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1/* mro.c
2 *
3 * Copyright (c) 2007 Brandon L Black
1129b882 4 * Copyright (c) 2007, 2008 Larry Wall and others
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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/*
4ac71550
TC
12 * 'Which order shall we go in?' said Frodo. 'Eldest first, or quickest first?
13 * You'll be last either way, Master Peregrin.'
14 *
15 * [p.101 of _The Lord of the Rings_, I/iii: "A Conspiracy Unmasked"]
cac98860
RGS
16 */
17
18/*
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19=head1 MRO Functions
20
21These functions are related to the method resolution order of perl classes
22
23=cut
24*/
25
26#include "EXTERN.h"
4befac30 27#define PERL_IN_MRO_C
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28#include "perl.h"
29
a3e6e81e
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30static const struct mro_alg dfs_alg =
31 {S_mro_get_linear_isa_dfs, "dfs", 3, 0, 0};
3d76853f 32
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33SV *
34Perl_mro_get_private_data(pTHX_ struct mro_meta *const smeta,
35 const struct mro_alg *const which)
36{
37 SV **data;
38 PERL_ARGS_ASSERT_MRO_GET_PRIVATE_DATA;
39
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40 data = (SV **)Perl_hv_common(aTHX_ smeta->mro_linear_all, NULL,
41 which->name, which->length, which->kflags,
42 HV_FETCH_JUST_SV, NULL, which->hash);
fa60396f
NC
43 if (!data)
44 return NULL;
45
46 /* If we've been asked to look up the private data for the current MRO, then
47 cache it. */
48 if (smeta->mro_which == which)
3a6fa573 49 smeta->mro_linear_current = *data;
fa60396f
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50
51 return *data;
52}
53
54SV *
55Perl_mro_set_private_data(pTHX_ struct mro_meta *const smeta,
56 const struct mro_alg *const which, SV *const data)
57{
58 PERL_ARGS_ASSERT_MRO_SET_PRIVATE_DATA;
59
9953ff72 60 if (!smeta->mro_linear_all) {
553e831a
NC
61 if (smeta->mro_which == which) {
62 /* If all we need to store is the current MRO's data, then don't use
63 memory on a hash with 1 element - store it direct, and signal
64 this by leaving the would-be-hash NULL. */
3a6fa573 65 smeta->mro_linear_current = data;
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66 return data;
67 } else {
68 HV *const hv = newHV();
69 /* Start with 2 buckets. It's unlikely we'll need more. */
70 HvMAX(hv) = 1;
9953ff72 71 smeta->mro_linear_all = hv;
553e831a 72
3a6fa573 73 if (smeta->mro_linear_current) {
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74 /* If we were storing something directly, put it in the hash
75 before we lose it. */
76 Perl_mro_set_private_data(aTHX_ smeta, smeta->mro_which,
3a6fa573 77 smeta->mro_linear_current);
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78 }
79 }
80 }
81
82 /* We get here if we're storing more than one linearisation for this stash,
83 or the linearisation we are storing is not that if its current MRO. */
84
85 if (smeta->mro_which == which) {
86 /* If we've been asked to store the private data for the current MRO,
87 then cache it. */
3a6fa573 88 smeta->mro_linear_current = data;
fa60396f
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89 }
90
9953ff72 91 if (!Perl_hv_common(aTHX_ smeta->mro_linear_all, NULL,
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92 which->name, which->length, which->kflags,
93 HV_FETCH_ISSTORE, data, which->hash)) {
94 Perl_croak(aTHX_ "panic: hv_store() failed in set_mro_private_data() "
95 "for '%.*s' %d", (int) which->length, which->name,
96 which->kflags);
97 }
98
99 return data;
100}
101
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102const struct mro_alg *
103Perl_mro_get_from_name(pTHX_ SV *name) {
104 SV **data;
105
106 PERL_ARGS_ASSERT_MRO_GET_FROM_NAME;
107
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108 data = (SV **)Perl_hv_common(aTHX_ PL_registered_mros, name, NULL, 0, 0,
109 HV_FETCH_JUST_SV, NULL, 0);
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110 if (!data)
111 return NULL;
112 assert(SvTYPE(*data) == SVt_IV);
113 assert(SvIOK(*data));
114 return INT2PTR(const struct mro_alg *, SvUVX(*data));
115}
116
117void
118Perl_mro_register(pTHX_ const struct mro_alg *mro) {
119 SV *wrapper = newSVuv(PTR2UV(mro));
120
121 PERL_ARGS_ASSERT_MRO_REGISTER;
122
123
124 if (!Perl_hv_common(aTHX_ PL_registered_mros, NULL,
125 mro->name, mro->length, mro->kflags,
126 HV_FETCH_ISSTORE, wrapper, mro->hash)) {
127 SvREFCNT_dec(wrapper);
128 Perl_croak(aTHX_ "panic: hv_store() failed in mro_register() "
129 "for '%.*s' %d", (int) mro->length, mro->name, mro->kflags);
3d76853f 130 }
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131}
132
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133struct mro_meta*
134Perl_mro_meta_init(pTHX_ HV* stash)
135{
9fe4aecf 136 struct mro_meta* newmeta;
e1a479c5 137
7918f24d 138 PERL_ARGS_ASSERT_MRO_META_INIT;
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139 assert(HvAUX(stash));
140 assert(!(HvAUX(stash)->xhv_mro_meta));
183086be 141 Newxz(newmeta, 1, struct mro_meta);
9fe4aecf 142 HvAUX(stash)->xhv_mro_meta = newmeta;
dd69841b 143 newmeta->cache_gen = 1;
70cd14a1 144 newmeta->pkg_gen = 1;
a3e6e81e 145 newmeta->mro_which = &dfs_alg;
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146
147 return newmeta;
148}
149
150#if defined(USE_ITHREADS)
151
152/* for sv_dup on new threads */
153struct mro_meta*
154Perl_mro_meta_dup(pTHX_ struct mro_meta* smeta, CLONE_PARAMS* param)
155{
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156 struct mro_meta* newmeta;
157
7918f24d 158 PERL_ARGS_ASSERT_MRO_META_DUP;
e1a479c5 159
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160 Newx(newmeta, 1, struct mro_meta);
161 Copy(smeta, newmeta, 1, struct mro_meta);
162
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163 if (newmeta->mro_linear_all) {
164 newmeta->mro_linear_all
a09252eb 165 = MUTABLE_HV(sv_dup_inc((const SV *)newmeta->mro_linear_all, param));
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166 /* This is just acting as a shortcut pointer, and will be automatically
167 updated on the first get. */
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168 newmeta->mro_linear_current = NULL;
169 } else if (newmeta->mro_linear_current) {
553e831a 170 /* Only the current MRO is stored, so this owns the data. */
3a6fa573 171 newmeta->mro_linear_current
a09252eb 172 = sv_dup_inc((const SV *)newmeta->mro_linear_current, param);
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173 }
174
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175 if (newmeta->mro_nextmethod)
176 newmeta->mro_nextmethod
a09252eb 177 = MUTABLE_HV(sv_dup_inc((const SV *)newmeta->mro_nextmethod, param));
a49ba3fc
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178 if (newmeta->isa)
179 newmeta->isa
a09252eb 180 = MUTABLE_HV(sv_dup_inc((const SV *)newmeta->isa, param));
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181
182 return newmeta;
183}
184
185#endif /* USE_ITHREADS */
186
187/*
188=for apidoc mro_get_linear_isa_dfs
189
190Returns the Depth-First Search linearization of @ISA
191the given stash. The return value is a read-only AV*.
192C<level> should be 0 (it is used internally in this
193function's recursion).
194
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195You are responsible for C<SvREFCNT_inc()> on the
196return value if you plan to store it anywhere
197semi-permanently (otherwise it might be deleted
198out from under you the next time the cache is
199invalidated).
200
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201=cut
202*/
4befac30 203static AV*
94d1e706 204S_mro_get_linear_isa_dfs(pTHX_ HV *stash, U32 level)
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205{
206 AV* retval;
207 GV** gvp;
208 GV* gv;
209 AV* av;
190d0b22 210 const HEK* stashhek;
e1a479c5 211 struct mro_meta* meta;
a49ba3fc 212 SV *our_name;
73519bd0 213 HV *stored = NULL;
e1a479c5 214
7918f24d 215 PERL_ARGS_ASSERT_MRO_GET_LINEAR_ISA_DFS;
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216 assert(HvAUX(stash));
217
00169e2c
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218 stashhek
219 = HvAUX(stash)->xhv_name && HvENAME_HEK_NN(stash)
220 ? HvENAME_HEK_NN(stash)
221 : HvNAME_HEK(stash);
222
190d0b22 223 if (!stashhek)
1e05feb3 224 Perl_croak(aTHX_ "Can't linearize anonymous symbol table");
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225
226 if (level > 100)
227 Perl_croak(aTHX_ "Recursive inheritance detected in package '%s'",
190d0b22 228 HEK_KEY(stashhek));
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229
230 meta = HvMROMETA(stash);
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231
232 /* return cache if valid */
a3e6e81e 233 if((retval = MUTABLE_AV(MRO_GET_PRIVATE_DATA(meta, &dfs_alg)))) {
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234 return retval;
235 }
236
237 /* not in cache, make a new one */
1c908217 238
ad64d0ec 239 retval = MUTABLE_AV(sv_2mortal(MUTABLE_SV(newAV())));
a49ba3fc
NC
240 /* We use this later in this function, but don't need a reference to it
241 beyond the end of this function, so reference count is fine. */
242 our_name = newSVhek(stashhek);
243 av_push(retval, our_name); /* add ourselves at the top */
e1a479c5 244
1c908217 245 /* fetch our @ISA */
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246 gvp = (GV**)hv_fetchs(stash, "ISA", FALSE);
247 av = (gvp && (gv = *gvp) && isGV_with_GP(gv)) ? GvAV(gv) : NULL;
248
a49ba3fc
NC
249 /* "stored" is used to keep track of all of the classnames we have added to
250 the MRO so far, so we can do a quick exists check and avoid adding
251 duplicate classnames to the MRO as we go.
252 It's then retained to be re-used as a fast lookup for ->isa(), by adding
253 our own name and "UNIVERSAL" to it. */
254
a49ba3fc 255 if(av && AvFILLp(av) >= 0) {
1c908217 256
ffd8da72
NC
257 SV **svp = AvARRAY(av);
258 I32 items = AvFILLp(av) + 1;
1c908217
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259
260 /* foreach(@ISA) */
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261 while (items--) {
262 SV* const sv = *svp++;
263 HV* const basestash = gv_stashsv(sv, 0);
ffd8da72
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264 SV *const *subrv_p;
265 I32 subrv_items;
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266
267 if (!basestash) {
1c908217
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268 /* if no stash exists for this @ISA member,
269 simply add it to the MRO and move on */
ffd8da72
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270 subrv_p = &sv;
271 subrv_items = 1;
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272 }
273 else {
1c908217 274 /* otherwise, recurse into ourselves for the MRO
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NC
275 of this @ISA member, and append their MRO to ours.
276 The recursive call could throw an exception, which
277 has memory management implications here, hence the use of
278 the mortal. */
ffd8da72
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279 const AV *const subrv
280 = mro_get_linear_isa_dfs(basestash, level + 1);
281
282 subrv_p = AvARRAY(subrv);
283 subrv_items = AvFILLp(subrv) + 1;
284 }
73519bd0
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285 if (stored) {
286 while(subrv_items--) {
287 SV *const subsv = *subrv_p++;
288 /* LVALUE fetch will create a new undefined SV if necessary
289 */
290 HE *const he = hv_fetch_ent(stored, subsv, 1, 0);
291 assert(he);
292 if(HeVAL(he) != &PL_sv_undef) {
293 /* It was newly created. Steal it for our new SV, and
294 replace it in the hash with the "real" thing. */
295 SV *const val = HeVAL(he);
296 HEK *const key = HeKEY_hek(he);
297
298 HeVAL(he) = &PL_sv_undef;
299 /* Save copying by making a shared hash key scalar. We
300 inline this here rather than calling
301 Perl_newSVpvn_share because we already have the
302 scalar, and we already have the hash key. */
303 assert(SvTYPE(val) == SVt_NULL);
304 sv_upgrade(val, SVt_PV);
305 SvPV_set(val, HEK_KEY(share_hek_hek(key)));
306 SvCUR_set(val, HEK_LEN(key));
307 SvREADONLY_on(val);
308 SvFAKE_on(val);
309 SvPOK_on(val);
310 if (HEK_UTF8(key))
311 SvUTF8_on(val);
312
313 av_push(retval, val);
314 }
ffd8da72 315 }
73519bd0
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316 } else {
317 /* We are the first (or only) parent. We can short cut the
318 complexity above, because our @ISA is simply us prepended
319 to our parent's @ISA, and our ->isa cache is simply our
320 parent's, with our name added. */
321 /* newSVsv() is slow. This code is only faster if we can avoid
322 it by ensuring that SVs in the arrays are shared hash key
323 scalar SVs, because we can "copy" them very efficiently.
324 Although to be fair, we can't *ensure* this, as a reference
325 to the internal array is returned by mro::get_linear_isa(),
326 so we'll have to be defensive just in case someone faffed
327 with it. */
328 if (basestash) {
329 SV **svp;
17eef65c 330 stored = MUTABLE_HV(sv_2mortal((SV*)newHVhv(HvMROMETA(basestash)->isa)));
73519bd0
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331 av_extend(retval, subrv_items);
332 AvFILLp(retval) = subrv_items;
333 svp = AvARRAY(retval);
334 while(subrv_items--) {
335 SV *const val = *subrv_p++;
336 *++svp = SvIsCOW_shared_hash(val)
337 ? newSVhek(SvSHARED_HEK_FROM_PV(SvPVX(val)))
338 : newSVsv(val);
339 }
340 } else {
341 /* They have no stash. So create ourselves an ->isa cache
342 as if we'd copied it from what theirs should be. */
343 stored = MUTABLE_HV(sv_2mortal(MUTABLE_SV(newHV())));
344 (void) hv_store(stored, "UNIVERSAL", 9, &PL_sv_undef, 0);
345 av_push(retval,
346 newSVhek(HeKEY_hek(hv_store_ent(stored, sv,
347 &PL_sv_undef, 0))));
348 }
349 }
e1a479c5 350 }
73519bd0
NC
351 } else {
352 /* We have no parents. */
353 stored = MUTABLE_HV(sv_2mortal(MUTABLE_SV(newHV())));
354 (void) hv_store(stored, "UNIVERSAL", 9, &PL_sv_undef, 0);
e1a479c5
BB
355 }
356
ed09b296 357 (void) hv_store_ent(stored, our_name, &PL_sv_undef, 0);
ed09b296
NC
358
359 SvREFCNT_inc_simple_void_NN(stored);
360 SvTEMP_off(stored);
361 SvREADONLY_on(stored);
362
363 meta->isa = stored;
364
0fd7ece8
NC
365 /* now that we're past the exception dangers, grab our own reference to
366 the AV we're about to use for the result. The reference owned by the
367 mortals' stack will be released soon, so everything will balance. */
368 SvREFCNT_inc_simple_void_NN(retval);
369 SvTEMP_off(retval);
fdef73f9 370
1c908217
RGS
371 /* we don't want anyone modifying the cache entry but us,
372 and we do so by replacing it completely */
e1a479c5 373 SvREADONLY_on(retval);
1c908217 374
a3e6e81e 375 return MUTABLE_AV(Perl_mro_set_private_data(aTHX_ meta, &dfs_alg,
fa60396f 376 MUTABLE_SV(retval)));
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377}
378
379/*
e1a479c5
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380=for apidoc mro_get_linear_isa
381
382Returns either C<mro_get_linear_isa_c3> or
383C<mro_get_linear_isa_dfs> for the given stash,
384dependant upon which MRO is in effect
385for that stash. The return value is a
386read-only AV*.
387
1c908217
RGS
388You are responsible for C<SvREFCNT_inc()> on the
389return value if you plan to store it anywhere
390semi-permanently (otherwise it might be deleted
391out from under you the next time the cache is
392invalidated).
393
e1a479c5
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394=cut
395*/
396AV*
397Perl_mro_get_linear_isa(pTHX_ HV *stash)
398{
399 struct mro_meta* meta;
7311f41d 400 AV *isa;
2c7f4b87 401
7918f24d 402 PERL_ARGS_ASSERT_MRO_GET_LINEAR_ISA;
2c7f4b87
BB
403 if(!SvOOK(stash))
404 Perl_croak(aTHX_ "Can't linearize anonymous symbol table");
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405
406 meta = HvMROMETA(stash);
3d76853f 407 if (!meta->mro_which)
14f97ce6 408 Perl_croak(aTHX_ "panic: invalid MRO!");
7311f41d
FC
409 isa = meta->mro_which->resolve(aTHX_ stash, 0);
410
411 if (!meta->isa) {
412 HV *const isa_hash = newHV();
413 /* Linearisation didn't build it for us, so do it here. */
414 SV *const *svp = AvARRAY(isa);
415 SV *const *const svp_end = svp + AvFILLp(isa) + 1;
416 const HEK *canon_name = HvENAME_HEK(stash);
417 if (!canon_name) canon_name = HvNAME_HEK(stash);
418
419 while (svp < svp_end) {
420 (void) hv_store_ent(isa_hash, *svp++, &PL_sv_undef, 0);
421 }
422
423 (void) hv_common(isa_hash, NULL, HEK_KEY(canon_name),
424 HEK_LEN(canon_name), HEK_FLAGS(canon_name),
425 HV_FETCH_ISSTORE, &PL_sv_undef,
426 HEK_HASH(canon_name));
427 (void) hv_store(isa_hash, "UNIVERSAL", 9, &PL_sv_undef, 0);
428
429 SvREADONLY_on(isa_hash);
430
431 meta->isa = isa_hash;
432 }
433
434 return isa;
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435}
436
437/*
438=for apidoc mro_isa_changed_in
439
1c908217 440Takes the necessary steps (cache invalidations, mostly)
e1a479c5
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441when the @ISA of the given package has changed. Invoked
442by the C<setisa> magic, should not need to invoke directly.
443
444=cut
445*/
446void
4df35a07 447Perl_mro_isa_changed_in(pTHX_ HV* stash)
e1a479c5
BB
448{
449 dVAR;
450 HV* isarev;
451 AV* linear_mro;
452 HE* iter;
453 SV** svp;
454 I32 items;
1e05feb3 455 bool is_universal;
4df35a07 456 struct mro_meta * meta;
80ebaca2 457 HV *isa = NULL;
e1a479c5 458
4df35a07
FC
459 const char * const stashname = HvENAME_get(stash);
460 const STRLEN stashname_len = HvENAMELEN_get(stash);
461
462 PERL_ARGS_ASSERT_MRO_ISA_CHANGED_IN;
7918f24d 463
2c7f4b87
BB
464 if(!stashname)
465 Perl_croak(aTHX_ "Can't call mro_isa_changed_in() on anonymous symbol table");
466
4df35a07
FC
467
468 /* wipe out the cached linearizations for this stash */
469 meta = HvMROMETA(stash);
470 if (meta->mro_linear_all) {
9953ff72
NC
471 SvREFCNT_dec(MUTABLE_SV(meta->mro_linear_all));
472 meta->mro_linear_all = NULL;
553e831a 473 /* This is just acting as a shortcut pointer. */
3a6fa573 474 meta->mro_linear_current = NULL;
4df35a07 475 } else if (meta->mro_linear_current) {
553e831a 476 /* Only the current MRO is stored, so this owns the data. */
3a6fa573
NC
477 SvREFCNT_dec(meta->mro_linear_current);
478 meta->mro_linear_current = NULL;
4df35a07
FC
479 }
480 if (meta->isa) {
80ebaca2
FC
481 /* Steal it for our own purposes. */
482 isa = (HV *)sv_2mortal((SV *)meta->isa);
5782d502 483 meta->isa = NULL;
6f86b615 484 }
70cd14a1 485
4df35a07
FC
486 /* Inc the package generation, since our @ISA changed */
487 meta->pkg_gen++;
488
e1a479c5
BB
489 /* Wipe the global method cache if this package
490 is UNIVERSAL or one of its parents */
dd69841b
BB
491
492 svp = hv_fetch(PL_isarev, stashname, stashname_len, 0);
85fbaab2 493 isarev = svp ? MUTABLE_HV(*svp) : NULL;
dd69841b
BB
494
495 if((stashname_len == 9 && strEQ(stashname, "UNIVERSAL"))
496 || (isarev && hv_exists(isarev, "UNIVERSAL", 9))) {
e1a479c5 497 PL_sub_generation++;
dd69841b
BB
498 is_universal = TRUE;
499 }
1e05feb3 500 else { /* Wipe the local method cache otherwise */
4df35a07 501 meta->cache_gen++;
1e05feb3
AL
502 is_universal = FALSE;
503 }
e1a479c5
BB
504
505 /* wipe next::method cache too */
4df35a07 506 if(meta->mro_nextmethod) hv_clear(meta->mro_nextmethod);
1e05feb3 507
e1a479c5 508 /* Iterate the isarev (classes that are our children),
80ebaca2
FC
509 wiping out their linearization, method and isa caches
510 and upating PL_isarev. */
dd69841b 511 if(isarev) {
80ebaca2
FC
512 HV *isa_hashes = NULL;
513
514 /* We have to iterate through isarev twice to avoid a chicken and
515 * egg problem: if A inherits from B and both are in isarev, A might
516 * be processed before B and use B’s previous linearisation.
517 */
518
519 /* First iteration: Wipe everything, but stash away the isa hashes
520 * since we still need them for updating PL_isarev.
521 */
522
523 if(hv_iterinit(isarev)) {
524 /* Only create the hash if we need it; i.e., if isarev has
525 any elements. */
526 isa_hashes = (HV *)sv_2mortal((SV *)newHV());
527 }
e1a479c5 528 while((iter = hv_iternext(isarev))) {
ec49eb61
NC
529 I32 len;
530 const char* const revkey = hv_iterkey(iter, &len);
531 HV* revstash = gv_stashpvn(revkey, len, 0);
bc2cbbac
BB
532 struct mro_meta* revmeta;
533
534 if(!revstash) continue;
535 revmeta = HvMROMETA(revstash);
9953ff72
NC
536 if (revmeta->mro_linear_all) {
537 SvREFCNT_dec(MUTABLE_SV(revmeta->mro_linear_all));
538 revmeta->mro_linear_all = NULL;
553e831a 539 /* This is just acting as a shortcut pointer. */
3a6fa573
NC
540 revmeta->mro_linear_current = NULL;
541 } else if (revmeta->mro_linear_current) {
553e831a 542 /* Only the current MRO is stored, so this owns the data. */
3a6fa573
NC
543 SvREFCNT_dec(revmeta->mro_linear_current);
544 revmeta->mro_linear_current = NULL;
553e831a 545 }
dd69841b
BB
546 if(!is_universal)
547 revmeta->cache_gen++;
e1a479c5
BB
548 if(revmeta->mro_nextmethod)
549 hv_clear(revmeta->mro_nextmethod);
80ebaca2
FC
550
551 (void)
552 hv_store(
553 isa_hashes, (const char*)&revstash, sizeof(HV *),
554 revmeta->isa ? (SV *)revmeta->isa : &PL_sv_undef, 0
555 );
556 revmeta->isa = NULL;
557 }
558
559 /* Second pass: Update PL_isarev. We can just use isa_hashes to
560 * avoid another round of stash lookups. */
561
562 /* isarev might be deleted from PL_isarev during this loop, so hang
563 * on to it. */
564 SvREFCNT_inc_simple_void_NN(sv_2mortal((SV *)isarev));
565
566 if(isa_hashes) {
567 hv_iterinit(isa_hashes);
568 while((iter = hv_iternext(isa_hashes))) {
569 HV* const revstash = *(HV **)HEK_KEY(HeKEY_hek(iter));
570 HV * const isa = (HV *)HeVAL(iter);
571 const HEK *namehek;
572
573 /* Re-calculate the linearisation, unless a previous iter-
574 ation was for a subclass of this class. */
575 if(!HvMROMETA(revstash)->isa)
576 (void)mro_get_linear_isa(revstash);
577
578 /* We're starting at the 2nd element, skipping revstash */
579 linear_mro = mro_get_linear_isa(revstash);
580 svp = AvARRAY(linear_mro) + 1;
581 items = AvFILLp(linear_mro);
582
583 namehek = HvENAME_HEK(revstash);
584 if (!namehek) namehek = HvNAME_HEK(revstash);
585
586 while (items--) {
587 SV* const sv = *svp++;
588 HV* mroisarev;
589
590 HE *he = hv_fetch_ent(PL_isarev, sv, TRUE, 0);
591
592 /* That fetch should not fail. But if it had to create
593 a new SV for us, then will need to upgrade it to an
594 HV (which sv_upgrade() can now do for us). */
595
596 mroisarev = MUTABLE_HV(HeVAL(he));
597
598 SvUPGRADE(MUTABLE_SV(mroisarev), SVt_PVHV);
599
600 /* This hash only ever contains PL_sv_yes. Storing it
601 over itself is almost as cheap as calling hv_exists,
602 so on aggregate we expect to save time by not making
603 two calls to the common HV code for the case where
604 it doesn't exist. */
605
606 (void)
607 hv_store(
608 mroisarev, HEK_KEY(namehek), HEK_LEN(namehek),
609 &PL_sv_yes, 0
610 );
611 }
612
613 if((SV *)isa != &PL_sv_undef)
614 mro_clean_isarev(
615 isa, HEK_KEY(namehek), HEK_LEN(namehek),
616 HvMROMETA(revstash)->isa
617 );
618 }
e1a479c5
BB
619 }
620 }
621
c9143745
FC
622 /* Now iterate our MRO (parents), adding ourselves and everything from
623 our isarev to their isarev.
1c908217
RGS
624 */
625
626 /* We're starting at the 2nd element, skipping ourselves here */
e1a479c5
BB
627 linear_mro = mro_get_linear_isa(stash);
628 svp = AvARRAY(linear_mro) + 1;
629 items = AvFILLp(linear_mro);
1c908217 630
e1a479c5
BB
631 while (items--) {
632 SV* const sv = *svp++;
e1a479c5
BB
633 HV* mroisarev;
634
117b69ca
NC
635 HE *he = hv_fetch_ent(PL_isarev, sv, TRUE, 0);
636
637 /* That fetch should not fail. But if it had to create a new SV for
4ea50411
NC
638 us, then will need to upgrade it to an HV (which sv_upgrade() can
639 now do for us. */
117b69ca 640
85fbaab2 641 mroisarev = MUTABLE_HV(HeVAL(he));
e1a479c5 642
ad64d0ec 643 SvUPGRADE(MUTABLE_SV(mroisarev), SVt_PVHV);
117b69ca 644
25270bc0
NC
645 /* This hash only ever contains PL_sv_yes. Storing it over itself is
646 almost as cheap as calling hv_exists, so on aggregate we expect to
647 save time by not making two calls to the common HV code for the
648 case where it doesn't exist. */
649
04fe65b0 650 (void)hv_store(mroisarev, stashname, stashname_len, &PL_sv_yes, 0);
80ebaca2
FC
651 }
652
80ebaca2
FC
653 /* Delete our name from our former parents’ isarevs. */
654 if(isa && HvARRAY(isa))
655 mro_clean_isarev(isa, stashname, stashname_len, meta->isa);
656}
657
658/* Deletes name from all the isarev entries listed in isa */
659STATIC void
660S_mro_clean_isarev(pTHX_ HV * const isa, const char * const name,
661 const STRLEN len, HV * const exceptions)
662{
663 HE* iter;
e1a479c5 664
80ebaca2
FC
665 PERL_ARGS_ASSERT_MRO_CLEAN_ISAREV;
666
667 /* Delete our name from our former parents’ isarevs. */
668 if(isa && HvARRAY(isa) && hv_iterinit(isa)) {
669 SV **svp;
670 while((iter = hv_iternext(isa))) {
671 I32 klen;
672 const char * const key = hv_iterkey(iter, &klen);
673 if(exceptions && hv_exists(exceptions, key, klen)) continue;
674 svp = hv_fetch(PL_isarev, key, klen, 0);
675 if(svp) {
676 HV * const isarev = (HV *)*svp;
677 (void)hv_delete(isarev, name, len, G_DISCARD);
678 if(!HvARRAY(isarev) || !HvKEYS(isarev))
679 (void)hv_delete(PL_isarev, key, klen, G_DISCARD);
e1a479c5
BB
680 }
681 }
682 }
683}
684
685/*
c8bbf675
FC
686=for apidoc mro_package_moved
687
d056e33c
FC
688Call this function to signal to a stash that it has been assigned to
689another spot in the stash hierarchy. C<stash> is the stash that has been
690assigned. C<oldstash> is the stash it replaces, if any. C<gv> is the glob
691that is actually being assigned to. C<newname> and C<newname_len> are the
692full name of the GV. If these last two arguments are omitted, they can be
35759254 693inferred from C<gv>. C<gv> can be omitted if C<newname> is given.
d056e33c 694
35759254 695This can also be called with a null first argument to
d056e33c
FC
696indicate that C<oldstash> has been deleted.
697
698This function invalidates isa caches on the old stash, on all subpackages
699nested inside it, and on the subclasses of all those, including
700non-existent packages that have corresponding entries in C<stash>.
c8bbf675 701
80ebaca2
FC
702It also sets the effective names (C<HvENAME>) on all the stashes as
703appropriate.
704
c8bbf675
FC
705=cut
706*/
707void
35759254
FC
708Perl_mro_package_moved(pTHX_ HV * const stash, HV * const oldstash,
709 const GV *gv, const char *newname,
62c1e33f 710 I32 newname_len)
c8bbf675 711{
80ebaca2
FC
712 HV *stashes;
713 HE* iter;
62c1e33f 714
35759254 715 assert(stash || oldstash);
80ebaca2 716 assert(gv || newname);
35759254
FC
717
718 /* Determine the name of the location that stash was assigned to
719 * or from which oldstash was removed.
720 *
928eb066 721 * We cannot reliably use the name in oldstash, because it may have
35759254
FC
722 * been deleted from the location in the symbol table that its name
723 * suggests, as in this case:
724 *
725 * $globref = \*foo::bar::;
726 * Symbol::delete_package("foo");
727 * *$globref = \%baz::;
728 * *$globref = *frelp::;
729 * # calls mro_package_moved(%frelp::, %baz::, *$globref, NULL, 0)
730 *
731 * If newname is not null, then we trust that the caller gave us the
732 * right name. Otherwise, we get it from the gv. But if the gv is not
733 * in the symbol table, then we just return.
734 */
d056e33c
FC
735 if(!newname && gv) {
736 SV * const namesv = sv_newmortal();
62c1e33f 737 STRLEN len;
d056e33c 738 gv_fullname4(namesv, gv, NULL, 0);
35759254 739 if(gv_fetchsv(namesv, GV_NOADD_NOINIT, SVt_PVGV) != gv) return;
62c1e33f
FC
740 newname = SvPV_const(namesv, len);
741 newname_len = len - 2; /* skip trailing :: */
d056e33c 742 }
35759254 743 if(newname_len < 0) newname_len = -newname_len;
c8bbf675 744
80ebaca2
FC
745 /* Get a list of all the affected classes. */
746 /* We cannot simply pass them all to mro_isa_changed_in to avoid
747 the list, as that function assumes that only one package has
748 changed. It does not work with:
749
750 @foo::ISA = qw( B B::B );
751 *B:: = delete $::{"A::"};
752
753 as neither B nor B::B can be updated before the other, since they
754 will reset caches on foo, which will see either B or B::B with the
755 wrong name. The names must be set on *all* affected stashes before
756 we do anything else.
757 */
758 stashes = (HV *) sv_2mortal((SV *)newHV());
b89cdb22
FC
759 mro_gather_and_rename(
760 stashes, (HV *) sv_2mortal((SV *)newHV()),
761 stash, oldstash, newname, newname_len
762 );
80ebaca2
FC
763
764 /* Iterate through the stashes, wiping isa linearisations, but leaving
765 the isa hash (which mro_isa_changed_in needs for adjusting the
766 isarev hashes belonging to parent classes). */
767 hv_iterinit(stashes);
768 while((iter = hv_iternext(stashes))) {
769 if(HeVAL(iter) != &PL_sv_yes && HvENAME(HeVAL(iter))) {
770 struct mro_meta* meta;
771 meta = HvMROMETA((HV *)HeVAL(iter));
772 if (meta->mro_linear_all) {
773 SvREFCNT_dec(MUTABLE_SV(meta->mro_linear_all));
774 meta->mro_linear_all = NULL;
775 /* This is just acting as a shortcut pointer. */
776 meta->mro_linear_current = NULL;
777 } else if (meta->mro_linear_current) {
778 /* Only the current MRO is stored, so this owns the data. */
779 SvREFCNT_dec(meta->mro_linear_current);
780 meta->mro_linear_current = NULL;
781 }
782 }
783 }
784
785 /* Once the caches have been wiped on all the classes, call
786 mro_isa_changed_in on each. */
787 hv_iterinit(stashes);
788 while((iter = hv_iternext(stashes))) {
b89cdb22 789 if(HvENAME(HeVAL(iter)))
80ebaca2 790 mro_isa_changed_in((HV *)HeVAL(iter));
80ebaca2
FC
791 }
792}
793
794void
b89cdb22
FC
795S_mro_gather_and_rename(pTHX_ HV * const stashes, HV * const seen_stashes,
796 HV *stash, HV *oldstash, const char *name,
797 I32 namlen)
80ebaca2
FC
798{
799 register XPVHV* xhv;
800 register HE *entry;
801 I32 riter = -1;
802 const bool stash_had_name = stash && HvENAME(stash);
803 HV *seen = NULL;
804 HV *isarev = NULL;
805 SV **svp;
806
807 PERL_ARGS_ASSERT_MRO_GATHER_AND_RENAME;
808
b89cdb22
FC
809 /* We use the seen_stashes hash to keep track of which packages have
810 been encountered so far. This must be separate from the main list of
811 stashes, as we need to distinguish between stashes being assigned
812 and stashes being replaced/deleted. (A nested stash can be on both
813 sides of an assignment. We cannot simply skip iterating through a
814 stash on the right if we have seen it on the left, as it will not
815 get its ename assigned to it.)
816
817 To avoid allocating extra SVs, instead of a bitfield we can make
818 bizarre use of immortals:
819
820 &PL_sv_undef: seen on the left (oldstash)
821 &PL_sv_no : seen on the right (stash)
822 &PL_sv_yes : seen on both sides
823
824 */
825
80ebaca2
FC
826 if(oldstash) {
827 /* Add to the big list. */
828 HE * const entry
829 = (HE *)
830 hv_common(
b89cdb22 831 seen_stashes, NULL, (const char *)&oldstash, sizeof(HV *), 0,
df5f182b 832 HV_FETCH_LVALUE|HV_FETCH_EMPTY_HE, NULL, 0
80ebaca2 833 );
b89cdb22 834 if(HeVAL(entry) == &PL_sv_undef || HeVAL(entry) == &PL_sv_yes) {
80ebaca2
FC
835 oldstash = NULL;
836 goto check_stash;
837 }
b89cdb22
FC
838 HeVAL(entry)
839 = HeVAL(entry) == &PL_sv_no ? &PL_sv_yes : &PL_sv_undef;
840 (void)
841 hv_store(
842 stashes, (const char *)&oldstash, sizeof(HV *),
843 SvREFCNT_inc_simple_NN((SV*)oldstash), 0
844 );
80ebaca2
FC
845
846 /* Update the effective name. */
847 if(HvENAME_get(oldstash)) {
848 const HEK * const enamehek = HvENAME_HEK(oldstash);
849 if(PL_stashcache)
d7fbb1de 850 (void)
80ebaca2
FC
851 hv_delete(PL_stashcache, name, namlen, G_DISCARD);
852 hv_ename_delete(oldstash, name, namlen);
853
854 /* If the name deletion caused a name change, then we are not
855 * going to call mro_isa_changed_in with this name (and not at all
856 * if it has become anonymous) so we need to delete old isarev
857 * entries here, both those in the superclasses and this class’s
858 * own list of subclasses. We simply delete the latter from
859 * from PL_isarev, since we still need it. hv_delete mortifies it
860 * for us, so sv_2mortal is not necessary. */
861 if(HvENAME_HEK(oldstash) != enamehek) {
862 const struct mro_meta * meta = HvMROMETA(oldstash);
863 if(meta->isa && HvARRAY(meta->isa))
864 mro_clean_isarev(meta->isa, name, namlen, NULL);
865 isarev = (HV *)hv_delete(PL_isarev, name, namlen, 0);
866 }
867 }
d7fbb1de 868 }
80ebaca2 869 check_stash:
8b9e80a3 870 if(stash) {
80ebaca2
FC
871 hv_ename_add(stash, name, namlen);
872
b89cdb22
FC
873 /* Add it to the big list if it needs
874 * mro_isa_changed_in called on it. That happens if it was
80ebaca2
FC
875 * detached from the symbol table (so it had no HvENAME) before
876 * being assigned to the spot named by the ‘name’ variable, because
877 * its cached isa linerisation is now stale (the effective name
878 * having changed), and subclasses will then use that cache when
879 * mro_package_moved calls mro_isa_changed_in. (See
8b9e80a3 880 * [perl #77358].)
80ebaca2 881 *
8b9e80a3 882 * If it did have a name, then its previous name is still
80ebaca2
FC
883 * used in isa caches, and there is no need for
884 * mro_package_moved to call mro_isa_changed_in.
8b9e80a3 885 */
80ebaca2
FC
886
887 entry
888 = (HE *)
889 hv_common(
b89cdb22 890 seen_stashes, NULL, (const char *)&stash, sizeof(HV *), 0,
df5f182b 891 HV_FETCH_LVALUE|HV_FETCH_EMPTY_HE, NULL, 0
80ebaca2 892 );
b89cdb22 893 if(HeVAL(entry) == &PL_sv_yes || HeVAL(entry) == &PL_sv_no)
80ebaca2 894 stash = NULL;
b89cdb22
FC
895 else {
896 HeVAL(entry)
897 = HeVAL(entry) == &PL_sv_undef ? &PL_sv_yes : &PL_sv_no;
898 if(!stash_had_name)
899 (void)
900 hv_store(
901 stashes, (const char *)&stash, sizeof(HV *),
902 SvREFCNT_inc_simple_NN((SV *)stash), 0
903 );
904 }
8b9e80a3 905 }
d7fbb1de 906
80ebaca2
FC
907 if(!stash && !oldstash)
908 /* Both stashes have been encountered already. */
909 return;
910
911 /* Add all the subclasses to the big list. */
912 if(
913 isarev
914 || (
915 (svp = hv_fetch(PL_isarev, name, namlen, 0))
916 && (isarev = MUTABLE_HV(*svp))
917 )
918 ) {
919 HE *iter;
920 hv_iterinit(isarev);
921 while((iter = hv_iternext(isarev))) {
922 I32 len;
923 const char* const revkey = hv_iterkey(iter, &len);
924 HV* revstash = gv_stashpvn(revkey, len, 0);
925
926 if(!revstash) continue;
b89cdb22
FC
927 (void)
928 hv_store(
929 stashes, (const char *)&revstash, sizeof(HV *),
930 SvREFCNT_inc_simple_NN((SV *)revstash), 0
931 );
80ebaca2
FC
932 }
933 }
d056e33c
FC
934
935 if(
936 (!stash || !HvARRAY(stash)) && (!oldstash || !HvARRAY(oldstash))
d7fbb1de 937 ) return;
c8bbf675
FC
938
939 /* This is partly based on code in hv_iternext_flags. We are not call-
940 ing that here, as we want to avoid resetting the hash iterator. */
941
d056e33c
FC
942 /* Skip the entire loop if the hash is empty. */
943 if(oldstash && HvUSEDKEYS(oldstash)) {
944 xhv = (XPVHV*)SvANY(oldstash);
dbe2fffc 945 seen = (HV *) sv_2mortal((SV *)newHV());
d056e33c 946
80ebaca2
FC
947 /* Iterate through entries in the oldstash, adding them to the
948 list, meanwhile doing the equivalent of $seen{$key} = 1.
d056e33c
FC
949 */
950
951 while (++riter <= (I32)xhv->xhv_max) {
952 entry = (HvARRAY(oldstash))[riter];
953
954 /* Iterate through the entries in this list */
955 for(; entry; entry = HeNEXT(entry)) {
956 const char* key;
957 I32 len;
958
959 /* If this entry is not a glob, ignore it.
960 Try the next. */
961 if (!isGV(HeVAL(entry))) continue;
962
963 key = hv_iterkey(entry, &len);
964 if(len > 1 && key[len-2] == ':' && key[len-1] == ':') {
965 HV * const oldsubstash = GvHV(HeVAL(entry));
966 SV ** const stashentry
967 = stash ? hv_fetch(stash, key, len, 0) : NULL;
35759254 968 HV *substash = NULL;
62c1e33f
FC
969
970 /* Avoid main::main::main::... */
971 if(oldsubstash == oldstash) continue;
972
d056e33c 973 if(
35759254
FC
974 (
975 stashentry && *stashentry
976 && (substash = GvHV(*stashentry))
977 )
00169e2c 978 || (oldsubstash && HvENAME_get(oldsubstash))
d056e33c 979 )
35759254
FC
980 {
981 /* Add :: and the key (minus the trailing ::)
982 to newname. */
983 SV *namesv
80ebaca2
FC
984 = newSVpvn_flags(name, namlen, SVs_TEMP);
985 {
986 const char *name;
987 STRLEN namlen;
988 sv_catpvs(namesv, "::");
989 sv_catpvn(namesv, key, len-2);
990 name = SvPV_const(namesv, namlen);
991 mro_gather_and_rename(
b89cdb22
FC
992 stashes, seen_stashes,
993 substash, oldsubstash, name, namlen
80ebaca2
FC
994 );
995 }
35759254 996 }
d056e33c
FC
997
998 (void)hv_store(seen, key, len, &PL_sv_yes, 0);
999 }
1000 }
1001 }
1002 }
c8bbf675
FC
1003
1004 /* Skip the entire loop if the hash is empty. */
d056e33c
FC
1005 if (stash && HvUSEDKEYS(stash)) {
1006 xhv = (XPVHV*)SvANY(stash);
b89cdb22 1007 riter = -1;
d056e33c
FC
1008
1009 /* Iterate through the new stash, skipping $seen{$key} items,
b89cdb22 1010 calling mro_gather_and_rename(stashes,seen,entry,NULL, ...). */
c8bbf675
FC
1011 while (++riter <= (I32)xhv->xhv_max) {
1012 entry = (HvARRAY(stash))[riter];
1013
1014 /* Iterate through the entries in this list */
1015 for(; entry; entry = HeNEXT(entry)) {
1016 const char* key;
1017 I32 len;
1018
1019 /* If this entry is not a glob, ignore it.
1020 Try the next. */
1021 if (!isGV(HeVAL(entry))) continue;
1022
1023 key = hv_iterkey(entry, &len);
1024 if(len > 1 && key[len-2] == ':' && key[len-1] == ':') {
d056e33c
FC
1025 HV *substash;
1026
1027 /* If this entry was seen when we iterated through the
1028 oldstash, skip it. */
1029 if(seen && hv_exists(seen, key, len)) continue;
1030
1031 /* We get here only if this stash has no corresponding
1032 entry in the stash being replaced. */
1033
1034 substash = GvHV(HeVAL(entry));
35759254 1035 if(substash) {
62c1e33f 1036 SV *namesv;
80ebaca2
FC
1037 const char *subname;
1038 STRLEN subnamlen;
62c1e33f
FC
1039
1040 /* Avoid checking main::main::main::... */
1041 if(substash == stash) continue;
1042
d056e33c
FC
1043 /* Add :: and the key (minus the trailing ::)
1044 to newname. */
62c1e33f 1045 namesv
80ebaca2 1046 = newSVpvn_flags(name, namlen, SVs_TEMP);
d056e33c
FC
1047 sv_catpvs(namesv, "::");
1048 sv_catpvn(namesv, key, len-2);
80ebaca2
FC
1049 subname = SvPV_const(namesv, subnamlen);
1050 mro_gather_and_rename(
b89cdb22
FC
1051 stashes, seen_stashes,
1052 substash, NULL, subname, subnamlen
d056e33c
FC
1053 );
1054 }
c8bbf675
FC
1055 }
1056 }
1057 }
1058 }
1059}
1060
1061/*
e1a479c5
BB
1062=for apidoc mro_method_changed_in
1063
47c9dd14
BB
1064Invalidates method caching on any child classes
1065of the given stash, so that they might notice
1066the changes in this one.
e1a479c5
BB
1067
1068Ideally, all instances of C<PL_sub_generation++> in
dd69841b
BB
1069perl source outside of C<mro.c> should be
1070replaced by calls to this.
1071
1072Perl automatically handles most of the common
1073ways a method might be redefined. However, there
1074are a few ways you could change a method in a stash
1075without the cache code noticing, in which case you
1076need to call this method afterwards:
e1a479c5 1077
dd69841b
BB
10781) Directly manipulating the stash HV entries from
1079XS code.
e1a479c5 1080
dd69841b
BB
10812) Assigning a reference to a readonly scalar
1082constant into a stash entry in order to create
1083a constant subroutine (like constant.pm
1084does).
1085
1086This same method is available from pure perl
1087via, C<mro::method_changed_in(classname)>.
e1a479c5
BB
1088
1089=cut
1090*/
1091void
1092Perl_mro_method_changed_in(pTHX_ HV *stash)
1093{
00169e2c
FC
1094 const char * const stashname = HvENAME_get(stash);
1095 const STRLEN stashname_len = HvENAMELEN_get(stash);
dd69841b 1096
1e05feb3 1097 SV ** const svp = hv_fetch(PL_isarev, stashname, stashname_len, 0);
85fbaab2 1098 HV * const isarev = svp ? MUTABLE_HV(*svp) : NULL;
e1a479c5 1099
7918f24d
NC
1100 PERL_ARGS_ASSERT_MRO_METHOD_CHANGED_IN;
1101
2c7f4b87
BB
1102 if(!stashname)
1103 Perl_croak(aTHX_ "Can't call mro_method_changed_in() on anonymous symbol table");
1104
70cd14a1
CB
1105 /* Inc the package generation, since a local method changed */
1106 HvMROMETA(stash)->pkg_gen++;
1107
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BB
1108 /* If stash is UNIVERSAL, or one of UNIVERSAL's parents,
1109 invalidate all method caches globally */
dd69841b
BB
1110 if((stashname_len == 9 && strEQ(stashname, "UNIVERSAL"))
1111 || (isarev && hv_exists(isarev, "UNIVERSAL", 9))) {
e1a479c5
BB
1112 PL_sub_generation++;
1113 return;
1114 }
1115
1116 /* else, invalidate the method caches of all child classes,
1117 but not itself */
dd69841b 1118 if(isarev) {
1e05feb3
AL
1119 HE* iter;
1120
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BB
1121 hv_iterinit(isarev);
1122 while((iter = hv_iternext(isarev))) {
ec49eb61
NC
1123 I32 len;
1124 const char* const revkey = hv_iterkey(iter, &len);
1125 HV* const revstash = gv_stashpvn(revkey, len, 0);
bc2cbbac
BB
1126 struct mro_meta* mrometa;
1127
1128 if(!revstash) continue;
1129 mrometa = HvMROMETA(revstash);
dd69841b 1130 mrometa->cache_gen++;
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BB
1131 if(mrometa->mro_nextmethod)
1132 hv_clear(mrometa->mro_nextmethod);
1133 }
1134 }
1135}
1136
31b9005d
NC
1137void
1138Perl_mro_set_mro(pTHX_ struct mro_meta *const meta, SV *const name)
1139{
1140 const struct mro_alg *const which = Perl_mro_get_from_name(aTHX_ name);
1141
1142 PERL_ARGS_ASSERT_MRO_SET_MRO;
1143
1144 if (!which)
1145 Perl_croak(aTHX_ "Invalid mro name: '%"SVf"'", name);
1146
1147 if(meta->mro_which != which) {
9953ff72 1148 if (meta->mro_linear_current && !meta->mro_linear_all) {
31b9005d
NC
1149 /* If we were storing something directly, put it in the hash before
1150 we lose it. */
1151 Perl_mro_set_private_data(aTHX_ meta, meta->mro_which,
3a6fa573 1152 MUTABLE_SV(meta->mro_linear_current));
31b9005d
NC
1153 }
1154 meta->mro_which = which;
1155 /* Scrub our cached pointer to the private data. */
3a6fa573 1156 meta->mro_linear_current = NULL;
31b9005d
NC
1157 /* Only affects local method cache, not
1158 even child classes */
1159 meta->cache_gen++;
1160 if(meta->mro_nextmethod)
1161 hv_clear(meta->mro_nextmethod);
1162 }
1163}
1164
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BB
1165#include "XSUB.h"
1166
e1a479c5 1167XS(XS_mro_method_changed_in);
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BB
1168
1169void
1170Perl_boot_core_mro(pTHX)
1171{
1172 dVAR;
1173 static const char file[] = __FILE__;
1174
a3e6e81e 1175 Perl_mro_register(aTHX_ &dfs_alg);
a3e6e81e 1176
e1a479c5 1177 newXSproto("mro::method_changed_in", XS_mro_method_changed_in, file, "$");
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BB
1178}
1179
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BB
1180XS(XS_mro_method_changed_in)
1181{
1182 dVAR;
1183 dXSARGS;
1184 SV* classname;
1185 HV* class_stash;
1186
e1a479c5 1187 if(items != 1)
afa74d42 1188 croak_xs_usage(cv, "classname");
e1a479c5
BB
1189
1190 classname = ST(0);
1191
1192 class_stash = gv_stashsv(classname, 0);
1193 if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname));
1194
1195 mro_method_changed_in(class_stash);
1196
1197 XSRETURN_EMPTY;
1198}
1199
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BB
1200/*
1201 * Local variables:
1202 * c-indentation-style: bsd
1203 * c-basic-offset: 4
1204 * indent-tabs-mode: t
1205 * End:
1206 *
1207 * ex: set ts=8 sts=4 sw=4 noet:
1208 */