| 1 | /* mro.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 | */ |
| 10 | |
| 11 | /* |
| 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"] |
| 16 | */ |
| 17 | |
| 18 | /* |
| 19 | =head1 MRO Functions |
| 20 | |
| 21 | These functions are related to the method resolution order of perl classes |
| 22 | |
| 23 | =cut |
| 24 | */ |
| 25 | |
| 26 | #include "EXTERN.h" |
| 27 | #define PERL_IN_MRO_C |
| 28 | #include "perl.h" |
| 29 | |
| 30 | static const struct mro_alg dfs_alg = |
| 31 | {S_mro_get_linear_isa_dfs, "dfs", 3, 0, 0}; |
| 32 | |
| 33 | SV * |
| 34 | Perl_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 | |
| 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); |
| 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) |
| 49 | smeta->mro_linear_current = *data; |
| 50 | |
| 51 | return *data; |
| 52 | } |
| 53 | |
| 54 | SV * |
| 55 | Perl_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 | |
| 60 | if (!smeta->mro_linear_all) { |
| 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. */ |
| 65 | smeta->mro_linear_current = data; |
| 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; |
| 71 | smeta->mro_linear_all = hv; |
| 72 | |
| 73 | if (smeta->mro_linear_current) { |
| 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, |
| 77 | smeta->mro_linear_current); |
| 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. */ |
| 88 | smeta->mro_linear_current = data; |
| 89 | } |
| 90 | |
| 91 | if (!Perl_hv_common(aTHX_ smeta->mro_linear_all, NULL, |
| 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 | |
| 102 | const struct mro_alg * |
| 103 | Perl_mro_get_from_name(pTHX_ SV *name) { |
| 104 | SV **data; |
| 105 | |
| 106 | PERL_ARGS_ASSERT_MRO_GET_FROM_NAME; |
| 107 | |
| 108 | data = (SV **)Perl_hv_common(aTHX_ PL_registered_mros, name, NULL, 0, 0, |
| 109 | HV_FETCH_JUST_SV, NULL, 0); |
| 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 | |
| 117 | /* |
| 118 | =for apidoc mro_register |
| 119 | Registers a custom mro plugin. See L<perlmroapi> for details. |
| 120 | |
| 121 | =cut |
| 122 | */ |
| 123 | |
| 124 | void |
| 125 | Perl_mro_register(pTHX_ const struct mro_alg *mro) { |
| 126 | SV *wrapper = newSVuv(PTR2UV(mro)); |
| 127 | |
| 128 | PERL_ARGS_ASSERT_MRO_REGISTER; |
| 129 | |
| 130 | |
| 131 | if (!Perl_hv_common(aTHX_ PL_registered_mros, NULL, |
| 132 | mro->name, mro->length, mro->kflags, |
| 133 | HV_FETCH_ISSTORE, wrapper, mro->hash)) { |
| 134 | SvREFCNT_dec(wrapper); |
| 135 | Perl_croak(aTHX_ "panic: hv_store() failed in mro_register() " |
| 136 | "for '%.*s' %d", (int) mro->length, mro->name, mro->kflags); |
| 137 | } |
| 138 | } |
| 139 | |
| 140 | struct mro_meta* |
| 141 | Perl_mro_meta_init(pTHX_ HV* stash) |
| 142 | { |
| 143 | struct mro_meta* newmeta; |
| 144 | |
| 145 | PERL_ARGS_ASSERT_MRO_META_INIT; |
| 146 | assert(HvAUX(stash)); |
| 147 | assert(!(HvAUX(stash)->xhv_mro_meta)); |
| 148 | Newxz(newmeta, 1, struct mro_meta); |
| 149 | HvAUX(stash)->xhv_mro_meta = newmeta; |
| 150 | newmeta->cache_gen = 1; |
| 151 | newmeta->pkg_gen = 1; |
| 152 | newmeta->mro_which = &dfs_alg; |
| 153 | |
| 154 | return newmeta; |
| 155 | } |
| 156 | |
| 157 | #if defined(USE_ITHREADS) |
| 158 | |
| 159 | /* for sv_dup on new threads */ |
| 160 | struct mro_meta* |
| 161 | Perl_mro_meta_dup(pTHX_ struct mro_meta* smeta, CLONE_PARAMS* param) |
| 162 | { |
| 163 | struct mro_meta* newmeta; |
| 164 | |
| 165 | PERL_ARGS_ASSERT_MRO_META_DUP; |
| 166 | |
| 167 | Newx(newmeta, 1, struct mro_meta); |
| 168 | Copy(smeta, newmeta, 1, struct mro_meta); |
| 169 | |
| 170 | if (newmeta->mro_linear_all) { |
| 171 | newmeta->mro_linear_all |
| 172 | = MUTABLE_HV(sv_dup_inc((const SV *)newmeta->mro_linear_all, param)); |
| 173 | /* This is just acting as a shortcut pointer, and will be automatically |
| 174 | updated on the first get. */ |
| 175 | newmeta->mro_linear_current = NULL; |
| 176 | } else if (newmeta->mro_linear_current) { |
| 177 | /* Only the current MRO is stored, so this owns the data. */ |
| 178 | newmeta->mro_linear_current |
| 179 | = sv_dup_inc((const SV *)newmeta->mro_linear_current, param); |
| 180 | } |
| 181 | |
| 182 | if (newmeta->mro_nextmethod) |
| 183 | newmeta->mro_nextmethod |
| 184 | = MUTABLE_HV(sv_dup_inc((const SV *)newmeta->mro_nextmethod, param)); |
| 185 | if (newmeta->isa) |
| 186 | newmeta->isa |
| 187 | = MUTABLE_HV(sv_dup_inc((const SV *)newmeta->isa, param)); |
| 188 | |
| 189 | return newmeta; |
| 190 | } |
| 191 | |
| 192 | #endif /* USE_ITHREADS */ |
| 193 | |
| 194 | /* |
| 195 | =for apidoc mro_get_linear_isa_dfs |
| 196 | |
| 197 | Returns the Depth-First Search linearization of @ISA |
| 198 | the given stash. The return value is a read-only AV*. |
| 199 | C<level> should be 0 (it is used internally in this |
| 200 | function's recursion). |
| 201 | |
| 202 | You are responsible for C<SvREFCNT_inc()> on the |
| 203 | return value if you plan to store it anywhere |
| 204 | semi-permanently (otherwise it might be deleted |
| 205 | out from under you the next time the cache is |
| 206 | invalidated). |
| 207 | |
| 208 | =cut |
| 209 | */ |
| 210 | static AV* |
| 211 | S_mro_get_linear_isa_dfs(pTHX_ HV *stash, U32 level) |
| 212 | { |
| 213 | AV* retval; |
| 214 | GV** gvp; |
| 215 | GV* gv; |
| 216 | AV* av; |
| 217 | const HEK* stashhek; |
| 218 | struct mro_meta* meta; |
| 219 | SV *our_name; |
| 220 | HV *stored = NULL; |
| 221 | |
| 222 | PERL_ARGS_ASSERT_MRO_GET_LINEAR_ISA_DFS; |
| 223 | assert(HvAUX(stash)); |
| 224 | |
| 225 | stashhek |
| 226 | = HvAUX(stash)->xhv_name_u.xhvnameu_name && HvENAME_HEK_NN(stash) |
| 227 | ? HvENAME_HEK_NN(stash) |
| 228 | : HvNAME_HEK(stash); |
| 229 | |
| 230 | if (!stashhek) |
| 231 | Perl_croak(aTHX_ "Can't linearize anonymous symbol table"); |
| 232 | |
| 233 | if (level > 100) |
| 234 | Perl_croak(aTHX_ |
| 235 | "Recursive inheritance detected in package '%"HEKf"'", |
| 236 | HEKfARG(stashhek)); |
| 237 | |
| 238 | meta = HvMROMETA(stash); |
| 239 | |
| 240 | /* return cache if valid */ |
| 241 | if((retval = MUTABLE_AV(MRO_GET_PRIVATE_DATA(meta, &dfs_alg)))) { |
| 242 | return retval; |
| 243 | } |
| 244 | |
| 245 | /* not in cache, make a new one */ |
| 246 | |
| 247 | retval = MUTABLE_AV(sv_2mortal(MUTABLE_SV(newAV()))); |
| 248 | /* We use this later in this function, but don't need a reference to it |
| 249 | beyond the end of this function, so reference count is fine. */ |
| 250 | our_name = newSVhek(stashhek); |
| 251 | av_push(retval, our_name); /* add ourselves at the top */ |
| 252 | |
| 253 | /* fetch our @ISA */ |
| 254 | gvp = (GV**)hv_fetchs(stash, "ISA", FALSE); |
| 255 | av = (gvp && (gv = *gvp) && isGV_with_GP(gv)) ? GvAV(gv) : NULL; |
| 256 | |
| 257 | /* "stored" is used to keep track of all of the classnames we have added to |
| 258 | the MRO so far, so we can do a quick exists check and avoid adding |
| 259 | duplicate classnames to the MRO as we go. |
| 260 | It's then retained to be re-used as a fast lookup for ->isa(), by adding |
| 261 | our own name and "UNIVERSAL" to it. */ |
| 262 | |
| 263 | if(av && AvFILLp(av) >= 0) { |
| 264 | |
| 265 | SV **svp = AvARRAY(av); |
| 266 | I32 items = AvFILLp(av) + 1; |
| 267 | |
| 268 | /* foreach(@ISA) */ |
| 269 | while (items--) { |
| 270 | SV* const sv = *svp++; |
| 271 | HV* const basestash = gv_stashsv(sv, 0); |
| 272 | SV *const *subrv_p; |
| 273 | I32 subrv_items; |
| 274 | |
| 275 | if (!basestash) { |
| 276 | /* if no stash exists for this @ISA member, |
| 277 | simply add it to the MRO and move on */ |
| 278 | subrv_p = &sv; |
| 279 | subrv_items = 1; |
| 280 | } |
| 281 | else { |
| 282 | /* otherwise, recurse into ourselves for the MRO |
| 283 | of this @ISA member, and append their MRO to ours. |
| 284 | The recursive call could throw an exception, which |
| 285 | has memory management implications here, hence the use of |
| 286 | the mortal. */ |
| 287 | const AV *const subrv |
| 288 | = mro_get_linear_isa_dfs(basestash, level + 1); |
| 289 | |
| 290 | subrv_p = AvARRAY(subrv); |
| 291 | subrv_items = AvFILLp(subrv) + 1; |
| 292 | } |
| 293 | if (stored) { |
| 294 | while(subrv_items--) { |
| 295 | SV *const subsv = *subrv_p++; |
| 296 | /* LVALUE fetch will create a new undefined SV if necessary |
| 297 | */ |
| 298 | HE *const he = hv_fetch_ent(stored, subsv, 1, 0); |
| 299 | assert(he); |
| 300 | if(HeVAL(he) != &PL_sv_undef) { |
| 301 | /* It was newly created. Steal it for our new SV, and |
| 302 | replace it in the hash with the "real" thing. */ |
| 303 | SV *const val = HeVAL(he); |
| 304 | HEK *const key = HeKEY_hek(he); |
| 305 | |
| 306 | HeVAL(he) = &PL_sv_undef; |
| 307 | /* Save copying by making a shared hash key scalar. We |
| 308 | inline this here rather than calling |
| 309 | Perl_newSVpvn_share because we already have the |
| 310 | scalar, and we already have the hash key. */ |
| 311 | assert(SvTYPE(val) == SVt_NULL); |
| 312 | sv_upgrade(val, SVt_PV); |
| 313 | SvPV_set(val, HEK_KEY(share_hek_hek(key))); |
| 314 | SvCUR_set(val, HEK_LEN(key)); |
| 315 | SvIsCOW_on(val); |
| 316 | SvPOK_on(val); |
| 317 | if (HEK_UTF8(key)) |
| 318 | SvUTF8_on(val); |
| 319 | |
| 320 | av_push(retval, val); |
| 321 | } |
| 322 | } |
| 323 | } else { |
| 324 | /* We are the first (or only) parent. We can short cut the |
| 325 | complexity above, because our @ISA is simply us prepended |
| 326 | to our parent's @ISA, and our ->isa cache is simply our |
| 327 | parent's, with our name added. */ |
| 328 | /* newSVsv() is slow. This code is only faster if we can avoid |
| 329 | it by ensuring that SVs in the arrays are shared hash key |
| 330 | scalar SVs, because we can "copy" them very efficiently. |
| 331 | Although to be fair, we can't *ensure* this, as a reference |
| 332 | to the internal array is returned by mro::get_linear_isa(), |
| 333 | so we'll have to be defensive just in case someone faffed |
| 334 | with it. */ |
| 335 | if (basestash) { |
| 336 | SV **svp; |
| 337 | stored = MUTABLE_HV(sv_2mortal((SV*)newHVhv(HvMROMETA(basestash)->isa))); |
| 338 | av_extend(retval, subrv_items); |
| 339 | AvFILLp(retval) = subrv_items; |
| 340 | svp = AvARRAY(retval); |
| 341 | while(subrv_items--) { |
| 342 | SV *const val = *subrv_p++; |
| 343 | *++svp = SvIsCOW_shared_hash(val) |
| 344 | ? newSVhek(SvSHARED_HEK_FROM_PV(SvPVX(val))) |
| 345 | : newSVsv(val); |
| 346 | } |
| 347 | } else { |
| 348 | /* They have no stash. So create ourselves an ->isa cache |
| 349 | as if we'd copied it from what theirs should be. */ |
| 350 | stored = MUTABLE_HV(sv_2mortal(MUTABLE_SV(newHV()))); |
| 351 | (void) hv_store(stored, "UNIVERSAL", 9, &PL_sv_undef, 0); |
| 352 | av_push(retval, |
| 353 | newSVhek(HeKEY_hek(hv_store_ent(stored, sv, |
| 354 | &PL_sv_undef, 0)))); |
| 355 | } |
| 356 | } |
| 357 | } |
| 358 | } else { |
| 359 | /* We have no parents. */ |
| 360 | stored = MUTABLE_HV(sv_2mortal(MUTABLE_SV(newHV()))); |
| 361 | (void) hv_store(stored, "UNIVERSAL", 9, &PL_sv_undef, 0); |
| 362 | } |
| 363 | |
| 364 | (void) hv_store_ent(stored, our_name, &PL_sv_undef, 0); |
| 365 | |
| 366 | SvREFCNT_inc_simple_void_NN(stored); |
| 367 | SvTEMP_off(stored); |
| 368 | SvREADONLY_on(stored); |
| 369 | |
| 370 | meta->isa = stored; |
| 371 | |
| 372 | /* now that we're past the exception dangers, grab our own reference to |
| 373 | the AV we're about to use for the result. The reference owned by the |
| 374 | mortals' stack will be released soon, so everything will balance. */ |
| 375 | SvREFCNT_inc_simple_void_NN(retval); |
| 376 | SvTEMP_off(retval); |
| 377 | |
| 378 | /* we don't want anyone modifying the cache entry but us, |
| 379 | and we do so by replacing it completely */ |
| 380 | SvREADONLY_on(retval); |
| 381 | |
| 382 | return MUTABLE_AV(Perl_mro_set_private_data(aTHX_ meta, &dfs_alg, |
| 383 | MUTABLE_SV(retval))); |
| 384 | } |
| 385 | |
| 386 | /* |
| 387 | =for apidoc mro_get_linear_isa |
| 388 | |
| 389 | Returns the mro linearisation for the given stash. By default, this |
| 390 | will be whatever C<mro_get_linear_isa_dfs> returns unless some |
| 391 | other MRO is in effect for the stash. The return value is a |
| 392 | read-only AV*. |
| 393 | |
| 394 | You are responsible for C<SvREFCNT_inc()> on the |
| 395 | return value if you plan to store it anywhere |
| 396 | semi-permanently (otherwise it might be deleted |
| 397 | out from under you the next time the cache is |
| 398 | invalidated). |
| 399 | |
| 400 | =cut |
| 401 | */ |
| 402 | AV* |
| 403 | Perl_mro_get_linear_isa(pTHX_ HV *stash) |
| 404 | { |
| 405 | struct mro_meta* meta; |
| 406 | AV *isa; |
| 407 | |
| 408 | PERL_ARGS_ASSERT_MRO_GET_LINEAR_ISA; |
| 409 | if(!SvOOK(stash)) |
| 410 | Perl_croak(aTHX_ "Can't linearize anonymous symbol table"); |
| 411 | |
| 412 | meta = HvMROMETA(stash); |
| 413 | if (!meta->mro_which) |
| 414 | Perl_croak(aTHX_ "panic: invalid MRO!"); |
| 415 | isa = meta->mro_which->resolve(aTHX_ stash, 0); |
| 416 | |
| 417 | if (meta->mro_which != &dfs_alg) { /* skip for dfs, for speed */ |
| 418 | SV * const namesv = |
| 419 | (HvENAME(stash)||HvNAME(stash)) |
| 420 | ? newSVhek(HvENAME_HEK(stash) |
| 421 | ? HvENAME_HEK(stash) |
| 422 | : HvNAME_HEK(stash)) |
| 423 | : NULL; |
| 424 | |
| 425 | if(namesv && (AvFILLp(isa) == -1 || !sv_eq(*AvARRAY(isa), namesv))) |
| 426 | { |
| 427 | AV * const old = isa; |
| 428 | SV **svp; |
| 429 | SV **ovp = AvARRAY(old); |
| 430 | SV * const * const oend = ovp + AvFILLp(old) + 1; |
| 431 | isa = (AV *)sv_2mortal((SV *)newAV()); |
| 432 | av_extend(isa, AvFILLp(isa) = AvFILLp(old)+1); |
| 433 | *AvARRAY(isa) = namesv; |
| 434 | svp = AvARRAY(isa)+1; |
| 435 | while (ovp < oend) *svp++ = SvREFCNT_inc(*ovp++); |
| 436 | } |
| 437 | else SvREFCNT_dec(namesv); |
| 438 | } |
| 439 | |
| 440 | if (!meta->isa) { |
| 441 | HV *const isa_hash = newHV(); |
| 442 | /* Linearisation didn't build it for us, so do it here. */ |
| 443 | SV *const *svp = AvARRAY(isa); |
| 444 | SV *const *const svp_end = svp + AvFILLp(isa) + 1; |
| 445 | const HEK *canon_name = HvENAME_HEK(stash); |
| 446 | if (!canon_name) canon_name = HvNAME_HEK(stash); |
| 447 | |
| 448 | while (svp < svp_end) { |
| 449 | (void) hv_store_ent(isa_hash, *svp++, &PL_sv_undef, 0); |
| 450 | } |
| 451 | |
| 452 | (void) hv_common(isa_hash, NULL, HEK_KEY(canon_name), |
| 453 | HEK_LEN(canon_name), HEK_FLAGS(canon_name), |
| 454 | HV_FETCH_ISSTORE, &PL_sv_undef, |
| 455 | HEK_HASH(canon_name)); |
| 456 | (void) hv_store(isa_hash, "UNIVERSAL", 9, &PL_sv_undef, 0); |
| 457 | |
| 458 | SvREADONLY_on(isa_hash); |
| 459 | |
| 460 | meta->isa = isa_hash; |
| 461 | } |
| 462 | |
| 463 | return isa; |
| 464 | } |
| 465 | |
| 466 | /* |
| 467 | =for apidoc mro_isa_changed_in |
| 468 | |
| 469 | Takes the necessary steps (cache invalidations, mostly) |
| 470 | when the @ISA of the given package has changed. Invoked |
| 471 | by the C<setisa> magic, should not need to invoke directly. |
| 472 | |
| 473 | =cut |
| 474 | */ |
| 475 | |
| 476 | /* Macro to avoid repeating the code five times. */ |
| 477 | #define CLEAR_LINEAR(mEta) \ |
| 478 | if (mEta->mro_linear_all) { \ |
| 479 | SvREFCNT_dec(MUTABLE_SV(mEta->mro_linear_all)); \ |
| 480 | mEta->mro_linear_all = NULL; \ |
| 481 | /* This is just acting as a shortcut pointer. */ \ |
| 482 | mEta->mro_linear_current = NULL; \ |
| 483 | } else if (mEta->mro_linear_current) { \ |
| 484 | /* Only the current MRO is stored, so this owns the data. */ \ |
| 485 | SvREFCNT_dec(mEta->mro_linear_current); \ |
| 486 | mEta->mro_linear_current = NULL; \ |
| 487 | } |
| 488 | |
| 489 | void |
| 490 | Perl_mro_isa_changed_in(pTHX_ HV* stash) |
| 491 | { |
| 492 | dVAR; |
| 493 | HV* isarev; |
| 494 | AV* linear_mro; |
| 495 | HE* iter; |
| 496 | SV** svp; |
| 497 | I32 items; |
| 498 | bool is_universal; |
| 499 | struct mro_meta * meta; |
| 500 | HV *isa = NULL; |
| 501 | |
| 502 | const char * const stashname = HvENAME_get(stash); |
| 503 | const STRLEN stashname_len = HvENAMELEN_get(stash); |
| 504 | const bool stashname_utf8 = HvENAMEUTF8(stash) ? 1 : 0; |
| 505 | |
| 506 | PERL_ARGS_ASSERT_MRO_ISA_CHANGED_IN; |
| 507 | |
| 508 | if(!stashname) |
| 509 | Perl_croak(aTHX_ "Can't call mro_isa_changed_in() on anonymous symbol table"); |
| 510 | |
| 511 | |
| 512 | /* wipe out the cached linearizations for this stash */ |
| 513 | meta = HvMROMETA(stash); |
| 514 | CLEAR_LINEAR(meta); |
| 515 | if (meta->isa) { |
| 516 | /* Steal it for our own purposes. */ |
| 517 | isa = (HV *)sv_2mortal((SV *)meta->isa); |
| 518 | meta->isa = NULL; |
| 519 | } |
| 520 | |
| 521 | /* Inc the package generation, since our @ISA changed */ |
| 522 | meta->pkg_gen++; |
| 523 | |
| 524 | /* Wipe the global method cache if this package |
| 525 | is UNIVERSAL or one of its parents */ |
| 526 | |
| 527 | svp = hv_fetch(PL_isarev, stashname, |
| 528 | stashname_utf8 ? -(I32)stashname_len : (I32)stashname_len, 0); |
| 529 | isarev = svp ? MUTABLE_HV(*svp) : NULL; |
| 530 | |
| 531 | if((stashname_len == 9 && strEQ(stashname, "UNIVERSAL")) |
| 532 | || (isarev && hv_exists(isarev, "UNIVERSAL", 9))) { |
| 533 | PL_sub_generation++; |
| 534 | is_universal = TRUE; |
| 535 | } |
| 536 | else { /* Wipe the local method cache otherwise */ |
| 537 | meta->cache_gen++; |
| 538 | is_universal = FALSE; |
| 539 | } |
| 540 | |
| 541 | /* wipe next::method cache too */ |
| 542 | if(meta->mro_nextmethod) hv_clear(meta->mro_nextmethod); |
| 543 | |
| 544 | /* Changes to @ISA might turn overloading on */ |
| 545 | HvAMAGIC_on(stash); |
| 546 | |
| 547 | /* DESTROY can be cached in SvSTASH. */ |
| 548 | if (!SvOBJECT(stash)) SvSTASH(stash) = NULL; |
| 549 | |
| 550 | /* Iterate the isarev (classes that are our children), |
| 551 | wiping out their linearization, method and isa caches |
| 552 | and upating PL_isarev. */ |
| 553 | if(isarev) { |
| 554 | HV *isa_hashes = NULL; |
| 555 | |
| 556 | /* We have to iterate through isarev twice to avoid a chicken and |
| 557 | * egg problem: if A inherits from B and both are in isarev, A might |
| 558 | * be processed before B and use B's previous linearisation. |
| 559 | */ |
| 560 | |
| 561 | /* First iteration: Wipe everything, but stash away the isa hashes |
| 562 | * since we still need them for updating PL_isarev. |
| 563 | */ |
| 564 | |
| 565 | if(hv_iterinit(isarev)) { |
| 566 | /* Only create the hash if we need it; i.e., if isarev has |
| 567 | any elements. */ |
| 568 | isa_hashes = (HV *)sv_2mortal((SV *)newHV()); |
| 569 | } |
| 570 | while((iter = hv_iternext(isarev))) { |
| 571 | HV* revstash = gv_stashsv(hv_iterkeysv(iter), 0); |
| 572 | struct mro_meta* revmeta; |
| 573 | |
| 574 | if(!revstash) continue; |
| 575 | revmeta = HvMROMETA(revstash); |
| 576 | CLEAR_LINEAR(revmeta); |
| 577 | if(!is_universal) |
| 578 | revmeta->cache_gen++; |
| 579 | if(revmeta->mro_nextmethod) |
| 580 | hv_clear(revmeta->mro_nextmethod); |
| 581 | if (!SvOBJECT(revstash)) SvSTASH(revstash) = NULL; |
| 582 | |
| 583 | (void) |
| 584 | hv_store( |
| 585 | isa_hashes, (const char*)&revstash, sizeof(HV *), |
| 586 | revmeta->isa ? (SV *)revmeta->isa : &PL_sv_undef, 0 |
| 587 | ); |
| 588 | revmeta->isa = NULL; |
| 589 | } |
| 590 | |
| 591 | /* Second pass: Update PL_isarev. We can just use isa_hashes to |
| 592 | * avoid another round of stash lookups. */ |
| 593 | |
| 594 | /* isarev might be deleted from PL_isarev during this loop, so hang |
| 595 | * on to it. */ |
| 596 | SvREFCNT_inc_simple_void_NN(sv_2mortal((SV *)isarev)); |
| 597 | |
| 598 | if(isa_hashes) { |
| 599 | hv_iterinit(isa_hashes); |
| 600 | while((iter = hv_iternext(isa_hashes))) { |
| 601 | HV* const revstash = *(HV **)HEK_KEY(HeKEY_hek(iter)); |
| 602 | HV * const isa = (HV *)HeVAL(iter); |
| 603 | const HEK *namehek; |
| 604 | |
| 605 | /* We're starting at the 2nd element, skipping revstash */ |
| 606 | linear_mro = mro_get_linear_isa(revstash); |
| 607 | svp = AvARRAY(linear_mro) + 1; |
| 608 | items = AvFILLp(linear_mro); |
| 609 | |
| 610 | namehek = HvENAME_HEK(revstash); |
| 611 | if (!namehek) namehek = HvNAME_HEK(revstash); |
| 612 | |
| 613 | while (items--) { |
| 614 | SV* const sv = *svp++; |
| 615 | HV* mroisarev; |
| 616 | |
| 617 | HE *he = hv_fetch_ent(PL_isarev, sv, TRUE, 0); |
| 618 | |
| 619 | /* That fetch should not fail. But if it had to create |
| 620 | a new SV for us, then will need to upgrade it to an |
| 621 | HV (which sv_upgrade() can now do for us). */ |
| 622 | |
| 623 | mroisarev = MUTABLE_HV(HeVAL(he)); |
| 624 | |
| 625 | SvUPGRADE(MUTABLE_SV(mroisarev), SVt_PVHV); |
| 626 | |
| 627 | /* This hash only ever contains PL_sv_yes. Storing it |
| 628 | over itself is almost as cheap as calling hv_exists, |
| 629 | so on aggregate we expect to save time by not making |
| 630 | two calls to the common HV code for the case where |
| 631 | it doesn't exist. */ |
| 632 | |
| 633 | (void) |
| 634 | hv_store( |
| 635 | mroisarev, HEK_KEY(namehek), |
| 636 | HEK_UTF8(namehek) ? -HEK_LEN(namehek) : HEK_LEN(namehek), |
| 637 | &PL_sv_yes, 0 |
| 638 | ); |
| 639 | } |
| 640 | |
| 641 | if((SV *)isa != &PL_sv_undef) |
| 642 | mro_clean_isarev( |
| 643 | isa, HEK_KEY(namehek), HEK_LEN(namehek), |
| 644 | HvMROMETA(revstash)->isa, (HEK_UTF8(namehek) ? SVf_UTF8 : 0) |
| 645 | ); |
| 646 | } |
| 647 | } |
| 648 | } |
| 649 | |
| 650 | /* Now iterate our MRO (parents), adding ourselves and everything from |
| 651 | our isarev to their isarev. |
| 652 | */ |
| 653 | |
| 654 | /* We're starting at the 2nd element, skipping ourselves here */ |
| 655 | linear_mro = mro_get_linear_isa(stash); |
| 656 | svp = AvARRAY(linear_mro) + 1; |
| 657 | items = AvFILLp(linear_mro); |
| 658 | |
| 659 | while (items--) { |
| 660 | SV* const sv = *svp++; |
| 661 | HV* mroisarev; |
| 662 | |
| 663 | HE *he = hv_fetch_ent(PL_isarev, sv, TRUE, 0); |
| 664 | |
| 665 | /* That fetch should not fail. But if it had to create a new SV for |
| 666 | us, then will need to upgrade it to an HV (which sv_upgrade() can |
| 667 | now do for us. */ |
| 668 | |
| 669 | mroisarev = MUTABLE_HV(HeVAL(he)); |
| 670 | |
| 671 | SvUPGRADE(MUTABLE_SV(mroisarev), SVt_PVHV); |
| 672 | |
| 673 | /* This hash only ever contains PL_sv_yes. Storing it over itself is |
| 674 | almost as cheap as calling hv_exists, so on aggregate we expect to |
| 675 | save time by not making two calls to the common HV code for the |
| 676 | case where it doesn't exist. */ |
| 677 | |
| 678 | (void)hv_store(mroisarev, stashname, |
| 679 | stashname_utf8 ? -(I32)stashname_len : (I32)stashname_len, &PL_sv_yes, 0); |
| 680 | } |
| 681 | |
| 682 | /* Delete our name from our former parents' isarevs. */ |
| 683 | if(isa && HvARRAY(isa)) |
| 684 | mro_clean_isarev(isa, stashname, stashname_len, meta->isa, |
| 685 | (stashname_utf8 ? SVf_UTF8 : 0) ); |
| 686 | } |
| 687 | |
| 688 | /* Deletes name from all the isarev entries listed in isa */ |
| 689 | STATIC void |
| 690 | S_mro_clean_isarev(pTHX_ HV * const isa, const char * const name, |
| 691 | const STRLEN len, HV * const exceptions, U32 flags) |
| 692 | { |
| 693 | HE* iter; |
| 694 | |
| 695 | PERL_ARGS_ASSERT_MRO_CLEAN_ISAREV; |
| 696 | |
| 697 | /* Delete our name from our former parents' isarevs. */ |
| 698 | if(isa && HvARRAY(isa) && hv_iterinit(isa)) { |
| 699 | SV **svp; |
| 700 | while((iter = hv_iternext(isa))) { |
| 701 | I32 klen; |
| 702 | const char * const key = hv_iterkey(iter, &klen); |
| 703 | if(exceptions && hv_exists(exceptions, key, HeKUTF8(iter) ? -klen : klen)) |
| 704 | continue; |
| 705 | svp = hv_fetch(PL_isarev, key, HeKUTF8(iter) ? -klen : klen, 0); |
| 706 | if(svp) { |
| 707 | HV * const isarev = (HV *)*svp; |
| 708 | (void)hv_delete(isarev, name, (flags & SVf_UTF8) ? -(I32)len : (I32)len, G_DISCARD); |
| 709 | if(!HvARRAY(isarev) || !HvUSEDKEYS(isarev)) |
| 710 | (void)hv_delete(PL_isarev, key, |
| 711 | HeKUTF8(iter) ? -klen : klen, G_DISCARD); |
| 712 | } |
| 713 | } |
| 714 | } |
| 715 | } |
| 716 | |
| 717 | /* |
| 718 | =for apidoc mro_package_moved |
| 719 | |
| 720 | Call this function to signal to a stash that it has been assigned to |
| 721 | another spot in the stash hierarchy. C<stash> is the stash that has been |
| 722 | assigned. C<oldstash> is the stash it replaces, if any. C<gv> is the glob |
| 723 | that is actually being assigned to. |
| 724 | |
| 725 | This can also be called with a null first argument to |
| 726 | indicate that C<oldstash> has been deleted. |
| 727 | |
| 728 | This function invalidates isa caches on the old stash, on all subpackages |
| 729 | nested inside it, and on the subclasses of all those, including |
| 730 | non-existent packages that have corresponding entries in C<stash>. |
| 731 | |
| 732 | It also sets the effective names (C<HvENAME>) on all the stashes as |
| 733 | appropriate. |
| 734 | |
| 735 | If the C<gv> is present and is not in the symbol table, then this function |
| 736 | simply returns. This checked will be skipped if C<flags & 1>. |
| 737 | |
| 738 | =cut |
| 739 | */ |
| 740 | void |
| 741 | Perl_mro_package_moved(pTHX_ HV * const stash, HV * const oldstash, |
| 742 | const GV * const gv, U32 flags) |
| 743 | { |
| 744 | SV *namesv; |
| 745 | HEK **namep; |
| 746 | I32 name_count; |
| 747 | HV *stashes; |
| 748 | HE* iter; |
| 749 | |
| 750 | PERL_ARGS_ASSERT_MRO_PACKAGE_MOVED; |
| 751 | assert(stash || oldstash); |
| 752 | |
| 753 | /* Determine the name(s) of the location that stash was assigned to |
| 754 | * or from which oldstash was removed. |
| 755 | * |
| 756 | * We cannot reliably use the name in oldstash, because it may have |
| 757 | * been deleted from the location in the symbol table that its name |
| 758 | * suggests, as in this case: |
| 759 | * |
| 760 | * $globref = \*foo::bar::; |
| 761 | * Symbol::delete_package("foo"); |
| 762 | * *$globref = \%baz::; |
| 763 | * *$globref = *frelp::; |
| 764 | * # calls mro_package_moved(%frelp::, %baz::, *$globref, NULL, 0) |
| 765 | * |
| 766 | * So we get it from the gv. But, since the gv may no longer be in the |
| 767 | * symbol table, we check that first. The only reliable way to tell is |
| 768 | * to see whether its stash has an effective name and whether the gv |
| 769 | * resides in that stash under its name. That effective name may be |
| 770 | * different from what gv_fullname4 would use. |
| 771 | * If flags & 1, the caller has asked us to skip the check. |
| 772 | */ |
| 773 | if(!(flags & 1)) { |
| 774 | SV **svp; |
| 775 | if( |
| 776 | !GvSTASH(gv) || !HvENAME(GvSTASH(gv)) || |
| 777 | !(svp = hv_fetch(GvSTASH(gv), GvNAME(gv), |
| 778 | GvNAMEUTF8(gv) ? -GvNAMELEN(gv) : GvNAMELEN(gv), 0)) || |
| 779 | *svp != (SV *)gv |
| 780 | ) return; |
| 781 | } |
| 782 | assert(SvOOK(GvSTASH(gv))); |
| 783 | assert(GvNAMELEN(gv)); |
| 784 | assert(GvNAME(gv)[GvNAMELEN(gv) - 1] == ':'); |
| 785 | assert(GvNAMELEN(gv) == 1 || GvNAME(gv)[GvNAMELEN(gv) - 2] == ':'); |
| 786 | name_count = HvAUX(GvSTASH(gv))->xhv_name_count; |
| 787 | if (!name_count) { |
| 788 | name_count = 1; |
| 789 | namep = &HvAUX(GvSTASH(gv))->xhv_name_u.xhvnameu_name; |
| 790 | } |
| 791 | else { |
| 792 | namep = HvAUX(GvSTASH(gv))->xhv_name_u.xhvnameu_names; |
| 793 | if (name_count < 0) ++namep, name_count = -name_count - 1; |
| 794 | } |
| 795 | if (name_count == 1) { |
| 796 | if (HEK_LEN(*namep) == 4 && strnEQ(HEK_KEY(*namep), "main", 4)) { |
| 797 | namesv = GvNAMELEN(gv) == 1 |
| 798 | ? newSVpvs_flags(":", SVs_TEMP) |
| 799 | : newSVpvs_flags("", SVs_TEMP); |
| 800 | } |
| 801 | else { |
| 802 | namesv = sv_2mortal(newSVhek(*namep)); |
| 803 | if (GvNAMELEN(gv) == 1) sv_catpvs(namesv, ":"); |
| 804 | else sv_catpvs(namesv, "::"); |
| 805 | } |
| 806 | if (GvNAMELEN(gv) != 1) { |
| 807 | sv_catpvn_flags( |
| 808 | namesv, GvNAME(gv), GvNAMELEN(gv) - 2, |
| 809 | /* skip trailing :: */ |
| 810 | GvNAMEUTF8(gv) ? SV_CATUTF8 : SV_CATBYTES |
| 811 | ); |
| 812 | } |
| 813 | } |
| 814 | else { |
| 815 | SV *aname; |
| 816 | namesv = sv_2mortal((SV *)newAV()); |
| 817 | while (name_count--) { |
| 818 | if(HEK_LEN(*namep) == 4 && strnEQ(HEK_KEY(*namep), "main", 4)){ |
| 819 | aname = GvNAMELEN(gv) == 1 |
| 820 | ? newSVpvs(":") |
| 821 | : newSVpvs(""); |
| 822 | namep++; |
| 823 | } |
| 824 | else { |
| 825 | aname = newSVhek(*namep++); |
| 826 | if (GvNAMELEN(gv) == 1) sv_catpvs(aname, ":"); |
| 827 | else sv_catpvs(aname, "::"); |
| 828 | } |
| 829 | if (GvNAMELEN(gv) != 1) { |
| 830 | sv_catpvn_flags( |
| 831 | aname, GvNAME(gv), GvNAMELEN(gv) - 2, |
| 832 | /* skip trailing :: */ |
| 833 | GvNAMEUTF8(gv) ? SV_CATUTF8 : SV_CATBYTES |
| 834 | ); |
| 835 | } |
| 836 | av_push((AV *)namesv, aname); |
| 837 | } |
| 838 | } |
| 839 | |
| 840 | /* Get a list of all the affected classes. */ |
| 841 | /* We cannot simply pass them all to mro_isa_changed_in to avoid |
| 842 | the list, as that function assumes that only one package has |
| 843 | changed. It does not work with: |
| 844 | |
| 845 | @foo::ISA = qw( B B::B ); |
| 846 | *B:: = delete $::{"A::"}; |
| 847 | |
| 848 | as neither B nor B::B can be updated before the other, since they |
| 849 | will reset caches on foo, which will see either B or B::B with the |
| 850 | wrong name. The names must be set on *all* affected stashes before |
| 851 | we do anything else. (And linearisations must be cleared, too.) |
| 852 | */ |
| 853 | stashes = (HV *) sv_2mortal((SV *)newHV()); |
| 854 | mro_gather_and_rename( |
| 855 | stashes, (HV *) sv_2mortal((SV *)newHV()), |
| 856 | stash, oldstash, namesv |
| 857 | ); |
| 858 | |
| 859 | /* Once the caches have been wiped on all the classes, call |
| 860 | mro_isa_changed_in on each. */ |
| 861 | hv_iterinit(stashes); |
| 862 | while((iter = hv_iternext(stashes))) { |
| 863 | HV * const stash = *(HV **)HEK_KEY(HeKEY_hek(iter)); |
| 864 | if(HvENAME(stash)) { |
| 865 | /* We have to restore the original meta->isa (that |
| 866 | mro_gather_and_rename set aside for us) this way, in case |
| 867 | one class in this list is a superclass of a another class |
| 868 | that we have already encountered. In such a case, meta->isa |
| 869 | will have been overwritten without old entries being deleted |
| 870 | from PL_isarev. */ |
| 871 | struct mro_meta * const meta = HvMROMETA(stash); |
| 872 | if(meta->isa != (HV *)HeVAL(iter)){ |
| 873 | SvREFCNT_dec(meta->isa); |
| 874 | meta->isa |
| 875 | = HeVAL(iter) == &PL_sv_yes |
| 876 | ? NULL |
| 877 | : (HV *)HeVAL(iter); |
| 878 | HeVAL(iter) = NULL; /* We donated our reference count. */ |
| 879 | } |
| 880 | mro_isa_changed_in(stash); |
| 881 | } |
| 882 | } |
| 883 | } |
| 884 | |
| 885 | STATIC void |
| 886 | S_mro_gather_and_rename(pTHX_ HV * const stashes, HV * const seen_stashes, |
| 887 | HV *stash, HV *oldstash, SV *namesv) |
| 888 | { |
| 889 | XPVHV* xhv; |
| 890 | HE *entry; |
| 891 | I32 riter = -1; |
| 892 | I32 items = 0; |
| 893 | const bool stash_had_name = stash && HvENAME(stash); |
| 894 | bool fetched_isarev = FALSE; |
| 895 | HV *seen = NULL; |
| 896 | HV *isarev = NULL; |
| 897 | SV **svp = NULL; |
| 898 | |
| 899 | PERL_ARGS_ASSERT_MRO_GATHER_AND_RENAME; |
| 900 | |
| 901 | /* We use the seen_stashes hash to keep track of which packages have |
| 902 | been encountered so far. This must be separate from the main list of |
| 903 | stashes, as we need to distinguish between stashes being assigned |
| 904 | and stashes being replaced/deleted. (A nested stash can be on both |
| 905 | sides of an assignment. We cannot simply skip iterating through a |
| 906 | stash on the right if we have seen it on the left, as it will not |
| 907 | get its ename assigned to it.) |
| 908 | |
| 909 | To avoid allocating extra SVs, instead of a bitfield we can make |
| 910 | bizarre use of immortals: |
| 911 | |
| 912 | &PL_sv_undef: seen on the left (oldstash) |
| 913 | &PL_sv_no : seen on the right (stash) |
| 914 | &PL_sv_yes : seen on both sides |
| 915 | |
| 916 | */ |
| 917 | |
| 918 | if(oldstash) { |
| 919 | /* Add to the big list. */ |
| 920 | struct mro_meta * meta; |
| 921 | HE * const entry |
| 922 | = (HE *) |
| 923 | hv_common( |
| 924 | seen_stashes, NULL, (const char *)&oldstash, sizeof(HV *), 0, |
| 925 | HV_FETCH_LVALUE|HV_FETCH_EMPTY_HE, NULL, 0 |
| 926 | ); |
| 927 | if(HeVAL(entry) == &PL_sv_undef || HeVAL(entry) == &PL_sv_yes) { |
| 928 | oldstash = NULL; |
| 929 | goto check_stash; |
| 930 | } |
| 931 | HeVAL(entry) |
| 932 | = HeVAL(entry) == &PL_sv_no ? &PL_sv_yes : &PL_sv_undef; |
| 933 | meta = HvMROMETA(oldstash); |
| 934 | (void) |
| 935 | hv_store( |
| 936 | stashes, (const char *)&oldstash, sizeof(HV *), |
| 937 | meta->isa |
| 938 | ? SvREFCNT_inc_simple_NN((SV *)meta->isa) |
| 939 | : &PL_sv_yes, |
| 940 | 0 |
| 941 | ); |
| 942 | CLEAR_LINEAR(meta); |
| 943 | |
| 944 | /* Update the effective name. */ |
| 945 | if(HvENAME_get(oldstash)) { |
| 946 | const HEK * const enamehek = HvENAME_HEK(oldstash); |
| 947 | if(SvTYPE(namesv) == SVt_PVAV) { |
| 948 | items = AvFILLp((AV *)namesv) + 1; |
| 949 | svp = AvARRAY((AV *)namesv); |
| 950 | } |
| 951 | else { |
| 952 | items = 1; |
| 953 | svp = &namesv; |
| 954 | } |
| 955 | while (items--) { |
| 956 | const U32 name_utf8 = SvUTF8(*svp); |
| 957 | STRLEN len; |
| 958 | const char *name = SvPVx_const(*svp, len); |
| 959 | if(PL_stashcache) { |
| 960 | DEBUG_o(Perl_deb(aTHX_ "mro_gather_and_rename clearing PL_stashcache for '%"SVf"'\n", |
| 961 | *svp)); |
| 962 | (void)hv_delete(PL_stashcache, name, name_utf8 ? -(I32)len : (I32)len, G_DISCARD); |
| 963 | } |
| 964 | ++svp; |
| 965 | hv_ename_delete(oldstash, name, len, name_utf8); |
| 966 | |
| 967 | if (!fetched_isarev) { |
| 968 | /* If the name deletion caused a name change, then we |
| 969 | * are not going to call mro_isa_changed_in with this |
| 970 | * name (and not at all if it has become anonymous) so |
| 971 | * we need to delete old isarev entries here, both |
| 972 | * those in the superclasses and this class's own list |
| 973 | * of subclasses. We simply delete the latter from |
| 974 | * PL_isarev, since we still need it. hv_delete morti- |
| 975 | * fies it for us, so sv_2mortal is not necessary. */ |
| 976 | if(HvENAME_HEK(oldstash) != enamehek) { |
| 977 | if(meta->isa && HvARRAY(meta->isa)) |
| 978 | mro_clean_isarev(meta->isa, name, len, 0, name_utf8); |
| 979 | isarev = (HV *)hv_delete(PL_isarev, name, |
| 980 | name_utf8 ? -(I32)len : (I32)len, 0); |
| 981 | fetched_isarev=TRUE; |
| 982 | } |
| 983 | } |
| 984 | } |
| 985 | } |
| 986 | } |
| 987 | check_stash: |
| 988 | if(stash) { |
| 989 | if(SvTYPE(namesv) == SVt_PVAV) { |
| 990 | items = AvFILLp((AV *)namesv) + 1; |
| 991 | svp = AvARRAY((AV *)namesv); |
| 992 | } |
| 993 | else { |
| 994 | items = 1; |
| 995 | svp = &namesv; |
| 996 | } |
| 997 | while (items--) { |
| 998 | const U32 name_utf8 = SvUTF8(*svp); |
| 999 | STRLEN len; |
| 1000 | const char *name = SvPVx_const(*svp++, len); |
| 1001 | hv_ename_add(stash, name, len, name_utf8); |
| 1002 | } |
| 1003 | |
| 1004 | /* Add it to the big list if it needs |
| 1005 | * mro_isa_changed_in called on it. That happens if it was |
| 1006 | * detached from the symbol table (so it had no HvENAME) before |
| 1007 | * being assigned to the spot named by the 'name' variable, because |
| 1008 | * its cached isa linearisation is now stale (the effective name |
| 1009 | * having changed), and subclasses will then use that cache when |
| 1010 | * mro_package_moved calls mro_isa_changed_in. (See |
| 1011 | * [perl #77358].) |
| 1012 | * |
| 1013 | * If it did have a name, then its previous name is still |
| 1014 | * used in isa caches, and there is no need for |
| 1015 | * mro_package_moved to call mro_isa_changed_in. |
| 1016 | */ |
| 1017 | |
| 1018 | entry |
| 1019 | = (HE *) |
| 1020 | hv_common( |
| 1021 | seen_stashes, NULL, (const char *)&stash, sizeof(HV *), 0, |
| 1022 | HV_FETCH_LVALUE|HV_FETCH_EMPTY_HE, NULL, 0 |
| 1023 | ); |
| 1024 | if(HeVAL(entry) == &PL_sv_yes || HeVAL(entry) == &PL_sv_no) |
| 1025 | stash = NULL; |
| 1026 | else { |
| 1027 | HeVAL(entry) |
| 1028 | = HeVAL(entry) == &PL_sv_undef ? &PL_sv_yes : &PL_sv_no; |
| 1029 | if(!stash_had_name) |
| 1030 | { |
| 1031 | struct mro_meta * const meta = HvMROMETA(stash); |
| 1032 | (void) |
| 1033 | hv_store( |
| 1034 | stashes, (const char *)&stash, sizeof(HV *), |
| 1035 | meta->isa |
| 1036 | ? SvREFCNT_inc_simple_NN((SV *)meta->isa) |
| 1037 | : &PL_sv_yes, |
| 1038 | 0 |
| 1039 | ); |
| 1040 | CLEAR_LINEAR(meta); |
| 1041 | } |
| 1042 | } |
| 1043 | } |
| 1044 | |
| 1045 | if(!stash && !oldstash) |
| 1046 | /* Both stashes have been encountered already. */ |
| 1047 | return; |
| 1048 | |
| 1049 | /* Add all the subclasses to the big list. */ |
| 1050 | if(!fetched_isarev) { |
| 1051 | /* If oldstash is not null, then we can use its HvENAME to look up |
| 1052 | the isarev hash, since all its subclasses will be listed there. |
| 1053 | It will always have an HvENAME. It the HvENAME was removed |
| 1054 | above, then fetch_isarev will be true, and this code will not be |
| 1055 | reached. |
| 1056 | |
| 1057 | If oldstash is null, then this is an empty spot with no stash in |
| 1058 | it, so subclasses could be listed in isarev hashes belonging to |
| 1059 | any of the names, so we have to check all of them. |
| 1060 | */ |
| 1061 | assert(!oldstash || HvENAME(oldstash)); |
| 1062 | if (oldstash) { |
| 1063 | /* Extra variable to avoid a compiler warning */ |
| 1064 | char * const hvename = HvENAME(oldstash); |
| 1065 | fetched_isarev = TRUE; |
| 1066 | svp = hv_fetch(PL_isarev, hvename, |
| 1067 | HvENAMEUTF8(oldstash) |
| 1068 | ? -HvENAMELEN_get(oldstash) |
| 1069 | : HvENAMELEN_get(oldstash), 0); |
| 1070 | if (svp) isarev = MUTABLE_HV(*svp); |
| 1071 | } |
| 1072 | else if(SvTYPE(namesv) == SVt_PVAV) { |
| 1073 | items = AvFILLp((AV *)namesv) + 1; |
| 1074 | svp = AvARRAY((AV *)namesv); |
| 1075 | } |
| 1076 | else { |
| 1077 | items = 1; |
| 1078 | svp = &namesv; |
| 1079 | } |
| 1080 | } |
| 1081 | if( |
| 1082 | isarev || !fetched_isarev |
| 1083 | ) { |
| 1084 | while (fetched_isarev || items--) { |
| 1085 | HE *iter; |
| 1086 | |
| 1087 | if (!fetched_isarev) { |
| 1088 | HE * const he = hv_fetch_ent(PL_isarev, *svp++, 0, 0); |
| 1089 | if (!he || !(isarev = MUTABLE_HV(HeVAL(he)))) continue; |
| 1090 | } |
| 1091 | |
| 1092 | hv_iterinit(isarev); |
| 1093 | while((iter = hv_iternext(isarev))) { |
| 1094 | HV* revstash = gv_stashsv(hv_iterkeysv(iter), 0); |
| 1095 | struct mro_meta * meta; |
| 1096 | |
| 1097 | if(!revstash) continue; |
| 1098 | meta = HvMROMETA(revstash); |
| 1099 | (void) |
| 1100 | hv_store( |
| 1101 | stashes, (const char *)&revstash, sizeof(HV *), |
| 1102 | meta->isa |
| 1103 | ? SvREFCNT_inc_simple_NN((SV *)meta->isa) |
| 1104 | : &PL_sv_yes, |
| 1105 | 0 |
| 1106 | ); |
| 1107 | CLEAR_LINEAR(meta); |
| 1108 | } |
| 1109 | |
| 1110 | if (fetched_isarev) break; |
| 1111 | } |
| 1112 | } |
| 1113 | |
| 1114 | /* This is partly based on code in hv_iternext_flags. We are not call- |
| 1115 | ing that here, as we want to avoid resetting the hash iterator. */ |
| 1116 | |
| 1117 | /* Skip the entire loop if the hash is empty. */ |
| 1118 | if(oldstash && HvUSEDKEYS(oldstash)) { |
| 1119 | xhv = (XPVHV*)SvANY(oldstash); |
| 1120 | seen = (HV *) sv_2mortal((SV *)newHV()); |
| 1121 | |
| 1122 | /* Iterate through entries in the oldstash, adding them to the |
| 1123 | list, meanwhile doing the equivalent of $seen{$key} = 1. |
| 1124 | */ |
| 1125 | |
| 1126 | while (++riter <= (I32)xhv->xhv_max) { |
| 1127 | entry = (HvARRAY(oldstash))[riter]; |
| 1128 | |
| 1129 | /* Iterate through the entries in this list */ |
| 1130 | for(; entry; entry = HeNEXT(entry)) { |
| 1131 | const char* key; |
| 1132 | I32 len; |
| 1133 | |
| 1134 | /* If this entry is not a glob, ignore it. |
| 1135 | Try the next. */ |
| 1136 | if (!isGV(HeVAL(entry))) continue; |
| 1137 | |
| 1138 | key = hv_iterkey(entry, &len); |
| 1139 | if ((len > 1 && key[len-2] == ':' && key[len-1] == ':') |
| 1140 | || (len == 1 && key[0] == ':')) { |
| 1141 | HV * const oldsubstash = GvHV(HeVAL(entry)); |
| 1142 | SV ** const stashentry |
| 1143 | = stash ? hv_fetch(stash, key, HeUTF8(entry) ? -(I32)len : (I32)len, 0) : NULL; |
| 1144 | HV *substash = NULL; |
| 1145 | |
| 1146 | /* Avoid main::main::main::... */ |
| 1147 | if(oldsubstash == oldstash) continue; |
| 1148 | |
| 1149 | if( |
| 1150 | ( |
| 1151 | stashentry && *stashentry |
| 1152 | && (substash = GvHV(*stashentry)) |
| 1153 | ) |
| 1154 | || (oldsubstash && HvENAME_get(oldsubstash)) |
| 1155 | ) |
| 1156 | { |
| 1157 | /* Add :: and the key (minus the trailing ::) |
| 1158 | to each name. */ |
| 1159 | SV *subname; |
| 1160 | if(SvTYPE(namesv) == SVt_PVAV) { |
| 1161 | SV *aname; |
| 1162 | items = AvFILLp((AV *)namesv) + 1; |
| 1163 | svp = AvARRAY((AV *)namesv); |
| 1164 | subname = sv_2mortal((SV *)newAV()); |
| 1165 | while (items--) { |
| 1166 | aname = newSVsv(*svp++); |
| 1167 | if (len == 1) |
| 1168 | sv_catpvs(aname, ":"); |
| 1169 | else { |
| 1170 | sv_catpvs(aname, "::"); |
| 1171 | sv_catpvn_flags( |
| 1172 | aname, key, len-2, |
| 1173 | HeUTF8(entry) |
| 1174 | ? SV_CATUTF8 : SV_CATBYTES |
| 1175 | ); |
| 1176 | } |
| 1177 | av_push((AV *)subname, aname); |
| 1178 | } |
| 1179 | } |
| 1180 | else { |
| 1181 | subname = sv_2mortal(newSVsv(namesv)); |
| 1182 | if (len == 1) sv_catpvs(subname, ":"); |
| 1183 | else { |
| 1184 | sv_catpvs(subname, "::"); |
| 1185 | sv_catpvn_flags( |
| 1186 | subname, key, len-2, |
| 1187 | HeUTF8(entry) ? SV_CATUTF8 : SV_CATBYTES |
| 1188 | ); |
| 1189 | } |
| 1190 | } |
| 1191 | mro_gather_and_rename( |
| 1192 | stashes, seen_stashes, |
| 1193 | substash, oldsubstash, subname |
| 1194 | ); |
| 1195 | } |
| 1196 | |
| 1197 | (void)hv_store(seen, key, HeUTF8(entry) ? -(I32)len : (I32)len, &PL_sv_yes, 0); |
| 1198 | } |
| 1199 | } |
| 1200 | } |
| 1201 | } |
| 1202 | |
| 1203 | /* Skip the entire loop if the hash is empty. */ |
| 1204 | if (stash && HvUSEDKEYS(stash)) { |
| 1205 | xhv = (XPVHV*)SvANY(stash); |
| 1206 | riter = -1; |
| 1207 | |
| 1208 | /* Iterate through the new stash, skipping $seen{$key} items, |
| 1209 | calling mro_gather_and_rename(stashes,seen,entry,NULL, ...). */ |
| 1210 | while (++riter <= (I32)xhv->xhv_max) { |
| 1211 | entry = (HvARRAY(stash))[riter]; |
| 1212 | |
| 1213 | /* Iterate through the entries in this list */ |
| 1214 | for(; entry; entry = HeNEXT(entry)) { |
| 1215 | const char* key; |
| 1216 | I32 len; |
| 1217 | |
| 1218 | /* If this entry is not a glob, ignore it. |
| 1219 | Try the next. */ |
| 1220 | if (!isGV(HeVAL(entry))) continue; |
| 1221 | |
| 1222 | key = hv_iterkey(entry, &len); |
| 1223 | if ((len > 1 && key[len-2] == ':' && key[len-1] == ':') |
| 1224 | || (len == 1 && key[0] == ':')) { |
| 1225 | HV *substash; |
| 1226 | |
| 1227 | /* If this entry was seen when we iterated through the |
| 1228 | oldstash, skip it. */ |
| 1229 | if(seen && hv_exists(seen, key, HeUTF8(entry) ? -(I32)len : (I32)len)) continue; |
| 1230 | |
| 1231 | /* We get here only if this stash has no corresponding |
| 1232 | entry in the stash being replaced. */ |
| 1233 | |
| 1234 | substash = GvHV(HeVAL(entry)); |
| 1235 | if(substash) { |
| 1236 | SV *subname; |
| 1237 | |
| 1238 | /* Avoid checking main::main::main::... */ |
| 1239 | if(substash == stash) continue; |
| 1240 | |
| 1241 | /* Add :: and the key (minus the trailing ::) |
| 1242 | to each name. */ |
| 1243 | if(SvTYPE(namesv) == SVt_PVAV) { |
| 1244 | SV *aname; |
| 1245 | items = AvFILLp((AV *)namesv) + 1; |
| 1246 | svp = AvARRAY((AV *)namesv); |
| 1247 | subname = sv_2mortal((SV *)newAV()); |
| 1248 | while (items--) { |
| 1249 | aname = newSVsv(*svp++); |
| 1250 | if (len == 1) |
| 1251 | sv_catpvs(aname, ":"); |
| 1252 | else { |
| 1253 | sv_catpvs(aname, "::"); |
| 1254 | sv_catpvn_flags( |
| 1255 | aname, key, len-2, |
| 1256 | HeUTF8(entry) |
| 1257 | ? SV_CATUTF8 : SV_CATBYTES |
| 1258 | ); |
| 1259 | } |
| 1260 | av_push((AV *)subname, aname); |
| 1261 | } |
| 1262 | } |
| 1263 | else { |
| 1264 | subname = sv_2mortal(newSVsv(namesv)); |
| 1265 | if (len == 1) sv_catpvs(subname, ":"); |
| 1266 | else { |
| 1267 | sv_catpvs(subname, "::"); |
| 1268 | sv_catpvn_flags( |
| 1269 | subname, key, len-2, |
| 1270 | HeUTF8(entry) ? SV_CATUTF8 : SV_CATBYTES |
| 1271 | ); |
| 1272 | } |
| 1273 | } |
| 1274 | mro_gather_and_rename( |
| 1275 | stashes, seen_stashes, |
| 1276 | substash, NULL, subname |
| 1277 | ); |
| 1278 | } |
| 1279 | } |
| 1280 | } |
| 1281 | } |
| 1282 | } |
| 1283 | } |
| 1284 | |
| 1285 | /* |
| 1286 | =for apidoc mro_method_changed_in |
| 1287 | |
| 1288 | Invalidates method caching on any child classes |
| 1289 | of the given stash, so that they might notice |
| 1290 | the changes in this one. |
| 1291 | |
| 1292 | Ideally, all instances of C<PL_sub_generation++> in |
| 1293 | perl source outside of F<mro.c> should be |
| 1294 | replaced by calls to this. |
| 1295 | |
| 1296 | Perl automatically handles most of the common |
| 1297 | ways a method might be redefined. However, there |
| 1298 | are a few ways you could change a method in a stash |
| 1299 | without the cache code noticing, in which case you |
| 1300 | need to call this method afterwards: |
| 1301 | |
| 1302 | 1) Directly manipulating the stash HV entries from |
| 1303 | XS code. |
| 1304 | |
| 1305 | 2) Assigning a reference to a readonly scalar |
| 1306 | constant into a stash entry in order to create |
| 1307 | a constant subroutine (like constant.pm |
| 1308 | does). |
| 1309 | |
| 1310 | This same method is available from pure perl |
| 1311 | via, C<mro::method_changed_in(classname)>. |
| 1312 | |
| 1313 | =cut |
| 1314 | */ |
| 1315 | void |
| 1316 | Perl_mro_method_changed_in(pTHX_ HV *stash) |
| 1317 | { |
| 1318 | const char * const stashname = HvENAME_get(stash); |
| 1319 | const STRLEN stashname_len = HvENAMELEN_get(stash); |
| 1320 | const bool stashname_utf8 = HvENAMEUTF8(stash) ? 1 : 0; |
| 1321 | |
| 1322 | SV ** const svp = hv_fetch(PL_isarev, stashname, |
| 1323 | stashname_utf8 ? -(I32)stashname_len : (I32)stashname_len, 0); |
| 1324 | HV * const isarev = svp ? MUTABLE_HV(*svp) : NULL; |
| 1325 | |
| 1326 | PERL_ARGS_ASSERT_MRO_METHOD_CHANGED_IN; |
| 1327 | |
| 1328 | if(!stashname) |
| 1329 | Perl_croak(aTHX_ "Can't call mro_method_changed_in() on anonymous symbol table"); |
| 1330 | |
| 1331 | /* Inc the package generation, since a local method changed */ |
| 1332 | HvMROMETA(stash)->pkg_gen++; |
| 1333 | |
| 1334 | /* DESTROY can be cached in SvSTASH. */ |
| 1335 | if (!SvOBJECT(stash)) SvSTASH(stash) = NULL; |
| 1336 | |
| 1337 | /* If stash is UNIVERSAL, or one of UNIVERSAL's parents, |
| 1338 | invalidate all method caches globally */ |
| 1339 | if((stashname_len == 9 && strEQ(stashname, "UNIVERSAL")) |
| 1340 | || (isarev && hv_exists(isarev, "UNIVERSAL", 9))) { |
| 1341 | PL_sub_generation++; |
| 1342 | return; |
| 1343 | } |
| 1344 | |
| 1345 | /* else, invalidate the method caches of all child classes, |
| 1346 | but not itself */ |
| 1347 | if(isarev) { |
| 1348 | HE* iter; |
| 1349 | |
| 1350 | hv_iterinit(isarev); |
| 1351 | while((iter = hv_iternext(isarev))) { |
| 1352 | HV* const revstash = gv_stashsv(hv_iterkeysv(iter), 0); |
| 1353 | struct mro_meta* mrometa; |
| 1354 | |
| 1355 | if(!revstash) continue; |
| 1356 | mrometa = HvMROMETA(revstash); |
| 1357 | mrometa->cache_gen++; |
| 1358 | if(mrometa->mro_nextmethod) |
| 1359 | hv_clear(mrometa->mro_nextmethod); |
| 1360 | if (!SvOBJECT(revstash)) SvSTASH(revstash) = NULL; |
| 1361 | } |
| 1362 | } |
| 1363 | |
| 1364 | /* The method change may be due to *{$package . "::()"} = \&nil; in |
| 1365 | overload.pm. */ |
| 1366 | HvAMAGIC_on(stash); |
| 1367 | } |
| 1368 | |
| 1369 | void |
| 1370 | Perl_mro_set_mro(pTHX_ struct mro_meta *const meta, SV *const name) |
| 1371 | { |
| 1372 | const struct mro_alg *const which = Perl_mro_get_from_name(aTHX_ name); |
| 1373 | |
| 1374 | PERL_ARGS_ASSERT_MRO_SET_MRO; |
| 1375 | |
| 1376 | if (!which) |
| 1377 | Perl_croak(aTHX_ "Invalid mro name: '%"SVf"'", name); |
| 1378 | |
| 1379 | if(meta->mro_which != which) { |
| 1380 | if (meta->mro_linear_current && !meta->mro_linear_all) { |
| 1381 | /* If we were storing something directly, put it in the hash before |
| 1382 | we lose it. */ |
| 1383 | Perl_mro_set_private_data(aTHX_ meta, meta->mro_which, |
| 1384 | MUTABLE_SV(meta->mro_linear_current)); |
| 1385 | } |
| 1386 | meta->mro_which = which; |
| 1387 | /* Scrub our cached pointer to the private data. */ |
| 1388 | meta->mro_linear_current = NULL; |
| 1389 | /* Only affects local method cache, not |
| 1390 | even child classes */ |
| 1391 | meta->cache_gen++; |
| 1392 | if(meta->mro_nextmethod) |
| 1393 | hv_clear(meta->mro_nextmethod); |
| 1394 | } |
| 1395 | } |
| 1396 | |
| 1397 | #include "XSUB.h" |
| 1398 | |
| 1399 | XS(XS_mro_method_changed_in); |
| 1400 | |
| 1401 | void |
| 1402 | Perl_boot_core_mro(pTHX) |
| 1403 | { |
| 1404 | dVAR; |
| 1405 | static const char file[] = __FILE__; |
| 1406 | |
| 1407 | Perl_mro_register(aTHX_ &dfs_alg); |
| 1408 | |
| 1409 | newXSproto("mro::method_changed_in", XS_mro_method_changed_in, file, "$"); |
| 1410 | } |
| 1411 | |
| 1412 | XS(XS_mro_method_changed_in) |
| 1413 | { |
| 1414 | dVAR; |
| 1415 | dXSARGS; |
| 1416 | SV* classname; |
| 1417 | HV* class_stash; |
| 1418 | |
| 1419 | if(items != 1) |
| 1420 | croak_xs_usage(cv, "classname"); |
| 1421 | |
| 1422 | classname = ST(0); |
| 1423 | |
| 1424 | class_stash = gv_stashsv(classname, 0); |
| 1425 | if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname)); |
| 1426 | |
| 1427 | mro_method_changed_in(class_stash); |
| 1428 | |
| 1429 | XSRETURN_EMPTY; |
| 1430 | } |
| 1431 | |
| 1432 | /* |
| 1433 | * Local variables: |
| 1434 | * c-indentation-style: bsd |
| 1435 | * c-basic-offset: 4 |
| 1436 | * indent-tabs-mode: nil |
| 1437 | * End: |
| 1438 | * |
| 1439 | * ex: set ts=8 sts=4 sw=4 et: |
| 1440 | */ |