| 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 | These functions are related to the method resolution order of perl classes |
| 21 | |
| 22 | =cut |
| 23 | */ |
| 24 | |
| 25 | #include "EXTERN.h" |
| 26 | #define PERL_IN_MRO_C |
| 27 | #include "perl.h" |
| 28 | |
| 29 | static const struct mro_alg dfs_alg = |
| 30 | {S_mro_get_linear_isa_dfs, "dfs", 3, 0, 0}; |
| 31 | |
| 32 | SV * |
| 33 | Perl_mro_get_private_data(pTHX_ struct mro_meta *const smeta, |
| 34 | const struct mro_alg *const which) |
| 35 | { |
| 36 | SV **data; |
| 37 | PERL_ARGS_ASSERT_MRO_GET_PRIVATE_DATA; |
| 38 | |
| 39 | data = (SV **)Perl_hv_common(aTHX_ smeta->mro_linear_all, NULL, |
| 40 | which->name, which->length, which->kflags, |
| 41 | HV_FETCH_JUST_SV, NULL, which->hash); |
| 42 | if (!data) |
| 43 | return NULL; |
| 44 | |
| 45 | /* If we've been asked to look up the private data for the current MRO, then |
| 46 | cache it. */ |
| 47 | if (smeta->mro_which == which) |
| 48 | smeta->mro_linear_current = *data; |
| 49 | |
| 50 | return *data; |
| 51 | } |
| 52 | |
| 53 | SV * |
| 54 | Perl_mro_set_private_data(pTHX_ struct mro_meta *const smeta, |
| 55 | const struct mro_alg *const which, SV *const data) |
| 56 | { |
| 57 | PERL_ARGS_ASSERT_MRO_SET_PRIVATE_DATA; |
| 58 | |
| 59 | if (!smeta->mro_linear_all) { |
| 60 | if (smeta->mro_which == which) { |
| 61 | /* If all we need to store is the current MRO's data, then don't use |
| 62 | memory on a hash with 1 element - store it direct, and signal |
| 63 | this by leaving the would-be-hash NULL. */ |
| 64 | smeta->mro_linear_current = data; |
| 65 | return data; |
| 66 | } else { |
| 67 | HV *const hv = newHV(); |
| 68 | /* Start with 2 buckets. It's unlikely we'll need more. */ |
| 69 | HvMAX(hv) = 1; |
| 70 | smeta->mro_linear_all = hv; |
| 71 | |
| 72 | if (smeta->mro_linear_current) { |
| 73 | /* If we were storing something directly, put it in the hash |
| 74 | before we lose it. */ |
| 75 | Perl_mro_set_private_data(aTHX_ smeta, smeta->mro_which, |
| 76 | smeta->mro_linear_current); |
| 77 | } |
| 78 | } |
| 79 | } |
| 80 | |
| 81 | /* We get here if we're storing more than one linearisation for this stash, |
| 82 | or the linearisation we are storing is not that if its current MRO. */ |
| 83 | |
| 84 | if (smeta->mro_which == which) { |
| 85 | /* If we've been asked to store the private data for the current MRO, |
| 86 | then cache it. */ |
| 87 | smeta->mro_linear_current = data; |
| 88 | } |
| 89 | |
| 90 | if (!Perl_hv_common(aTHX_ smeta->mro_linear_all, NULL, |
| 91 | which->name, which->length, which->kflags, |
| 92 | HV_FETCH_ISSTORE, data, which->hash)) { |
| 93 | Perl_croak(aTHX_ "panic: hv_store() failed in set_mro_private_data() " |
| 94 | "for '%.*s' %d", (int) which->length, which->name, |
| 95 | which->kflags); |
| 96 | } |
| 97 | |
| 98 | return data; |
| 99 | } |
| 100 | |
| 101 | const struct mro_alg * |
| 102 | Perl_mro_get_from_name(pTHX_ SV *name) { |
| 103 | SV **data; |
| 104 | |
| 105 | PERL_ARGS_ASSERT_MRO_GET_FROM_NAME; |
| 106 | |
| 107 | data = (SV **)Perl_hv_common(aTHX_ PL_registered_mros, name, NULL, 0, 0, |
| 108 | HV_FETCH_JUST_SV, NULL, 0); |
| 109 | if (!data) |
| 110 | return NULL; |
| 111 | assert(SvTYPE(*data) == SVt_IV); |
| 112 | assert(SvIOK(*data)); |
| 113 | return INT2PTR(const struct mro_alg *, SvUVX(*data)); |
| 114 | } |
| 115 | |
| 116 | /* |
| 117 | =for apidoc mro_register |
| 118 | Registers a custom mro plugin. See L<perlmroapi> for details. |
| 119 | |
| 120 | =cut |
| 121 | */ |
| 122 | |
| 123 | void |
| 124 | Perl_mro_register(pTHX_ const struct mro_alg *mro) { |
| 125 | SV *wrapper = newSVuv(PTR2UV(mro)); |
| 126 | |
| 127 | PERL_ARGS_ASSERT_MRO_REGISTER; |
| 128 | |
| 129 | |
| 130 | if (!Perl_hv_common(aTHX_ PL_registered_mros, NULL, |
| 131 | mro->name, mro->length, mro->kflags, |
| 132 | HV_FETCH_ISSTORE, wrapper, mro->hash)) { |
| 133 | SvREFCNT_dec_NN(wrapper); |
| 134 | Perl_croak(aTHX_ "panic: hv_store() failed in mro_register() " |
| 135 | "for '%.*s' %d", (int) mro->length, mro->name, mro->kflags); |
| 136 | } |
| 137 | } |
| 138 | |
| 139 | struct mro_meta* |
| 140 | Perl_mro_meta_init(pTHX_ HV* stash) |
| 141 | { |
| 142 | struct mro_meta* newmeta; |
| 143 | |
| 144 | PERL_ARGS_ASSERT_MRO_META_INIT; |
| 145 | PERL_UNUSED_CONTEXT; |
| 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 | newmeta->super = NULL; |
| 190 | |
| 191 | return newmeta; |
| 192 | } |
| 193 | |
| 194 | #endif /* USE_ITHREADS */ |
| 195 | |
| 196 | /* |
| 197 | =for apidoc mro_get_linear_isa_dfs |
| 198 | |
| 199 | Returns the Depth-First Search linearization of @ISA |
| 200 | the given stash. The return value is a read-only AV*. |
| 201 | C<level> should be 0 (it is used internally in this |
| 202 | function's recursion). |
| 203 | |
| 204 | You are responsible for C<SvREFCNT_inc()> on the |
| 205 | return value if you plan to store it anywhere |
| 206 | semi-permanently (otherwise it might be deleted |
| 207 | out from under you the next time the cache is |
| 208 | invalidated). |
| 209 | |
| 210 | =cut |
| 211 | */ |
| 212 | static AV* |
| 213 | S_mro_get_linear_isa_dfs(pTHX_ HV *stash, U32 level) |
| 214 | { |
| 215 | AV* retval; |
| 216 | GV** gvp; |
| 217 | GV* gv; |
| 218 | AV* av; |
| 219 | const HEK* stashhek; |
| 220 | struct mro_meta* meta; |
| 221 | SV *our_name; |
| 222 | HV *stored = NULL; |
| 223 | |
| 224 | PERL_ARGS_ASSERT_MRO_GET_LINEAR_ISA_DFS; |
| 225 | assert(HvAUX(stash)); |
| 226 | |
| 227 | stashhek |
| 228 | = HvAUX(stash)->xhv_name_u.xhvnameu_name && HvENAME_HEK_NN(stash) |
| 229 | ? HvENAME_HEK_NN(stash) |
| 230 | : HvNAME_HEK(stash); |
| 231 | |
| 232 | if (!stashhek) |
| 233 | Perl_croak(aTHX_ "Can't linearize anonymous symbol table"); |
| 234 | |
| 235 | if (level > 100) |
| 236 | Perl_croak(aTHX_ |
| 237 | "Recursive inheritance detected in package '%"HEKf"'", |
| 238 | HEKfARG(stashhek)); |
| 239 | |
| 240 | meta = HvMROMETA(stash); |
| 241 | |
| 242 | /* return cache if valid */ |
| 243 | if((retval = MUTABLE_AV(MRO_GET_PRIVATE_DATA(meta, &dfs_alg)))) { |
| 244 | return retval; |
| 245 | } |
| 246 | |
| 247 | /* not in cache, make a new one */ |
| 248 | |
| 249 | retval = MUTABLE_AV(sv_2mortal(MUTABLE_SV(newAV()))); |
| 250 | /* We use this later in this function, but don't need a reference to it |
| 251 | beyond the end of this function, so reference count is fine. */ |
| 252 | our_name = newSVhek(stashhek); |
| 253 | av_push(retval, our_name); /* add ourselves at the top */ |
| 254 | |
| 255 | /* fetch our @ISA */ |
| 256 | gvp = (GV**)hv_fetchs(stash, "ISA", FALSE); |
| 257 | av = (gvp && (gv = *gvp) && isGV_with_GP(gv)) ? GvAV(gv) : NULL; |
| 258 | |
| 259 | /* "stored" is used to keep track of all of the classnames we have added to |
| 260 | the MRO so far, so we can do a quick exists check and avoid adding |
| 261 | duplicate classnames to the MRO as we go. |
| 262 | It's then retained to be re-used as a fast lookup for ->isa(), by adding |
| 263 | our own name and "UNIVERSAL" to it. */ |
| 264 | |
| 265 | if(av && AvFILLp(av) >= 0) { |
| 266 | |
| 267 | SV **svp = AvARRAY(av); |
| 268 | I32 items = AvFILLp(av) + 1; |
| 269 | |
| 270 | /* foreach(@ISA) */ |
| 271 | while (items--) { |
| 272 | SV* const sv = *svp ? *svp : &PL_sv_undef; |
| 273 | HV* const basestash = gv_stashsv(sv, 0); |
| 274 | SV *const *subrv_p; |
| 275 | I32 subrv_items; |
| 276 | svp++; |
| 277 | |
| 278 | if (!basestash) { |
| 279 | /* if no stash exists for this @ISA member, |
| 280 | simply add it to the MRO and move on */ |
| 281 | subrv_p = &sv; |
| 282 | subrv_items = 1; |
| 283 | } |
| 284 | else { |
| 285 | /* otherwise, recurse into ourselves for the MRO |
| 286 | of this @ISA member, and append their MRO to ours. |
| 287 | The recursive call could throw an exception, which |
| 288 | has memory management implications here, hence the use of |
| 289 | the mortal. */ |
| 290 | const AV *const subrv |
| 291 | = mro_get_linear_isa_dfs(basestash, level + 1); |
| 292 | |
| 293 | subrv_p = AvARRAY(subrv); |
| 294 | subrv_items = AvFILLp(subrv) + 1; |
| 295 | } |
| 296 | if (stored) { |
| 297 | while(subrv_items--) { |
| 298 | SV *const subsv = *subrv_p++; |
| 299 | /* LVALUE fetch will create a new undefined SV if necessary |
| 300 | */ |
| 301 | HE *const he = hv_fetch_ent(stored, subsv, 1, 0); |
| 302 | assert(he); |
| 303 | if(HeVAL(he) != &PL_sv_undef) { |
| 304 | /* It was newly created. Steal it for our new SV, and |
| 305 | replace it in the hash with the "real" thing. */ |
| 306 | SV *const val = HeVAL(he); |
| 307 | HEK *const key = HeKEY_hek(he); |
| 308 | |
| 309 | HeVAL(he) = &PL_sv_undef; |
| 310 | sv_sethek(val, key); |
| 311 | av_push(retval, val); |
| 312 | } |
| 313 | } |
| 314 | } else { |
| 315 | /* We are the first (or only) parent. We can short cut the |
| 316 | complexity above, because our @ISA is simply us prepended |
| 317 | to our parent's @ISA, and our ->isa cache is simply our |
| 318 | parent's, with our name added. */ |
| 319 | /* newSVsv() is slow. This code is only faster if we can avoid |
| 320 | it by ensuring that SVs in the arrays are shared hash key |
| 321 | scalar SVs, because we can "copy" them very efficiently. |
| 322 | Although to be fair, we can't *ensure* this, as a reference |
| 323 | to the internal array is returned by mro::get_linear_isa(), |
| 324 | so we'll have to be defensive just in case someone faffed |
| 325 | with it. */ |
| 326 | if (basestash) { |
| 327 | SV **svp; |
| 328 | stored = MUTABLE_HV(sv_2mortal((SV*)newHVhv(HvMROMETA(basestash)->isa))); |
| 329 | av_extend(retval, subrv_items); |
| 330 | AvFILLp(retval) = subrv_items; |
| 331 | svp = AvARRAY(retval); |
| 332 | while(subrv_items--) { |
| 333 | SV *const val = *subrv_p++; |
| 334 | *++svp = SvIsCOW_shared_hash(val) |
| 335 | ? newSVhek(SvSHARED_HEK_FROM_PV(SvPVX(val))) |
| 336 | : newSVsv(val); |
| 337 | } |
| 338 | } else { |
| 339 | /* They have no stash. So create ourselves an ->isa cache |
| 340 | as if we'd copied it from what theirs should be. */ |
| 341 | stored = MUTABLE_HV(sv_2mortal(MUTABLE_SV(newHV()))); |
| 342 | (void) hv_store(stored, "UNIVERSAL", 9, &PL_sv_undef, 0); |
| 343 | av_push(retval, |
| 344 | newSVhek(HeKEY_hek(hv_store_ent(stored, sv, |
| 345 | &PL_sv_undef, 0)))); |
| 346 | } |
| 347 | } |
| 348 | } |
| 349 | } else { |
| 350 | /* We have no parents. */ |
| 351 | stored = MUTABLE_HV(sv_2mortal(MUTABLE_SV(newHV()))); |
| 352 | (void) hv_store(stored, "UNIVERSAL", 9, &PL_sv_undef, 0); |
| 353 | } |
| 354 | |
| 355 | (void) hv_store_ent(stored, our_name, &PL_sv_undef, 0); |
| 356 | |
| 357 | SvREFCNT_inc_simple_void_NN(stored); |
| 358 | SvTEMP_off(stored); |
| 359 | SvREADONLY_on(stored); |
| 360 | |
| 361 | meta->isa = stored; |
| 362 | |
| 363 | /* now that we're past the exception dangers, grab our own reference to |
| 364 | the AV we're about to use for the result. The reference owned by the |
| 365 | mortals' stack will be released soon, so everything will balance. */ |
| 366 | SvREFCNT_inc_simple_void_NN(retval); |
| 367 | SvTEMP_off(retval); |
| 368 | |
| 369 | /* we don't want anyone modifying the cache entry but us, |
| 370 | and we do so by replacing it completely */ |
| 371 | SvREADONLY_on(retval); |
| 372 | |
| 373 | return MUTABLE_AV(Perl_mro_set_private_data(aTHX_ meta, &dfs_alg, |
| 374 | MUTABLE_SV(retval))); |
| 375 | } |
| 376 | |
| 377 | /* |
| 378 | =for apidoc mro_get_linear_isa |
| 379 | |
| 380 | Returns the mro linearisation for the given stash. By default, this |
| 381 | will be whatever C<mro_get_linear_isa_dfs> returns unless some |
| 382 | other MRO is in effect for the stash. The return value is a |
| 383 | read-only AV*. |
| 384 | |
| 385 | You are responsible for C<SvREFCNT_inc()> on the |
| 386 | return value if you plan to store it anywhere |
| 387 | semi-permanently (otherwise it might be deleted |
| 388 | out from under you the next time the cache is |
| 389 | invalidated). |
| 390 | |
| 391 | =cut |
| 392 | */ |
| 393 | AV* |
| 394 | Perl_mro_get_linear_isa(pTHX_ HV *stash) |
| 395 | { |
| 396 | struct mro_meta* meta; |
| 397 | AV *isa; |
| 398 | |
| 399 | PERL_ARGS_ASSERT_MRO_GET_LINEAR_ISA; |
| 400 | if(!SvOOK(stash)) |
| 401 | Perl_croak(aTHX_ "Can't linearize anonymous symbol table"); |
| 402 | |
| 403 | meta = HvMROMETA(stash); |
| 404 | if (!meta->mro_which) |
| 405 | Perl_croak(aTHX_ "panic: invalid MRO!"); |
| 406 | isa = meta->mro_which->resolve(aTHX_ stash, 0); |
| 407 | |
| 408 | if (meta->mro_which != &dfs_alg) { /* skip for dfs, for speed */ |
| 409 | SV * const namesv = |
| 410 | (HvENAME(stash)||HvNAME(stash)) |
| 411 | ? newSVhek(HvENAME_HEK(stash) |
| 412 | ? HvENAME_HEK(stash) |
| 413 | : HvNAME_HEK(stash)) |
| 414 | : NULL; |
| 415 | |
| 416 | if(namesv && (AvFILLp(isa) == -1 || !sv_eq(*AvARRAY(isa), namesv))) |
| 417 | { |
| 418 | AV * const old = isa; |
| 419 | SV **svp; |
| 420 | SV **ovp = AvARRAY(old); |
| 421 | SV * const * const oend = ovp + AvFILLp(old) + 1; |
| 422 | isa = (AV *)sv_2mortal((SV *)newAV()); |
| 423 | av_extend(isa, AvFILLp(isa) = AvFILLp(old)+1); |
| 424 | *AvARRAY(isa) = namesv; |
| 425 | svp = AvARRAY(isa)+1; |
| 426 | while (ovp < oend) *svp++ = SvREFCNT_inc(*ovp++); |
| 427 | } |
| 428 | else SvREFCNT_dec(namesv); |
| 429 | } |
| 430 | |
| 431 | if (!meta->isa) { |
| 432 | HV *const isa_hash = newHV(); |
| 433 | /* Linearisation didn't build it for us, so do it here. */ |
| 434 | SV *const *svp = AvARRAY(isa); |
| 435 | SV *const *const svp_end = svp + AvFILLp(isa) + 1; |
| 436 | const HEK *canon_name = HvENAME_HEK(stash); |
| 437 | if (!canon_name) canon_name = HvNAME_HEK(stash); |
| 438 | |
| 439 | while (svp < svp_end) { |
| 440 | (void) hv_store_ent(isa_hash, *svp++, &PL_sv_undef, 0); |
| 441 | } |
| 442 | |
| 443 | (void) hv_common(isa_hash, NULL, HEK_KEY(canon_name), |
| 444 | HEK_LEN(canon_name), HEK_FLAGS(canon_name), |
| 445 | HV_FETCH_ISSTORE, &PL_sv_undef, |
| 446 | HEK_HASH(canon_name)); |
| 447 | (void) hv_store(isa_hash, "UNIVERSAL", 9, &PL_sv_undef, 0); |
| 448 | |
| 449 | SvREADONLY_on(isa_hash); |
| 450 | |
| 451 | meta->isa = isa_hash; |
| 452 | } |
| 453 | |
| 454 | return isa; |
| 455 | } |
| 456 | |
| 457 | /* |
| 458 | =for apidoc mro_isa_changed_in |
| 459 | |
| 460 | Takes the necessary steps (cache invalidations, mostly) |
| 461 | when the @ISA of the given package has changed. Invoked |
| 462 | by the C<setisa> magic, should not need to invoke directly. |
| 463 | |
| 464 | =cut |
| 465 | */ |
| 466 | |
| 467 | /* Macro to avoid repeating the code five times. */ |
| 468 | #define CLEAR_LINEAR(mEta) \ |
| 469 | if (mEta->mro_linear_all) { \ |
| 470 | SvREFCNT_dec(MUTABLE_SV(mEta->mro_linear_all)); \ |
| 471 | mEta->mro_linear_all = NULL; \ |
| 472 | /* This is just acting as a shortcut pointer. */ \ |
| 473 | mEta->mro_linear_current = NULL; \ |
| 474 | } else if (mEta->mro_linear_current) { \ |
| 475 | /* Only the current MRO is stored, so this owns the data. */ \ |
| 476 | SvREFCNT_dec(mEta->mro_linear_current); \ |
| 477 | mEta->mro_linear_current = NULL; \ |
| 478 | } |
| 479 | |
| 480 | void |
| 481 | Perl_mro_isa_changed_in(pTHX_ HV* stash) |
| 482 | { |
| 483 | HV* isarev; |
| 484 | AV* linear_mro; |
| 485 | HE* iter; |
| 486 | SV** svp; |
| 487 | I32 items; |
| 488 | bool is_universal; |
| 489 | struct mro_meta * meta; |
| 490 | HV *isa = NULL; |
| 491 | |
| 492 | const HEK * const stashhek = HvENAME_HEK(stash); |
| 493 | const char * const stashname = HvENAME_get(stash); |
| 494 | const STRLEN stashname_len = HvENAMELEN_get(stash); |
| 495 | |
| 496 | PERL_ARGS_ASSERT_MRO_ISA_CHANGED_IN; |
| 497 | |
| 498 | if(!stashname) |
| 499 | Perl_croak(aTHX_ "Can't call mro_isa_changed_in() on anonymous symbol table"); |
| 500 | |
| 501 | |
| 502 | /* wipe out the cached linearizations for this stash */ |
| 503 | meta = HvMROMETA(stash); |
| 504 | CLEAR_LINEAR(meta); |
| 505 | if (meta->isa) { |
| 506 | /* Steal it for our own purposes. */ |
| 507 | isa = (HV *)sv_2mortal((SV *)meta->isa); |
| 508 | meta->isa = NULL; |
| 509 | } |
| 510 | |
| 511 | /* Inc the package generation, since our @ISA changed */ |
| 512 | meta->pkg_gen++; |
| 513 | |
| 514 | /* Wipe the global method cache if this package |
| 515 | is UNIVERSAL or one of its parents */ |
| 516 | |
| 517 | svp = hv_fetchhek(PL_isarev, stashhek, 0); |
| 518 | isarev = svp ? MUTABLE_HV(*svp) : NULL; |
| 519 | |
| 520 | if((stashname_len == 9 && strEQ(stashname, "UNIVERSAL")) |
| 521 | || (isarev && hv_exists(isarev, "UNIVERSAL", 9))) { |
| 522 | PL_sub_generation++; |
| 523 | is_universal = TRUE; |
| 524 | } |
| 525 | else { /* Wipe the local method cache otherwise */ |
| 526 | meta->cache_gen++; |
| 527 | is_universal = FALSE; |
| 528 | } |
| 529 | |
| 530 | /* wipe next::method cache too */ |
| 531 | if(meta->mro_nextmethod) hv_clear(meta->mro_nextmethod); |
| 532 | |
| 533 | /* Changes to @ISA might turn overloading on */ |
| 534 | HvAMAGIC_on(stash); |
| 535 | /* pessimise derefs for now. Will get recalculated by Gv_AMupdate() */ |
| 536 | HvAUX(stash)->xhv_aux_flags &= ~HvAUXf_NO_DEREF; |
| 537 | |
| 538 | /* DESTROY can be cached in SvSTASH. */ |
| 539 | if (!SvOBJECT(stash)) SvSTASH(stash) = NULL; |
| 540 | |
| 541 | /* Iterate the isarev (classes that are our children), |
| 542 | wiping out their linearization, method and isa caches |
| 543 | and upating PL_isarev. */ |
| 544 | if(isarev) { |
| 545 | HV *isa_hashes = NULL; |
| 546 | |
| 547 | /* We have to iterate through isarev twice to avoid a chicken and |
| 548 | * egg problem: if A inherits from B and both are in isarev, A might |
| 549 | * be processed before B and use B's previous linearisation. |
| 550 | */ |
| 551 | |
| 552 | /* First iteration: Wipe everything, but stash away the isa hashes |
| 553 | * since we still need them for updating PL_isarev. |
| 554 | */ |
| 555 | |
| 556 | if(hv_iterinit(isarev)) { |
| 557 | /* Only create the hash if we need it; i.e., if isarev has |
| 558 | any elements. */ |
| 559 | isa_hashes = (HV *)sv_2mortal((SV *)newHV()); |
| 560 | } |
| 561 | while((iter = hv_iternext(isarev))) { |
| 562 | HV* revstash = gv_stashsv(hv_iterkeysv(iter), 0); |
| 563 | struct mro_meta* revmeta; |
| 564 | |
| 565 | if(!revstash) continue; |
| 566 | revmeta = HvMROMETA(revstash); |
| 567 | CLEAR_LINEAR(revmeta); |
| 568 | if(!is_universal) |
| 569 | revmeta->cache_gen++; |
| 570 | if(revmeta->mro_nextmethod) |
| 571 | hv_clear(revmeta->mro_nextmethod); |
| 572 | if (!SvOBJECT(revstash)) SvSTASH(revstash) = NULL; |
| 573 | |
| 574 | (void) |
| 575 | hv_store( |
| 576 | isa_hashes, (const char*)&revstash, sizeof(HV *), |
| 577 | revmeta->isa ? (SV *)revmeta->isa : &PL_sv_undef, 0 |
| 578 | ); |
| 579 | revmeta->isa = NULL; |
| 580 | } |
| 581 | |
| 582 | /* Second pass: Update PL_isarev. We can just use isa_hashes to |
| 583 | * avoid another round of stash lookups. */ |
| 584 | |
| 585 | /* isarev might be deleted from PL_isarev during this loop, so hang |
| 586 | * on to it. */ |
| 587 | SvREFCNT_inc_simple_void_NN(sv_2mortal((SV *)isarev)); |
| 588 | |
| 589 | if(isa_hashes) { |
| 590 | hv_iterinit(isa_hashes); |
| 591 | while((iter = hv_iternext(isa_hashes))) { |
| 592 | HV* const revstash = *(HV **)HEK_KEY(HeKEY_hek(iter)); |
| 593 | HV * const isa = (HV *)HeVAL(iter); |
| 594 | const HEK *namehek; |
| 595 | |
| 596 | /* We're starting at the 2nd element, skipping revstash */ |
| 597 | linear_mro = mro_get_linear_isa(revstash); |
| 598 | svp = AvARRAY(linear_mro) + 1; |
| 599 | items = AvFILLp(linear_mro); |
| 600 | |
| 601 | namehek = HvENAME_HEK(revstash); |
| 602 | if (!namehek) namehek = HvNAME_HEK(revstash); |
| 603 | |
| 604 | while (items--) { |
| 605 | SV* const sv = *svp++; |
| 606 | HV* mroisarev; |
| 607 | |
| 608 | HE *he = hv_fetch_ent(PL_isarev, sv, TRUE, 0); |
| 609 | |
| 610 | /* That fetch should not fail. But if it had to create |
| 611 | a new SV for us, then will need to upgrade it to an |
| 612 | HV (which sv_upgrade() can now do for us). */ |
| 613 | |
| 614 | mroisarev = MUTABLE_HV(HeVAL(he)); |
| 615 | |
| 616 | SvUPGRADE(MUTABLE_SV(mroisarev), SVt_PVHV); |
| 617 | |
| 618 | /* This hash only ever contains PL_sv_yes. Storing it |
| 619 | over itself is almost as cheap as calling hv_exists, |
| 620 | so on aggregate we expect to save time by not making |
| 621 | two calls to the common HV code for the case where |
| 622 | it doesn't exist. */ |
| 623 | |
| 624 | (void) |
| 625 | hv_storehek(mroisarev, namehek, &PL_sv_yes); |
| 626 | } |
| 627 | |
| 628 | if ((SV *)isa != &PL_sv_undef) { |
| 629 | assert(namehek); |
| 630 | mro_clean_isarev( |
| 631 | isa, HEK_KEY(namehek), HEK_LEN(namehek), |
| 632 | HvMROMETA(revstash)->isa, HEK_HASH(namehek), |
| 633 | HEK_UTF8(namehek) |
| 634 | ); |
| 635 | } |
| 636 | } |
| 637 | } |
| 638 | } |
| 639 | |
| 640 | /* Now iterate our MRO (parents), adding ourselves and everything from |
| 641 | our isarev to their isarev. |
| 642 | */ |
| 643 | |
| 644 | /* We're starting at the 2nd element, skipping ourselves here */ |
| 645 | linear_mro = mro_get_linear_isa(stash); |
| 646 | svp = AvARRAY(linear_mro) + 1; |
| 647 | items = AvFILLp(linear_mro); |
| 648 | |
| 649 | while (items--) { |
| 650 | SV* const sv = *svp++; |
| 651 | HV* mroisarev; |
| 652 | |
| 653 | HE *he = hv_fetch_ent(PL_isarev, sv, TRUE, 0); |
| 654 | |
| 655 | /* That fetch should not fail. But if it had to create a new SV for |
| 656 | us, then will need to upgrade it to an HV (which sv_upgrade() can |
| 657 | now do for us. */ |
| 658 | |
| 659 | mroisarev = MUTABLE_HV(HeVAL(he)); |
| 660 | |
| 661 | SvUPGRADE(MUTABLE_SV(mroisarev), SVt_PVHV); |
| 662 | |
| 663 | /* This hash only ever contains PL_sv_yes. Storing it over itself is |
| 664 | almost as cheap as calling hv_exists, so on aggregate we expect to |
| 665 | save time by not making two calls to the common HV code for the |
| 666 | case where it doesn't exist. */ |
| 667 | |
| 668 | (void)hv_storehek(mroisarev, stashhek, &PL_sv_yes); |
| 669 | } |
| 670 | |
| 671 | /* Delete our name from our former parents' isarevs. */ |
| 672 | if(isa && HvARRAY(isa)) |
| 673 | mro_clean_isarev(isa, stashname, stashname_len, meta->isa, |
| 674 | HEK_HASH(stashhek), HEK_UTF8(stashhek)); |
| 675 | } |
| 676 | |
| 677 | /* Deletes name from all the isarev entries listed in isa */ |
| 678 | STATIC void |
| 679 | S_mro_clean_isarev(pTHX_ HV * const isa, const char * const name, |
| 680 | const STRLEN len, HV * const exceptions, U32 hash, |
| 681 | U32 flags) |
| 682 | { |
| 683 | HE* iter; |
| 684 | |
| 685 | PERL_ARGS_ASSERT_MRO_CLEAN_ISAREV; |
| 686 | |
| 687 | /* Delete our name from our former parents' isarevs. */ |
| 688 | if(isa && HvARRAY(isa) && hv_iterinit(isa)) { |
| 689 | SV **svp; |
| 690 | while((iter = hv_iternext(isa))) { |
| 691 | I32 klen; |
| 692 | const char * const key = hv_iterkey(iter, &klen); |
| 693 | if(exceptions && hv_exists(exceptions, key, HeKUTF8(iter) ? -klen : klen)) |
| 694 | continue; |
| 695 | svp = hv_fetch(PL_isarev, key, HeKUTF8(iter) ? -klen : klen, 0); |
| 696 | if(svp) { |
| 697 | HV * const isarev = (HV *)*svp; |
| 698 | (void)hv_common(isarev, NULL, name, len, flags, |
| 699 | G_DISCARD|HV_DELETE, NULL, hash); |
| 700 | if(!HvARRAY(isarev) || !HvUSEDKEYS(isarev)) |
| 701 | (void)hv_delete(PL_isarev, key, |
| 702 | HeKUTF8(iter) ? -klen : klen, G_DISCARD); |
| 703 | } |
| 704 | } |
| 705 | } |
| 706 | } |
| 707 | |
| 708 | /* |
| 709 | =for apidoc mro_package_moved |
| 710 | |
| 711 | Call this function to signal to a stash that it has been assigned to |
| 712 | another spot in the stash hierarchy. C<stash> is the stash that has been |
| 713 | assigned. C<oldstash> is the stash it replaces, if any. C<gv> is the glob |
| 714 | that is actually being assigned to. |
| 715 | |
| 716 | This can also be called with a null first argument to |
| 717 | indicate that C<oldstash> has been deleted. |
| 718 | |
| 719 | This function invalidates isa caches on the old stash, on all subpackages |
| 720 | nested inside it, and on the subclasses of all those, including |
| 721 | non-existent packages that have corresponding entries in C<stash>. |
| 722 | |
| 723 | It also sets the effective names (C<HvENAME>) on all the stashes as |
| 724 | appropriate. |
| 725 | |
| 726 | If the C<gv> is present and is not in the symbol table, then this function |
| 727 | simply returns. This checked will be skipped if C<flags & 1>. |
| 728 | |
| 729 | =cut |
| 730 | */ |
| 731 | void |
| 732 | Perl_mro_package_moved(pTHX_ HV * const stash, HV * const oldstash, |
| 733 | const GV * const gv, U32 flags) |
| 734 | { |
| 735 | SV *namesv; |
| 736 | HEK **namep; |
| 737 | I32 name_count; |
| 738 | HV *stashes; |
| 739 | HE* iter; |
| 740 | |
| 741 | PERL_ARGS_ASSERT_MRO_PACKAGE_MOVED; |
| 742 | assert(stash || oldstash); |
| 743 | |
| 744 | /* Determine the name(s) of the location that stash was assigned to |
| 745 | * or from which oldstash was removed. |
| 746 | * |
| 747 | * We cannot reliably use the name in oldstash, because it may have |
| 748 | * been deleted from the location in the symbol table that its name |
| 749 | * suggests, as in this case: |
| 750 | * |
| 751 | * $globref = \*foo::bar::; |
| 752 | * Symbol::delete_package("foo"); |
| 753 | * *$globref = \%baz::; |
| 754 | * *$globref = *frelp::; |
| 755 | * # calls mro_package_moved(%frelp::, %baz::, *$globref, NULL, 0) |
| 756 | * |
| 757 | * So we get it from the gv. But, since the gv may no longer be in the |
| 758 | * symbol table, we check that first. The only reliable way to tell is |
| 759 | * to see whether its stash has an effective name and whether the gv |
| 760 | * resides in that stash under its name. That effective name may be |
| 761 | * different from what gv_fullname4 would use. |
| 762 | * If flags & 1, the caller has asked us to skip the check. |
| 763 | */ |
| 764 | if(!(flags & 1)) { |
| 765 | SV **svp; |
| 766 | if( |
| 767 | !GvSTASH(gv) || !HvENAME(GvSTASH(gv)) || |
| 768 | !(svp = hv_fetchhek(GvSTASH(gv), GvNAME_HEK(gv), 0)) || |
| 769 | *svp != (SV *)gv |
| 770 | ) return; |
| 771 | } |
| 772 | assert(SvOOK(GvSTASH(gv))); |
| 773 | assert(GvNAMELEN(gv)); |
| 774 | assert(GvNAME(gv)[GvNAMELEN(gv) - 1] == ':'); |
| 775 | assert(GvNAMELEN(gv) == 1 || GvNAME(gv)[GvNAMELEN(gv) - 2] == ':'); |
| 776 | name_count = HvAUX(GvSTASH(gv))->xhv_name_count; |
| 777 | if (!name_count) { |
| 778 | name_count = 1; |
| 779 | namep = &HvAUX(GvSTASH(gv))->xhv_name_u.xhvnameu_name; |
| 780 | } |
| 781 | else { |
| 782 | namep = HvAUX(GvSTASH(gv))->xhv_name_u.xhvnameu_names; |
| 783 | if (name_count < 0) ++namep, name_count = -name_count - 1; |
| 784 | } |
| 785 | if (name_count == 1) { |
| 786 | if (HEK_LEN(*namep) == 4 && strnEQ(HEK_KEY(*namep), "main", 4)) { |
| 787 | namesv = GvNAMELEN(gv) == 1 |
| 788 | ? newSVpvs_flags(":", SVs_TEMP) |
| 789 | : newSVpvs_flags("", SVs_TEMP); |
| 790 | } |
| 791 | else { |
| 792 | namesv = sv_2mortal(newSVhek(*namep)); |
| 793 | if (GvNAMELEN(gv) == 1) sv_catpvs(namesv, ":"); |
| 794 | else sv_catpvs(namesv, "::"); |
| 795 | } |
| 796 | if (GvNAMELEN(gv) != 1) { |
| 797 | sv_catpvn_flags( |
| 798 | namesv, GvNAME(gv), GvNAMELEN(gv) - 2, |
| 799 | /* skip trailing :: */ |
| 800 | GvNAMEUTF8(gv) ? SV_CATUTF8 : SV_CATBYTES |
| 801 | ); |
| 802 | } |
| 803 | } |
| 804 | else { |
| 805 | SV *aname; |
| 806 | namesv = sv_2mortal((SV *)newAV()); |
| 807 | while (name_count--) { |
| 808 | if(HEK_LEN(*namep) == 4 && strnEQ(HEK_KEY(*namep), "main", 4)){ |
| 809 | aname = GvNAMELEN(gv) == 1 |
| 810 | ? newSVpvs(":") |
| 811 | : newSVpvs(""); |
| 812 | namep++; |
| 813 | } |
| 814 | else { |
| 815 | aname = newSVhek(*namep++); |
| 816 | if (GvNAMELEN(gv) == 1) sv_catpvs(aname, ":"); |
| 817 | else sv_catpvs(aname, "::"); |
| 818 | } |
| 819 | if (GvNAMELEN(gv) != 1) { |
| 820 | sv_catpvn_flags( |
| 821 | aname, GvNAME(gv), GvNAMELEN(gv) - 2, |
| 822 | /* skip trailing :: */ |
| 823 | GvNAMEUTF8(gv) ? SV_CATUTF8 : SV_CATBYTES |
| 824 | ); |
| 825 | } |
| 826 | av_push((AV *)namesv, aname); |
| 827 | } |
| 828 | } |
| 829 | |
| 830 | /* Get a list of all the affected classes. */ |
| 831 | /* We cannot simply pass them all to mro_isa_changed_in to avoid |
| 832 | the list, as that function assumes that only one package has |
| 833 | changed. It does not work with: |
| 834 | |
| 835 | @foo::ISA = qw( B B::B ); |
| 836 | *B:: = delete $::{"A::"}; |
| 837 | |
| 838 | as neither B nor B::B can be updated before the other, since they |
| 839 | will reset caches on foo, which will see either B or B::B with the |
| 840 | wrong name. The names must be set on *all* affected stashes before |
| 841 | we do anything else. (And linearisations must be cleared, too.) |
| 842 | */ |
| 843 | stashes = (HV *) sv_2mortal((SV *)newHV()); |
| 844 | mro_gather_and_rename( |
| 845 | stashes, (HV *) sv_2mortal((SV *)newHV()), |
| 846 | stash, oldstash, namesv |
| 847 | ); |
| 848 | |
| 849 | /* Once the caches have been wiped on all the classes, call |
| 850 | mro_isa_changed_in on each. */ |
| 851 | hv_iterinit(stashes); |
| 852 | while((iter = hv_iternext(stashes))) { |
| 853 | HV * const stash = *(HV **)HEK_KEY(HeKEY_hek(iter)); |
| 854 | if(HvENAME(stash)) { |
| 855 | /* We have to restore the original meta->isa (that |
| 856 | mro_gather_and_rename set aside for us) this way, in case |
| 857 | one class in this list is a superclass of a another class |
| 858 | that we have already encountered. In such a case, meta->isa |
| 859 | will have been overwritten without old entries being deleted |
| 860 | from PL_isarev. */ |
| 861 | struct mro_meta * const meta = HvMROMETA(stash); |
| 862 | if(meta->isa != (HV *)HeVAL(iter)){ |
| 863 | SvREFCNT_dec(meta->isa); |
| 864 | meta->isa |
| 865 | = HeVAL(iter) == &PL_sv_yes |
| 866 | ? NULL |
| 867 | : (HV *)HeVAL(iter); |
| 868 | HeVAL(iter) = NULL; /* We donated our reference count. */ |
| 869 | } |
| 870 | mro_isa_changed_in(stash); |
| 871 | } |
| 872 | } |
| 873 | } |
| 874 | |
| 875 | STATIC void |
| 876 | S_mro_gather_and_rename(pTHX_ HV * const stashes, HV * const seen_stashes, |
| 877 | HV *stash, HV *oldstash, SV *namesv) |
| 878 | { |
| 879 | XPVHV* xhv; |
| 880 | HE *entry; |
| 881 | I32 riter = -1; |
| 882 | I32 items = 0; |
| 883 | const bool stash_had_name = stash && HvENAME(stash); |
| 884 | bool fetched_isarev = FALSE; |
| 885 | HV *seen = NULL; |
| 886 | HV *isarev = NULL; |
| 887 | SV **svp = NULL; |
| 888 | |
| 889 | PERL_ARGS_ASSERT_MRO_GATHER_AND_RENAME; |
| 890 | |
| 891 | /* We use the seen_stashes hash to keep track of which packages have |
| 892 | been encountered so far. This must be separate from the main list of |
| 893 | stashes, as we need to distinguish between stashes being assigned |
| 894 | and stashes being replaced/deleted. (A nested stash can be on both |
| 895 | sides of an assignment. We cannot simply skip iterating through a |
| 896 | stash on the right if we have seen it on the left, as it will not |
| 897 | get its ename assigned to it.) |
| 898 | |
| 899 | To avoid allocating extra SVs, instead of a bitfield we can make |
| 900 | bizarre use of immortals: |
| 901 | |
| 902 | &PL_sv_undef: seen on the left (oldstash) |
| 903 | &PL_sv_no : seen on the right (stash) |
| 904 | &PL_sv_yes : seen on both sides |
| 905 | |
| 906 | */ |
| 907 | |
| 908 | if(oldstash) { |
| 909 | /* Add to the big list. */ |
| 910 | struct mro_meta * meta; |
| 911 | HE * const entry |
| 912 | = (HE *) |
| 913 | hv_common( |
| 914 | seen_stashes, NULL, (const char *)&oldstash, sizeof(HV *), 0, |
| 915 | HV_FETCH_LVALUE|HV_FETCH_EMPTY_HE, NULL, 0 |
| 916 | ); |
| 917 | if(HeVAL(entry) == &PL_sv_undef || HeVAL(entry) == &PL_sv_yes) { |
| 918 | oldstash = NULL; |
| 919 | goto check_stash; |
| 920 | } |
| 921 | HeVAL(entry) |
| 922 | = HeVAL(entry) == &PL_sv_no ? &PL_sv_yes : &PL_sv_undef; |
| 923 | meta = HvMROMETA(oldstash); |
| 924 | (void) |
| 925 | hv_store( |
| 926 | stashes, (const char *)&oldstash, sizeof(HV *), |
| 927 | meta->isa |
| 928 | ? SvREFCNT_inc_simple_NN((SV *)meta->isa) |
| 929 | : &PL_sv_yes, |
| 930 | 0 |
| 931 | ); |
| 932 | CLEAR_LINEAR(meta); |
| 933 | |
| 934 | /* Update the effective name. */ |
| 935 | if(HvENAME_get(oldstash)) { |
| 936 | const HEK * const enamehek = HvENAME_HEK(oldstash); |
| 937 | if(SvTYPE(namesv) == SVt_PVAV) { |
| 938 | items = AvFILLp((AV *)namesv) + 1; |
| 939 | svp = AvARRAY((AV *)namesv); |
| 940 | } |
| 941 | else { |
| 942 | items = 1; |
| 943 | svp = &namesv; |
| 944 | } |
| 945 | while (items--) { |
| 946 | const U32 name_utf8 = SvUTF8(*svp); |
| 947 | STRLEN len; |
| 948 | const char *name = SvPVx_const(*svp, len); |
| 949 | if(PL_stashcache) { |
| 950 | DEBUG_o(Perl_deb(aTHX_ "mro_gather_and_rename clearing PL_stashcache for '%"SVf"'\n", |
| 951 | SVfARG(*svp))); |
| 952 | (void)hv_delete(PL_stashcache, name, name_utf8 ? -(I32)len : (I32)len, G_DISCARD); |
| 953 | } |
| 954 | ++svp; |
| 955 | hv_ename_delete(oldstash, name, len, name_utf8); |
| 956 | |
| 957 | if (!fetched_isarev) { |
| 958 | /* If the name deletion caused a name change, then we |
| 959 | * are not going to call mro_isa_changed_in with this |
| 960 | * name (and not at all if it has become anonymous) so |
| 961 | * we need to delete old isarev entries here, both |
| 962 | * those in the superclasses and this class's own list |
| 963 | * of subclasses. We simply delete the latter from |
| 964 | * PL_isarev, since we still need it. hv_delete morti- |
| 965 | * fies it for us, so sv_2mortal is not necessary. */ |
| 966 | if(HvENAME_HEK(oldstash) != enamehek) { |
| 967 | if(meta->isa && HvARRAY(meta->isa)) |
| 968 | mro_clean_isarev(meta->isa, name, len, 0, 0, |
| 969 | name_utf8 ? HVhek_UTF8 : 0); |
| 970 | isarev = (HV *)hv_delete(PL_isarev, name, |
| 971 | name_utf8 ? -(I32)len : (I32)len, 0); |
| 972 | fetched_isarev=TRUE; |
| 973 | } |
| 974 | } |
| 975 | } |
| 976 | } |
| 977 | } |
| 978 | check_stash: |
| 979 | if(stash) { |
| 980 | if(SvTYPE(namesv) == SVt_PVAV) { |
| 981 | items = AvFILLp((AV *)namesv) + 1; |
| 982 | svp = AvARRAY((AV *)namesv); |
| 983 | } |
| 984 | else { |
| 985 | items = 1; |
| 986 | svp = &namesv; |
| 987 | } |
| 988 | while (items--) { |
| 989 | const U32 name_utf8 = SvUTF8(*svp); |
| 990 | STRLEN len; |
| 991 | const char *name = SvPVx_const(*svp++, len); |
| 992 | hv_ename_add(stash, name, len, name_utf8); |
| 993 | } |
| 994 | |
| 995 | /* Add it to the big list if it needs |
| 996 | * mro_isa_changed_in called on it. That happens if it was |
| 997 | * detached from the symbol table (so it had no HvENAME) before |
| 998 | * being assigned to the spot named by the 'name' variable, because |
| 999 | * its cached isa linearisation is now stale (the effective name |
| 1000 | * having changed), and subclasses will then use that cache when |
| 1001 | * mro_package_moved calls mro_isa_changed_in. (See |
| 1002 | * [perl #77358].) |
| 1003 | * |
| 1004 | * If it did have a name, then its previous name is still |
| 1005 | * used in isa caches, and there is no need for |
| 1006 | * mro_package_moved to call mro_isa_changed_in. |
| 1007 | */ |
| 1008 | |
| 1009 | entry |
| 1010 | = (HE *) |
| 1011 | hv_common( |
| 1012 | seen_stashes, NULL, (const char *)&stash, sizeof(HV *), 0, |
| 1013 | HV_FETCH_LVALUE|HV_FETCH_EMPTY_HE, NULL, 0 |
| 1014 | ); |
| 1015 | if(HeVAL(entry) == &PL_sv_yes || HeVAL(entry) == &PL_sv_no) |
| 1016 | stash = NULL; |
| 1017 | else { |
| 1018 | HeVAL(entry) |
| 1019 | = HeVAL(entry) == &PL_sv_undef ? &PL_sv_yes : &PL_sv_no; |
| 1020 | if(!stash_had_name) |
| 1021 | { |
| 1022 | struct mro_meta * const meta = HvMROMETA(stash); |
| 1023 | (void) |
| 1024 | hv_store( |
| 1025 | stashes, (const char *)&stash, sizeof(HV *), |
| 1026 | meta->isa |
| 1027 | ? SvREFCNT_inc_simple_NN((SV *)meta->isa) |
| 1028 | : &PL_sv_yes, |
| 1029 | 0 |
| 1030 | ); |
| 1031 | CLEAR_LINEAR(meta); |
| 1032 | } |
| 1033 | } |
| 1034 | } |
| 1035 | |
| 1036 | if(!stash && !oldstash) |
| 1037 | /* Both stashes have been encountered already. */ |
| 1038 | return; |
| 1039 | |
| 1040 | /* Add all the subclasses to the big list. */ |
| 1041 | if(!fetched_isarev) { |
| 1042 | /* If oldstash is not null, then we can use its HvENAME to look up |
| 1043 | the isarev hash, since all its subclasses will be listed there. |
| 1044 | It will always have an HvENAME. It the HvENAME was removed |
| 1045 | above, then fetch_isarev will be true, and this code will not be |
| 1046 | reached. |
| 1047 | |
| 1048 | If oldstash is null, then this is an empty spot with no stash in |
| 1049 | it, so subclasses could be listed in isarev hashes belonging to |
| 1050 | any of the names, so we have to check all of them. |
| 1051 | */ |
| 1052 | assert(!oldstash || HvENAME(oldstash)); |
| 1053 | if (oldstash) { |
| 1054 | /* Extra variable to avoid a compiler warning */ |
| 1055 | const HEK * const hvename = HvENAME_HEK(oldstash); |
| 1056 | fetched_isarev = TRUE; |
| 1057 | svp = hv_fetchhek(PL_isarev, hvename, 0); |
| 1058 | if (svp) isarev = MUTABLE_HV(*svp); |
| 1059 | } |
| 1060 | else if(SvTYPE(namesv) == SVt_PVAV) { |
| 1061 | items = AvFILLp((AV *)namesv) + 1; |
| 1062 | svp = AvARRAY((AV *)namesv); |
| 1063 | } |
| 1064 | else { |
| 1065 | items = 1; |
| 1066 | svp = &namesv; |
| 1067 | } |
| 1068 | } |
| 1069 | if( |
| 1070 | isarev || !fetched_isarev |
| 1071 | ) { |
| 1072 | while (fetched_isarev || items--) { |
| 1073 | HE *iter; |
| 1074 | |
| 1075 | if (!fetched_isarev) { |
| 1076 | HE * const he = hv_fetch_ent(PL_isarev, *svp++, 0, 0); |
| 1077 | if (!he || !(isarev = MUTABLE_HV(HeVAL(he)))) continue; |
| 1078 | } |
| 1079 | |
| 1080 | hv_iterinit(isarev); |
| 1081 | while((iter = hv_iternext(isarev))) { |
| 1082 | HV* revstash = gv_stashsv(hv_iterkeysv(iter), 0); |
| 1083 | struct mro_meta * meta; |
| 1084 | |
| 1085 | if(!revstash) continue; |
| 1086 | meta = HvMROMETA(revstash); |
| 1087 | (void) |
| 1088 | hv_store( |
| 1089 | stashes, (const char *)&revstash, sizeof(HV *), |
| 1090 | meta->isa |
| 1091 | ? SvREFCNT_inc_simple_NN((SV *)meta->isa) |
| 1092 | : &PL_sv_yes, |
| 1093 | 0 |
| 1094 | ); |
| 1095 | CLEAR_LINEAR(meta); |
| 1096 | } |
| 1097 | |
| 1098 | if (fetched_isarev) break; |
| 1099 | } |
| 1100 | } |
| 1101 | |
| 1102 | /* This is partly based on code in hv_iternext_flags. We are not call- |
| 1103 | ing that here, as we want to avoid resetting the hash iterator. */ |
| 1104 | |
| 1105 | /* Skip the entire loop if the hash is empty. */ |
| 1106 | if(oldstash && HvUSEDKEYS(oldstash)) { |
| 1107 | xhv = (XPVHV*)SvANY(oldstash); |
| 1108 | seen = (HV *) sv_2mortal((SV *)newHV()); |
| 1109 | |
| 1110 | /* Iterate through entries in the oldstash, adding them to the |
| 1111 | list, meanwhile doing the equivalent of $seen{$key} = 1. |
| 1112 | */ |
| 1113 | |
| 1114 | while (++riter <= (I32)xhv->xhv_max) { |
| 1115 | entry = (HvARRAY(oldstash))[riter]; |
| 1116 | |
| 1117 | /* Iterate through the entries in this list */ |
| 1118 | for(; entry; entry = HeNEXT(entry)) { |
| 1119 | const char* key; |
| 1120 | I32 len; |
| 1121 | |
| 1122 | /* If this entry is not a glob, ignore it. |
| 1123 | Try the next. */ |
| 1124 | if (!isGV(HeVAL(entry))) continue; |
| 1125 | |
| 1126 | key = hv_iterkey(entry, &len); |
| 1127 | if ((len > 1 && key[len-2] == ':' && key[len-1] == ':') |
| 1128 | || (len == 1 && key[0] == ':')) { |
| 1129 | HV * const oldsubstash = GvHV(HeVAL(entry)); |
| 1130 | SV ** const stashentry |
| 1131 | = stash ? hv_fetch(stash, key, HeUTF8(entry) ? -(I32)len : (I32)len, 0) : NULL; |
| 1132 | HV *substash = NULL; |
| 1133 | |
| 1134 | /* Avoid main::main::main::... */ |
| 1135 | if(oldsubstash == oldstash) continue; |
| 1136 | |
| 1137 | if( |
| 1138 | ( |
| 1139 | stashentry && *stashentry && isGV(*stashentry) |
| 1140 | && (substash = GvHV(*stashentry)) |
| 1141 | ) |
| 1142 | || (oldsubstash && HvENAME_get(oldsubstash)) |
| 1143 | ) |
| 1144 | { |
| 1145 | /* Add :: and the key (minus the trailing ::) |
| 1146 | to each name. */ |
| 1147 | SV *subname; |
| 1148 | if(SvTYPE(namesv) == SVt_PVAV) { |
| 1149 | SV *aname; |
| 1150 | items = AvFILLp((AV *)namesv) + 1; |
| 1151 | svp = AvARRAY((AV *)namesv); |
| 1152 | subname = sv_2mortal((SV *)newAV()); |
| 1153 | while (items--) { |
| 1154 | aname = newSVsv(*svp++); |
| 1155 | if (len == 1) |
| 1156 | sv_catpvs(aname, ":"); |
| 1157 | else { |
| 1158 | sv_catpvs(aname, "::"); |
| 1159 | sv_catpvn_flags( |
| 1160 | aname, key, len-2, |
| 1161 | HeUTF8(entry) |
| 1162 | ? SV_CATUTF8 : SV_CATBYTES |
| 1163 | ); |
| 1164 | } |
| 1165 | av_push((AV *)subname, aname); |
| 1166 | } |
| 1167 | } |
| 1168 | else { |
| 1169 | subname = sv_2mortal(newSVsv(namesv)); |
| 1170 | if (len == 1) sv_catpvs(subname, ":"); |
| 1171 | else { |
| 1172 | sv_catpvs(subname, "::"); |
| 1173 | sv_catpvn_flags( |
| 1174 | subname, key, len-2, |
| 1175 | HeUTF8(entry) ? SV_CATUTF8 : SV_CATBYTES |
| 1176 | ); |
| 1177 | } |
| 1178 | } |
| 1179 | mro_gather_and_rename( |
| 1180 | stashes, seen_stashes, |
| 1181 | substash, oldsubstash, subname |
| 1182 | ); |
| 1183 | } |
| 1184 | |
| 1185 | (void)hv_store(seen, key, HeUTF8(entry) ? -(I32)len : (I32)len, &PL_sv_yes, 0); |
| 1186 | } |
| 1187 | } |
| 1188 | } |
| 1189 | } |
| 1190 | |
| 1191 | /* Skip the entire loop if the hash is empty. */ |
| 1192 | if (stash && HvUSEDKEYS(stash)) { |
| 1193 | xhv = (XPVHV*)SvANY(stash); |
| 1194 | riter = -1; |
| 1195 | |
| 1196 | /* Iterate through the new stash, skipping $seen{$key} items, |
| 1197 | calling mro_gather_and_rename(stashes,seen,entry,NULL, ...). */ |
| 1198 | while (++riter <= (I32)xhv->xhv_max) { |
| 1199 | entry = (HvARRAY(stash))[riter]; |
| 1200 | |
| 1201 | /* Iterate through the entries in this list */ |
| 1202 | for(; entry; entry = HeNEXT(entry)) { |
| 1203 | const char* key; |
| 1204 | I32 len; |
| 1205 | |
| 1206 | /* If this entry is not a glob, ignore it. |
| 1207 | Try the next. */ |
| 1208 | if (!isGV(HeVAL(entry))) continue; |
| 1209 | |
| 1210 | key = hv_iterkey(entry, &len); |
| 1211 | if ((len > 1 && key[len-2] == ':' && key[len-1] == ':') |
| 1212 | || (len == 1 && key[0] == ':')) { |
| 1213 | HV *substash; |
| 1214 | |
| 1215 | /* If this entry was seen when we iterated through the |
| 1216 | oldstash, skip it. */ |
| 1217 | if(seen && hv_exists(seen, key, HeUTF8(entry) ? -(I32)len : (I32)len)) continue; |
| 1218 | |
| 1219 | /* We get here only if this stash has no corresponding |
| 1220 | entry in the stash being replaced. */ |
| 1221 | |
| 1222 | substash = GvHV(HeVAL(entry)); |
| 1223 | if(substash) { |
| 1224 | SV *subname; |
| 1225 | |
| 1226 | /* Avoid checking main::main::main::... */ |
| 1227 | if(substash == stash) continue; |
| 1228 | |
| 1229 | /* Add :: and the key (minus the trailing ::) |
| 1230 | to each name. */ |
| 1231 | if(SvTYPE(namesv) == SVt_PVAV) { |
| 1232 | SV *aname; |
| 1233 | items = AvFILLp((AV *)namesv) + 1; |
| 1234 | svp = AvARRAY((AV *)namesv); |
| 1235 | subname = sv_2mortal((SV *)newAV()); |
| 1236 | while (items--) { |
| 1237 | aname = newSVsv(*svp++); |
| 1238 | if (len == 1) |
| 1239 | sv_catpvs(aname, ":"); |
| 1240 | else { |
| 1241 | sv_catpvs(aname, "::"); |
| 1242 | sv_catpvn_flags( |
| 1243 | aname, key, len-2, |
| 1244 | HeUTF8(entry) |
| 1245 | ? SV_CATUTF8 : SV_CATBYTES |
| 1246 | ); |
| 1247 | } |
| 1248 | av_push((AV *)subname, aname); |
| 1249 | } |
| 1250 | } |
| 1251 | else { |
| 1252 | subname = sv_2mortal(newSVsv(namesv)); |
| 1253 | if (len == 1) sv_catpvs(subname, ":"); |
| 1254 | else { |
| 1255 | sv_catpvs(subname, "::"); |
| 1256 | sv_catpvn_flags( |
| 1257 | subname, key, len-2, |
| 1258 | HeUTF8(entry) ? SV_CATUTF8 : SV_CATBYTES |
| 1259 | ); |
| 1260 | } |
| 1261 | } |
| 1262 | mro_gather_and_rename( |
| 1263 | stashes, seen_stashes, |
| 1264 | substash, NULL, subname |
| 1265 | ); |
| 1266 | } |
| 1267 | } |
| 1268 | } |
| 1269 | } |
| 1270 | } |
| 1271 | } |
| 1272 | |
| 1273 | /* |
| 1274 | =for apidoc mro_method_changed_in |
| 1275 | |
| 1276 | Invalidates method caching on any child classes |
| 1277 | of the given stash, so that they might notice |
| 1278 | the changes in this one. |
| 1279 | |
| 1280 | Ideally, all instances of C<PL_sub_generation++> in |
| 1281 | perl source outside of F<mro.c> should be |
| 1282 | replaced by calls to this. |
| 1283 | |
| 1284 | Perl automatically handles most of the common |
| 1285 | ways a method might be redefined. However, there |
| 1286 | are a few ways you could change a method in a stash |
| 1287 | without the cache code noticing, in which case you |
| 1288 | need to call this method afterwards: |
| 1289 | |
| 1290 | 1) Directly manipulating the stash HV entries from |
| 1291 | XS code. |
| 1292 | |
| 1293 | 2) Assigning a reference to a readonly scalar |
| 1294 | constant into a stash entry in order to create |
| 1295 | a constant subroutine (like constant.pm |
| 1296 | does). |
| 1297 | |
| 1298 | This same method is available from pure perl |
| 1299 | via, C<mro::method_changed_in(classname)>. |
| 1300 | |
| 1301 | =cut |
| 1302 | */ |
| 1303 | void |
| 1304 | Perl_mro_method_changed_in(pTHX_ HV *stash) |
| 1305 | { |
| 1306 | const char * const stashname = HvENAME_get(stash); |
| 1307 | const STRLEN stashname_len = HvENAMELEN_get(stash); |
| 1308 | |
| 1309 | SV ** const svp = hv_fetchhek(PL_isarev, HvENAME_HEK(stash), 0); |
| 1310 | HV * const isarev = svp ? MUTABLE_HV(*svp) : NULL; |
| 1311 | |
| 1312 | PERL_ARGS_ASSERT_MRO_METHOD_CHANGED_IN; |
| 1313 | |
| 1314 | if(!stashname) |
| 1315 | Perl_croak(aTHX_ "Can't call mro_method_changed_in() on anonymous symbol table"); |
| 1316 | |
| 1317 | /* Inc the package generation, since a local method changed */ |
| 1318 | HvMROMETA(stash)->pkg_gen++; |
| 1319 | |
| 1320 | /* DESTROY can be cached in SvSTASH. */ |
| 1321 | if (!SvOBJECT(stash)) SvSTASH(stash) = NULL; |
| 1322 | |
| 1323 | /* If stash is UNIVERSAL, or one of UNIVERSAL's parents, |
| 1324 | invalidate all method caches globally */ |
| 1325 | if((stashname_len == 9 && strEQ(stashname, "UNIVERSAL")) |
| 1326 | || (isarev && hv_exists(isarev, "UNIVERSAL", 9))) { |
| 1327 | PL_sub_generation++; |
| 1328 | return; |
| 1329 | } |
| 1330 | |
| 1331 | /* else, invalidate the method caches of all child classes, |
| 1332 | but not itself */ |
| 1333 | if(isarev) { |
| 1334 | HE* iter; |
| 1335 | |
| 1336 | hv_iterinit(isarev); |
| 1337 | while((iter = hv_iternext(isarev))) { |
| 1338 | HV* const revstash = gv_stashsv(hv_iterkeysv(iter), 0); |
| 1339 | struct mro_meta* mrometa; |
| 1340 | |
| 1341 | if(!revstash) continue; |
| 1342 | mrometa = HvMROMETA(revstash); |
| 1343 | mrometa->cache_gen++; |
| 1344 | if(mrometa->mro_nextmethod) |
| 1345 | hv_clear(mrometa->mro_nextmethod); |
| 1346 | if (!SvOBJECT(revstash)) SvSTASH(revstash) = NULL; |
| 1347 | } |
| 1348 | } |
| 1349 | |
| 1350 | /* The method change may be due to *{$package . "::()"} = \&nil; in |
| 1351 | overload.pm. */ |
| 1352 | HvAMAGIC_on(stash); |
| 1353 | /* pessimise derefs for now. Will get recalculated by Gv_AMupdate() */ |
| 1354 | HvAUX(stash)->xhv_aux_flags &= ~HvAUXf_NO_DEREF; |
| 1355 | } |
| 1356 | |
| 1357 | void |
| 1358 | Perl_mro_set_mro(pTHX_ struct mro_meta *const meta, SV *const name) |
| 1359 | { |
| 1360 | const struct mro_alg *const which = Perl_mro_get_from_name(aTHX_ name); |
| 1361 | |
| 1362 | PERL_ARGS_ASSERT_MRO_SET_MRO; |
| 1363 | |
| 1364 | if (!which) |
| 1365 | Perl_croak(aTHX_ "Invalid mro name: '%"SVf"'", name); |
| 1366 | |
| 1367 | if(meta->mro_which != which) { |
| 1368 | if (meta->mro_linear_current && !meta->mro_linear_all) { |
| 1369 | /* If we were storing something directly, put it in the hash before |
| 1370 | we lose it. */ |
| 1371 | Perl_mro_set_private_data(aTHX_ meta, meta->mro_which, |
| 1372 | MUTABLE_SV(meta->mro_linear_current)); |
| 1373 | } |
| 1374 | meta->mro_which = which; |
| 1375 | /* Scrub our cached pointer to the private data. */ |
| 1376 | meta->mro_linear_current = NULL; |
| 1377 | /* Only affects local method cache, not |
| 1378 | even child classes */ |
| 1379 | meta->cache_gen++; |
| 1380 | if(meta->mro_nextmethod) |
| 1381 | hv_clear(meta->mro_nextmethod); |
| 1382 | } |
| 1383 | } |
| 1384 | |
| 1385 | #include "XSUB.h" |
| 1386 | |
| 1387 | XS(XS_mro_method_changed_in); |
| 1388 | |
| 1389 | void |
| 1390 | Perl_boot_core_mro(pTHX) |
| 1391 | { |
| 1392 | static const char file[] = __FILE__; |
| 1393 | |
| 1394 | Perl_mro_register(aTHX_ &dfs_alg); |
| 1395 | |
| 1396 | newXSproto("mro::method_changed_in", XS_mro_method_changed_in, file, "$"); |
| 1397 | } |
| 1398 | |
| 1399 | XS(XS_mro_method_changed_in) |
| 1400 | { |
| 1401 | dXSARGS; |
| 1402 | SV* classname; |
| 1403 | HV* class_stash; |
| 1404 | |
| 1405 | if(items != 1) |
| 1406 | croak_xs_usage(cv, "classname"); |
| 1407 | |
| 1408 | classname = ST(0); |
| 1409 | |
| 1410 | class_stash = gv_stashsv(classname, 0); |
| 1411 | if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname)); |
| 1412 | |
| 1413 | mro_method_changed_in(class_stash); |
| 1414 | |
| 1415 | XSRETURN_EMPTY; |
| 1416 | } |
| 1417 | |
| 1418 | /* |
| 1419 | * Local variables: |
| 1420 | * c-indentation-style: bsd |
| 1421 | * c-basic-offset: 4 |
| 1422 | * indent-tabs-mode: nil |
| 1423 | * End: |
| 1424 | * |
| 1425 | * ex: set ts=8 sts=4 sw=4 et: |
| 1426 | */ |