_MRO_REGISTER; | |
131 | |
132 | |
133 if (!Perl_hv_common(aTHX_ PL_registered_mros, NULL, | |
134 mro->name, mro->length, mro->kflags, | |
135 HV_FETCH_ISSTORE, wrapper, mro->hash)) { | |
136 SvREFCNT_dec_NN(wrapper); | |
137 Perl_croak(aTHX_ "panic: hv_store() failed in mro_register() " | |
138 "for '%.*s' %d", (int) mro->length, mro->name, mro->kflags); | |
139 } | |
140 } | |
141 | |
142 struct mro_meta* | |
143 Perl_mro_meta_init(pTHX_ HV* stash) | |
144 { | |
145 struct mro_meta* newmeta; | |
146 | |
147 PERL_ARGS_ASSERT_MRO_META_INIT; | |
148 PERL_UNUSED_CONTEXT; | |
149 assert(HvAUX(stash)); | |
150 assert(!(HvAUX(stash)->xhv_mro_meta)); | |
151 Newxz(newmeta, 1, struct mro_meta); | |
152 HvAUX(stash)->xhv_mro_meta = newmeta; | |
153 newmeta->cache_gen = 1; | |
154 newmeta->pkg_gen = 1; | |
155 newmeta->mro_which = &dfs_alg; | |
156 | |
157 return newmeta; | |
158 } | |
159 | |
160 #if defined(USE_ITHREADS) | |
161 | |
162 /* for sv_dup on new threads */ | |
163 struct mro_meta* | |
164 Perl_mro_meta_dup(pTHX_ struct mro_meta* smeta, CLONE_PARAMS* param) | |
165 { | |
166 struct mro_meta* newmeta; | |
167 | |
168 PERL_ARGS_ASSERT_MRO_META_DUP; | |
169 | |
170 Newx(newmeta, 1, struct mro_meta); | |
171 Copy(smeta, newmeta, 1, struct mro_meta); | |
172 | |
173 if (newmeta->mro_linear_all) { | |
174 newmeta->mro_linear_all | |
175 = MUTABLE_HV(sv_dup_inc((const SV *)newmeta->mro_linear_all, param)); | |
176 /* This is just acting as a shortcut pointer, and will be automatically | |
177 updated on the first get. */ | |
178 newmeta->mro_linear_current = NULL; | |
179 } else if (newmeta->mro_linear_current) { | |
180 /* Only the current MRO is stored, so this owns the data. */ | |
181 newmeta->mro_linear_current | |
182 = sv_dup_inc((const SV *)newmeta->mro_linear_current, param); | |
183 } | |
184 | |
185 if (newmeta->mro_nextmethod) | |
186 newmeta->mro_nextmethod | |
187 = MUTABLE_HV(sv_dup_inc((const SV *)newmeta->mro_nextmethod, param)); | |
188 if (newmeta->isa) | |
189 newmeta->isa | |
190 = MUTABLE_HV(sv_dup_inc((const SV *)newmeta->isa, param)); | |
191 | |
192 newmeta->super = NULL; | |
193 | |
194 return newmeta; | |
195 } | |
196 | |
197 #endif /* USE_ITHREADS */ | |
198 | |
199 /* | |
200 =for apidoc mro_get_linear_isa_dfs | |
201 | |
202 Returns the Depth-First Search linearization of @ISA | |
203 the given stash. The return value is a read-only AV*. | |
204 C<level> should be 0 (it is used internally in this | |
205 function's recursion). | |
206 | |
207 You are responsible for C<SvREFCNT_inc()> on the | |
208 return value if you plan to store it anywhere | |
209 semi-permanently (otherwise it might be deleted | |
210 out from under you the next time the cache is | |
211 invalidated). | |
212 | |
213 =cut | |
214 */ | |
215 static AV* | |
216 S_mro_get_linear_isa_dfs(pTHX_ HV *stash, U32 level) | |
217 { | |
218 AV* retval; | |
219 GV** gvp; | |
220 GV* gv; | |
221 AV* av; | |
222 const HEK* stashhek; | |
223 struct mro_meta* meta; | |
224 SV *our_name; | |
225 HV *stored = NULL; | |
226 | |
227 PERL_ARGS_ASSERT_MRO_GET_LINEAR_ISA_DFS; | |
228 assert(HvAUX(stash)); | |
229 | |
230 stashhek | |
231 = HvAUX(stash)->xhv_name_u.xhvnameu_name && HvENAME_HEK_NN(stash) | |
232 ? HvENAME_HEK_NN(stash) | |
233 : HvNAME_HEK(stash); | |
234 | |
235 if (!stashhek) | |
236 Perl_croak(aTHX_ "Can't linearize anonymous symbol table"); | |
237 | |
238 if (level > 100) | |
239 Perl_croak(aTHX_ | |
240 "Recursive inheritance detected in package '%"HEKf"'", | |
241 HEKfARG(stashhek)); | |
242 | |
243 meta = HvMROMETA(stash); | |
244 | |
245 /* return cache if valid */ | |
246 if((retval = MUTABLE_AV(MRO_GET_PRIVATE_DATA(meta, &dfs_alg)))) { | |
247 return retval; | |
248 } | |
249 | |
250 /* not in cache, make a new one */ | |
251 | |
252 retval = MUTABLE_AV(sv_2mortal(MUTABLE_SV(newAV()))); | |
253 /* We use this later in this function, but don't need a reference to it | |
254 beyond the end of this function, so reference count is fine. */ | |
255 our_name = newSVhek(stashhek); | |
256 av_push(retval, our_name); /* add ourselves at the top */ | |
257 | |
258 /* fetch our @ISA */ | |
259 gvp = (GV**)hv_fetchs(stash, "ISA", FALSE); | |
260 av = (gvp && (gv = *gvp) && isGV_with_GP(gv)) ? GvAV(gv) : NULL; | |
261 | |
262 /* "stored" is used to keep track of all of the classnames we have added to | |
263 the MRO so far, so we can do a quick exists check and avoid adding | |
264 duplicate classnames to the MRO as we go. | |
265 It's then retained to be re-used as a fast lookup for ->isa(), by adding | |
266 our own name and "UNIVERSAL" to it. */ | |
267 | |
268 if(av && AvFILLp(av) >= 0) { | |
269 | |
270 SV **svp = AvARRAY(av); | |
271 I32 items = AvFILLp(av) + 1; | |
272 | |
273 /* foreach(@ISA) */ | |
274 while (items--) { | |
275 SV* const sv = *svp ? *svp : &PL_sv_undef; | |
276 HV* const basestash = gv_stashsv(sv, 0); | |
277 SV *const *subrv_p; | |
278 I32 subrv_items; | |
279 svp++; | |
280 | |
281 if (!basestash) { | |
282 /* if no stash exists for this @ISA member, | |
283 simply add it to the MRO and move on */ | |
284 subrv_p = &sv; | |
285 subrv_items = 1; | |
286 } | |
287 else { | |
288 /* otherwise, recurse into ourselves for the MRO | |
289 of this @ISA member, and append their MRO to ours. | |
290 The recursive call could throw an exception, which | |
291 has memory management implications here, hence the use of | |
292 the mortal. */ | |
293 const AV *const subrv | |
294 = mro_get_linear_isa_dfs(basestash, level + 1); | |
295 | |
296 subrv_p = AvARRAY(subrv); | |
297 subrv_items = AvFILLp(subrv) + 1; | |
298 } | |
299 if (stored) { | |
300 while(subrv_items--) { | |
301 SV *const subsv = *subrv_p++; | |
302 /* LVALUE fetch will create a new undefined SV if necessary | |
303 */ | |
304 HE *const he = hv_fetch_ent(stored, subsv, 1, 0); | |
305 assert(he); | |
306 if(HeVAL(he) != &PL_sv_undef) { | |
307 /* It was newly created. Steal it for our new SV, and | |
308 replace it in the hash with the "real" thing. */ | |
309 SV *const val = HeVAL(he); | |
310 HEK *const key = HeKEY_hek(he); | |
311 | |
312 HeVAL(he) = &PL_sv_undef; | |
313 sv_sethek(val, key); | |
314 av_push(retval, val); | |
315 } | |
316 } | |
317 } else { | |
318 /* We are the first (or only) parent. We can short cut the | |
319 complexity above, because our @ISA is simply us prepended | |
320 to our parent's @ISA, and our ->isa cache is simply our | |
321 parent's, with our name added. */ | |
322 /* newSVsv() is slow. This code is only faster if we can avoid | |
323 it by ensuring that SVs in the arrays are shared hash key | |
324 scalar SVs, because we can "copy" them very efficiently. | |
325 Although to be fair, we can't *ensure* this, as a reference | |
326 to the internal array is returned by mro::get_linear_isa(), | |
327 so we'll have to be defensive just in case someone faffed | |
328 with it. */ | |
329 if (basestash) { | |
330 SV **svp; | |
331 stored = MUTABLE_HV(sv_2mortal((SV*)newHVhv(HvMROMETA(basestash)->isa))); | |
332 av_extend(retval, subrv_items); | |
333 AvFILLp(retval) = subrv_items; | |
334 svp = AvARRAY(retval); | |
335 while(subrv_items--) { | |
336 SV *const val = *subrv_p++; | |
337 *++svp = SvIsCOW_shared_hash(val) | |
338 ? newSVhek(SvSHARED_HEK_FROM_PV(SvPVX(val))) | |
339 : newSVsv(val); | |
340 } | |
341 } else { | |
342 /* They have no stash. So create ourselves an ->isa cache | |
343 as if we'd copied it from what theirs should be. */ | |
344 stored = MUTABLE_HV(sv_2mortal(MUTABLE_SV(newHV()))); | |
345 (void) hv_store(stored, "UNIVERSAL", 9, &PL_sv_undef, 0); | |
346 av_push(retval, | |
347 newSVhek(HeKEY_hek(hv_store_ent(stored, sv, | |
348 &PL_sv_undef, 0)))); | |
349 } | |
350 } | |
351 } | |
352 } else { | |
353 /* We have no parents. */ | |
354 stored = MUTABLE_HV(sv_2mortal(MUTABLE_SV(newHV()))); | |
355 (void) hv_store(stored, "UNIVERSAL", 9, &PL_sv_undef, 0); | |
356 } | |
357 | |
358 (void) hv_store_ent(stored, our_name, &PL_sv_undef, 0); | |
359 | |
360 SvREFCNT_inc_simple_void_NN(stored); | |
361 SvTEMP_off(stored); | |
362 SvREADONLY_on(stored); | |
363 | |
364 meta->isa = stored; | |
365 | |
366 /* now that we're past the exception dangers, grab our own reference to | |
367 the AV we're about to use for the result. The reference owned by the | |
368 mortals' stack will be released soon, so everything will balance. */ | |
369 SvREFCNT_inc_simple_void_NN(retval); | |
370 SvTEMP_off(retval); | |
371 | |
372 /* we don't want anyone modifying the cache entry but us, | |
373 and we do so by replacing it completely */ | |
374 SvREADONLY_on(retval); | |
375 | |
376 return MUTABLE_AV(Perl_mro_set_private_data(aTHX_ meta, &dfs_alg, | |
377 MUTABLE_SV(retval))); | |
378 } | |
379 | |
380 /* | |
381 =for apidoc mro_get_linear_isa | |
382 | |
383 Returns the mro linearisation for the given stash. By default, this | |
384 will be whatever C<mro_get_linear_isa_dfs> returns unless some | |
385 other MRO is in effect for the stash. The return value is a | |
386 read-only AV*. | |
387 | |
388 You are responsible for C<SvREFCNT_inc()> on the | |
389 return value if you plan to store it anywhere | |
390 semi-permanently (otherwise it might be deleted | |
391 out from under you the next time the cache is | |
392 invalidated). | |
393 | |
394 =cut | |
395 */ | |
396 AV* | |
397 Perl_mro_get_linear_isa(pTHX_ HV *stash) | |
398 { | |
399 struct mro_meta* meta; | |
400 AV *isa; | |
401 | |
402 PERL_ARGS_ASSERT_MRO_GET_LINEAR_ISA; | |
403 if(!SvOOK(stash)) | |
404 Perl_croak(aTHX_ "Can't linearize anonymous symbol table"); | |
405 | |
406 meta = HvMROMETA(stash); | |
407 if (!meta->mro_which) | |
408 Perl_croak(aTHX_ "panic: invalid MRO!"); | |
409 isa = meta->mro_which->resolve(aTHX_ stash, 0); | |
410 | |
411 if (meta->mro_which != &dfs_alg) { /* skip for dfs, for speed */ | |
412 SV * const namesv = | |
413 (HvENAME(stash)||HvNAME(stash)) | |
414 ? newSVhek(HvENAME_HEK(stash) | |
415 ? HvENAME_HEK(stash) | |
416 : HvNAME_HEK(stash)) | |
417 : NULL; | |
418 | |
419 if(namesv && (AvFILLp(isa) == -1 || !sv_eq(*AvARRAY(isa), namesv))) | |
420 { | |
421 AV * const old = isa; | |
422 SV **svp; | |
423 SV **ovp = AvARRAY(old); | |
424 SV * const * const oend = ovp + AvFILLp(old) + 1; | |
425 isa = (AV *)sv_2mortal((SV *)newAV()); | |
426 av_extend(isa, AvFILLp(isa) = AvFILLp(old)+1); | |
427 *AvARRAY(isa) = namesv; | |
428 svp = AvARRAY(isa)+1; | |
429 while (ovp < oend) *svp++ = SvREFCNT_inc(*ovp++); | |
430 } | |
431 else SvREFCNT_dec(namesv); | |
432 } | |
433 | |
434 if (!meta->isa) { | |
435 HV *const isa_hash = newHV(); | |
436 /* Linearisation didn't build it for us, so do it here. */ | |
437 SV *const *svp = AvARRAY(isa); | |
438 SV *const *const svp_end = svp + AvFILLp(isa) + 1; | |
439 const HEK *canon_name = HvENAME_HEK(stash); | |
440 if (!canon_name) canon_name = HvNAME_HEK(stash); | |
441 | |
442 while (svp < svp_end) { | |
443 (void) hv_store_ent(isa_hash, *svp++, &PL_sv_undef, 0); | |
444 } | |
445 | |
446 (void) hv_common(isa_hash, NULL, HEK_KEY(canon_name), | |
447 HEK_LEN(canon_name), HEK_FLAGS(canon_name), | |
448 HV_FETCH_ISSTORE, &PL_sv_undef, | |
449 HEK_HASH(canon_name)); | |
450 (void) hv_store(isa_hash, "UNIVERSAL", 9, &PL_sv_undef, 0); | |
451 | |
452 SvREADONLY_on(isa_hash); | |
453 | |
454 meta->isa = isa_hash; | |
455 } | |
456 | |
457 return isa; | |
458 } | |
459 | |
460 /* | |
461 =for apidoc mro_isa_changed_in | |
462 | |
463 Takes the necessary steps (cache invalidations, mostly) | |
464 when the @ISA of the given package has changed. Invoked | |
465 by the C<setisa> magic, should not need to invoke directly. | |
466 | |
467 =cut | |
468 */ | |
469 | |
470 /* Macro to avoid repeating the code five times. */ | |
471 #define CLEAR_LINEAR(mEta) \ | |
472 if (mEta->mro_linear_all) { \ | |
473 SvREFCNT_dec(MUTABLE_SV(mEta->mro_linear_all)); \ | |
474 mEta->mro_linear_all = NULL; \ | |
475 /* This is just acting as a shortcut pointer. */ \ | |
476 mEta->mro_linear_current = NULL; \ | |
477 } else if (mEta->mro_linear_current) { \ | |
478 /* Only the current MRO is stored, so this owns the data. */ \ | |
479 SvREFCNT_dec(mEta->mro_linear_current); \ | |
480 mEta->mro_linear_current = NULL; \ | |
481 } | |
482 | |
483 void | |
484 Perl_mro_isa_changed_in(pTHX_ HV* stash) | |
485 { | |
486 HV* isarev; | |
487 AV* linear_mro; | |
488 HE* iter; | |
489 SV** svp; | |
490 I32 items; | |
491 bool is_universal; | |
492 struct mro_meta * meta; | |
493 HV *isa = NULL; | |
494 | |
495 const HEK * const stashhek = HvENAME_HEK(stash); | |
496 const char * const stashname = HvENAME_get(stash); | |
497 const STRLEN stashname_len = HvENAMELEN_get(stash); | |
498 | |
499 PERL_ARGS_ASSERT_MRO_ISA_CHANGED_IN; | |
500 | |
501 if(!stashname) | |
502 Perl_croak(aTHX_ "Can't call mro_isa_changed_in() on anonymous symbol table"); | |
503 | |
504 | |
505 /* wipe out the cached linearizations for this stash */ | |
506 meta = HvMROMETA(stash); | |
507 CLEAR_LINEAR(meta); | |
508 if (meta->isa) { | |
509 /* Steal it for our own purposes. */ | |
510 isa = (HV *)sv_2mortal((SV *)meta->isa); | |
511 meta->isa = NULL; | |
512 } | |
513 | |
514 /* Inc the package generation, since our @ISA changed */ | |
515 meta->pkg_gen++; | |
516 | |
517 /* Wipe the global method cache if this package | |
518 is UNIVERSAL or one of its parents */ | |
519 | |
520 svp = hv_fetchhek(PL_isarev, stashhek, 0); | |
521 isarev = svp ? MUTABLE_HV(*svp) : NULL; | |
522 | |
523 if((stashname_len == 9 && strEQ(stashname, "UNIVERSAL")) | |
524 || (isarev && hv_exists(isarev, "UNIVERSAL", 9))) { | |
525 PL_sub_generation++; | |
526 is_universal = TRUE; | |
527 } | |
528 else { /* Wipe the local method cache otherwise */ | |
529 meta->cache_gen++; | |
530 is_universal = FALSE; | |
531 } | |
532 | |
533 /* wipe next::method cache too */ | |
534 if(meta->mro_nextmethod) hv_clear(meta->mro_nextmethod); | |
535 | |
536 /* Changes to @ISA might turn overloading on */ | |
537 HvAMAGIC_on(stash); | |
538 /* pessimise derefs for now. Will get recalculated by Gv_AMupdate() */ | |
539 HvAUX(stash)->xhv_aux_flags &= ~HvAUXf_NO_DEREF; | |
540 | |
541 /* DESTROY can be cached in SvSTASH. */ | |
542 if (!SvOBJECT(stash)) SvSTASH(stash) = NULL; | |
543 | |
544 /* Iterate the isarev (classes that are our children), | |
545 wiping out their linearization, method and isa caches | |
546 and upating PL_isarev. */ | |
547 if(isarev) { | |
548 HV *isa_hashes = NULL; | |
549 | |
550 /* We have to iterate through isarev twice to avoid a chicken and | |
551 * egg problem: if A inherits from B and both are in isarev, A might | |
552 * be processed before B and use B's previous linearisation. | |
553 */ | |
554 | |
555 /* First iteration: Wipe everything, but stash away the isa hashes | |
556 * since we still need them for updating PL_isarev. | |
557 */ | |
558 | |
559 if(hv_iterinit(isarev)) { | |
560 /* Only create the hash if we need it; i.e., if isarev has | |
561 any elements. */ | |
562 isa_hashes = (HV *)sv_2mortal((SV *)newHV()); | |
563 } | |
564 while((iter = hv_iternext(isarev))) { | |
565 HV* revstash = gv_stashsv(hv_iterkeysv(iter), 0); | |
566 struct mro_meta* revmeta; | |
567 | |
568 if(!revstash) continue; | |
569 revmeta = HvMROMETA(revstash); | |
570 CLEAR_LINEAR(revmeta); | |
571 if(!is_universal) | |
572 revmeta->cache_gen++; | |
573 if(revmeta->mro_nextmethod) | |
574 hv_clear(revmeta->mro_nextmethod); | |
575 if (!SvOBJECT(revstash)) SvSTASH(revstash) = NULL; | |
576 | |
577 (void) | |
578 hv_store( | |
579 isa_hashes, (const char*)&revstash, sizeof(HV *), | |
580 revmeta->isa ? (SV *)revmeta->isa : &PL_sv_undef, 0 | |
581 ); | |
582 revmeta->isa = NULL; | |
583 } | |
584 | |
585 /* Second pass: Update PL_isarev. We can just use isa_hashes to | |
586 * avoid another round of stash lookups. */ | |
587 | |
588 /* isarev might be deleted from PL_isarev during this loop, so hang | |
589 * on to it. */ | |
590 SvREFCNT_inc_simple_void_NN(sv_2mortal((SV *)isarev)); | |
591 | |
592 if(isa_hashes) { | |
593 hv_iterinit(isa_hashes); | |
594 while((iter = hv_iternext(isa_hashes))) { | |
595 HV* const revstash = *(HV **)HEK_KEY(HeKEY_hek(iter)); | |
596 HV * const isa = (HV *)HeVAL(iter); | |
597 const HEK *namehek; | |
598 | |
599 /* We're starting at the 2nd element, skipping revstash */ | |
600 linear_mro = mro_get_linear_isa(revstash); | |
601 svp = AvARRAY(linear_mro) + 1; | |
602 items = AvFILLp(linear_mro); | |
603 | |
604 namehek = HvENAME_HEK(revstash); | |
605 if (!namehek) namehek = HvNAME_HEK(revstash); | |
606 | |
607 while (items--) { | |
608 SV* const sv = *svp++; | |
609 HV* mroisarev; | |
610 | |
611 HE *he = hv_fetch_ent(PL_isarev, sv, TRUE, 0); | |
612 | |
613 /* That fetch should not fail. But if it had to create | |
614 a new SV for us, then will need to upgrade it to an | |
615 HV (which sv_upgrade() can now do for us). */ | |
616 | |
617 mroisarev = MUTABLE_HV(HeVAL(he)); | |
618 | |
619 SvUPGRADE(MUTABLE_SV(mroisarev), SVt_PVHV); | |
620 | |
621 /* This hash only ever contains PL_sv_yes. Storing it | |
622 over itself is almost as cheap as calling hv_exists, | |
623 so on aggregate we expect to save time by not making | |
624 two calls to the common HV code for the case where | |
625 it doesn't exist. */ | |
626 | |
627 (void) | |
628 hv_storehek(mroisarev, namehek, &PL_sv_yes); | |
629 } | |
630 | |
631 if ((SV *)isa != &PL_sv_undef) { | |
632 assert(namehek); | |
633 mro_clean_isarev( | |
634 isa, HEK_KEY(namehek), HEK_LEN(namehek), | |
635 HvMROMETA(revstash)->isa, HEK_HASH(namehek), | |
636 HEK_UTF8(namehek) | |
637 ); | |
638 } | |
639 } | |
640 } | |
641 } | |
642 | |
643 /* Now iterate our MRO (parents), adding ourselves and everything from | |
644 our isarev to their isarev. | |
645 */ | |
646 | |
647 /* We're starting at the 2nd element, skipping ourselves here */ | |
648 linear_mro = mro_get_linear_isa(stash); | |
649 svp = AvARRAY(linear_mro) + 1; | |
650 items = AvFILLp(linear_mro); | |
651 | |
652 while (items--) { | |
653 SV* const sv = *svp++; | |
654 HV* mroisarev; | |
655 | |
656 HE *he = hv_fetch_ent(PL_isarev, sv, TRUE, 0); | |
657 | |
658 /* That fetch should not fail. But if it had to create a new SV for | |
659 us, then will need to upgrade it to an HV (which sv_upgrade() can | |
660 now do for us. */ | |
661 | |
662 mroisarev = MUTABLE_HV(HeVAL(he)); | |
663 | |
664 SvUPGRADE(MUTABLE_SV(mroisarev), SVt_PVHV); | |
665 | |
666 /* This hash only ever contains PL_sv_yes. Storing it over itself is | |
667 almost as cheap as calling hv_exists, so on aggregate we expect to | |
668 save time by not making two calls to the common HV code for the | |
669 case where it doesn't exist. */ | |
670 | |
671 (void)hv_storehek(mroisarev, stashhek, &PL_sv_yes); | |
672 } | |
673 | |
674 /* Delete our name from our former parents' isarevs. */ | |
675 if(isa && HvARRAY(isa)) | |
676 mro_clean_isarev(isa, stashname, stashname_len, meta->isa, | |
677 HEK_HASH(stashhek), HEK_UTF8(stashhek)); | |
678 } | |
679 | |
680 /* Deletes name from all the isarev entries listed in isa */ | |
681 STATIC void | |
682 S_mro_clean_isarev(pTHX_ HV * const isa, const char * const name, | |
683 const STRLEN len, HV * const exceptions, U32 hash, | |
684 U32 flags) | |
685 { | |
686 HE* iter; | |
687 | |
688 PERL_ARGS_ASSERT_MRO_CLEAN_ISAREV; | |
689 | |
690 /* Delete our name from our former parents' isarevs. */ | |
691 if(HvARRAY(isa) && hv_iterinit(isa)) { | |
692 SV **svp; | |
693 while((iter = hv_iternext(isa))) { | |
694 I32 klen; | |
695 const char * const key = hv_iterkey(iter, &klen); | |
696 if(exceptions && hv_exists(exceptions, key, HeKUTF8(iter) ? -klen : klen)) | |
697 continue; | |
698 svp = hv_fetch(PL_isarev, key, HeKUTF8(iter) ? -klen : klen, 0); | |
699 if(svp) { | |
700 HV * const isarev = (HV *)*svp; | |
701 (void)hv_common(isarev, NULL, name, len, flags, | |
702 G_DISCARD|HV_DELETE, NULL, hash); | |
703 if(!HvARRAY(isarev) || !HvUSEDKEYS(isarev)) | |
704 (void)hv_delete(PL_isarev, key, | |
705 HeKUTF8(iter) ? -klen : klen, G_DISCARD); | |
706 } | |
707 } | |
708 } | |
709 } | |
710 | |
711 /* | |
712 =for apidoc mro_package_moved | |
713 | |
714 Call this function to signal to a stash that it has been assigned to | |
715 another spot in the stash hierarchy. C<stash> is the stash that has been | |
716 assigned. C<oldstash> is the stash it replaces, if any. C<gv> is the glob | |
717 that is actually being assigned to. | |
718 | |
719 This can also be called with a null first argument to | |
720 indicate that C<oldstash> has been deleted. | |
721 | |
722 This function invalidates isa caches on the old stash, on all subpackages | |
723 nested inside it, and on the subclasses of all those, including | |
724 non-existent packages that have corresponding entries in C<stash>. | |
725 | |
726 It also sets the effective names (C<HvENAME>) on all the stashes as | |
727 appropriate. | |
728 | |
729 If the C<gv> is present and is not in the symbol table, then this function | |
730 simply returns. This checked will be skipped if C<flags & 1>. | |
731 | |
732 =cut | |
733 */ | |
734 void | |
735 Perl_mro_package_moved(pTHX_ HV * const stash, HV * const oldstash, | |
736 const GV * const gv, U32 flags) | |
737 { | |
738 SV *namesv; | |
739 HEK **namep; | |
740 I32 name_count; | |
741 HV *stashes; | |
742 HE* iter; | |
743 | |
744 PERL_ARGS_ASSERT_MRO_PACKAGE_MOVED; | |
745 assert(stash || oldstash); | |
746 | |
747 /* Determine the name(s) of the location that stash was assigned to | |
748 * or from which oldstash was removed. | |
749 * | |
750 * We cannot reliably use the name in oldstash, because it may have | |
751 * been deleted from the location in the symbol table that its name | |
752 * suggests, as in this case: | |
753 * | |
754 * $globref = \*foo::bar::; | |
755 * Symbol::delete_package("foo"); | |
756 * *$globref = \%baz::; | |
757 * *$globref = *frelp::; | |
758 * # calls mro_package_moved(%frelp::, %baz::, *$globref, NULL, 0) | |
759 * | |
760 * So we get it from the gv. But, since the gv may no longer be in the | |
761 * symbol table, we check that first. The only reliable way to tell is | |
762 * to see whether its stash has an effective name and whether the gv | |
763 * resides in that stash under its name. That effective name may be | |
764 * different from what gv_fullname4 would use. | |
765 * If flags & 1, the caller has asked us to skip the check. | |
766 */ | |
767 if(!(flags & 1)) { | |
768 SV **svp; | |
769 if( | |
770 !GvSTASH(gv) || !HvENAME(GvSTASH(gv)) || | |
771 !(svp = hv_fetchhek(GvSTASH(gv), GvNAME_HEK(gv), 0)) || | |
772 *svp != (SV *)gv | |
773 ) return; | |
774 } | |
775 assert(SvOOK(GvSTASH(gv))); | |
776 assert(GvNAMELEN(gv)); | |
777 assert(GvNAME(gv)[GvNAMELEN(gv) - 1] == ':'); | |
778 assert(GvNAMELEN(gv) == 1 || GvNAME(gv)[GvNAMELEN(gv) - 2] == ':'); | |
779 name_count = HvAUX(GvSTASH(gv))->xhv_name_count; | |
780 if (!name_count) { | |
781 name_count = 1; | |
782 namep = &HvAUX(GvSTASH(gv))->xhv_name_u.xhvnameu_name; | |
783 } | |
784 else { | |
785 namep = HvAUX(GvSTASH(gv))->xhv_name_u.xhvnameu_names; | |
786 if (name_count < 0) ++namep, name_count = -name_count - 1; | |
787 } | |
788 if (name_count == 1) { | |
789 if (HEK_LEN(*namep) == 4 && strnEQ(HEK_KEY(*namep), "main", 4)) { | |
790 namesv = GvNAMELEN(gv) == 1 | |
791 ? newSVpvs_flags(":", SVs_TEMP) | |
792 : newSVpvs_flags("", SVs_TEMP); | |
793 } | |
794 else { | |
795 namesv = sv_2mortal(newSVhek(*namep)); | |
796 if (GvNAMELEN(gv) == 1) sv_catpvs(namesv, ":"); | |
797 else sv_catpvs(namesv, "::"); | |
798 } | |
799 if (GvNAMELEN(gv) != 1) { | |
800 sv_catpvn_flags( | |
801 namesv, GvNAME(gv), GvNAMELEN(gv) - 2, | |
802 /* skip trailing :: */ | |
803 GvNAMEUTF8(gv) ? SV_CATUTF8 : SV_CATBYTES | |
804 ); | |
805 } | |
806 } | |
807 else { | |
808 SV *aname; | |
809 namesv = sv_2mortal((SV *)newAV()); | |
810 while (name_count--) { | |
811 if(HEK_LEN(*namep) == 4 && strnEQ(HEK_KEY(*namep), "main", 4)){ | |
812 aname = GvNAMELEN(gv) == 1 | |
813 ? newSVpvs(":") | |
814 : newSVpvs(""); | |
815 namep++; | |
816 } | |
817 else { | |
818 aname = newSVhek(*namep++); | |
819 if (GvNAMELEN(gv) == 1) sv_catpvs(aname, ":"); | |
820 else sv_catpvs(aname, "::"); | |
821 } | |
822 if (GvNAMELEN(gv) != 1) { | |
823 sv_catpvn_flags( | |
824 aname, GvNAME(gv), GvNAMELEN(gv) - 2, | |
825 /* skip trailing :: */ | |
826 GvNAMEUTF8(gv) ? SV_CATUTF8 : SV_CATBYTES | |
827 ); | |
828 } | |
829 av_push((AV *)namesv, aname); | |
830 } | |
831 } | |
832 | |
833 /* Get a list of all the affected classes. */ | |
834 /* We cannot simply pass them all to mro_isa_changed_in to avoid | |
835 the list, as that function assumes that only one package has | |
836 changed. It does not work with: | |
837 | |
838 @foo::ISA = qw( B B::B ); | |
839 *B:: = delete $::{"A::"}; | |
840 | |
841 as neither B nor B::B can be updated before the other, since they | |
842 will reset caches on foo, which will see either B or B::B with the | |
843 wrong name. The names must be set on *all* affected stashes before | |
844 we do anything else. (And linearisations must be cleared, too.) | |
845 */ | |
846 stashes = (HV *) sv_2mortal((SV *)newHV()); | |
847 mro_gather_and_rename( | |
848 stashes, (HV *) sv_2mortal((SV *)newHV()), | |
849 stash, oldstash, namesv | |
850 ); | |
851 | |
852 /* Once the caches have been wiped on all the classes, call | |
853 mro_isa_changed_in on each. */ | |
854 hv_iterinit(stashes); | |
855 while((iter = hv_iternext(stashes))) { | |
856 HV * const stash = *(HV **)HEK_KEY(HeKEY_hek(iter)); | |
857 if(HvENAME(stash)) { | |
858 /* We have to restore the original meta->isa (that | |
859 mro_gather_and_rename set aside for us) this way, in case | |
860 one class in this list is a superclass of a another class | |
861 that we have already encountered. In such a case, meta->isa | |
862 | |
863 from PL_isarev. */ | |
864 struct mro_meta * const meta = HvMROMETA(stash); | |
865 if(meta->isa != (HV *)HeVAL(iter)){ | |
866 SvREFCNT_dec(meta->isa); | |
867 meta->isa | |
868 = HeVAL(iter) == &PL_sv_yes | |
869 ? NULL | |
870 : (HV *)HeVAL(iter); | |
871 HeVAL(iter) = NULL; /* We donated our reference count. */ | |
872 } | |
873 mro_isa_changed_in(stash); | |
874 } | |
875 } | |
876 } | |
877 | |
878 STATIC void | |
879 S_mro_gather_and_rename(pTHX_ HV * const stashes, HV * const seen_stashes, | |
880 HV *stash, HV *oldstash, SV *namesv) | |
881 { | |
882 XPVHV* xhv; | |
883 HE *entry; | |
884 I32 riter = -1; | |
885 I32 items = 0; | |
886 const bool stash_had_name = stash && HvENAME(stash); | |
887 bool fetched_isarev = FALSE; | |
888 HV *seen = NULL; | |
889 HV *isarev = NULL; | |
890 SV **svp = NULL; | |
891 | |
892 PERL_ARGS_ASSERT_MRO_GATHER_AND_RENAME; | |
893 | |
894 /* We use the seen_stashes hash to keep track of which packages have | |
895 been encountered so far. This must be separate from the main list of | |
896 stashes, as we need to distinguish between stashes being assigned | |
897 and stashes being replaced/deleted. (A nested stash can be on both | |
898 sides of an assignment. We cannot simply skip iterating through a | |
899 stash on the right if we have seen it on the left, as it will not | |
900 get its ename assigned to it.) | |
901 | |
902 To avoid allocating extra SVs, instead of a bitfield we can make | |
903 bizarre use of immortals: | |
904 | |
905 &PL_sv_undef: seen on the left (oldstash) | |
906 &PL_sv_no : seen on the right (stash) | |
907 &PL_sv_yes : seen on both sides | |
908 | |
909 */ | |
910 | |
911 if(oldstash) { | |
912 /* Add to the big list. */ | |
913 struct mro_meta * meta; | |
914 HE * const entry | |
915 = (HE *) | |
916 hv_common( | |
917 seen_stashes, NULL, (const char *)&oldstash, sizeof(HV *), 0, | |
918 HV_FETCH_LVALUE|HV_FETCH_EMPTY_HE, NULL, 0 | |
919 ); | |
920 if(HeVAL(entry) == &PL_sv_undef || HeVAL(entry) == &PL_sv_yes) { | |
921 oldstash = NULL; | |
922 goto check_stash; | |
923 } | |
924 HeVAL(entry) | |
925 = HeVAL(entry) == &PL_sv_no ? &PL_sv_yes : &PL_sv_undef; | |
926 meta = HvMROMETA(oldstash); | |
927 (void) | |
928 hv_store( | |
929 stashes, (const char *)&oldstash, sizeof(HV *), | |
930 meta->isa | |
931 ? SvREFCNT_inc_simple_NN((SV *)meta->isa) | |
932 : &PL_sv_yes, | |
933 0 | |
934 ); | |
935 CLEAR_LINEAR(meta); | |
936 | |
937 /* Update the effective name. */ | |
938 if(HvENAME_get(oldstash)) { | |
939 const HEK * const enamehek = HvENAME_HEK(oldstash); | |
940 if(SvTYPE(namesv) == SVt_PVAV) { | |
941 items = AvFILLp((AV *)namesv) + 1; | |
942 svp = AvARRAY((AV *)namesv); | |
943 } | |
944 else { | |
945 items = 1; | |
946 svp = &namesv; | |
947 } | |
948 while (items--) { | |
949 const U32 name_utf8 = SvUTF8(*svp); | |
950 STRLEN len; | |
951 const char *name = SvPVx_const(*svp, len); | |
952 if(PL_stashcache) { | |
953 DEBUG_o(Perl_deb(aTHX_ "mro_gather_and_rename clearing PL_stashcache for '%"SVf"'\n", | |
954 SVfARG(*svp))); | |
955 (void)hv_delete(PL_stashcache, name, name_utf8 ? -(I32)len : (I32)len, G_DISCARD); | |
956 } | |
957 ++svp; | |
958 hv_ename_delete(oldstash, name, len, name_utf8); | |
959 | |
960 if (!fetched_isarev) { | |
961 /* If the name deletion caused a name change, then we | |
962 * are not going to call mro_isa_changed_in with this | |
963 * name (and not at all if it has become anonymous) so | |
964 * we need to delete old isarev entries here, both | |
965 * those in the superclasses and this class's own list | |
966 * of subclasses. We simply delete the latter from | |
967 * PL_isarev, since we still need it. hv_delete morti- | |
968 * fies it for us, so sv_2mortal is not necessary. */ | |
969 if(HvENAME_HEK(oldstash) != enamehek) { | |
970 if(meta->isa && HvARRAY(meta->isa)) | |
971 mro_clean_isarev(meta->isa, name, len, 0, 0, | |
972 name_utf8 ? HVhek_UTF8 : 0); | |
973 isarev = (HV *)hv_delete(PL_isarev, name, | |
974 name_utf8 ? -(I32)len : (I32)len, 0); | |
975 fetched_isarev=TRUE; | |
976 } | |
977 } | |
978 } | |
979 } | |
980 } | |
981 check_stash: | |
982 if(stash) { | |
983 if(SvTYPE(namesv) == SVt_PVAV) { | |
984 items = AvFILLp((AV *)namesv) + 1; | |
985 svp = AvARRAY((AV *)namesv); | |
986 } | |
987 else { | |
988 items = 1; | |
989 svp = &namesv; | |
990 } | |
991 while (items--) { | |
992 const U32 name_utf8 = SvUTF8(*svp); | |
993 STRLEN len; | |
994 const char *name = SvPVx_const(*svp++, len); | |
995 hv_ename_add(stash, name, len, name_utf8); | |
996 } | |
997 | |
998 /* Add it to the big list if it needs | |
999 * mro_isa_changed_in called on it. That happens if it was | |
1000 * detached from the symbol table (so it had no HvENAME) before | |
1001 * being assigned to the spot named by the 'name' variable, because | |
1002 * its cached isa linearisation is now stale (the effective name | |
1003 * having changed), and subclasses will then use that cache when | |
1004 * mro_package_moved calls mro_isa_changed_in. (See | |
1005 * [perl #77358].) | |
1006 * | |
1007 * If it did have a name, then its previous name is still | |
1008 * used in isa caches, and there is no need for | |
1009 * mro_package_moved to call mro_isa_changed_in. | |
1010 */ | |
1011 | |
1012 entry | |
1013 = (HE *) | |
1014 hv_common( | |
1015 seen_stashes, NULL, (const char *)&stash, sizeof(HV *), 0, | |
1016 HV_FETCH_LVALUE|HV_FETCH_EMPTY_HE, NULL, 0 | |
1017 ); | |
1018 if(HeVAL(entry) == &PL_sv_yes || HeVAL(entry) == &PL_sv_no) | |
1019 stash = NULL; | |
1020 else { | |
1021 HeVAL(entry) | |
1022 = HeVAL(entry) == &PL_sv_undef ? &PL_sv_yes : &PL_sv_no; | |
1023 if(!stash_had_name) | |
1024 { | |
1025 struct mro_meta * const meta = HvMROMETA(stash); | |
1026 (void) | |
1027 hv_store( | |
1028 stashes, (const char *)&stash, sizeof(HV *), | |
1029 meta->isa | |
1030 ? SvREFCNT_inc_simple_NN((SV *)meta->isa) | |
1031 : &PL_sv_yes, | |
1032 0 | |
1033 ); | |
1034 CLEAR_LINEAR(meta); | |
1035 } | |
1036 } | |
1037 } | |
1038 | |
1039 if(!stash && !oldstash) | |
1040 /* Both stashes have been encountered already. */ | |
1041 return; | |
1042 | |
1043 /* Add all the subclasses to the big list. */ | |
1044 if(!fetched_isarev) { | |
1045 /* If oldstash is not null, then we can use its HvENAME to look up | |
1046 the isarev hash, since all its subclasses will be listed there. | |
1047 It will always have an HvENAME. It the HvENAME was removed | |
1048 above, then fetch_isarev will be true, and this code will not be | |
1049 reached. | |
1050 | |
1051 If oldstash is null, then this is an empty spot with no stash in | |
1052 it, so subclasses could be listed in isarev hashes belonging to | |
1053 any of the names, so we have to check all of them. | |
1054 */ | |
1055 assert(!oldstash || HvENAME(oldstash)); | |
1056 if (oldstash) { | |
1057 /* Extra variable to avoid a compiler warning */ | |
1058 const HEK * const hvename = HvENAME_HEK(oldstash); | |
1059 fetched_isarev = TRUE; | |
1060 svp = hv_fetchhek(PL_isarev, hvename, 0); | |
1061 if (svp) isarev = MUTABLE_HV(*svp); | |
1062 } | |
1063 else if(SvTYPE(namesv) == SVt_PVAV) { | |
1064 items = AvFILLp((AV *)namesv) + 1; | |
1065 svp = AvARRAY((AV *)namesv); | |
1066 } | |
1067 else { | |
1068 items = 1; | |
1069 svp = &namesv; | |
1070 } | |
1071 } | |
1072 if( | |
1073 isarev || !fetched_isarev | |
1074 ) { | |
1075 while (fetched_isarev || items--) { | |
1076 HE *iter; | |
1077 | |
1078 if (!fetched_isarev) { | |
1079 HE * const he = hv_fetch_ent(PL_isarev, *svp++, 0, 0); | |
1080 if (!he || !(isarev = MUTABLE_HV(HeVAL(he)))) continue; | |
1081 } | |
1082 | |
1083 hv_iterinit(isarev); | |
1084 while((iter = hv_iternext(isarev))) { | |
1085 HV* revstash = gv_stashsv(hv_iterkeysv(iter), 0); | |
1086 struct mro_meta * meta; | |
1087 | |
1088 if(!revstash) continue; | |
1089 meta = HvMROMETA(revstash); | |
1090 (void) | |
1091 hv_store( | |
1092 stashes, (const char *)&revstash, sizeof(HV *), | |
1093 meta->isa | |
1094 ? SvREFCNT_inc_simple_NN((SV *)meta->isa) | |
1095 : &PL_sv_yes, | |
1096 0 | |
1097 ); | |
1098 CLEAR_LINEAR(meta); | |
1099 } | |
1100 | |
1101 if (fetched_isarev) break; | |
1102 } | |
1103 } | |
1104 | |
1105 /* This is partly based on code in hv_iternext_flags. We are not call- | |
1106 ing that here, as we want to avoid resetting the hash iterator. */ | |
1107 | |
1108 /* Skip the entire loop if the hash is empty. */ | |
1109 if(oldstash && HvUSEDKEYS(oldstash)) { | |
1110 xhv = (XPVHV*)SvANY(oldstash); | |
1111 seen = (HV *) sv_2mortal((SV *)newHV()); | |
1112 | |
1113 /* Iterate through entries in the oldstash, adding them to the | |
1114 list, meanwhile doing the equivalent of $seen{$key} = 1. | |
1115 */ | |
1116 | |
1117 while (++riter <= (I32)xhv->xhv_max) { | |
1118 entry = (HvARRAY(oldstash))[riter]; | |
1119 | |
1120 /* Iterate through the entries in this list */ | |
1121 for(; entry; entry = HeNEXT(entry)) { | |
1122 const char* key; | |
1123 I32 len; | |
1124 | |
1125 /* If this entry is not a glob, ignore it. | |
1126 Try the next. */ | |
1127 if (!isGV(HeVAL(entry))) continue; | |
1128 | |
1129 key = hv_iterkey(entry, &len); | |
1130 if ((len > 1 && key[len-2] == ':' && key[len-1] == ':') | |
1131 || (len == 1 && key[0] == ':')) { | |
1132 HV * const oldsubstash = GvHV(HeVAL(entry)); | |
1133 SV ** const stashentry | |
1134 = stash ? hv_fetch(stash, key, HeUTF8(entry) ? -(I32)len : (I32)len, 0) : NULL; | |
1135 HV *substash = NULL; | |
1136 | |
1137 /* Avoid main::main::main::... */ | |
1138 if(oldsubstash == oldstash) continue; | |
1139 | |
1140 if( | |
1141 ( | |
1142 stashentry && *stashentry && isGV(*stashentry) | |
1143 && (substash = GvHV(*stashentry)) | |
1144 ) | |
1145 || (oldsubstash && HvENAME_get(oldsubstash)) | |
1146 ) | |
1147 { | |
1148 /* Add :: and the key (minus the trailing ::) | |
1149 to each name. */ | |
1150 SV *subname; | |
1151 if(SvTYPE(namesv) == SVt_PVAV) { | |
1152 SV *aname; | |
1153 items = AvFILLp((AV *)namesv) + 1; | |
1154 svp = AvARRAY((AV *)namesv); | |
1155 subname = sv_2mortal((SV *)newAV()); | |
1156 while (items--) { | |
1157 aname = newSVsv(*svp++); | |
1158 if (len == 1) | |
1159 sv_catpvs(aname, ":"); | |
1160 else { | |
1161 sv_catpvs(aname, "::"); | |
1162 sv_catpvn_flags( | |
1163 aname, key, len-2, | |
1164 HeUTF8(entry) | |
1165 ? SV_CATUTF8 : SV_CATBYTES | |
1166 ); | |
1167 } | |
1168 av_push((AV *)subname, aname); | |
1169 } | |
1170 } | |
1171 else { | |
1172 subname = sv_2mortal(newSVsv(namesv)); | |
1173 if (len == 1) sv_catpvs(subname, ":"); | |
1174 else { | |
1175 sv_catpvs(subname, "::"); | |
1176 sv_catpvn_flags( | |
1177 subname, key, len-2, | |
1178 HeUTF8(entry) ? SV_CATUTF8 : SV_CATBYTES | |
1179 ); | |
1180 } | |
1181 } | |
1182 mro_gather_and_rename( | |
1183 stashes, seen_stashes, | |
1184 substash, oldsubstash, subname | |
1185 ); | |
1186 } | |
1187 | |
1188 (void)hv_store(seen, key, HeUTF8(entry) ? -(I32)len : (I32)len, &PL_sv_yes, 0); | |
1189 } | |
1190 } | |
1191 } | |
1192 } | |
1193 | |
1194 /* Skip the entire loop if the hash is empty. */ | |
1195 if (stash && HvUSEDKEYS(stash)) { | |
1196 xhv = (XPVHV*)SvANY(stash); | |
1197 riter = -1; | |
1198 | |
1199 /* Iterate through the new stash, skipping $seen{$key} items, | |
1200 calling mro_gather_and_rename(stashes,seen,entry,NULL, ...). */ | |
1201 while (++riter <= (I32)xhv->xhv_max) { | |
1202 entry = (HvARRAY(stash))[riter]; | |
1203 | |
1204 /* Iterate through the entries in this list */ | |
1205 for(; entry; entry = HeNEXT(entry)) { | |
1206 const char* key; | |
1207 I32 len; | |
1208 | |
1209 /* If this entry is not a glob, ignore it. | |
1210 Try the next. */ | |
1211 if (!isGV(HeVAL(entry))) continue; | |
1212 | |
1213 key = hv_iterkey(entry, &len); | |
1214 if ((len > 1 && key[len-2] == ':' && key[len-1] == ':') | |
1215 || (len == 1 && key[0] == ':')) { | |
1216 HV *substash; | |
1217 | |
1218 /* If this entry was seen when we iterated through the | |
1219 oldstash, skip it. */ | |
1220 if(seen && hv_exists(seen, key, HeUTF8(entry) ? -(I32)len : (I32)len)) continue; | |
1221 | |
1222 /* We get here only if this stash has no corresponding | |
1223 entry in the stash being replaced. */ | |
1224 | |
1225 substash = GvHV(HeVAL(entry)); | |
1226 if(substash) { | |
1227 SV *subname; | |
1228 | |
1229 /* Avoid checking main::main::main::... */ | |
1230 if(substash == stash) continue; | |
1231 | |
1232 /* Add :: and the key (minus the trailing ::) | |
1233 to each name. */ | |
1234 if(SvTYPE(namesv) == SVt_PVAV) { | |
1235 SV *aname; | |
1236 items = AvFILLp((AV *)namesv) + 1; | |
1237 svp = AvARRAY((AV *)namesv); | |
1238 subname = sv_2mortal((SV *)newAV()); | |
1239 while (items--) { | |
1240 aname = newSVsv(*svp++); | |
1241 if (len == 1) | |
1242 sv_catpvs(aname, ":"); | |
1243 else { | |
1244 sv_catpvs(aname, "::"); | |
1245 sv_catpvn_flags( | |
1246 aname, key, len-2, | |
1247 HeUTF8(entry) | |
1248 ? SV_CATUTF8 : SV_CATBYTES | |
1249 ); | |
1250 } | |
1251 av_push((AV *)subname, aname); | |
1252 } | |
1253 } | |
1254 else { | |
1255 subname = sv_2mortal(newSVsv(namesv)); | |
1256 if (len == 1) sv_catpvs(subname, ":"); | |
1257 else { | |
1258 sv_catpvs(subname, "::"); | |
1259 sv_catpvn_flags( | |
1260 subname, key, len-2, | |
1261 HeUTF8(entry) ? SV_CATUTF8 : SV_CATBYTES | |
1262 ); | |
1263 } | |
1264 } | |
1265 mro_gather_and_rename( | |
1266 stashes, seen_stashes, | |
1267 substash, NULL, subname | |
1268 ); | |
1269 } | |
1270 } | |
1271 } | |
1272 } | |
1273 } | |
1274 } | |
1275 | |
1276 /* | |
1277 =for apidoc mro_method_changed_in | |
1278 | |
1279 Invalidates method caching on any child classes | |
1280 of the given stash, so that they might notice | |
1281 the changes in this one. | |
1282 | |
1283 Ideally, all instances of C<PL_sub_generation++> in | |
1284 perl source outside of F<mro.c> should be | |
1285 replaced by calls to this. | |
1286 | |
1287 Perl automatically handles most of the common | |
1288 ways a method might be redefined. However, there | |
1289 are a few ways you could change a method in a stash | |
1290 without the cache code noticing, in which case you | |
1291 need to call this method afterwards: | |
1292 | |
1293 1) Directly manipulating the stash HV entries from | |
1294 XS code. | |
1295 | |
1296 2) Assigning a reference to a readonly scalar | |
1297 constant into a stash entry in order to create | |
1298 a constant subroutine (like constant.pm | |
1299 does). | |
1300 | |
1301 This same method is available from pure perl | |
1302 via, C<mro::method_changed_in(classname)>. | |
1303 | |
1304 =cut | |
1305 */ | |
1306 void | |
1307 Perl_mro_method_changed_in(pTHX_ HV *stash) | |
1308 { | |
1309 const char * const stashname = HvENAME_get(stash); | |
1310 const STRLEN stashname_len = HvENAMELEN_get(stash); | |
1311 | |
1312 SV ** const svp = hv_fetchhek(PL_isarev, HvENAME_HEK(stash), 0); | |
1313 HV * const isarev = svp ? MUTABLE_HV(*svp) : NULL; | |
1314 | |
1315 PERL_ARGS_ASSERT_MRO_METHOD_CHANGED_IN; | |
1316 | |
1317 if(!stashname) | |
1318 Perl_croak(aTHX_ "Can't call mro_method_changed_in() on anonymous symbol table"); | |
1319 | |
1320 /* Inc the package generation, since a local method changed */ | |
1321 HvMROMETA(stash)->pkg_gen++; | |
1322 | |
1323 /* DESTROY can be cached in SvSTASH. */ | |
1324 if (!SvOBJECT(stash)) SvSTASH(stash) = NULL; | |
1325 | |
1326 /* If stash is UNIVERSAL, or one of UNIVERSAL's parents, | |
1327 invalidate all method caches globally */ | |
1328 if((stashname_len == 9 && strEQ(stashname, "UNIVERSAL")) | |
1329 || (isarev && hv_exists(isarev, "UNIVERSAL", 9))) { | |
1330 PL_sub_generation++; | |
1331 return; | |
1332 } | |
1333 | |
1334 /* else, invalidate the method caches of all child classes, | |
1335 but not itself */ | |
1336 if(isarev) { | |
1337 HE* iter; | |
1338 | |
1339 hv_iterinit(isarev); | |
1340 while((iter = hv_iternext(isarev))) { | |
1341 HV* const revstash = gv_stashsv(hv_iterkeysv(iter), 0); | |
1342 struct mro_meta* mrometa; | |
1343 | |
1344 if(!revstash) continue; | |
1345 mrometa = HvMROMETA(revstash); | |
1346 mrometa->cache_gen++; | |
1347 if(mrometa->mro_nextmethod) | |
1348 hv_clear(mrometa->mro_nextmethod); | |
1349 if (!SvOBJECT(revstash)) SvSTASH(revstash) = NULL; | |
1350 } | |
1351 } | |
1352 | |
1353 /* The method change may be due to *{$package . "::()"} = \&nil; in | |
1354 overload.pm. */ | |
1355 HvAMAGIC_on(stash); | |
1356 /* pessimise derefs for now. Will get recalculated by Gv_AMupdate() */ | |
1357 HvAUX(stash)->xhv_aux_flags &= ~HvAUXf_NO_DEREF; | |
1358 } | |
1359 | |
1360 void | |
1361 Perl_mro_set_mro(pTHX_ struct mro_meta *const meta, SV *const name) | |
1362 { | |
1363 const struct mro_alg *const which = Perl_mro_get_from_name(aTHX_ name); | |
1364 | |
1365 PERL_ARGS_ASSERT_MRO_SET_MRO; | |
1366 | |
1367 if (!which) | |
1368 Perl_croak(aTHX_ "Invalid mro name: '%"SVf"'", name); | |
1369 | |
1370 if(meta->mro_which != which) { | |
1371 if (meta->mro_linear_current && !meta->mro_linear_all) { | |
1372 /* If we were storing something directly, put it in the hash before | |
1373 we lose it. */ | |
1374 Perl_mro_set_private_data(aTHX_ meta, meta->mro_which, | |
1375 MUTABLE_SV(meta->mro_linear_current)); | |
1376 } | |
1377 meta->mro_which = which; | |
1378 /* Scrub our cached pointer to the private data. */ | |
1379 meta->mro_linear_current = NULL; | |
1380 /* Only affects local method cache, not | |
1381 even child classes */ | |
1382 meta->cache_gen++; | |
1383 if(meta->mro_nextmethod) | |
1384 hv_clear(meta->mro_nextmethod); | |
1385 } | |
1386 } | |
1387 | |
1388 #include "XSUB.h" | |
1389 | |
1390 XS(XS_mro_method_changed_in); | |
1391 | |
1392 void | |
1393 Perl_boot_core_mro(pTHX) | |
1394 { | |
1395 static const char file[] = __FILE__; | |
1396 | |
1397 Perl_mro_register(aTHX_ &dfs_alg); | |
1398 | |
1399 newXSproto("mro::method_changed_in", XS_mro_method_changed_in, file, "$"); | |
1400 } | |
1401 | |
1402 XS(XS_mro_method_changed_in) | |
1403 { | |
1404 dXSARGS; | |
1405 SV* classname; | |
1406 HV* class_stash; | |
1407 | |
1408 if(items != 1) | |
1409 croak_xs_usage(cv, "classname"); | |
1410 | |
1411 classname = ST(0); | |
1412 | |
1413 class_stash = gv_stashsv(classname, 0); | |
1414 if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname)); | |
1415 | |
1416 mro_method_changed_in(class_stash); | |
1417 | |
1418 XSRETURN_EMPTY; | |
1419 } | |
1420 | |
1421 /* | |
1422 * ex: set ts=8 sts=4 sw=4 et: | |
1423 */ |