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e1a479c5 |
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 | /* |
cac98860 |
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 | /* |
e1a479c5 |
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 | #include "perl.h" |
25 | |
26 | struct mro_meta* |
27 | Perl_mro_meta_init(pTHX_ HV* stash) |
28 | { |
9fe4aecf |
29 | struct mro_meta* newmeta; |
e1a479c5 |
30 | |
31 | assert(stash); |
32 | assert(HvAUX(stash)); |
33 | assert(!(HvAUX(stash)->xhv_mro_meta)); |
183086be |
34 | Newxz(newmeta, 1, struct mro_meta); |
9fe4aecf |
35 | HvAUX(stash)->xhv_mro_meta = newmeta; |
36 | newmeta->sub_generation = 1; |
e1a479c5 |
37 | |
38 | /* Manually flag UNIVERSAL as being universal. |
39 | This happens early in perl booting (when universal.c |
40 | does the newXS calls for UNIVERSAL::*), and infects |
41 | other packages as they are added to UNIVERSAL's MRO |
42 | */ |
43 | if(HvNAMELEN_get(stash) == 9 |
44 | && strEQ(HEK_KEY(HvAUX(stash)->xhv_name), "UNIVERSAL")) { |
45 | HvMROMETA(stash)->is_universal = 1; |
46 | } |
47 | |
48 | return newmeta; |
49 | } |
50 | |
51 | #if defined(USE_ITHREADS) |
52 | |
53 | /* for sv_dup on new threads */ |
54 | struct mro_meta* |
55 | Perl_mro_meta_dup(pTHX_ struct mro_meta* smeta, CLONE_PARAMS* param) |
56 | { |
e1a479c5 |
57 | struct mro_meta* newmeta; |
58 | |
59 | assert(smeta); |
60 | |
33e12d9d |
61 | Newx(newmeta, 1, struct mro_meta); |
62 | Copy(smeta, newmeta, 1, struct mro_meta); |
63 | |
64 | if (newmeta->mro_linear_dfs) |
65 | newmeta->mro_linear_dfs |
66 | = (AV*) SvREFCNT_inc(sv_dup((SV*)newmeta->mro_linear_dfs, param)); |
67 | if (newmeta->mro_linear_c3) |
68 | newmeta->mro_linear_c3 |
69 | = (AV*) SvREFCNT_inc(sv_dup((SV*)newmeta->mro_linear_c3, param)); |
70 | if (newmeta->mro_isarev) |
71 | newmeta->mro_isarev |
72 | = (HV*) SvREFCNT_inc(sv_dup((SV*)newmeta->mro_isarev, param)); |
73 | if (newmeta->mro_nextmethod) |
74 | newmeta->mro_nextmethod |
75 | = (HV*) SvREFCNT_inc(sv_dup((SV*)newmeta->mro_nextmethod, param)); |
e1a479c5 |
76 | |
77 | return newmeta; |
78 | } |
79 | |
80 | #endif /* USE_ITHREADS */ |
81 | |
82 | /* |
83 | =for apidoc mro_get_linear_isa_dfs |
84 | |
85 | Returns the Depth-First Search linearization of @ISA |
86 | the given stash. The return value is a read-only AV*. |
87 | C<level> should be 0 (it is used internally in this |
88 | function's recursion). |
89 | |
1c908217 |
90 | You are responsible for C<SvREFCNT_inc()> on the |
91 | return value if you plan to store it anywhere |
92 | semi-permanently (otherwise it might be deleted |
93 | out from under you the next time the cache is |
94 | invalidated). |
95 | |
e1a479c5 |
96 | =cut |
97 | */ |
98 | AV* |
99 | Perl_mro_get_linear_isa_dfs(pTHX_ HV *stash, I32 level) |
100 | { |
101 | AV* retval; |
102 | GV** gvp; |
103 | GV* gv; |
104 | AV* av; |
e1a479c5 |
105 | const char* stashname; |
106 | struct mro_meta* meta; |
107 | |
108 | assert(stash); |
109 | assert(HvAUX(stash)); |
110 | |
111 | stashname = HvNAME_get(stash); |
112 | if (!stashname) |
113 | Perl_croak(aTHX_ |
114 | "Can't linearize anonymous symbol table"); |
115 | |
116 | if (level > 100) |
117 | Perl_croak(aTHX_ "Recursive inheritance detected in package '%s'", |
118 | stashname); |
119 | |
120 | meta = HvMROMETA(stash); |
1c908217 |
121 | |
122 | /* return cache if valid */ |
e1a479c5 |
123 | if((retval = meta->mro_linear_dfs)) { |
e1a479c5 |
124 | return retval; |
125 | } |
126 | |
127 | /* not in cache, make a new one */ |
1c908217 |
128 | |
e1a479c5 |
129 | retval = newAV(); |
130 | av_push(retval, newSVpv(stashname, 0)); /* add ourselves at the top */ |
131 | |
1c908217 |
132 | /* fetch our @ISA */ |
e1a479c5 |
133 | gvp = (GV**)hv_fetchs(stash, "ISA", FALSE); |
134 | av = (gvp && (gv = *gvp) && isGV_with_GP(gv)) ? GvAV(gv) : NULL; |
135 | |
640da897 |
136 | if(av && AvFILLp(av) >= 0) { |
1c908217 |
137 | |
138 | /* "stored" is used to keep track of all of the classnames |
139 | we have added to the MRO so far, so we can do a quick |
140 | exists check and avoid adding duplicate classnames to |
141 | the MRO as we go. */ |
142 | |
e1a479c5 |
143 | HV* stored = (HV*)sv_2mortal((SV*)newHV()); |
ffd8da72 |
144 | SV **svp = AvARRAY(av); |
145 | I32 items = AvFILLp(av) + 1; |
1c908217 |
146 | |
147 | /* foreach(@ISA) */ |
e1a479c5 |
148 | while (items--) { |
149 | SV* const sv = *svp++; |
150 | HV* const basestash = gv_stashsv(sv, 0); |
ffd8da72 |
151 | SV *const *subrv_p; |
152 | I32 subrv_items; |
e1a479c5 |
153 | |
154 | if (!basestash) { |
1c908217 |
155 | /* if no stash exists for this @ISA member, |
156 | simply add it to the MRO and move on */ |
ffd8da72 |
157 | subrv_p = &sv; |
158 | subrv_items = 1; |
e1a479c5 |
159 | } |
160 | else { |
1c908217 |
161 | /* otherwise, recurse into ourselves for the MRO |
162 | of this @ISA member, and append their MRO to ours */ |
ffd8da72 |
163 | const AV *const subrv |
164 | = mro_get_linear_isa_dfs(basestash, level + 1); |
165 | |
166 | subrv_p = AvARRAY(subrv); |
167 | subrv_items = AvFILLp(subrv) + 1; |
168 | } |
169 | while(subrv_items--) { |
170 | SV *const subsv = *subrv_p++; |
171 | if(!hv_exists_ent(stored, subsv, 0)) { |
ffd8da72 |
172 | hv_store_ent(stored, subsv, &PL_sv_undef, 0); |
25270bc0 |
173 | av_push(retval, newSVsv(subsv)); |
ffd8da72 |
174 | } |
e1a479c5 |
175 | } |
176 | } |
177 | } |
178 | |
1c908217 |
179 | /* we don't want anyone modifying the cache entry but us, |
180 | and we do so by replacing it completely */ |
e1a479c5 |
181 | SvREADONLY_on(retval); |
1c908217 |
182 | |
e1a479c5 |
183 | meta->mro_linear_dfs = retval; |
184 | return retval; |
185 | } |
186 | |
187 | /* |
188 | =for apidoc mro_get_linear_isa_c3 |
189 | |
190 | Returns the C3 linearization of @ISA |
191 | the given stash. The return value is a read-only AV*. |
192 | C<level> should be 0 (it is used internally in this |
193 | function's recursion). |
194 | |
1c908217 |
195 | You are responsible for C<SvREFCNT_inc()> on the |
196 | return value if you plan to store it anywhere |
197 | semi-permanently (otherwise it might be deleted |
198 | out from under you the next time the cache is |
199 | invalidated). |
200 | |
e1a479c5 |
201 | =cut |
202 | */ |
203 | |
204 | AV* |
205 | Perl_mro_get_linear_isa_c3(pTHX_ HV* stash, I32 level) |
206 | { |
207 | AV* retval; |
208 | GV** gvp; |
209 | GV* gv; |
210 | AV* isa; |
211 | const char* stashname; |
212 | STRLEN stashname_len; |
213 | struct mro_meta* meta; |
214 | |
215 | assert(stash); |
216 | assert(HvAUX(stash)); |
217 | |
218 | stashname = HvNAME_get(stash); |
219 | stashname_len = HvNAMELEN_get(stash); |
220 | if (!stashname) |
221 | Perl_croak(aTHX_ |
222 | "Can't linearize anonymous symbol table"); |
223 | |
224 | if (level > 100) |
225 | Perl_croak(aTHX_ "Recursive inheritance detected in package '%s'", |
226 | stashname); |
227 | |
228 | meta = HvMROMETA(stash); |
1c908217 |
229 | |
230 | /* return cache if valid */ |
e1a479c5 |
231 | if((retval = meta->mro_linear_c3)) { |
e1a479c5 |
232 | return retval; |
233 | } |
234 | |
235 | /* not in cache, make a new one */ |
236 | |
237 | retval = newAV(); |
238 | av_push(retval, newSVpvn(stashname, stashname_len)); /* us first */ |
239 | |
240 | gvp = (GV**)hv_fetchs(stash, "ISA", FALSE); |
241 | isa = (gvp && (gv = *gvp) && isGV_with_GP(gv)) ? GvAV(gv) : NULL; |
242 | |
1c908217 |
243 | /* For a better idea how the rest of this works, see the much clearer |
244 | pure perl version in Algorithm::C3 0.01: |
245 | http://search.cpan.org/src/STEVAN/Algorithm-C3-0.01/lib/Algorithm/C3.pm |
246 | (later versions go about it differently than this code for speed reasons) |
247 | */ |
8638e433 |
248 | |
e1a479c5 |
249 | if(isa && AvFILLp(isa) >= 0) { |
250 | SV** seqs_ptr; |
251 | I32 seqs_items; |
252 | HV* tails = (HV*)sv_2mortal((SV*)newHV()); |
253 | AV* seqs = (AV*)sv_2mortal((SV*)newAV()); |
8638e433 |
254 | I32* heads; |
255 | |
256 | /* This builds @seqs, which is an array of arrays. |
257 | The members of @seqs are the MROs of |
258 | the members of @ISA, followed by @ISA itself. |
259 | */ |
e1a479c5 |
260 | I32 items = AvFILLp(isa) + 1; |
261 | SV** isa_ptr = AvARRAY(isa); |
262 | while(items--) { |
263 | AV* isa_lin; |
264 | SV* isa_item = *isa_ptr++; |
265 | HV* isa_item_stash = gv_stashsv(isa_item, 0); |
266 | if(!isa_item_stash) { |
8638e433 |
267 | /* if no stash, make a temporary fake MRO |
268 | containing just itself */ |
269 | isa_lin = (AV*)sv_2mortal((SV*)newAV()); |
e1a479c5 |
270 | av_push(isa_lin, newSVsv(isa_item)); |
271 | } |
272 | else { |
273 | isa_lin = mro_get_linear_isa_c3(isa_item_stash, level + 1); /* recursion */ |
274 | } |
8638e433 |
275 | av_push(seqs, (SV*)isa_lin); |
e1a479c5 |
276 | } |
8638e433 |
277 | av_push(seqs, (SV*)isa); |
278 | |
279 | /* This builds "heads", which as an array of integer array |
280 | indices, one per seq, which point at the virtual "head" |
281 | of the seq (initially zero) */ |
282 | Newxz(heads, AvFILLp(seqs)+1, I32); |
283 | |
284 | /* This builds %tails, which has one key for every class |
285 | mentioned in the tail of any sequence in @seqs (tail meaning |
286 | everything after the first class, the "head"). The value |
287 | is how many times this key appears in the tails of @seqs. |
288 | */ |
e1a479c5 |
289 | seqs_ptr = AvARRAY(seqs); |
290 | seqs_items = AvFILLp(seqs) + 1; |
291 | while(seqs_items--) { |
292 | AV* seq = (AV*)*seqs_ptr++; |
293 | I32 seq_items = AvFILLp(seq); |
294 | if(seq_items > 0) { |
295 | SV** seq_ptr = AvARRAY(seq) + 1; |
296 | while(seq_items--) { |
297 | SV* seqitem = *seq_ptr++; |
298 | HE* he = hv_fetch_ent(tails, seqitem, 0, 0); |
299 | if(!he) { |
300 | hv_store_ent(tails, seqitem, newSViv(1), 0); |
301 | } |
302 | else { |
303 | SV* val = HeVAL(he); |
304 | sv_inc(val); |
305 | } |
306 | } |
307 | } |
308 | } |
309 | |
8638e433 |
310 | /* This loop won't terminate until we either finish building |
311 | the MRO, or get an exception. */ |
e1a479c5 |
312 | while(1) { |
313 | SV* seqhead = NULL; |
314 | SV* cand = NULL; |
315 | SV* winner = NULL; |
316 | SV* val; |
317 | HE* tail_entry; |
318 | AV* seq; |
8638e433 |
319 | int s; |
320 | |
321 | /* "foreach $seq (@seqs)" */ |
e1a479c5 |
322 | SV** avptr = AvARRAY(seqs); |
8638e433 |
323 | for(s = 0; s <= AvFILLp(seqs); s++) { |
e1a479c5 |
324 | SV** svp; |
8638e433 |
325 | seq = (AV*)(avptr[s]); |
326 | if(!seq) continue; /* skip empty seqs */ |
327 | svp = av_fetch(seq, heads[s], 0); |
328 | seqhead = *svp; /* seqhead = head of this seq */ |
e1a479c5 |
329 | if(!winner) { |
8638e433 |
330 | /* if we haven't found a winner for this round yet, |
331 | and this seqhead is not in tails (or the count |
332 | for it in tails has dropped to zero), then this |
333 | seqhead is our new winner, and is added to the |
334 | final MRO immediately */ |
e1a479c5 |
335 | cand = seqhead; |
336 | if((tail_entry = hv_fetch_ent(tails, cand, 0, 0)) |
337 | && (val = HeVAL(tail_entry)) |
25270bc0 |
338 | && (SvIVX(val) > 0)) |
e1a479c5 |
339 | continue; |
340 | winner = newSVsv(cand); |
341 | av_push(retval, winner); |
8638e433 |
342 | /* note however that even when we find a winner, |
343 | we continue looping over @seqs to do housekeeping */ |
e1a479c5 |
344 | } |
345 | if(!sv_cmp(seqhead, winner)) { |
8638e433 |
346 | /* Once we have a winner (including the iteration |
347 | where we first found him), inc the head ptr |
348 | for any seq which had the winner as a head, |
349 | NULL out any seq which is now empty, |
350 | and adjust tails for consistency */ |
351 | |
352 | int new_head = ++heads[s]; |
353 | if(new_head > AvFILLp(seq)) { |
354 | avptr[s] = NULL; |
355 | } |
356 | else { |
357 | /* Because we know this new seqhead used to be |
358 | a tail, we can assume it is in tails and has |
359 | a positive value, which we need to dec */ |
360 | svp = av_fetch(seq, new_head, 0); |
361 | seqhead = *svp; |
362 | tail_entry = hv_fetch_ent(tails, seqhead, 0, 0); |
363 | val = HeVAL(tail_entry); |
364 | sv_dec(val); |
365 | } |
e1a479c5 |
366 | } |
367 | } |
8638e433 |
368 | |
369 | /* if we found no candidates, we are done building the MRO. |
370 | !cand means no seqs have any entries left to check */ |
371 | if(!cand) { |
372 | Safefree(heads); |
373 | break; |
374 | } |
375 | |
376 | /* If we had candidates, but nobody won, then the @ISA |
377 | hierarchy is not C3-incompatible */ |
e1a479c5 |
378 | if(!winner) { |
8638e433 |
379 | /* we have to do some cleanup before we croak */ |
380 | SV** svp = AvARRAY(seqs); |
381 | items = AvFILLp(seqs) + 1; |
382 | while (items--) |
383 | *svp++ = NULL; |
384 | |
e1a479c5 |
385 | SvREFCNT_dec(retval); |
8638e433 |
386 | Safefree(heads); |
387 | |
e1a479c5 |
388 | Perl_croak(aTHX_ "Inconsistent hierarchy during C3 merge of class '%s': " |
389 | "merging failed on parent '%"SVf"'", stashname, SVfARG(cand)); |
390 | } |
391 | } |
392 | } |
393 | |
1c908217 |
394 | /* we don't want anyone modifying the cache entry but us, |
395 | and we do so by replacing it completely */ |
e1a479c5 |
396 | SvREADONLY_on(retval); |
1c908217 |
397 | |
e1a479c5 |
398 | meta->mro_linear_c3 = retval; |
399 | return retval; |
400 | } |
401 | |
402 | /* |
403 | =for apidoc mro_get_linear_isa |
404 | |
405 | Returns either C<mro_get_linear_isa_c3> or |
406 | C<mro_get_linear_isa_dfs> for the given stash, |
407 | dependant upon which MRO is in effect |
408 | for that stash. The return value is a |
409 | read-only AV*. |
410 | |
1c908217 |
411 | You are responsible for C<SvREFCNT_inc()> on the |
412 | return value if you plan to store it anywhere |
413 | semi-permanently (otherwise it might be deleted |
414 | out from under you the next time the cache is |
415 | invalidated). |
416 | |
e1a479c5 |
417 | =cut |
418 | */ |
419 | AV* |
420 | Perl_mro_get_linear_isa(pTHX_ HV *stash) |
421 | { |
422 | struct mro_meta* meta; |
423 | assert(stash); |
424 | assert(HvAUX(stash)); |
425 | |
426 | meta = HvMROMETA(stash); |
427 | if(meta->mro_which == MRO_DFS) { |
428 | return mro_get_linear_isa_dfs(stash, 0); |
429 | } else if(meta->mro_which == MRO_C3) { |
430 | return mro_get_linear_isa_c3(stash, 0); |
431 | } else { |
14f97ce6 |
432 | Perl_croak(aTHX_ "panic: invalid MRO!"); |
e1a479c5 |
433 | } |
7caa839c |
434 | return NULL; /* NOT REACHED */ |
e1a479c5 |
435 | } |
436 | |
437 | /* |
438 | =for apidoc mro_isa_changed_in |
439 | |
1c908217 |
440 | Takes the necessary steps (cache invalidations, mostly) |
e1a479c5 |
441 | when the @ISA of the given package has changed. Invoked |
442 | by the C<setisa> magic, should not need to invoke directly. |
443 | |
444 | =cut |
445 | */ |
446 | void |
447 | Perl_mro_isa_changed_in(pTHX_ HV* stash) |
448 | { |
449 | dVAR; |
450 | HV* isarev; |
451 | AV* linear_mro; |
452 | HE* iter; |
453 | SV** svp; |
454 | I32 items; |
455 | struct mro_meta* meta; |
456 | char* stashname; |
457 | |
458 | stashname = HvNAME_get(stash); |
459 | |
460 | /* wipe out the cached linearizations for this stash */ |
461 | meta = HvMROMETA(stash); |
462 | SvREFCNT_dec((SV*)meta->mro_linear_dfs); |
463 | SvREFCNT_dec((SV*)meta->mro_linear_c3); |
464 | meta->mro_linear_dfs = NULL; |
465 | meta->mro_linear_c3 = NULL; |
466 | |
467 | /* Wipe the global method cache if this package |
468 | is UNIVERSAL or one of its parents */ |
469 | if(meta->is_universal) |
470 | PL_sub_generation++; |
471 | |
472 | /* Wipe the local method cache otherwise */ |
473 | else |
474 | meta->sub_generation++; |
475 | |
476 | /* wipe next::method cache too */ |
477 | if(meta->mro_nextmethod) hv_clear(meta->mro_nextmethod); |
478 | |
479 | /* Iterate the isarev (classes that are our children), |
480 | wiping out their linearization and method caches */ |
481 | if((isarev = meta->mro_isarev)) { |
482 | hv_iterinit(isarev); |
483 | while((iter = hv_iternext(isarev))) { |
484 | SV* revkey = hv_iterkeysv(iter); |
485 | HV* revstash = gv_stashsv(revkey, 0); |
486 | struct mro_meta* revmeta = HvMROMETA(revstash); |
487 | SvREFCNT_dec((SV*)revmeta->mro_linear_dfs); |
488 | SvREFCNT_dec((SV*)revmeta->mro_linear_c3); |
489 | revmeta->mro_linear_dfs = NULL; |
490 | revmeta->mro_linear_c3 = NULL; |
491 | if(!meta->is_universal) |
492 | revmeta->sub_generation++; |
493 | if(revmeta->mro_nextmethod) |
494 | hv_clear(revmeta->mro_nextmethod); |
495 | } |
496 | } |
497 | |
1c908217 |
498 | /* Now iterate our MRO (parents), and do a few things: |
499 | 1) instantiate with the "fake" flag if they don't exist |
500 | 2) flag them as universal if we are universal |
501 | 3) Add everything from our isarev to their isarev |
502 | */ |
503 | |
504 | /* We're starting at the 2nd element, skipping ourselves here */ |
e1a479c5 |
505 | linear_mro = mro_get_linear_isa(stash); |
506 | svp = AvARRAY(linear_mro) + 1; |
507 | items = AvFILLp(linear_mro); |
1c908217 |
508 | |
e1a479c5 |
509 | while (items--) { |
510 | SV* const sv = *svp++; |
511 | struct mro_meta* mrometa; |
512 | HV* mroisarev; |
513 | |
514 | HV* mrostash = gv_stashsv(sv, 0); |
515 | if(!mrostash) { |
516 | mrostash = gv_stashsv(sv, GV_ADD); |
517 | /* |
518 | We created the package on the fly, so |
519 | that we could store isarev information. |
520 | This flag lets gv_fetchmeth know about it, |
521 | so that it can still generate the very useful |
522 | "Can't locate package Foo for @Bar::ISA" warning. |
523 | */ |
524 | HvMROMETA(mrostash)->fake = 1; |
525 | } |
526 | |
527 | mrometa = HvMROMETA(mrostash); |
528 | mroisarev = mrometa->mro_isarev; |
529 | |
530 | /* is_universal is viral */ |
531 | if(meta->is_universal) |
532 | mrometa->is_universal = 1; |
533 | |
534 | if(!mroisarev) |
535 | mroisarev = mrometa->mro_isarev = newHV(); |
536 | |
25270bc0 |
537 | /* This hash only ever contains PL_sv_yes. Storing it over itself is |
538 | almost as cheap as calling hv_exists, so on aggregate we expect to |
539 | save time by not making two calls to the common HV code for the |
540 | case where it doesn't exist. */ |
541 | |
542 | hv_store(mroisarev, stashname, strlen(stashname), &PL_sv_yes, 0); |
e1a479c5 |
543 | |
544 | if(isarev) { |
545 | hv_iterinit(isarev); |
546 | while((iter = hv_iternext(isarev))) { |
547 | SV* revkey = hv_iterkeysv(iter); |
25270bc0 |
548 | hv_store_ent(mroisarev, revkey, &PL_sv_yes, 0); |
e1a479c5 |
549 | } |
550 | } |
551 | } |
552 | } |
553 | |
554 | /* |
555 | =for apidoc mro_method_changed_in |
556 | |
557 | Like C<mro_isa_changed_in>, but invalidates method |
558 | caching on any child classes of the given stash, so |
559 | that they might notice the changes in this one. |
560 | |
561 | Ideally, all instances of C<PL_sub_generation++> in |
562 | the perl source should be replaced by calls to this. |
563 | Some already are, but some are more difficult to |
564 | replace. |
565 | |
566 | Perl has always had problems with method caches |
567 | getting out of sync when one directly manipulates |
568 | stashes via things like C<%{Foo::} = %{Bar::}> or |
569 | C<${Foo::}{bar} = ...> or the equivalent. If |
570 | you do this in core or XS code, call this afterwards |
571 | on the destination stash to get things back in sync. |
572 | |
573 | If you're doing such a thing from pure perl, use |
574 | C<mro::method_changed_in(classname)>, which |
575 | just calls this. |
576 | |
577 | =cut |
578 | */ |
579 | void |
580 | Perl_mro_method_changed_in(pTHX_ HV *stash) |
581 | { |
582 | struct mro_meta* meta = HvMROMETA(stash); |
583 | HV* isarev; |
584 | HE* iter; |
585 | |
586 | /* If stash is UNIVERSAL, or one of UNIVERSAL's parents, |
587 | invalidate all method caches globally */ |
588 | if(meta->is_universal) { |
589 | PL_sub_generation++; |
590 | return; |
591 | } |
592 | |
593 | /* else, invalidate the method caches of all child classes, |
594 | but not itself */ |
595 | if((isarev = meta->mro_isarev)) { |
596 | hv_iterinit(isarev); |
597 | while((iter = hv_iternext(isarev))) { |
598 | SV* revkey = hv_iterkeysv(iter); |
599 | HV* revstash = gv_stashsv(revkey, 0); |
600 | struct mro_meta* mrometa = HvMROMETA(revstash); |
601 | mrometa->sub_generation++; |
602 | if(mrometa->mro_nextmethod) |
603 | hv_clear(mrometa->mro_nextmethod); |
604 | } |
605 | } |
606 | } |
607 | |
608 | /* These two are static helpers for next::method and friends, |
609 | and re-implement a bunch of the code from pp_caller() in |
610 | a more efficient manner for this particular usage. |
611 | */ |
612 | |
613 | STATIC I32 |
614 | __dopoptosub_at(const PERL_CONTEXT *cxstk, I32 startingblock) { |
615 | I32 i; |
616 | for (i = startingblock; i >= 0; i--) { |
617 | if(CxTYPE((PERL_CONTEXT*)(&cxstk[i])) == CXt_SUB) return i; |
618 | } |
619 | return i; |
620 | } |
621 | |
622 | STATIC SV* |
623 | __nextcan(pTHX_ SV* self, I32 throw_nomethod) |
624 | { |
625 | register I32 cxix; |
626 | register const PERL_CONTEXT *ccstack = cxstack; |
627 | const PERL_SI *top_si = PL_curstackinfo; |
628 | HV* selfstash; |
629 | GV* cvgv; |
630 | SV *stashname; |
631 | const char *fq_subname; |
632 | const char *subname; |
633 | STRLEN fq_subname_len; |
634 | STRLEN stashname_len; |
635 | STRLEN subname_len; |
636 | SV* sv; |
637 | GV** gvp; |
638 | AV* linear_av; |
639 | SV** linear_svp; |
640 | SV* linear_sv; |
641 | HV* curstash; |
642 | GV* candidate = NULL; |
643 | CV* cand_cv = NULL; |
644 | const char *hvname; |
645 | I32 items; |
646 | struct mro_meta* selfmeta; |
647 | HV* nmcache; |
648 | HE* cache_entry; |
649 | |
650 | if(sv_isobject(self)) |
651 | selfstash = SvSTASH(SvRV(self)); |
652 | else |
653 | selfstash = gv_stashsv(self, 0); |
654 | |
655 | assert(selfstash); |
656 | |
657 | hvname = HvNAME_get(selfstash); |
658 | if (!hvname) |
659 | Perl_croak(aTHX_ "Can't use anonymous symbol table for method lookup"); |
660 | |
661 | cxix = __dopoptosub_at(cxstack, cxstack_ix); |
662 | |
663 | /* This block finds the contextually-enclosing fully-qualified subname, |
664 | much like looking at (caller($i))[3] until you find a real sub that |
665 | isn't ANON, etc */ |
666 | for (;;) { |
667 | /* we may be in a higher stacklevel, so dig down deeper */ |
668 | while (cxix < 0) { |
669 | if(top_si->si_type == PERLSI_MAIN) |
670 | Perl_croak(aTHX_ "next::method/next::can/maybe::next::method must be used in method context"); |
671 | top_si = top_si->si_prev; |
672 | ccstack = top_si->si_cxstack; |
673 | cxix = __dopoptosub_at(ccstack, top_si->si_cxix); |
674 | } |
675 | |
676 | if(CxTYPE((PERL_CONTEXT*)(&ccstack[cxix])) != CXt_SUB |
677 | || (PL_DBsub && GvCV(PL_DBsub) && ccstack[cxix].blk_sub.cv == GvCV(PL_DBsub))) { |
678 | cxix = __dopoptosub_at(ccstack, cxix - 1); |
679 | continue; |
680 | } |
681 | |
682 | { |
683 | const I32 dbcxix = __dopoptosub_at(ccstack, cxix - 1); |
684 | if (PL_DBsub && GvCV(PL_DBsub) && dbcxix >= 0 && ccstack[dbcxix].blk_sub.cv == GvCV(PL_DBsub)) { |
685 | if(CxTYPE((PERL_CONTEXT*)(&ccstack[dbcxix])) != CXt_SUB) { |
686 | cxix = dbcxix; |
687 | continue; |
688 | } |
689 | } |
690 | } |
691 | |
692 | cvgv = CvGV(ccstack[cxix].blk_sub.cv); |
693 | |
694 | if(!isGV(cvgv)) { |
695 | cxix = __dopoptosub_at(ccstack, cxix - 1); |
696 | continue; |
697 | } |
698 | |
699 | /* we found a real sub here */ |
700 | sv = sv_2mortal(newSV(0)); |
701 | |
702 | gv_efullname3(sv, cvgv, NULL); |
703 | |
704 | fq_subname = SvPVX(sv); |
705 | fq_subname_len = SvCUR(sv); |
706 | |
707 | subname = strrchr(fq_subname, ':'); |
708 | if(!subname) |
709 | Perl_croak(aTHX_ "next::method/next::can/maybe::next::method cannot find enclosing method"); |
710 | |
711 | subname++; |
712 | subname_len = fq_subname_len - (subname - fq_subname); |
713 | if(subname_len == 8 && strEQ(subname, "__ANON__")) { |
714 | cxix = __dopoptosub_at(ccstack, cxix - 1); |
715 | continue; |
716 | } |
717 | break; |
718 | } |
719 | |
720 | /* If we made it to here, we found our context */ |
721 | |
1c908217 |
722 | /* Initialize the next::method cache for this stash |
723 | if necessary */ |
e1a479c5 |
724 | selfmeta = HvMROMETA(selfstash); |
725 | if(!(nmcache = selfmeta->mro_nextmethod)) { |
726 | nmcache = selfmeta->mro_nextmethod = newHV(); |
727 | } |
728 | |
1c908217 |
729 | /* Use the cached coderef if it exists */ |
640da897 |
730 | else if((cache_entry = hv_fetch_ent(nmcache, sv, 0, 0))) { |
e1a479c5 |
731 | SV* val = HeVAL(cache_entry); |
732 | if(val == &PL_sv_undef) { |
733 | if(throw_nomethod) |
734 | Perl_croak(aTHX_ "No next::method '%s' found for %s", subname, hvname); |
735 | } |
736 | return val; |
737 | } |
738 | |
739 | /* beyond here is just for cache misses, so perf isn't as critical */ |
740 | |
741 | stashname_len = subname - fq_subname - 2; |
742 | stashname = sv_2mortal(newSVpvn(fq_subname, stashname_len)); |
743 | |
744 | linear_av = mro_get_linear_isa_c3(selfstash, 0); /* has ourselves at the top of the list */ |
745 | |
746 | linear_svp = AvARRAY(linear_av); |
747 | items = AvFILLp(linear_av) + 1; |
748 | |
1c908217 |
749 | /* Walk down our MRO, skipping everything up |
750 | to the contextually enclosing class */ |
e1a479c5 |
751 | while (items--) { |
752 | linear_sv = *linear_svp++; |
753 | assert(linear_sv); |
754 | if(sv_eq(linear_sv, stashname)) |
755 | break; |
756 | } |
757 | |
1c908217 |
758 | /* Now search the remainder of the MRO for the |
759 | same method name as the contextually enclosing |
760 | method */ |
e1a479c5 |
761 | if(items > 0) { |
762 | while (items--) { |
763 | linear_sv = *linear_svp++; |
764 | assert(linear_sv); |
765 | curstash = gv_stashsv(linear_sv, FALSE); |
766 | |
767 | if (!curstash || (HvMROMETA(curstash)->fake && !HvFILL(curstash))) { |
b0c482e3 |
768 | if (ckWARN(WARN_SYNTAX)) |
769 | Perl_warner(aTHX_ packWARN(WARN_SYNTAX), "Can't locate package %"SVf" for @%s::ISA", |
e1a479c5 |
770 | (void*)linear_sv, hvname); |
771 | continue; |
772 | } |
773 | |
774 | assert(curstash); |
775 | |
776 | gvp = (GV**)hv_fetch(curstash, subname, subname_len, 0); |
777 | if (!gvp) continue; |
778 | |
779 | candidate = *gvp; |
780 | assert(candidate); |
781 | |
782 | if (SvTYPE(candidate) != SVt_PVGV) |
783 | gv_init(candidate, curstash, subname, subname_len, TRUE); |
1c908217 |
784 | |
785 | /* Notably, we only look for real entries, not method cache |
786 | entries, because in C3 the method cache of a parent is not |
787 | valid for the child */ |
e1a479c5 |
788 | if (SvTYPE(candidate) == SVt_PVGV && (cand_cv = GvCV(candidate)) && !GvCVGEN(candidate)) { |
789 | SvREFCNT_inc_simple_void_NN((SV*)cand_cv); |
790 | hv_store_ent(nmcache, newSVsv(sv), (SV*)cand_cv, 0); |
791 | return (SV*)cand_cv; |
792 | } |
793 | } |
794 | } |
795 | |
796 | hv_store_ent(nmcache, newSVsv(sv), &PL_sv_undef, 0); |
797 | if(throw_nomethod) |
798 | Perl_croak(aTHX_ "No next::method '%s' found for %s", subname, hvname); |
799 | return &PL_sv_undef; |
800 | } |
801 | |
802 | #include "XSUB.h" |
803 | |
804 | XS(XS_mro_get_linear_isa); |
805 | XS(XS_mro_set_mro); |
806 | XS(XS_mro_get_mro); |
807 | XS(XS_mro_get_isarev); |
808 | XS(XS_mro_is_universal); |
c5860d66 |
809 | XS(XS_mro_get_global_sub_gen); |
810 | XS(XS_mro_invalidate_method_caches); |
e1a479c5 |
811 | XS(XS_mro_get_sub_generation); |
812 | XS(XS_mro_method_changed_in); |
813 | XS(XS_next_can); |
814 | XS(XS_next_method); |
815 | XS(XS_maybe_next_method); |
816 | |
817 | void |
818 | Perl_boot_core_mro(pTHX) |
819 | { |
820 | dVAR; |
821 | static const char file[] = __FILE__; |
822 | |
823 | newXSproto("mro::get_linear_isa", XS_mro_get_linear_isa, file, "$;$"); |
824 | newXSproto("mro::set_mro", XS_mro_set_mro, file, "$$"); |
825 | newXSproto("mro::get_mro", XS_mro_get_mro, file, "$"); |
826 | newXSproto("mro::get_isarev", XS_mro_get_isarev, file, "$"); |
827 | newXSproto("mro::is_universal", XS_mro_is_universal, file, "$"); |
c5860d66 |
828 | newXSproto("mro::get_global_sub_generation", XS_mro_get_global_sub_gen, file, ""); |
829 | newXSproto("mro::invalidate_all_method_caches", XS_mro_invalidate_method_caches, file, ""); |
e1a479c5 |
830 | newXSproto("mro::get_sub_generation", XS_mro_get_sub_generation, file, "$"); |
831 | newXSproto("mro::method_changed_in", XS_mro_method_changed_in, file, "$"); |
832 | newXS("next::can", XS_next_can, file); |
833 | newXS("next::method", XS_next_method, file); |
834 | newXS("maybe::next::method", XS_maybe_next_method, file); |
835 | } |
836 | |
837 | XS(XS_mro_get_linear_isa) { |
838 | dVAR; |
839 | dXSARGS; |
840 | AV* RETVAL; |
841 | HV* class_stash; |
842 | SV* classname; |
843 | |
844 | PERL_UNUSED_ARG(cv); |
845 | |
846 | if(items < 1 || items > 2) |
847 | Perl_croak(aTHX_ "Usage: mro::get_linear_isa(classname [, type ])"); |
848 | |
849 | classname = ST(0); |
850 | class_stash = gv_stashsv(classname, 0); |
851 | if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname)); |
852 | |
853 | if(items > 1) { |
854 | char* which = SvPV_nolen(ST(1)); |
855 | if(strEQ(which, "dfs")) |
856 | RETVAL = mro_get_linear_isa_dfs(class_stash, 0); |
857 | else if(strEQ(which, "c3")) |
858 | RETVAL = mro_get_linear_isa_c3(class_stash, 0); |
859 | else |
860 | Perl_croak(aTHX_ "Invalid mro name: '%s'", which); |
861 | } |
862 | else { |
863 | RETVAL = mro_get_linear_isa(class_stash); |
864 | } |
865 | |
866 | ST(0) = newRV_inc((SV*)RETVAL); |
867 | sv_2mortal(ST(0)); |
868 | XSRETURN(1); |
869 | } |
870 | |
871 | XS(XS_mro_set_mro) |
872 | { |
873 | dVAR; |
874 | dXSARGS; |
875 | SV* classname; |
876 | char* whichstr; |
877 | mro_alg which; |
878 | HV* class_stash; |
879 | struct mro_meta* meta; |
880 | |
881 | PERL_UNUSED_ARG(cv); |
882 | |
883 | if (items != 2) |
884 | Perl_croak(aTHX_ "Usage: mro::set_mro(classname, type)"); |
885 | |
886 | classname = ST(0); |
887 | whichstr = SvPV_nolen(ST(1)); |
888 | class_stash = gv_stashsv(classname, GV_ADD); |
889 | if(!class_stash) Perl_croak(aTHX_ "Cannot create class: '%"SVf"'!", SVfARG(classname)); |
890 | meta = HvMROMETA(class_stash); |
891 | |
892 | if(strEQ(whichstr, "dfs")) |
893 | which = MRO_DFS; |
894 | else if(strEQ(whichstr, "c3")) |
895 | which = MRO_C3; |
896 | else |
897 | Perl_croak(aTHX_ "Invalid mro name: '%s'", whichstr); |
898 | |
899 | if(meta->mro_which != which) { |
900 | meta->mro_which = which; |
901 | /* Only affects local method cache, not |
902 | even child classes */ |
903 | meta->sub_generation++; |
904 | if(meta->mro_nextmethod) |
905 | hv_clear(meta->mro_nextmethod); |
906 | } |
907 | |
908 | XSRETURN_EMPTY; |
909 | } |
910 | |
911 | |
912 | XS(XS_mro_get_mro) |
913 | { |
914 | dVAR; |
915 | dXSARGS; |
916 | SV* classname; |
917 | HV* class_stash; |
918 | struct mro_meta* meta; |
919 | |
920 | PERL_UNUSED_ARG(cv); |
921 | |
922 | if (items != 1) |
923 | Perl_croak(aTHX_ "Usage: mro::get_mro(classname)"); |
924 | |
925 | classname = ST(0); |
926 | class_stash = gv_stashsv(classname, 0); |
927 | if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname)); |
928 | meta = HvMROMETA(class_stash); |
929 | |
930 | if(meta->mro_which == MRO_DFS) |
931 | ST(0) = sv_2mortal(newSVpvn("dfs", 3)); |
932 | else |
933 | ST(0) = sv_2mortal(newSVpvn("c3", 2)); |
934 | |
935 | XSRETURN(1); |
936 | } |
937 | |
938 | XS(XS_mro_get_isarev) |
939 | { |
940 | dVAR; |
941 | dXSARGS; |
942 | SV* classname; |
943 | HV* class_stash; |
944 | HV* isarev; |
945 | |
946 | PERL_UNUSED_ARG(cv); |
947 | |
948 | if (items != 1) |
949 | Perl_croak(aTHX_ "Usage: mro::get_isarev(classname)"); |
950 | |
951 | classname = ST(0); |
952 | |
953 | class_stash = gv_stashsv(classname, 0); |
954 | if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname)); |
955 | |
956 | SP -= items; |
957 | |
958 | if((isarev = HvMROMETA(class_stash)->mro_isarev)) { |
959 | HE* iter; |
960 | hv_iterinit(isarev); |
961 | while((iter = hv_iternext(isarev))) |
962 | XPUSHs(hv_iterkeysv(iter)); |
963 | } |
964 | |
965 | PUTBACK; |
966 | return; |
967 | } |
968 | |
969 | XS(XS_mro_is_universal) |
970 | { |
971 | dVAR; |
972 | dXSARGS; |
973 | SV* classname; |
974 | HV* class_stash; |
975 | |
976 | PERL_UNUSED_ARG(cv); |
977 | |
978 | if (items != 1) |
979 | Perl_croak(aTHX_ "Usage: mro::get_mro(classname)"); |
980 | |
981 | classname = ST(0); |
982 | class_stash = gv_stashsv(classname, 0); |
983 | if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname)); |
984 | |
9edc5bb8 |
985 | if (HvMROMETA(class_stash)->is_universal) |
986 | XSRETURN_YES; |
987 | else |
988 | XSRETURN_NO; |
e1a479c5 |
989 | } |
990 | |
c5860d66 |
991 | XS(XS_mro_get_global_sub_gen) |
e1a479c5 |
992 | { |
993 | dVAR; |
994 | dXSARGS; |
995 | |
996 | PERL_UNUSED_ARG(cv); |
997 | |
998 | if (items != 0) |
999 | Perl_croak(aTHX_ "Usage: mro::get_global_sub_generation()"); |
1000 | |
1001 | ST(0) = sv_2mortal(newSViv(PL_sub_generation)); |
1002 | XSRETURN(1); |
1003 | } |
1004 | |
c5860d66 |
1005 | XS(XS_mro_invalidate_method_caches) |
e1a479c5 |
1006 | { |
1007 | dVAR; |
1008 | dXSARGS; |
1009 | |
1010 | PERL_UNUSED_ARG(cv); |
1011 | |
1012 | if (items != 0) |
1013 | Perl_croak(aTHX_ "Usage: mro::invalidate_all_method_caches()"); |
1014 | |
1015 | PL_sub_generation++; |
1016 | |
1017 | XSRETURN_EMPTY; |
1018 | } |
1019 | |
1020 | XS(XS_mro_get_sub_generation) |
1021 | { |
1022 | dVAR; |
1023 | dXSARGS; |
1024 | SV* classname; |
1025 | HV* class_stash; |
1026 | |
1027 | PERL_UNUSED_ARG(cv); |
1028 | |
1029 | if(items != 1) |
1030 | Perl_croak(aTHX_ "Usage: mro::get_sub_generation(classname)"); |
1031 | |
1032 | classname = ST(0); |
1033 | class_stash = gv_stashsv(classname, 0); |
1034 | if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname)); |
1035 | |
1036 | ST(0) = sv_2mortal(newSViv(HvMROMETA(class_stash)->sub_generation)); |
1037 | XSRETURN(1); |
1038 | } |
1039 | |
1040 | XS(XS_mro_method_changed_in) |
1041 | { |
1042 | dVAR; |
1043 | dXSARGS; |
1044 | SV* classname; |
1045 | HV* class_stash; |
1046 | |
1047 | PERL_UNUSED_ARG(cv); |
1048 | |
1049 | if(items != 1) |
1050 | Perl_croak(aTHX_ "Usage: mro::method_changed_in(classname)"); |
1051 | |
1052 | classname = ST(0); |
1053 | |
1054 | class_stash = gv_stashsv(classname, 0); |
1055 | if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname)); |
1056 | |
1057 | mro_method_changed_in(class_stash); |
1058 | |
1059 | XSRETURN_EMPTY; |
1060 | } |
1061 | |
1062 | XS(XS_next_can) |
1063 | { |
1064 | dVAR; |
1065 | dXSARGS; |
1066 | SV* self = ST(0); |
1067 | SV* methcv = __nextcan(aTHX_ self, 0); |
1068 | |
1069 | PERL_UNUSED_ARG(cv); |
1070 | PERL_UNUSED_VAR(items); |
1071 | |
1072 | if(methcv == &PL_sv_undef) { |
1073 | ST(0) = &PL_sv_undef; |
1074 | } |
1075 | else { |
1076 | ST(0) = sv_2mortal(newRV_inc(methcv)); |
1077 | } |
1078 | |
1079 | XSRETURN(1); |
1080 | } |
1081 | |
1082 | XS(XS_next_method) |
1083 | { |
1084 | dMARK; |
1085 | dAX; |
1086 | SV* self = ST(0); |
1087 | SV* methcv = __nextcan(aTHX_ self, 1); |
1088 | |
1089 | PERL_UNUSED_ARG(cv); |
1090 | |
1091 | PL_markstack_ptr++; |
1092 | call_sv(methcv, GIMME_V); |
1093 | } |
1094 | |
1095 | XS(XS_maybe_next_method) |
1096 | { |
1097 | dMARK; |
1098 | dAX; |
1099 | SV* self = ST(0); |
1100 | SV* methcv = __nextcan(aTHX_ self, 0); |
1101 | |
1102 | PERL_UNUSED_ARG(cv); |
1103 | |
1104 | if(methcv == &PL_sv_undef) { |
1105 | ST(0) = &PL_sv_undef; |
1106 | XSRETURN(1); |
1107 | } |
1108 | |
1109 | PL_markstack_ptr++; |
1110 | call_sv(methcv, GIMME_V); |
1111 | } |
1112 | |
1113 | /* |
1114 | * Local variables: |
1115 | * c-indentation-style: bsd |
1116 | * c-basic-offset: 4 |
1117 | * indent-tabs-mode: t |
1118 | * End: |
1119 | * |
1120 | * ex: set ts=8 sts=4 sw=4 noet: |
1121 | */ |