| 1 | /* mro.c |
| 2 | * |
| 3 | * Copyright (c) 2007 Brandon L Black |
| 4 | * |
| 5 | * You may distribute under the terms of either the GNU General Public |
| 6 | * License or the Artistic License, as specified in the README file. |
| 7 | * |
| 8 | */ |
| 9 | |
| 10 | /* |
| 11 | * "Which order shall we go in?" said Frodo. "Eldest first, or quickest first? |
| 12 | * You'll be last either way, Master Peregrin." |
| 13 | */ |
| 14 | |
| 15 | /* |
| 16 | =head1 MRO Functions |
| 17 | |
| 18 | These functions are related to the method resolution order of perl classes |
| 19 | |
| 20 | =cut |
| 21 | */ |
| 22 | |
| 23 | #include "EXTERN.h" |
| 24 | #define PERL_IN_MRO_C |
| 25 | #include "perl.h" |
| 26 | |
| 27 | struct mro_alg { |
| 28 | const char *name; |
| 29 | AV *(*resolve)(pTHX_ HV* stash, I32 level); |
| 30 | }; |
| 31 | |
| 32 | /* First one is the default */ |
| 33 | static struct mro_alg mros[] = { |
| 34 | {"dfs", S_mro_get_linear_isa_dfs}, |
| 35 | {"c3", S_mro_get_linear_isa_c3} |
| 36 | }; |
| 37 | |
| 38 | #define NUMBER_OF_MROS (sizeof(mros)/sizeof(struct mro_alg)) |
| 39 | |
| 40 | static const struct mro_alg * |
| 41 | S_get_mro_from_name(pTHX_ const char *const name) { |
| 42 | const struct mro_alg *algo = mros; |
| 43 | const struct mro_alg *const end = mros + NUMBER_OF_MROS; |
| 44 | while (algo < end) { |
| 45 | if(strEQ(name, algo->name)) |
| 46 | return algo; |
| 47 | ++algo; |
| 48 | } |
| 49 | return NULL; |
| 50 | } |
| 51 | |
| 52 | struct mro_meta* |
| 53 | Perl_mro_meta_init(pTHX_ HV* stash) |
| 54 | { |
| 55 | struct mro_meta* newmeta; |
| 56 | |
| 57 | PERL_ARGS_ASSERT_MRO_META_INIT; |
| 58 | assert(HvAUX(stash)); |
| 59 | assert(!(HvAUX(stash)->xhv_mro_meta)); |
| 60 | Newxz(newmeta, 1, struct mro_meta); |
| 61 | HvAUX(stash)->xhv_mro_meta = newmeta; |
| 62 | newmeta->cache_gen = 1; |
| 63 | newmeta->pkg_gen = 1; |
| 64 | newmeta->mro_which = mros; |
| 65 | |
| 66 | return newmeta; |
| 67 | } |
| 68 | |
| 69 | #if defined(USE_ITHREADS) |
| 70 | |
| 71 | /* for sv_dup on new threads */ |
| 72 | struct mro_meta* |
| 73 | Perl_mro_meta_dup(pTHX_ struct mro_meta* smeta, CLONE_PARAMS* param) |
| 74 | { |
| 75 | struct mro_meta* newmeta; |
| 76 | |
| 77 | PERL_ARGS_ASSERT_MRO_META_DUP; |
| 78 | |
| 79 | Newx(newmeta, 1, struct mro_meta); |
| 80 | Copy(smeta, newmeta, 1, struct mro_meta); |
| 81 | |
| 82 | if (newmeta->mro_linear_dfs) |
| 83 | newmeta->mro_linear_dfs |
| 84 | = (AV*) SvREFCNT_inc(sv_dup((SV*)newmeta->mro_linear_dfs, param)); |
| 85 | if (newmeta->mro_linear_c3) |
| 86 | newmeta->mro_linear_c3 |
| 87 | = (AV*) SvREFCNT_inc(sv_dup((SV*)newmeta->mro_linear_c3, param)); |
| 88 | if (newmeta->mro_nextmethod) |
| 89 | newmeta->mro_nextmethod |
| 90 | = (HV*) SvREFCNT_inc(sv_dup((SV*)newmeta->mro_nextmethod, param)); |
| 91 | if (newmeta->isa) |
| 92 | newmeta->isa |
| 93 | = (HV*) SvREFCNT_inc(sv_dup((SV*)newmeta->isa, param)); |
| 94 | |
| 95 | return newmeta; |
| 96 | } |
| 97 | |
| 98 | #endif /* USE_ITHREADS */ |
| 99 | |
| 100 | HV * |
| 101 | Perl_get_isa_hash(pTHX_ HV *const stash) |
| 102 | { |
| 103 | dVAR; |
| 104 | struct mro_meta *const meta = HvMROMETA(stash); |
| 105 | |
| 106 | PERL_ARGS_ASSERT_GET_ISA_HASH; |
| 107 | |
| 108 | if (!meta->isa) { |
| 109 | AV *const isa = mro_get_linear_isa(stash); |
| 110 | if (!meta->isa) { |
| 111 | HV *const isa_hash = newHV(); |
| 112 | /* Linearisation didn't build it for us, so do it here. */ |
| 113 | SV *const *svp = AvARRAY(isa); |
| 114 | SV *const *const svp_end = svp + AvFILLp(isa) + 1; |
| 115 | const HEK *const canon_name = HvNAME_HEK(stash); |
| 116 | |
| 117 | while (svp < svp_end) { |
| 118 | (void) hv_store_ent(isa_hash, *svp++, &PL_sv_undef, 0); |
| 119 | } |
| 120 | |
| 121 | (void) hv_common(isa_hash, NULL, HEK_KEY(canon_name), |
| 122 | HEK_LEN(canon_name), HEK_FLAGS(canon_name), |
| 123 | HV_FETCH_ISSTORE, &PL_sv_undef, |
| 124 | HEK_HASH(canon_name)); |
| 125 | (void) hv_store(isa_hash, "UNIVERSAL", 9, &PL_sv_undef, 0); |
| 126 | |
| 127 | SvREADONLY_on(isa_hash); |
| 128 | |
| 129 | meta->isa = isa_hash; |
| 130 | } |
| 131 | } |
| 132 | return meta->isa; |
| 133 | } |
| 134 | |
| 135 | /* |
| 136 | =for apidoc mro_get_linear_isa_dfs |
| 137 | |
| 138 | Returns the Depth-First Search linearization of @ISA |
| 139 | the given stash. The return value is a read-only AV*. |
| 140 | C<level> should be 0 (it is used internally in this |
| 141 | function's recursion). |
| 142 | |
| 143 | You are responsible for C<SvREFCNT_inc()> on the |
| 144 | return value if you plan to store it anywhere |
| 145 | semi-permanently (otherwise it might be deleted |
| 146 | out from under you the next time the cache is |
| 147 | invalidated). |
| 148 | |
| 149 | =cut |
| 150 | */ |
| 151 | static AV* |
| 152 | S_mro_get_linear_isa_dfs(pTHX_ HV *stash, I32 level) |
| 153 | { |
| 154 | AV* retval; |
| 155 | GV** gvp; |
| 156 | GV* gv; |
| 157 | AV* av; |
| 158 | const HEK* stashhek; |
| 159 | struct mro_meta* meta; |
| 160 | SV *our_name; |
| 161 | HV *stored; |
| 162 | |
| 163 | PERL_ARGS_ASSERT_MRO_GET_LINEAR_ISA_DFS; |
| 164 | assert(HvAUX(stash)); |
| 165 | |
| 166 | stashhek = HvNAME_HEK(stash); |
| 167 | if (!stashhek) |
| 168 | Perl_croak(aTHX_ "Can't linearize anonymous symbol table"); |
| 169 | |
| 170 | if (level > 100) |
| 171 | Perl_croak(aTHX_ "Recursive inheritance detected in package '%s'", |
| 172 | HEK_KEY(stashhek)); |
| 173 | |
| 174 | meta = HvMROMETA(stash); |
| 175 | |
| 176 | /* return cache if valid */ |
| 177 | if((retval = meta->mro_linear_dfs)) { |
| 178 | return retval; |
| 179 | } |
| 180 | |
| 181 | /* not in cache, make a new one */ |
| 182 | |
| 183 | retval = (AV*)sv_2mortal((SV *)newAV()); |
| 184 | /* We use this later in this function, but don't need a reference to it |
| 185 | beyond the end of this function, so reference count is fine. */ |
| 186 | our_name = newSVhek(stashhek); |
| 187 | av_push(retval, our_name); /* add ourselves at the top */ |
| 188 | |
| 189 | /* fetch our @ISA */ |
| 190 | gvp = (GV**)hv_fetchs(stash, "ISA", FALSE); |
| 191 | av = (gvp && (gv = *gvp) && isGV_with_GP(gv)) ? GvAV(gv) : NULL; |
| 192 | |
| 193 | /* "stored" is used to keep track of all of the classnames we have added to |
| 194 | the MRO so far, so we can do a quick exists check and avoid adding |
| 195 | duplicate classnames to the MRO as we go. |
| 196 | It's then retained to be re-used as a fast lookup for ->isa(), by adding |
| 197 | our own name and "UNIVERSAL" to it. */ |
| 198 | |
| 199 | stored = (HV*)sv_2mortal((SV*)newHV()); |
| 200 | |
| 201 | if(av && AvFILLp(av) >= 0) { |
| 202 | |
| 203 | SV **svp = AvARRAY(av); |
| 204 | I32 items = AvFILLp(av) + 1; |
| 205 | |
| 206 | /* foreach(@ISA) */ |
| 207 | while (items--) { |
| 208 | SV* const sv = *svp++; |
| 209 | HV* const basestash = gv_stashsv(sv, 0); |
| 210 | SV *const *subrv_p; |
| 211 | I32 subrv_items; |
| 212 | |
| 213 | if (!basestash) { |
| 214 | /* if no stash exists for this @ISA member, |
| 215 | simply add it to the MRO and move on */ |
| 216 | subrv_p = &sv; |
| 217 | subrv_items = 1; |
| 218 | } |
| 219 | else { |
| 220 | /* otherwise, recurse into ourselves for the MRO |
| 221 | of this @ISA member, and append their MRO to ours. |
| 222 | The recursive call could throw an exception, which |
| 223 | has memory management implications here, hence the use of |
| 224 | the mortal. */ |
| 225 | const AV *const subrv |
| 226 | = mro_get_linear_isa_dfs(basestash, level + 1); |
| 227 | |
| 228 | subrv_p = AvARRAY(subrv); |
| 229 | subrv_items = AvFILLp(subrv) + 1; |
| 230 | } |
| 231 | while(subrv_items--) { |
| 232 | SV *const subsv = *subrv_p++; |
| 233 | /* LVALUE fetch will create a new undefined SV if necessary |
| 234 | */ |
| 235 | HE *const he = hv_fetch_ent(stored, subsv, 1, 0); |
| 236 | assert(he); |
| 237 | if(HeVAL(he) != &PL_sv_undef) { |
| 238 | /* It was newly created. Steal it for our new SV, and |
| 239 | replace it in the hash with the "real" thing. */ |
| 240 | SV *const val = HeVAL(he); |
| 241 | HEK *const key = HeKEY_hek(he); |
| 242 | |
| 243 | HeVAL(he) = &PL_sv_undef; |
| 244 | /* Save copying by making a shared hash key scalar. We |
| 245 | inline this here rather than calling Perl_newSVpvn_share |
| 246 | because we already have the scalar, and we already have |
| 247 | the hash key. */ |
| 248 | assert(SvTYPE(val) == SVt_NULL); |
| 249 | sv_upgrade(val, SVt_PV); |
| 250 | SvPV_set(val, HEK_KEY(share_hek_hek(key))); |
| 251 | SvCUR_set(val, HEK_LEN(key)); |
| 252 | SvREADONLY_on(val); |
| 253 | SvFAKE_on(val); |
| 254 | SvPOK_on(val); |
| 255 | if (HEK_UTF8(key)) |
| 256 | SvUTF8_on(val); |
| 257 | |
| 258 | av_push(retval, val); |
| 259 | } |
| 260 | } |
| 261 | } |
| 262 | } |
| 263 | |
| 264 | (void) hv_store_ent(stored, our_name, &PL_sv_undef, 0); |
| 265 | (void) hv_store(stored, "UNIVERSAL", 9, &PL_sv_undef, 0); |
| 266 | |
| 267 | SvREFCNT_inc_simple_void_NN(stored); |
| 268 | SvTEMP_off(stored); |
| 269 | SvREADONLY_on(stored); |
| 270 | |
| 271 | meta->isa = stored; |
| 272 | |
| 273 | /* now that we're past the exception dangers, grab our own reference to |
| 274 | the AV we're about to use for the result. The reference owned by the |
| 275 | mortals' stack will be released soon, so everything will balance. */ |
| 276 | SvREFCNT_inc_simple_void_NN(retval); |
| 277 | SvTEMP_off(retval); |
| 278 | |
| 279 | /* we don't want anyone modifying the cache entry but us, |
| 280 | and we do so by replacing it completely */ |
| 281 | SvREADONLY_on(retval); |
| 282 | |
| 283 | meta->mro_linear_dfs = retval; |
| 284 | return retval; |
| 285 | } |
| 286 | |
| 287 | /* |
| 288 | =for apidoc mro_get_linear_isa_c3 |
| 289 | |
| 290 | Returns the C3 linearization of @ISA |
| 291 | the given stash. The return value is a read-only AV*. |
| 292 | C<level> should be 0 (it is used internally in this |
| 293 | function's recursion). |
| 294 | |
| 295 | You are responsible for C<SvREFCNT_inc()> on the |
| 296 | return value if you plan to store it anywhere |
| 297 | semi-permanently (otherwise it might be deleted |
| 298 | out from under you the next time the cache is |
| 299 | invalidated). |
| 300 | |
| 301 | =cut |
| 302 | */ |
| 303 | |
| 304 | static AV* |
| 305 | S_mro_get_linear_isa_c3(pTHX_ HV* stash, I32 level) |
| 306 | { |
| 307 | AV* retval; |
| 308 | GV** gvp; |
| 309 | GV* gv; |
| 310 | AV* isa; |
| 311 | const HEK* stashhek; |
| 312 | struct mro_meta* meta; |
| 313 | |
| 314 | PERL_ARGS_ASSERT_MRO_GET_LINEAR_ISA_C3; |
| 315 | assert(HvAUX(stash)); |
| 316 | |
| 317 | stashhek = HvNAME_HEK(stash); |
| 318 | if (!stashhek) |
| 319 | Perl_croak(aTHX_ "Can't linearize anonymous symbol table"); |
| 320 | |
| 321 | if (level > 100) |
| 322 | Perl_croak(aTHX_ "Recursive inheritance detected in package '%s'", |
| 323 | HEK_KEY(stashhek)); |
| 324 | |
| 325 | meta = HvMROMETA(stash); |
| 326 | |
| 327 | /* return cache if valid */ |
| 328 | if((retval = meta->mro_linear_c3)) { |
| 329 | return retval; |
| 330 | } |
| 331 | |
| 332 | /* not in cache, make a new one */ |
| 333 | |
| 334 | gvp = (GV**)hv_fetchs(stash, "ISA", FALSE); |
| 335 | isa = (gvp && (gv = *gvp) && isGV_with_GP(gv)) ? GvAV(gv) : NULL; |
| 336 | |
| 337 | /* For a better idea how the rest of this works, see the much clearer |
| 338 | pure perl version in Algorithm::C3 0.01: |
| 339 | http://search.cpan.org/src/STEVAN/Algorithm-C3-0.01/lib/Algorithm/C3.pm |
| 340 | (later versions go about it differently than this code for speed reasons) |
| 341 | */ |
| 342 | |
| 343 | if(isa && AvFILLp(isa) >= 0) { |
| 344 | SV** seqs_ptr; |
| 345 | I32 seqs_items; |
| 346 | HV* const tails = (HV*)sv_2mortal((SV*)newHV()); |
| 347 | AV* const seqs = (AV*)sv_2mortal((SV*)newAV()); |
| 348 | I32* heads; |
| 349 | |
| 350 | /* This builds @seqs, which is an array of arrays. |
| 351 | The members of @seqs are the MROs of |
| 352 | the members of @ISA, followed by @ISA itself. |
| 353 | */ |
| 354 | I32 items = AvFILLp(isa) + 1; |
| 355 | SV** isa_ptr = AvARRAY(isa); |
| 356 | while(items--) { |
| 357 | SV* const isa_item = *isa_ptr++; |
| 358 | HV* const isa_item_stash = gv_stashsv(isa_item, 0); |
| 359 | if(!isa_item_stash) { |
| 360 | /* if no stash, make a temporary fake MRO |
| 361 | containing just itself */ |
| 362 | AV* const isa_lin = newAV(); |
| 363 | av_push(isa_lin, newSVsv(isa_item)); |
| 364 | av_push(seqs, (SV*)isa_lin); |
| 365 | } |
| 366 | else { |
| 367 | /* recursion */ |
| 368 | AV* const isa_lin = mro_get_linear_isa_c3(isa_item_stash, level + 1); |
| 369 | av_push(seqs, SvREFCNT_inc_simple_NN((SV*)isa_lin)); |
| 370 | } |
| 371 | } |
| 372 | av_push(seqs, SvREFCNT_inc_simple_NN((SV*)isa)); |
| 373 | |
| 374 | /* This builds "heads", which as an array of integer array |
| 375 | indices, one per seq, which point at the virtual "head" |
| 376 | of the seq (initially zero) */ |
| 377 | Newxz(heads, AvFILLp(seqs)+1, I32); |
| 378 | |
| 379 | /* This builds %tails, which has one key for every class |
| 380 | mentioned in the tail of any sequence in @seqs (tail meaning |
| 381 | everything after the first class, the "head"). The value |
| 382 | is how many times this key appears in the tails of @seqs. |
| 383 | */ |
| 384 | seqs_ptr = AvARRAY(seqs); |
| 385 | seqs_items = AvFILLp(seqs) + 1; |
| 386 | while(seqs_items--) { |
| 387 | AV* const seq = (AV*)*seqs_ptr++; |
| 388 | I32 seq_items = AvFILLp(seq); |
| 389 | if(seq_items > 0) { |
| 390 | SV** seq_ptr = AvARRAY(seq) + 1; |
| 391 | while(seq_items--) { |
| 392 | SV* const seqitem = *seq_ptr++; |
| 393 | /* LVALUE fetch will create a new undefined SV if necessary |
| 394 | */ |
| 395 | HE* const he = hv_fetch_ent(tails, seqitem, 1, 0); |
| 396 | if(he) { |
| 397 | SV* const val = HeVAL(he); |
| 398 | /* This will increment undef to 1, which is what we |
| 399 | want for a newly created entry. */ |
| 400 | sv_inc(val); |
| 401 | } |
| 402 | } |
| 403 | } |
| 404 | } |
| 405 | |
| 406 | /* Initialize retval to build the return value in */ |
| 407 | retval = newAV(); |
| 408 | av_push(retval, newSVhek(stashhek)); /* us first */ |
| 409 | |
| 410 | /* This loop won't terminate until we either finish building |
| 411 | the MRO, or get an exception. */ |
| 412 | while(1) { |
| 413 | SV* cand = NULL; |
| 414 | SV* winner = NULL; |
| 415 | int s; |
| 416 | |
| 417 | /* "foreach $seq (@seqs)" */ |
| 418 | SV** const avptr = AvARRAY(seqs); |
| 419 | for(s = 0; s <= AvFILLp(seqs); s++) { |
| 420 | SV** svp; |
| 421 | AV * const seq = (AV*)(avptr[s]); |
| 422 | SV* seqhead; |
| 423 | if(!seq) continue; /* skip empty seqs */ |
| 424 | svp = av_fetch(seq, heads[s], 0); |
| 425 | seqhead = *svp; /* seqhead = head of this seq */ |
| 426 | if(!winner) { |
| 427 | HE* tail_entry; |
| 428 | SV* val; |
| 429 | /* if we haven't found a winner for this round yet, |
| 430 | and this seqhead is not in tails (or the count |
| 431 | for it in tails has dropped to zero), then this |
| 432 | seqhead is our new winner, and is added to the |
| 433 | final MRO immediately */ |
| 434 | cand = seqhead; |
| 435 | if((tail_entry = hv_fetch_ent(tails, cand, 0, 0)) |
| 436 | && (val = HeVAL(tail_entry)) |
| 437 | && (SvIVX(val) > 0)) |
| 438 | continue; |
| 439 | winner = newSVsv(cand); |
| 440 | av_push(retval, winner); |
| 441 | /* note however that even when we find a winner, |
| 442 | we continue looping over @seqs to do housekeeping */ |
| 443 | } |
| 444 | if(!sv_cmp(seqhead, winner)) { |
| 445 | /* Once we have a winner (including the iteration |
| 446 | where we first found him), inc the head ptr |
| 447 | for any seq which had the winner as a head, |
| 448 | NULL out any seq which is now empty, |
| 449 | and adjust tails for consistency */ |
| 450 | |
| 451 | const int new_head = ++heads[s]; |
| 452 | if(new_head > AvFILLp(seq)) { |
| 453 | SvREFCNT_dec(avptr[s]); |
| 454 | avptr[s] = NULL; |
| 455 | } |
| 456 | else { |
| 457 | HE* tail_entry; |
| 458 | SV* val; |
| 459 | /* Because we know this new seqhead used to be |
| 460 | a tail, we can assume it is in tails and has |
| 461 | a positive value, which we need to dec */ |
| 462 | svp = av_fetch(seq, new_head, 0); |
| 463 | seqhead = *svp; |
| 464 | tail_entry = hv_fetch_ent(tails, seqhead, 0, 0); |
| 465 | val = HeVAL(tail_entry); |
| 466 | sv_dec(val); |
| 467 | } |
| 468 | } |
| 469 | } |
| 470 | |
| 471 | /* if we found no candidates, we are done building the MRO. |
| 472 | !cand means no seqs have any entries left to check */ |
| 473 | if(!cand) { |
| 474 | Safefree(heads); |
| 475 | break; |
| 476 | } |
| 477 | |
| 478 | /* If we had candidates, but nobody won, then the @ISA |
| 479 | hierarchy is not C3-incompatible */ |
| 480 | if(!winner) { |
| 481 | /* we have to do some cleanup before we croak */ |
| 482 | |
| 483 | SvREFCNT_dec(retval); |
| 484 | Safefree(heads); |
| 485 | |
| 486 | Perl_croak(aTHX_ "Inconsistent hierarchy during C3 merge of class '%s': " |
| 487 | "merging failed on parent '%"SVf"'", HEK_KEY(stashhek), SVfARG(cand)); |
| 488 | } |
| 489 | } |
| 490 | } |
| 491 | else { /* @ISA was undefined or empty */ |
| 492 | /* build a retval containing only ourselves */ |
| 493 | retval = newAV(); |
| 494 | av_push(retval, newSVhek(stashhek)); |
| 495 | } |
| 496 | |
| 497 | /* we don't want anyone modifying the cache entry but us, |
| 498 | and we do so by replacing it completely */ |
| 499 | SvREADONLY_on(retval); |
| 500 | |
| 501 | meta->mro_linear_c3 = retval; |
| 502 | return retval; |
| 503 | } |
| 504 | |
| 505 | /* |
| 506 | =for apidoc mro_get_linear_isa |
| 507 | |
| 508 | Returns either C<mro_get_linear_isa_c3> or |
| 509 | C<mro_get_linear_isa_dfs> for the given stash, |
| 510 | dependant upon which MRO is in effect |
| 511 | for that stash. The return value is a |
| 512 | read-only AV*. |
| 513 | |
| 514 | You are responsible for C<SvREFCNT_inc()> on the |
| 515 | return value if you plan to store it anywhere |
| 516 | semi-permanently (otherwise it might be deleted |
| 517 | out from under you the next time the cache is |
| 518 | invalidated). |
| 519 | |
| 520 | =cut |
| 521 | */ |
| 522 | AV* |
| 523 | Perl_mro_get_linear_isa(pTHX_ HV *stash) |
| 524 | { |
| 525 | struct mro_meta* meta; |
| 526 | |
| 527 | PERL_ARGS_ASSERT_MRO_GET_LINEAR_ISA; |
| 528 | if(!SvOOK(stash)) |
| 529 | Perl_croak(aTHX_ "Can't linearize anonymous symbol table"); |
| 530 | |
| 531 | meta = HvMROMETA(stash); |
| 532 | if (!meta->mro_which) |
| 533 | Perl_croak(aTHX_ "panic: invalid MRO!"); |
| 534 | return meta->mro_which->resolve(aTHX_ stash, 0); |
| 535 | } |
| 536 | |
| 537 | /* |
| 538 | =for apidoc mro_isa_changed_in |
| 539 | |
| 540 | Takes the necessary steps (cache invalidations, mostly) |
| 541 | when the @ISA of the given package has changed. Invoked |
| 542 | by the C<setisa> magic, should not need to invoke directly. |
| 543 | |
| 544 | =cut |
| 545 | */ |
| 546 | void |
| 547 | Perl_mro_isa_changed_in(pTHX_ HV* stash) |
| 548 | { |
| 549 | dVAR; |
| 550 | HV* isarev; |
| 551 | AV* linear_mro; |
| 552 | HE* iter; |
| 553 | SV** svp; |
| 554 | I32 items; |
| 555 | bool is_universal; |
| 556 | struct mro_meta * meta; |
| 557 | |
| 558 | const char * const stashname = HvNAME_get(stash); |
| 559 | const STRLEN stashname_len = HvNAMELEN_get(stash); |
| 560 | |
| 561 | PERL_ARGS_ASSERT_MRO_ISA_CHANGED_IN; |
| 562 | |
| 563 | if(!stashname) |
| 564 | Perl_croak(aTHX_ "Can't call mro_isa_changed_in() on anonymous symbol table"); |
| 565 | |
| 566 | /* wipe out the cached linearizations for this stash */ |
| 567 | meta = HvMROMETA(stash); |
| 568 | SvREFCNT_dec((SV*)meta->mro_linear_dfs); |
| 569 | SvREFCNT_dec((SV*)meta->mro_linear_c3); |
| 570 | meta->mro_linear_dfs = NULL; |
| 571 | meta->mro_linear_c3 = NULL; |
| 572 | if (meta->isa) { |
| 573 | SvREFCNT_dec(meta->isa); |
| 574 | meta->isa = NULL; |
| 575 | } |
| 576 | |
| 577 | /* Inc the package generation, since our @ISA changed */ |
| 578 | meta->pkg_gen++; |
| 579 | |
| 580 | /* Wipe the global method cache if this package |
| 581 | is UNIVERSAL or one of its parents */ |
| 582 | |
| 583 | svp = hv_fetch(PL_isarev, stashname, stashname_len, 0); |
| 584 | isarev = svp ? (HV*)*svp : NULL; |
| 585 | |
| 586 | if((stashname_len == 9 && strEQ(stashname, "UNIVERSAL")) |
| 587 | || (isarev && hv_exists(isarev, "UNIVERSAL", 9))) { |
| 588 | PL_sub_generation++; |
| 589 | is_universal = TRUE; |
| 590 | } |
| 591 | else { /* Wipe the local method cache otherwise */ |
| 592 | meta->cache_gen++; |
| 593 | is_universal = FALSE; |
| 594 | } |
| 595 | |
| 596 | /* wipe next::method cache too */ |
| 597 | if(meta->mro_nextmethod) hv_clear(meta->mro_nextmethod); |
| 598 | |
| 599 | /* Iterate the isarev (classes that are our children), |
| 600 | wiping out their linearization and method caches */ |
| 601 | if(isarev) { |
| 602 | hv_iterinit(isarev); |
| 603 | while((iter = hv_iternext(isarev))) { |
| 604 | I32 len; |
| 605 | const char* const revkey = hv_iterkey(iter, &len); |
| 606 | HV* revstash = gv_stashpvn(revkey, len, 0); |
| 607 | struct mro_meta* revmeta; |
| 608 | |
| 609 | if(!revstash) continue; |
| 610 | revmeta = HvMROMETA(revstash); |
| 611 | SvREFCNT_dec((SV*)revmeta->mro_linear_dfs); |
| 612 | SvREFCNT_dec((SV*)revmeta->mro_linear_c3); |
| 613 | revmeta->mro_linear_dfs = NULL; |
| 614 | revmeta->mro_linear_c3 = NULL; |
| 615 | if(!is_universal) |
| 616 | revmeta->cache_gen++; |
| 617 | if(revmeta->mro_nextmethod) |
| 618 | hv_clear(revmeta->mro_nextmethod); |
| 619 | } |
| 620 | } |
| 621 | |
| 622 | /* Now iterate our MRO (parents), and do a few things: |
| 623 | 1) instantiate with the "fake" flag if they don't exist |
| 624 | 2) flag them as universal if we are universal |
| 625 | 3) Add everything from our isarev to their isarev |
| 626 | */ |
| 627 | |
| 628 | /* We're starting at the 2nd element, skipping ourselves here */ |
| 629 | linear_mro = mro_get_linear_isa(stash); |
| 630 | svp = AvARRAY(linear_mro) + 1; |
| 631 | items = AvFILLp(linear_mro); |
| 632 | |
| 633 | while (items--) { |
| 634 | SV* const sv = *svp++; |
| 635 | HV* mroisarev; |
| 636 | |
| 637 | HE *he = hv_fetch_ent(PL_isarev, sv, TRUE, 0); |
| 638 | |
| 639 | /* That fetch should not fail. But if it had to create a new SV for |
| 640 | us, then will need to upgrade it to an HV (which sv_upgrade() can |
| 641 | now do for us. */ |
| 642 | |
| 643 | mroisarev = (HV*)HeVAL(he); |
| 644 | |
| 645 | SvUPGRADE((SV*)mroisarev, SVt_PVHV); |
| 646 | |
| 647 | /* This hash only ever contains PL_sv_yes. Storing it over itself is |
| 648 | almost as cheap as calling hv_exists, so on aggregate we expect to |
| 649 | save time by not making two calls to the common HV code for the |
| 650 | case where it doesn't exist. */ |
| 651 | |
| 652 | (void)hv_store(mroisarev, stashname, stashname_len, &PL_sv_yes, 0); |
| 653 | |
| 654 | if(isarev) { |
| 655 | hv_iterinit(isarev); |
| 656 | while((iter = hv_iternext(isarev))) { |
| 657 | I32 revkeylen; |
| 658 | char* const revkey = hv_iterkey(iter, &revkeylen); |
| 659 | (void)hv_store(mroisarev, revkey, revkeylen, &PL_sv_yes, 0); |
| 660 | } |
| 661 | } |
| 662 | } |
| 663 | } |
| 664 | |
| 665 | /* |
| 666 | =for apidoc mro_method_changed_in |
| 667 | |
| 668 | Invalidates method caching on any child classes |
| 669 | of the given stash, so that they might notice |
| 670 | the changes in this one. |
| 671 | |
| 672 | Ideally, all instances of C<PL_sub_generation++> in |
| 673 | perl source outside of C<mro.c> should be |
| 674 | replaced by calls to this. |
| 675 | |
| 676 | Perl automatically handles most of the common |
| 677 | ways a method might be redefined. However, there |
| 678 | are a few ways you could change a method in a stash |
| 679 | without the cache code noticing, in which case you |
| 680 | need to call this method afterwards: |
| 681 | |
| 682 | 1) Directly manipulating the stash HV entries from |
| 683 | XS code. |
| 684 | |
| 685 | 2) Assigning a reference to a readonly scalar |
| 686 | constant into a stash entry in order to create |
| 687 | a constant subroutine (like constant.pm |
| 688 | does). |
| 689 | |
| 690 | This same method is available from pure perl |
| 691 | via, C<mro::method_changed_in(classname)>. |
| 692 | |
| 693 | =cut |
| 694 | */ |
| 695 | void |
| 696 | Perl_mro_method_changed_in(pTHX_ HV *stash) |
| 697 | { |
| 698 | const char * const stashname = HvNAME_get(stash); |
| 699 | const STRLEN stashname_len = HvNAMELEN_get(stash); |
| 700 | |
| 701 | SV ** const svp = hv_fetch(PL_isarev, stashname, stashname_len, 0); |
| 702 | HV * const isarev = svp ? (HV*)*svp : NULL; |
| 703 | |
| 704 | PERL_ARGS_ASSERT_MRO_METHOD_CHANGED_IN; |
| 705 | |
| 706 | if(!stashname) |
| 707 | Perl_croak(aTHX_ "Can't call mro_method_changed_in() on anonymous symbol table"); |
| 708 | |
| 709 | /* Inc the package generation, since a local method changed */ |
| 710 | HvMROMETA(stash)->pkg_gen++; |
| 711 | |
| 712 | /* If stash is UNIVERSAL, or one of UNIVERSAL's parents, |
| 713 | invalidate all method caches globally */ |
| 714 | if((stashname_len == 9 && strEQ(stashname, "UNIVERSAL")) |
| 715 | || (isarev && hv_exists(isarev, "UNIVERSAL", 9))) { |
| 716 | PL_sub_generation++; |
| 717 | return; |
| 718 | } |
| 719 | |
| 720 | /* else, invalidate the method caches of all child classes, |
| 721 | but not itself */ |
| 722 | if(isarev) { |
| 723 | HE* iter; |
| 724 | |
| 725 | hv_iterinit(isarev); |
| 726 | while((iter = hv_iternext(isarev))) { |
| 727 | I32 len; |
| 728 | const char* const revkey = hv_iterkey(iter, &len); |
| 729 | HV* const revstash = gv_stashpvn(revkey, len, 0); |
| 730 | struct mro_meta* mrometa; |
| 731 | |
| 732 | if(!revstash) continue; |
| 733 | mrometa = HvMROMETA(revstash); |
| 734 | mrometa->cache_gen++; |
| 735 | if(mrometa->mro_nextmethod) |
| 736 | hv_clear(mrometa->mro_nextmethod); |
| 737 | } |
| 738 | } |
| 739 | } |
| 740 | |
| 741 | /* These two are static helpers for next::method and friends, |
| 742 | and re-implement a bunch of the code from pp_caller() in |
| 743 | a more efficient manner for this particular usage. |
| 744 | */ |
| 745 | |
| 746 | STATIC I32 |
| 747 | __dopoptosub_at(const PERL_CONTEXT *cxstk, I32 startingblock) { |
| 748 | I32 i; |
| 749 | for (i = startingblock; i >= 0; i--) { |
| 750 | if(CxTYPE((PERL_CONTEXT*)(&cxstk[i])) == CXt_SUB) return i; |
| 751 | } |
| 752 | return i; |
| 753 | } |
| 754 | |
| 755 | #include "XSUB.h" |
| 756 | |
| 757 | XS(XS_mro_get_linear_isa); |
| 758 | XS(XS_mro_set_mro); |
| 759 | XS(XS_mro_get_mro); |
| 760 | XS(XS_mro_get_isarev); |
| 761 | XS(XS_mro_is_universal); |
| 762 | XS(XS_mro_invalidate_method_caches); |
| 763 | XS(XS_mro_method_changed_in); |
| 764 | XS(XS_mro_get_pkg_gen); |
| 765 | XS(XS_mro_nextcan); |
| 766 | |
| 767 | void |
| 768 | Perl_boot_core_mro(pTHX) |
| 769 | { |
| 770 | dVAR; |
| 771 | static const char file[] = __FILE__; |
| 772 | |
| 773 | newXSproto("mro::get_linear_isa", XS_mro_get_linear_isa, file, "$;$"); |
| 774 | newXSproto("mro::set_mro", XS_mro_set_mro, file, "$$"); |
| 775 | newXSproto("mro::get_mro", XS_mro_get_mro, file, "$"); |
| 776 | newXSproto("mro::get_isarev", XS_mro_get_isarev, file, "$"); |
| 777 | newXSproto("mro::is_universal", XS_mro_is_universal, file, "$"); |
| 778 | newXSproto("mro::invalidate_all_method_caches", XS_mro_invalidate_method_caches, file, ""); |
| 779 | newXSproto("mro::method_changed_in", XS_mro_method_changed_in, file, "$"); |
| 780 | newXSproto("mro::get_pkg_gen", XS_mro_get_pkg_gen, file, "$"); |
| 781 | newXS("mro::_nextcan", XS_mro_nextcan, file); |
| 782 | } |
| 783 | |
| 784 | XS(XS_mro_get_linear_isa) { |
| 785 | dVAR; |
| 786 | dXSARGS; |
| 787 | AV* RETVAL; |
| 788 | HV* class_stash; |
| 789 | SV* classname; |
| 790 | |
| 791 | if(items < 1 || items > 2) |
| 792 | croak_xs_usage(cv, "classname [, type ]"); |
| 793 | |
| 794 | classname = ST(0); |
| 795 | class_stash = gv_stashsv(classname, 0); |
| 796 | |
| 797 | if(!class_stash) { |
| 798 | /* No stash exists yet, give them just the classname */ |
| 799 | AV* isalin = newAV(); |
| 800 | av_push(isalin, newSVsv(classname)); |
| 801 | ST(0) = sv_2mortal(newRV_noinc((SV*)isalin)); |
| 802 | XSRETURN(1); |
| 803 | } |
| 804 | else if(items > 1) { |
| 805 | const char* const which = SvPV_nolen(ST(1)); |
| 806 | const struct mro_alg *const algo = S_get_mro_from_name(aTHX_ which); |
| 807 | if (!algo) |
| 808 | Perl_croak(aTHX_ "Invalid mro name: '%s'", which); |
| 809 | RETVAL = algo->resolve(aTHX_ class_stash, 0); |
| 810 | } |
| 811 | else { |
| 812 | RETVAL = mro_get_linear_isa(class_stash); |
| 813 | } |
| 814 | |
| 815 | ST(0) = newRV_inc((SV*)RETVAL); |
| 816 | sv_2mortal(ST(0)); |
| 817 | XSRETURN(1); |
| 818 | } |
| 819 | |
| 820 | XS(XS_mro_set_mro) |
| 821 | { |
| 822 | dVAR; |
| 823 | dXSARGS; |
| 824 | SV* classname; |
| 825 | const char* whichstr; |
| 826 | const struct mro_alg *which; |
| 827 | HV* class_stash; |
| 828 | struct mro_meta* meta; |
| 829 | |
| 830 | if (items != 2) |
| 831 | croak_xs_usage(cv, "classname, type"); |
| 832 | |
| 833 | classname = ST(0); |
| 834 | whichstr = SvPV_nolen(ST(1)); |
| 835 | class_stash = gv_stashsv(classname, GV_ADD); |
| 836 | if(!class_stash) Perl_croak(aTHX_ "Cannot create class: '%"SVf"'!", SVfARG(classname)); |
| 837 | meta = HvMROMETA(class_stash); |
| 838 | |
| 839 | which = S_get_mro_from_name(aTHX_ whichstr); |
| 840 | if (!which) |
| 841 | Perl_croak(aTHX_ "Invalid mro name: '%s'", whichstr); |
| 842 | |
| 843 | if(meta->mro_which != which) { |
| 844 | meta->mro_which = which; |
| 845 | /* Only affects local method cache, not |
| 846 | even child classes */ |
| 847 | meta->cache_gen++; |
| 848 | if(meta->mro_nextmethod) |
| 849 | hv_clear(meta->mro_nextmethod); |
| 850 | } |
| 851 | |
| 852 | XSRETURN_EMPTY; |
| 853 | } |
| 854 | |
| 855 | |
| 856 | XS(XS_mro_get_mro) |
| 857 | { |
| 858 | dVAR; |
| 859 | dXSARGS; |
| 860 | SV* classname; |
| 861 | HV* class_stash; |
| 862 | |
| 863 | if (items != 1) |
| 864 | croak_xs_usage(cv, "classname"); |
| 865 | |
| 866 | classname = ST(0); |
| 867 | class_stash = gv_stashsv(classname, 0); |
| 868 | |
| 869 | ST(0) = sv_2mortal(newSVpv(class_stash |
| 870 | ? HvMROMETA(class_stash)->mro_which->name |
| 871 | : "dfs", 0)); |
| 872 | XSRETURN(1); |
| 873 | } |
| 874 | |
| 875 | XS(XS_mro_get_isarev) |
| 876 | { |
| 877 | dVAR; |
| 878 | dXSARGS; |
| 879 | SV* classname; |
| 880 | HE* he; |
| 881 | HV* isarev; |
| 882 | AV* ret_array; |
| 883 | |
| 884 | if (items != 1) |
| 885 | croak_xs_usage(cv, "classname"); |
| 886 | |
| 887 | classname = ST(0); |
| 888 | |
| 889 | SP -= items; |
| 890 | |
| 891 | |
| 892 | he = hv_fetch_ent(PL_isarev, classname, 0, 0); |
| 893 | isarev = he ? (HV*)HeVAL(he) : NULL; |
| 894 | |
| 895 | ret_array = newAV(); |
| 896 | if(isarev) { |
| 897 | HE* iter; |
| 898 | hv_iterinit(isarev); |
| 899 | while((iter = hv_iternext(isarev))) |
| 900 | av_push(ret_array, newSVsv(hv_iterkeysv(iter))); |
| 901 | } |
| 902 | mXPUSHs(newRV_noinc((SV*)ret_array)); |
| 903 | |
| 904 | PUTBACK; |
| 905 | return; |
| 906 | } |
| 907 | |
| 908 | XS(XS_mro_is_universal) |
| 909 | { |
| 910 | dVAR; |
| 911 | dXSARGS; |
| 912 | SV* classname; |
| 913 | HV* isarev; |
| 914 | char* classname_pv; |
| 915 | STRLEN classname_len; |
| 916 | HE* he; |
| 917 | |
| 918 | if (items != 1) |
| 919 | croak_xs_usage(cv, "classname"); |
| 920 | |
| 921 | classname = ST(0); |
| 922 | |
| 923 | classname_pv = SvPV(classname,classname_len); |
| 924 | |
| 925 | he = hv_fetch_ent(PL_isarev, classname, 0, 0); |
| 926 | isarev = he ? (HV*)HeVAL(he) : NULL; |
| 927 | |
| 928 | if((classname_len == 9 && strEQ(classname_pv, "UNIVERSAL")) |
| 929 | || (isarev && hv_exists(isarev, "UNIVERSAL", 9))) |
| 930 | XSRETURN_YES; |
| 931 | else |
| 932 | XSRETURN_NO; |
| 933 | } |
| 934 | |
| 935 | XS(XS_mro_invalidate_method_caches) |
| 936 | { |
| 937 | dVAR; |
| 938 | dXSARGS; |
| 939 | |
| 940 | if (items != 0) |
| 941 | croak_xs_usage(cv, ""); |
| 942 | |
| 943 | PL_sub_generation++; |
| 944 | |
| 945 | XSRETURN_EMPTY; |
| 946 | } |
| 947 | |
| 948 | XS(XS_mro_method_changed_in) |
| 949 | { |
| 950 | dVAR; |
| 951 | dXSARGS; |
| 952 | SV* classname; |
| 953 | HV* class_stash; |
| 954 | |
| 955 | if(items != 1) |
| 956 | croak_xs_usage(cv, "classname"); |
| 957 | |
| 958 | classname = ST(0); |
| 959 | |
| 960 | class_stash = gv_stashsv(classname, 0); |
| 961 | if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname)); |
| 962 | |
| 963 | mro_method_changed_in(class_stash); |
| 964 | |
| 965 | XSRETURN_EMPTY; |
| 966 | } |
| 967 | |
| 968 | XS(XS_mro_get_pkg_gen) |
| 969 | { |
| 970 | dVAR; |
| 971 | dXSARGS; |
| 972 | SV* classname; |
| 973 | HV* class_stash; |
| 974 | |
| 975 | if(items != 1) |
| 976 | croak_xs_usage(cv, "classname"); |
| 977 | |
| 978 | classname = ST(0); |
| 979 | |
| 980 | class_stash = gv_stashsv(classname, 0); |
| 981 | |
| 982 | SP -= items; |
| 983 | |
| 984 | mXPUSHi(class_stash ? HvMROMETA(class_stash)->pkg_gen : 0); |
| 985 | |
| 986 | PUTBACK; |
| 987 | return; |
| 988 | } |
| 989 | |
| 990 | XS(XS_mro_nextcan) |
| 991 | { |
| 992 | dVAR; |
| 993 | dXSARGS; |
| 994 | SV* self = ST(0); |
| 995 | const I32 throw_nomethod = SvIVX(ST(1)); |
| 996 | register I32 cxix = cxstack_ix; |
| 997 | register const PERL_CONTEXT *ccstack = cxstack; |
| 998 | const PERL_SI *top_si = PL_curstackinfo; |
| 999 | HV* selfstash; |
| 1000 | SV *stashname; |
| 1001 | const char *fq_subname; |
| 1002 | const char *subname; |
| 1003 | STRLEN stashname_len; |
| 1004 | STRLEN subname_len; |
| 1005 | SV* sv; |
| 1006 | GV** gvp; |
| 1007 | AV* linear_av; |
| 1008 | SV** linear_svp; |
| 1009 | const char *hvname; |
| 1010 | I32 entries; |
| 1011 | struct mro_meta* selfmeta; |
| 1012 | HV* nmcache; |
| 1013 | I32 i; |
| 1014 | |
| 1015 | PERL_UNUSED_ARG(cv); |
| 1016 | |
| 1017 | SP -= items; |
| 1018 | |
| 1019 | if(sv_isobject(self)) |
| 1020 | selfstash = SvSTASH(SvRV(self)); |
| 1021 | else |
| 1022 | selfstash = gv_stashsv(self, GV_ADD); |
| 1023 | |
| 1024 | assert(selfstash); |
| 1025 | |
| 1026 | hvname = HvNAME_get(selfstash); |
| 1027 | if (!hvname) |
| 1028 | Perl_croak(aTHX_ "Can't use anonymous symbol table for method lookup"); |
| 1029 | |
| 1030 | /* This block finds the contextually-enclosing fully-qualified subname, |
| 1031 | much like looking at (caller($i))[3] until you find a real sub that |
| 1032 | isn't ANON, etc (also skips over pureperl next::method, etc) */ |
| 1033 | for(i = 0; i < 2; i++) { |
| 1034 | cxix = __dopoptosub_at(ccstack, cxix); |
| 1035 | for (;;) { |
| 1036 | GV* cvgv; |
| 1037 | STRLEN fq_subname_len; |
| 1038 | |
| 1039 | /* we may be in a higher stacklevel, so dig down deeper */ |
| 1040 | while (cxix < 0) { |
| 1041 | if(top_si->si_type == PERLSI_MAIN) |
| 1042 | Perl_croak(aTHX_ "next::method/next::can/maybe::next::method must be used in method context"); |
| 1043 | top_si = top_si->si_prev; |
| 1044 | ccstack = top_si->si_cxstack; |
| 1045 | cxix = __dopoptosub_at(ccstack, top_si->si_cxix); |
| 1046 | } |
| 1047 | |
| 1048 | if(CxTYPE((PERL_CONTEXT*)(&ccstack[cxix])) != CXt_SUB |
| 1049 | || (PL_DBsub && GvCV(PL_DBsub) && ccstack[cxix].blk_sub.cv == GvCV(PL_DBsub))) { |
| 1050 | cxix = __dopoptosub_at(ccstack, cxix - 1); |
| 1051 | continue; |
| 1052 | } |
| 1053 | |
| 1054 | { |
| 1055 | const I32 dbcxix = __dopoptosub_at(ccstack, cxix - 1); |
| 1056 | if (PL_DBsub && GvCV(PL_DBsub) && dbcxix >= 0 && ccstack[dbcxix].blk_sub.cv == GvCV(PL_DBsub)) { |
| 1057 | if(CxTYPE((PERL_CONTEXT*)(&ccstack[dbcxix])) != CXt_SUB) { |
| 1058 | cxix = dbcxix; |
| 1059 | continue; |
| 1060 | } |
| 1061 | } |
| 1062 | } |
| 1063 | |
| 1064 | cvgv = CvGV(ccstack[cxix].blk_sub.cv); |
| 1065 | |
| 1066 | if(!isGV(cvgv)) { |
| 1067 | cxix = __dopoptosub_at(ccstack, cxix - 1); |
| 1068 | continue; |
| 1069 | } |
| 1070 | |
| 1071 | /* we found a real sub here */ |
| 1072 | sv = sv_2mortal(newSV(0)); |
| 1073 | |
| 1074 | gv_efullname3(sv, cvgv, NULL); |
| 1075 | |
| 1076 | fq_subname = SvPVX(sv); |
| 1077 | fq_subname_len = SvCUR(sv); |
| 1078 | |
| 1079 | subname = strrchr(fq_subname, ':'); |
| 1080 | if(!subname) |
| 1081 | Perl_croak(aTHX_ "next::method/next::can/maybe::next::method cannot find enclosing method"); |
| 1082 | |
| 1083 | subname++; |
| 1084 | subname_len = fq_subname_len - (subname - fq_subname); |
| 1085 | if(subname_len == 8 && strEQ(subname, "__ANON__")) { |
| 1086 | cxix = __dopoptosub_at(ccstack, cxix - 1); |
| 1087 | continue; |
| 1088 | } |
| 1089 | break; |
| 1090 | } |
| 1091 | cxix--; |
| 1092 | } |
| 1093 | |
| 1094 | /* If we made it to here, we found our context */ |
| 1095 | |
| 1096 | /* Initialize the next::method cache for this stash |
| 1097 | if necessary */ |
| 1098 | selfmeta = HvMROMETA(selfstash); |
| 1099 | if(!(nmcache = selfmeta->mro_nextmethod)) { |
| 1100 | nmcache = selfmeta->mro_nextmethod = newHV(); |
| 1101 | } |
| 1102 | else { /* Use the cached coderef if it exists */ |
| 1103 | HE* cache_entry = hv_fetch_ent(nmcache, sv, 0, 0); |
| 1104 | if (cache_entry) { |
| 1105 | SV* const val = HeVAL(cache_entry); |
| 1106 | if(val == &PL_sv_undef) { |
| 1107 | if(throw_nomethod) |
| 1108 | Perl_croak(aTHX_ "No next::method '%s' found for %s", subname, hvname); |
| 1109 | XSRETURN_EMPTY; |
| 1110 | } |
| 1111 | mXPUSHs(newRV_inc(val)); |
| 1112 | XSRETURN(1); |
| 1113 | } |
| 1114 | } |
| 1115 | |
| 1116 | /* beyond here is just for cache misses, so perf isn't as critical */ |
| 1117 | |
| 1118 | stashname_len = subname - fq_subname - 2; |
| 1119 | stashname = newSVpvn_flags(fq_subname, stashname_len, SVs_TEMP); |
| 1120 | |
| 1121 | linear_av = mro_get_linear_isa_c3(selfstash, 0); /* has ourselves at the top of the list */ |
| 1122 | |
| 1123 | linear_svp = AvARRAY(linear_av); |
| 1124 | entries = AvFILLp(linear_av) + 1; |
| 1125 | |
| 1126 | /* Walk down our MRO, skipping everything up |
| 1127 | to the contextually enclosing class */ |
| 1128 | while (entries--) { |
| 1129 | SV * const linear_sv = *linear_svp++; |
| 1130 | assert(linear_sv); |
| 1131 | if(sv_eq(linear_sv, stashname)) |
| 1132 | break; |
| 1133 | } |
| 1134 | |
| 1135 | /* Now search the remainder of the MRO for the |
| 1136 | same method name as the contextually enclosing |
| 1137 | method */ |
| 1138 | if(entries > 0) { |
| 1139 | while (entries--) { |
| 1140 | SV * const linear_sv = *linear_svp++; |
| 1141 | HV* curstash; |
| 1142 | GV* candidate; |
| 1143 | CV* cand_cv; |
| 1144 | |
| 1145 | assert(linear_sv); |
| 1146 | curstash = gv_stashsv(linear_sv, FALSE); |
| 1147 | |
| 1148 | if (!curstash) { |
| 1149 | if (ckWARN(WARN_SYNTAX)) |
| 1150 | Perl_warner(aTHX_ packWARN(WARN_SYNTAX), "Can't locate package %"SVf" for @%s::ISA", |
| 1151 | (void*)linear_sv, hvname); |
| 1152 | continue; |
| 1153 | } |
| 1154 | |
| 1155 | assert(curstash); |
| 1156 | |
| 1157 | gvp = (GV**)hv_fetch(curstash, subname, subname_len, 0); |
| 1158 | if (!gvp) continue; |
| 1159 | |
| 1160 | candidate = *gvp; |
| 1161 | assert(candidate); |
| 1162 | |
| 1163 | if (SvTYPE(candidate) != SVt_PVGV) |
| 1164 | gv_init(candidate, curstash, subname, subname_len, TRUE); |
| 1165 | |
| 1166 | /* Notably, we only look for real entries, not method cache |
| 1167 | entries, because in C3 the method cache of a parent is not |
| 1168 | valid for the child */ |
| 1169 | if (SvTYPE(candidate) == SVt_PVGV && (cand_cv = GvCV(candidate)) && !GvCVGEN(candidate)) { |
| 1170 | SvREFCNT_inc_simple_void_NN((SV*)cand_cv); |
| 1171 | (void)hv_store_ent(nmcache, newSVsv(sv), (SV*)cand_cv, 0); |
| 1172 | mXPUSHs(newRV_inc((SV*)cand_cv)); |
| 1173 | XSRETURN(1); |
| 1174 | } |
| 1175 | } |
| 1176 | } |
| 1177 | |
| 1178 | (void)hv_store_ent(nmcache, newSVsv(sv), &PL_sv_undef, 0); |
| 1179 | if(throw_nomethod) |
| 1180 | Perl_croak(aTHX_ "No next::method '%s' found for %s", subname, hvname); |
| 1181 | XSRETURN_EMPTY; |
| 1182 | } |
| 1183 | |
| 1184 | /* |
| 1185 | * Local variables: |
| 1186 | * c-indentation-style: bsd |
| 1187 | * c-basic-offset: 4 |
| 1188 | * indent-tabs-mode: t |
| 1189 | * End: |
| 1190 | * |
| 1191 | * ex: set ts=8 sts=4 sw=4 noet: |
| 1192 | */ |