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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; |
dd69841b |
36 | newmeta->cache_gen = 1; |
e1a479c5 |
37 | |
38 | return newmeta; |
39 | } |
40 | |
41 | #if defined(USE_ITHREADS) |
42 | |
43 | /* for sv_dup on new threads */ |
44 | struct mro_meta* |
45 | Perl_mro_meta_dup(pTHX_ struct mro_meta* smeta, CLONE_PARAMS* param) |
46 | { |
e1a479c5 |
47 | struct mro_meta* newmeta; |
48 | |
49 | assert(smeta); |
50 | |
33e12d9d |
51 | Newx(newmeta, 1, struct mro_meta); |
52 | Copy(smeta, newmeta, 1, struct mro_meta); |
53 | |
54 | if (newmeta->mro_linear_dfs) |
55 | newmeta->mro_linear_dfs |
56 | = (AV*) SvREFCNT_inc(sv_dup((SV*)newmeta->mro_linear_dfs, param)); |
57 | if (newmeta->mro_linear_c3) |
58 | newmeta->mro_linear_c3 |
59 | = (AV*) SvREFCNT_inc(sv_dup((SV*)newmeta->mro_linear_c3, param)); |
33e12d9d |
60 | if (newmeta->mro_nextmethod) |
61 | newmeta->mro_nextmethod |
62 | = (HV*) SvREFCNT_inc(sv_dup((SV*)newmeta->mro_nextmethod, param)); |
e1a479c5 |
63 | |
64 | return newmeta; |
65 | } |
66 | |
67 | #endif /* USE_ITHREADS */ |
68 | |
69 | /* |
70 | =for apidoc mro_get_linear_isa_dfs |
71 | |
72 | Returns the Depth-First Search linearization of @ISA |
73 | the given stash. The return value is a read-only AV*. |
74 | C<level> should be 0 (it is used internally in this |
75 | function's recursion). |
76 | |
1c908217 |
77 | You are responsible for C<SvREFCNT_inc()> on the |
78 | return value if you plan to store it anywhere |
79 | semi-permanently (otherwise it might be deleted |
80 | out from under you the next time the cache is |
81 | invalidated). |
82 | |
e1a479c5 |
83 | =cut |
84 | */ |
85 | AV* |
86 | Perl_mro_get_linear_isa_dfs(pTHX_ HV *stash, I32 level) |
87 | { |
88 | AV* retval; |
89 | GV** gvp; |
90 | GV* gv; |
91 | AV* av; |
e1a479c5 |
92 | const char* stashname; |
93 | struct mro_meta* meta; |
94 | |
95 | assert(stash); |
96 | assert(HvAUX(stash)); |
97 | |
98 | stashname = HvNAME_get(stash); |
99 | if (!stashname) |
100 | Perl_croak(aTHX_ |
101 | "Can't linearize anonymous symbol table"); |
102 | |
103 | if (level > 100) |
104 | Perl_croak(aTHX_ "Recursive inheritance detected in package '%s'", |
105 | stashname); |
106 | |
107 | meta = HvMROMETA(stash); |
1c908217 |
108 | |
109 | /* return cache if valid */ |
e1a479c5 |
110 | if((retval = meta->mro_linear_dfs)) { |
e1a479c5 |
111 | return retval; |
112 | } |
113 | |
114 | /* not in cache, make a new one */ |
1c908217 |
115 | |
e1a479c5 |
116 | retval = newAV(); |
117 | av_push(retval, newSVpv(stashname, 0)); /* add ourselves at the top */ |
118 | |
1c908217 |
119 | /* fetch our @ISA */ |
e1a479c5 |
120 | gvp = (GV**)hv_fetchs(stash, "ISA", FALSE); |
121 | av = (gvp && (gv = *gvp) && isGV_with_GP(gv)) ? GvAV(gv) : NULL; |
122 | |
640da897 |
123 | if(av && AvFILLp(av) >= 0) { |
1c908217 |
124 | |
125 | /* "stored" is used to keep track of all of the classnames |
126 | we have added to the MRO so far, so we can do a quick |
127 | exists check and avoid adding duplicate classnames to |
128 | the MRO as we go. */ |
129 | |
e1a479c5 |
130 | HV* stored = (HV*)sv_2mortal((SV*)newHV()); |
ffd8da72 |
131 | SV **svp = AvARRAY(av); |
132 | I32 items = AvFILLp(av) + 1; |
1c908217 |
133 | |
134 | /* foreach(@ISA) */ |
e1a479c5 |
135 | while (items--) { |
136 | SV* const sv = *svp++; |
137 | HV* const basestash = gv_stashsv(sv, 0); |
ffd8da72 |
138 | SV *const *subrv_p; |
139 | I32 subrv_items; |
e1a479c5 |
140 | |
141 | if (!basestash) { |
1c908217 |
142 | /* if no stash exists for this @ISA member, |
143 | simply add it to the MRO and move on */ |
ffd8da72 |
144 | subrv_p = &sv; |
145 | subrv_items = 1; |
e1a479c5 |
146 | } |
147 | else { |
1c908217 |
148 | /* otherwise, recurse into ourselves for the MRO |
149 | of this @ISA member, and append their MRO to ours */ |
ffd8da72 |
150 | const AV *const subrv |
151 | = mro_get_linear_isa_dfs(basestash, level + 1); |
152 | |
153 | subrv_p = AvARRAY(subrv); |
154 | subrv_items = AvFILLp(subrv) + 1; |
155 | } |
156 | while(subrv_items--) { |
157 | SV *const subsv = *subrv_p++; |
158 | if(!hv_exists_ent(stored, subsv, 0)) { |
ffd8da72 |
159 | hv_store_ent(stored, subsv, &PL_sv_undef, 0); |
25270bc0 |
160 | av_push(retval, newSVsv(subsv)); |
ffd8da72 |
161 | } |
e1a479c5 |
162 | } |
163 | } |
164 | } |
165 | |
1c908217 |
166 | /* we don't want anyone modifying the cache entry but us, |
167 | and we do so by replacing it completely */ |
e1a479c5 |
168 | SvREADONLY_on(retval); |
1c908217 |
169 | |
e1a479c5 |
170 | meta->mro_linear_dfs = retval; |
171 | return retval; |
172 | } |
173 | |
174 | /* |
175 | =for apidoc mro_get_linear_isa_c3 |
176 | |
177 | Returns the C3 linearization of @ISA |
178 | the given stash. The return value is a read-only AV*. |
179 | C<level> should be 0 (it is used internally in this |
180 | function's recursion). |
181 | |
1c908217 |
182 | You are responsible for C<SvREFCNT_inc()> on the |
183 | return value if you plan to store it anywhere |
184 | semi-permanently (otherwise it might be deleted |
185 | out from under you the next time the cache is |
186 | invalidated). |
187 | |
e1a479c5 |
188 | =cut |
189 | */ |
190 | |
191 | AV* |
192 | Perl_mro_get_linear_isa_c3(pTHX_ HV* stash, I32 level) |
193 | { |
194 | AV* retval; |
195 | GV** gvp; |
196 | GV* gv; |
197 | AV* isa; |
198 | const char* stashname; |
199 | STRLEN stashname_len; |
200 | struct mro_meta* meta; |
201 | |
202 | assert(stash); |
203 | assert(HvAUX(stash)); |
204 | |
205 | stashname = HvNAME_get(stash); |
206 | stashname_len = HvNAMELEN_get(stash); |
207 | if (!stashname) |
208 | Perl_croak(aTHX_ |
209 | "Can't linearize anonymous symbol table"); |
210 | |
211 | if (level > 100) |
212 | Perl_croak(aTHX_ "Recursive inheritance detected in package '%s'", |
213 | stashname); |
214 | |
215 | meta = HvMROMETA(stash); |
1c908217 |
216 | |
217 | /* return cache if valid */ |
e1a479c5 |
218 | if((retval = meta->mro_linear_c3)) { |
e1a479c5 |
219 | return retval; |
220 | } |
221 | |
222 | /* not in cache, make a new one */ |
223 | |
224 | retval = newAV(); |
225 | av_push(retval, newSVpvn(stashname, stashname_len)); /* us first */ |
226 | |
227 | gvp = (GV**)hv_fetchs(stash, "ISA", FALSE); |
228 | isa = (gvp && (gv = *gvp) && isGV_with_GP(gv)) ? GvAV(gv) : NULL; |
229 | |
1c908217 |
230 | /* For a better idea how the rest of this works, see the much clearer |
231 | pure perl version in Algorithm::C3 0.01: |
232 | http://search.cpan.org/src/STEVAN/Algorithm-C3-0.01/lib/Algorithm/C3.pm |
233 | (later versions go about it differently than this code for speed reasons) |
234 | */ |
8638e433 |
235 | |
e1a479c5 |
236 | if(isa && AvFILLp(isa) >= 0) { |
237 | SV** seqs_ptr; |
238 | I32 seqs_items; |
239 | HV* tails = (HV*)sv_2mortal((SV*)newHV()); |
240 | AV* seqs = (AV*)sv_2mortal((SV*)newAV()); |
8638e433 |
241 | I32* heads; |
242 | |
243 | /* This builds @seqs, which is an array of arrays. |
244 | The members of @seqs are the MROs of |
245 | the members of @ISA, followed by @ISA itself. |
246 | */ |
e1a479c5 |
247 | I32 items = AvFILLp(isa) + 1; |
248 | SV** isa_ptr = AvARRAY(isa); |
249 | while(items--) { |
250 | AV* isa_lin; |
251 | SV* isa_item = *isa_ptr++; |
252 | HV* isa_item_stash = gv_stashsv(isa_item, 0); |
253 | if(!isa_item_stash) { |
8638e433 |
254 | /* if no stash, make a temporary fake MRO |
255 | containing just itself */ |
256 | isa_lin = (AV*)sv_2mortal((SV*)newAV()); |
e1a479c5 |
257 | av_push(isa_lin, newSVsv(isa_item)); |
258 | } |
259 | else { |
260 | isa_lin = mro_get_linear_isa_c3(isa_item_stash, level + 1); /* recursion */ |
261 | } |
8638e433 |
262 | av_push(seqs, (SV*)isa_lin); |
e1a479c5 |
263 | } |
8638e433 |
264 | av_push(seqs, (SV*)isa); |
265 | |
266 | /* This builds "heads", which as an array of integer array |
267 | indices, one per seq, which point at the virtual "head" |
268 | of the seq (initially zero) */ |
269 | Newxz(heads, AvFILLp(seqs)+1, I32); |
270 | |
271 | /* This builds %tails, which has one key for every class |
272 | mentioned in the tail of any sequence in @seqs (tail meaning |
273 | everything after the first class, the "head"). The value |
274 | is how many times this key appears in the tails of @seqs. |
275 | */ |
e1a479c5 |
276 | seqs_ptr = AvARRAY(seqs); |
277 | seqs_items = AvFILLp(seqs) + 1; |
278 | while(seqs_items--) { |
279 | AV* seq = (AV*)*seqs_ptr++; |
280 | I32 seq_items = AvFILLp(seq); |
281 | if(seq_items > 0) { |
282 | SV** seq_ptr = AvARRAY(seq) + 1; |
283 | while(seq_items--) { |
284 | SV* seqitem = *seq_ptr++; |
285 | HE* he = hv_fetch_ent(tails, seqitem, 0, 0); |
286 | if(!he) { |
287 | hv_store_ent(tails, seqitem, newSViv(1), 0); |
288 | } |
289 | else { |
290 | SV* val = HeVAL(he); |
291 | sv_inc(val); |
292 | } |
293 | } |
294 | } |
295 | } |
296 | |
8638e433 |
297 | /* This loop won't terminate until we either finish building |
298 | the MRO, or get an exception. */ |
e1a479c5 |
299 | while(1) { |
300 | SV* seqhead = NULL; |
301 | SV* cand = NULL; |
302 | SV* winner = NULL; |
303 | SV* val; |
304 | HE* tail_entry; |
305 | AV* seq; |
8638e433 |
306 | int s; |
307 | |
308 | /* "foreach $seq (@seqs)" */ |
e1a479c5 |
309 | SV** avptr = AvARRAY(seqs); |
8638e433 |
310 | for(s = 0; s <= AvFILLp(seqs); s++) { |
e1a479c5 |
311 | SV** svp; |
8638e433 |
312 | seq = (AV*)(avptr[s]); |
313 | if(!seq) continue; /* skip empty seqs */ |
314 | svp = av_fetch(seq, heads[s], 0); |
315 | seqhead = *svp; /* seqhead = head of this seq */ |
e1a479c5 |
316 | if(!winner) { |
8638e433 |
317 | /* if we haven't found a winner for this round yet, |
318 | and this seqhead is not in tails (or the count |
319 | for it in tails has dropped to zero), then this |
320 | seqhead is our new winner, and is added to the |
321 | final MRO immediately */ |
e1a479c5 |
322 | cand = seqhead; |
323 | if((tail_entry = hv_fetch_ent(tails, cand, 0, 0)) |
324 | && (val = HeVAL(tail_entry)) |
25270bc0 |
325 | && (SvIVX(val) > 0)) |
e1a479c5 |
326 | continue; |
327 | winner = newSVsv(cand); |
328 | av_push(retval, winner); |
8638e433 |
329 | /* note however that even when we find a winner, |
330 | we continue looping over @seqs to do housekeeping */ |
e1a479c5 |
331 | } |
332 | if(!sv_cmp(seqhead, winner)) { |
8638e433 |
333 | /* Once we have a winner (including the iteration |
334 | where we first found him), inc the head ptr |
335 | for any seq which had the winner as a head, |
336 | NULL out any seq which is now empty, |
337 | and adjust tails for consistency */ |
338 | |
339 | int new_head = ++heads[s]; |
340 | if(new_head > AvFILLp(seq)) { |
341 | avptr[s] = NULL; |
342 | } |
343 | else { |
344 | /* Because we know this new seqhead used to be |
345 | a tail, we can assume it is in tails and has |
346 | a positive value, which we need to dec */ |
347 | svp = av_fetch(seq, new_head, 0); |
348 | seqhead = *svp; |
349 | tail_entry = hv_fetch_ent(tails, seqhead, 0, 0); |
350 | val = HeVAL(tail_entry); |
351 | sv_dec(val); |
352 | } |
e1a479c5 |
353 | } |
354 | } |
8638e433 |
355 | |
356 | /* if we found no candidates, we are done building the MRO. |
357 | !cand means no seqs have any entries left to check */ |
358 | if(!cand) { |
359 | Safefree(heads); |
360 | break; |
361 | } |
362 | |
363 | /* If we had candidates, but nobody won, then the @ISA |
364 | hierarchy is not C3-incompatible */ |
e1a479c5 |
365 | if(!winner) { |
8638e433 |
366 | /* we have to do some cleanup before we croak */ |
367 | SV** svp = AvARRAY(seqs); |
368 | items = AvFILLp(seqs) + 1; |
369 | while (items--) |
370 | *svp++ = NULL; |
371 | |
e1a479c5 |
372 | SvREFCNT_dec(retval); |
8638e433 |
373 | Safefree(heads); |
374 | |
e1a479c5 |
375 | Perl_croak(aTHX_ "Inconsistent hierarchy during C3 merge of class '%s': " |
376 | "merging failed on parent '%"SVf"'", stashname, SVfARG(cand)); |
377 | } |
378 | } |
379 | } |
380 | |
1c908217 |
381 | /* we don't want anyone modifying the cache entry but us, |
382 | and we do so by replacing it completely */ |
e1a479c5 |
383 | SvREADONLY_on(retval); |
1c908217 |
384 | |
e1a479c5 |
385 | meta->mro_linear_c3 = retval; |
386 | return retval; |
387 | } |
388 | |
389 | /* |
390 | =for apidoc mro_get_linear_isa |
391 | |
392 | Returns either C<mro_get_linear_isa_c3> or |
393 | C<mro_get_linear_isa_dfs> for the given stash, |
394 | dependant upon which MRO is in effect |
395 | for that stash. The return value is a |
396 | read-only AV*. |
397 | |
1c908217 |
398 | You are responsible for C<SvREFCNT_inc()> on the |
399 | return value if you plan to store it anywhere |
400 | semi-permanently (otherwise it might be deleted |
401 | out from under you the next time the cache is |
402 | invalidated). |
403 | |
e1a479c5 |
404 | =cut |
405 | */ |
406 | AV* |
407 | Perl_mro_get_linear_isa(pTHX_ HV *stash) |
408 | { |
409 | struct mro_meta* meta; |
410 | assert(stash); |
411 | assert(HvAUX(stash)); |
412 | |
413 | meta = HvMROMETA(stash); |
414 | if(meta->mro_which == MRO_DFS) { |
415 | return mro_get_linear_isa_dfs(stash, 0); |
416 | } else if(meta->mro_which == MRO_C3) { |
417 | return mro_get_linear_isa_c3(stash, 0); |
418 | } else { |
14f97ce6 |
419 | Perl_croak(aTHX_ "panic: invalid MRO!"); |
e1a479c5 |
420 | } |
7caa839c |
421 | return NULL; /* NOT REACHED */ |
e1a479c5 |
422 | } |
423 | |
424 | /* |
425 | =for apidoc mro_isa_changed_in |
426 | |
1c908217 |
427 | Takes the necessary steps (cache invalidations, mostly) |
e1a479c5 |
428 | when the @ISA of the given package has changed. Invoked |
429 | by the C<setisa> magic, should not need to invoke directly. |
430 | |
431 | =cut |
432 | */ |
433 | void |
434 | Perl_mro_isa_changed_in(pTHX_ HV* stash) |
435 | { |
436 | dVAR; |
437 | HV* isarev; |
438 | AV* linear_mro; |
439 | HE* iter; |
440 | SV** svp; |
441 | I32 items; |
442 | struct mro_meta* meta; |
443 | char* stashname; |
dd69841b |
444 | STRLEN stashname_len; |
445 | bool is_universal = FALSE; |
e1a479c5 |
446 | |
447 | stashname = HvNAME_get(stash); |
dd69841b |
448 | stashname_len = HvNAMELEN_get(stash); |
e1a479c5 |
449 | |
450 | /* wipe out the cached linearizations for this stash */ |
451 | meta = HvMROMETA(stash); |
452 | SvREFCNT_dec((SV*)meta->mro_linear_dfs); |
453 | SvREFCNT_dec((SV*)meta->mro_linear_c3); |
454 | meta->mro_linear_dfs = NULL; |
455 | meta->mro_linear_c3 = NULL; |
456 | |
457 | /* Wipe the global method cache if this package |
458 | is UNIVERSAL or one of its parents */ |
dd69841b |
459 | |
460 | svp = hv_fetch(PL_isarev, stashname, stashname_len, 0); |
461 | isarev = svp ? (HV*)*svp : NULL; |
462 | |
463 | if((stashname_len == 9 && strEQ(stashname, "UNIVERSAL")) |
464 | || (isarev && hv_exists(isarev, "UNIVERSAL", 9))) { |
e1a479c5 |
465 | PL_sub_generation++; |
dd69841b |
466 | is_universal = TRUE; |
467 | } |
e1a479c5 |
468 | |
469 | /* Wipe the local method cache otherwise */ |
470 | else |
dd69841b |
471 | meta->cache_gen++; |
e1a479c5 |
472 | |
473 | /* wipe next::method cache too */ |
474 | if(meta->mro_nextmethod) hv_clear(meta->mro_nextmethod); |
475 | |
476 | /* Iterate the isarev (classes that are our children), |
477 | wiping out their linearization and method caches */ |
dd69841b |
478 | if(isarev) { |
e1a479c5 |
479 | hv_iterinit(isarev); |
480 | while((iter = hv_iternext(isarev))) { |
481 | SV* revkey = hv_iterkeysv(iter); |
482 | HV* revstash = gv_stashsv(revkey, 0); |
bc2cbbac |
483 | struct mro_meta* revmeta; |
484 | |
485 | if(!revstash) continue; |
486 | revmeta = HvMROMETA(revstash); |
e1a479c5 |
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; |
dd69841b |
491 | if(!is_universal) |
492 | revmeta->cache_gen++; |
e1a479c5 |
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--) { |
dd69841b |
510 | HE* he; |
e1a479c5 |
511 | SV* const sv = *svp++; |
e1a479c5 |
512 | HV* mroisarev; |
513 | |
dd69841b |
514 | he = hv_fetch_ent(PL_isarev, sv, 0, 0); |
515 | if(!he) { |
516 | he = hv_store_ent(PL_isarev, sv, (SV*)newHV(), 0); |
e1a479c5 |
517 | } |
dd69841b |
518 | mroisarev = (HV*)HeVAL(he); |
e1a479c5 |
519 | |
25270bc0 |
520 | /* This hash only ever contains PL_sv_yes. Storing it over itself is |
521 | almost as cheap as calling hv_exists, so on aggregate we expect to |
522 | save time by not making two calls to the common HV code for the |
523 | case where it doesn't exist. */ |
524 | |
dd69841b |
525 | hv_store(mroisarev, stashname, stashname_len, &PL_sv_yes, 0); |
e1a479c5 |
526 | |
527 | if(isarev) { |
528 | hv_iterinit(isarev); |
529 | while((iter = hv_iternext(isarev))) { |
dd69841b |
530 | I32 revkeylen; |
531 | char* revkey = hv_iterkey(iter, &revkeylen); |
532 | hv_store(mroisarev, revkey, revkeylen, &PL_sv_yes, 0); |
e1a479c5 |
533 | } |
534 | } |
535 | } |
536 | } |
537 | |
538 | /* |
539 | =for apidoc mro_method_changed_in |
540 | |
47c9dd14 |
541 | Invalidates method caching on any child classes |
542 | of the given stash, so that they might notice |
543 | the changes in this one. |
e1a479c5 |
544 | |
545 | Ideally, all instances of C<PL_sub_generation++> in |
dd69841b |
546 | perl source outside of C<mro.c> should be |
547 | replaced by calls to this. |
548 | |
549 | Perl automatically handles most of the common |
550 | ways a method might be redefined. However, there |
551 | are a few ways you could change a method in a stash |
552 | without the cache code noticing, in which case you |
553 | need to call this method afterwards: |
e1a479c5 |
554 | |
dd69841b |
555 | 1) Directly manipulating the stash HV entries from |
556 | XS code. |
e1a479c5 |
557 | |
dd69841b |
558 | 2) Assigning a reference to a readonly scalar |
559 | constant into a stash entry in order to create |
560 | a constant subroutine (like constant.pm |
561 | does). |
562 | |
563 | This same method is available from pure perl |
564 | via, C<mro::method_changed_in(classname)>. |
e1a479c5 |
565 | |
566 | =cut |
567 | */ |
568 | void |
569 | Perl_mro_method_changed_in(pTHX_ HV *stash) |
570 | { |
dd69841b |
571 | SV** svp; |
e1a479c5 |
572 | HV* isarev; |
573 | HE* iter; |
dd69841b |
574 | char* stashname; |
575 | STRLEN stashname_len; |
576 | |
577 | stashname = HvNAME_get(stash); |
578 | stashname_len = HvNAMELEN_get(stash); |
579 | |
580 | svp = hv_fetch(PL_isarev, stashname, stashname_len, 0); |
581 | isarev = svp ? (HV*)*svp : NULL; |
e1a479c5 |
582 | |
583 | /* If stash is UNIVERSAL, or one of UNIVERSAL's parents, |
584 | invalidate all method caches globally */ |
dd69841b |
585 | if((stashname_len == 9 && strEQ(stashname, "UNIVERSAL")) |
586 | || (isarev && hv_exists(isarev, "UNIVERSAL", 9))) { |
e1a479c5 |
587 | PL_sub_generation++; |
588 | return; |
589 | } |
590 | |
591 | /* else, invalidate the method caches of all child classes, |
592 | but not itself */ |
dd69841b |
593 | if(isarev) { |
e1a479c5 |
594 | hv_iterinit(isarev); |
595 | while((iter = hv_iternext(isarev))) { |
596 | SV* revkey = hv_iterkeysv(iter); |
597 | HV* revstash = gv_stashsv(revkey, 0); |
bc2cbbac |
598 | struct mro_meta* mrometa; |
599 | |
600 | if(!revstash) continue; |
601 | mrometa = HvMROMETA(revstash); |
dd69841b |
602 | mrometa->cache_gen++; |
e1a479c5 |
603 | if(mrometa->mro_nextmethod) |
604 | hv_clear(mrometa->mro_nextmethod); |
605 | } |
606 | } |
607 | } |
608 | |
609 | /* These two are static helpers for next::method and friends, |
610 | and re-implement a bunch of the code from pp_caller() in |
611 | a more efficient manner for this particular usage. |
612 | */ |
613 | |
614 | STATIC I32 |
615 | __dopoptosub_at(const PERL_CONTEXT *cxstk, I32 startingblock) { |
616 | I32 i; |
617 | for (i = startingblock; i >= 0; i--) { |
618 | if(CxTYPE((PERL_CONTEXT*)(&cxstk[i])) == CXt_SUB) return i; |
619 | } |
620 | return i; |
621 | } |
622 | |
623 | STATIC SV* |
624 | __nextcan(pTHX_ SV* self, I32 throw_nomethod) |
625 | { |
626 | register I32 cxix; |
627 | register const PERL_CONTEXT *ccstack = cxstack; |
628 | const PERL_SI *top_si = PL_curstackinfo; |
629 | HV* selfstash; |
630 | GV* cvgv; |
631 | SV *stashname; |
632 | const char *fq_subname; |
633 | const char *subname; |
634 | STRLEN fq_subname_len; |
635 | STRLEN stashname_len; |
636 | STRLEN subname_len; |
637 | SV* sv; |
638 | GV** gvp; |
639 | AV* linear_av; |
640 | SV** linear_svp; |
641 | SV* linear_sv; |
642 | HV* curstash; |
643 | GV* candidate = NULL; |
644 | CV* cand_cv = NULL; |
645 | const char *hvname; |
646 | I32 items; |
647 | struct mro_meta* selfmeta; |
648 | HV* nmcache; |
649 | HE* cache_entry; |
650 | |
651 | if(sv_isobject(self)) |
652 | selfstash = SvSTASH(SvRV(self)); |
653 | else |
654 | selfstash = gv_stashsv(self, 0); |
655 | |
656 | assert(selfstash); |
657 | |
658 | hvname = HvNAME_get(selfstash); |
659 | if (!hvname) |
660 | Perl_croak(aTHX_ "Can't use anonymous symbol table for method lookup"); |
661 | |
662 | cxix = __dopoptosub_at(cxstack, cxstack_ix); |
663 | |
664 | /* This block finds the contextually-enclosing fully-qualified subname, |
665 | much like looking at (caller($i))[3] until you find a real sub that |
666 | isn't ANON, etc */ |
667 | for (;;) { |
668 | /* we may be in a higher stacklevel, so dig down deeper */ |
669 | while (cxix < 0) { |
670 | if(top_si->si_type == PERLSI_MAIN) |
671 | Perl_croak(aTHX_ "next::method/next::can/maybe::next::method must be used in method context"); |
672 | top_si = top_si->si_prev; |
673 | ccstack = top_si->si_cxstack; |
674 | cxix = __dopoptosub_at(ccstack, top_si->si_cxix); |
675 | } |
676 | |
677 | if(CxTYPE((PERL_CONTEXT*)(&ccstack[cxix])) != CXt_SUB |
678 | || (PL_DBsub && GvCV(PL_DBsub) && ccstack[cxix].blk_sub.cv == GvCV(PL_DBsub))) { |
679 | cxix = __dopoptosub_at(ccstack, cxix - 1); |
680 | continue; |
681 | } |
682 | |
683 | { |
684 | const I32 dbcxix = __dopoptosub_at(ccstack, cxix - 1); |
685 | if (PL_DBsub && GvCV(PL_DBsub) && dbcxix >= 0 && ccstack[dbcxix].blk_sub.cv == GvCV(PL_DBsub)) { |
686 | if(CxTYPE((PERL_CONTEXT*)(&ccstack[dbcxix])) != CXt_SUB) { |
687 | cxix = dbcxix; |
688 | continue; |
689 | } |
690 | } |
691 | } |
692 | |
693 | cvgv = CvGV(ccstack[cxix].blk_sub.cv); |
694 | |
695 | if(!isGV(cvgv)) { |
696 | cxix = __dopoptosub_at(ccstack, cxix - 1); |
697 | continue; |
698 | } |
699 | |
700 | /* we found a real sub here */ |
701 | sv = sv_2mortal(newSV(0)); |
702 | |
703 | gv_efullname3(sv, cvgv, NULL); |
704 | |
705 | fq_subname = SvPVX(sv); |
706 | fq_subname_len = SvCUR(sv); |
707 | |
708 | subname = strrchr(fq_subname, ':'); |
709 | if(!subname) |
710 | Perl_croak(aTHX_ "next::method/next::can/maybe::next::method cannot find enclosing method"); |
711 | |
712 | subname++; |
713 | subname_len = fq_subname_len - (subname - fq_subname); |
714 | if(subname_len == 8 && strEQ(subname, "__ANON__")) { |
715 | cxix = __dopoptosub_at(ccstack, cxix - 1); |
716 | continue; |
717 | } |
718 | break; |
719 | } |
720 | |
721 | /* If we made it to here, we found our context */ |
722 | |
1c908217 |
723 | /* Initialize the next::method cache for this stash |
724 | if necessary */ |
e1a479c5 |
725 | selfmeta = HvMROMETA(selfstash); |
726 | if(!(nmcache = selfmeta->mro_nextmethod)) { |
727 | nmcache = selfmeta->mro_nextmethod = newHV(); |
728 | } |
729 | |
1c908217 |
730 | /* Use the cached coderef if it exists */ |
640da897 |
731 | else if((cache_entry = hv_fetch_ent(nmcache, sv, 0, 0))) { |
e1a479c5 |
732 | SV* val = HeVAL(cache_entry); |
733 | if(val == &PL_sv_undef) { |
734 | if(throw_nomethod) |
735 | Perl_croak(aTHX_ "No next::method '%s' found for %s", subname, hvname); |
736 | } |
737 | return val; |
738 | } |
739 | |
740 | /* beyond here is just for cache misses, so perf isn't as critical */ |
741 | |
742 | stashname_len = subname - fq_subname - 2; |
743 | stashname = sv_2mortal(newSVpvn(fq_subname, stashname_len)); |
744 | |
745 | linear_av = mro_get_linear_isa_c3(selfstash, 0); /* has ourselves at the top of the list */ |
746 | |
747 | linear_svp = AvARRAY(linear_av); |
748 | items = AvFILLp(linear_av) + 1; |
749 | |
1c908217 |
750 | /* Walk down our MRO, skipping everything up |
751 | to the contextually enclosing class */ |
e1a479c5 |
752 | while (items--) { |
753 | linear_sv = *linear_svp++; |
754 | assert(linear_sv); |
755 | if(sv_eq(linear_sv, stashname)) |
756 | break; |
757 | } |
758 | |
1c908217 |
759 | /* Now search the remainder of the MRO for the |
760 | same method name as the contextually enclosing |
761 | method */ |
e1a479c5 |
762 | if(items > 0) { |
763 | while (items--) { |
764 | linear_sv = *linear_svp++; |
765 | assert(linear_sv); |
766 | curstash = gv_stashsv(linear_sv, FALSE); |
767 | |
dd69841b |
768 | if (!curstash) { |
b0c482e3 |
769 | if (ckWARN(WARN_SYNTAX)) |
770 | Perl_warner(aTHX_ packWARN(WARN_SYNTAX), "Can't locate package %"SVf" for @%s::ISA", |
e1a479c5 |
771 | (void*)linear_sv, hvname); |
772 | continue; |
773 | } |
774 | |
775 | assert(curstash); |
776 | |
777 | gvp = (GV**)hv_fetch(curstash, subname, subname_len, 0); |
778 | if (!gvp) continue; |
779 | |
780 | candidate = *gvp; |
781 | assert(candidate); |
782 | |
783 | if (SvTYPE(candidate) != SVt_PVGV) |
784 | gv_init(candidate, curstash, subname, subname_len, TRUE); |
1c908217 |
785 | |
786 | /* Notably, we only look for real entries, not method cache |
787 | entries, because in C3 the method cache of a parent is not |
788 | valid for the child */ |
e1a479c5 |
789 | if (SvTYPE(candidate) == SVt_PVGV && (cand_cv = GvCV(candidate)) && !GvCVGEN(candidate)) { |
790 | SvREFCNT_inc_simple_void_NN((SV*)cand_cv); |
791 | hv_store_ent(nmcache, newSVsv(sv), (SV*)cand_cv, 0); |
792 | return (SV*)cand_cv; |
793 | } |
794 | } |
795 | } |
796 | |
797 | hv_store_ent(nmcache, newSVsv(sv), &PL_sv_undef, 0); |
798 | if(throw_nomethod) |
799 | Perl_croak(aTHX_ "No next::method '%s' found for %s", subname, hvname); |
800 | return &PL_sv_undef; |
801 | } |
802 | |
803 | #include "XSUB.h" |
804 | |
805 | XS(XS_mro_get_linear_isa); |
806 | XS(XS_mro_set_mro); |
807 | XS(XS_mro_get_mro); |
808 | XS(XS_mro_get_isarev); |
809 | XS(XS_mro_is_universal); |
c5860d66 |
810 | XS(XS_mro_invalidate_method_caches); |
e1a479c5 |
811 | XS(XS_mro_method_changed_in); |
812 | XS(XS_next_can); |
813 | XS(XS_next_method); |
814 | XS(XS_maybe_next_method); |
815 | |
816 | void |
817 | Perl_boot_core_mro(pTHX) |
818 | { |
819 | dVAR; |
820 | static const char file[] = __FILE__; |
821 | |
822 | newXSproto("mro::get_linear_isa", XS_mro_get_linear_isa, file, "$;$"); |
823 | newXSproto("mro::set_mro", XS_mro_set_mro, file, "$$"); |
824 | newXSproto("mro::get_mro", XS_mro_get_mro, file, "$"); |
825 | newXSproto("mro::get_isarev", XS_mro_get_isarev, file, "$"); |
826 | newXSproto("mro::is_universal", XS_mro_is_universal, file, "$"); |
c5860d66 |
827 | newXSproto("mro::invalidate_all_method_caches", XS_mro_invalidate_method_caches, file, ""); |
e1a479c5 |
828 | newXSproto("mro::method_changed_in", XS_mro_method_changed_in, file, "$"); |
829 | newXS("next::can", XS_next_can, file); |
830 | newXS("next::method", XS_next_method, file); |
831 | newXS("maybe::next::method", XS_maybe_next_method, file); |
832 | } |
833 | |
834 | XS(XS_mro_get_linear_isa) { |
835 | dVAR; |
836 | dXSARGS; |
837 | AV* RETVAL; |
838 | HV* class_stash; |
839 | SV* classname; |
840 | |
841 | PERL_UNUSED_ARG(cv); |
842 | |
843 | if(items < 1 || items > 2) |
844 | Perl_croak(aTHX_ "Usage: mro::get_linear_isa(classname [, type ])"); |
845 | |
846 | classname = ST(0); |
847 | class_stash = gv_stashsv(classname, 0); |
848 | if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname)); |
849 | |
850 | if(items > 1) { |
851 | char* which = SvPV_nolen(ST(1)); |
852 | if(strEQ(which, "dfs")) |
853 | RETVAL = mro_get_linear_isa_dfs(class_stash, 0); |
854 | else if(strEQ(which, "c3")) |
855 | RETVAL = mro_get_linear_isa_c3(class_stash, 0); |
856 | else |
857 | Perl_croak(aTHX_ "Invalid mro name: '%s'", which); |
858 | } |
859 | else { |
860 | RETVAL = mro_get_linear_isa(class_stash); |
861 | } |
862 | |
863 | ST(0) = newRV_inc((SV*)RETVAL); |
864 | sv_2mortal(ST(0)); |
865 | XSRETURN(1); |
866 | } |
867 | |
868 | XS(XS_mro_set_mro) |
869 | { |
870 | dVAR; |
871 | dXSARGS; |
872 | SV* classname; |
873 | char* whichstr; |
874 | mro_alg which; |
875 | HV* class_stash; |
876 | struct mro_meta* meta; |
877 | |
878 | PERL_UNUSED_ARG(cv); |
879 | |
880 | if (items != 2) |
881 | Perl_croak(aTHX_ "Usage: mro::set_mro(classname, type)"); |
882 | |
883 | classname = ST(0); |
884 | whichstr = SvPV_nolen(ST(1)); |
885 | class_stash = gv_stashsv(classname, GV_ADD); |
886 | if(!class_stash) Perl_croak(aTHX_ "Cannot create class: '%"SVf"'!", SVfARG(classname)); |
887 | meta = HvMROMETA(class_stash); |
888 | |
889 | if(strEQ(whichstr, "dfs")) |
890 | which = MRO_DFS; |
891 | else if(strEQ(whichstr, "c3")) |
892 | which = MRO_C3; |
893 | else |
894 | Perl_croak(aTHX_ "Invalid mro name: '%s'", whichstr); |
895 | |
896 | if(meta->mro_which != which) { |
897 | meta->mro_which = which; |
898 | /* Only affects local method cache, not |
899 | even child classes */ |
dd69841b |
900 | meta->cache_gen++; |
e1a479c5 |
901 | if(meta->mro_nextmethod) |
902 | hv_clear(meta->mro_nextmethod); |
903 | } |
904 | |
905 | XSRETURN_EMPTY; |
906 | } |
907 | |
908 | |
909 | XS(XS_mro_get_mro) |
910 | { |
911 | dVAR; |
912 | dXSARGS; |
913 | SV* classname; |
914 | HV* class_stash; |
915 | struct mro_meta* meta; |
916 | |
917 | PERL_UNUSED_ARG(cv); |
918 | |
919 | if (items != 1) |
920 | Perl_croak(aTHX_ "Usage: mro::get_mro(classname)"); |
921 | |
922 | classname = ST(0); |
923 | class_stash = gv_stashsv(classname, 0); |
924 | if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname)); |
925 | meta = HvMROMETA(class_stash); |
926 | |
927 | if(meta->mro_which == MRO_DFS) |
928 | ST(0) = sv_2mortal(newSVpvn("dfs", 3)); |
929 | else |
930 | ST(0) = sv_2mortal(newSVpvn("c3", 2)); |
931 | |
932 | XSRETURN(1); |
933 | } |
934 | |
935 | XS(XS_mro_get_isarev) |
936 | { |
937 | dVAR; |
938 | dXSARGS; |
939 | SV* classname; |
940 | HV* class_stash; |
dd69841b |
941 | SV** svp; |
e1a479c5 |
942 | HV* isarev; |
dd69841b |
943 | char* stashname; |
944 | STRLEN stashname_len; |
e1a479c5 |
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; |
dd69841b |
957 | |
958 | stashname = HvNAME_get(class_stash); |
959 | stashname_len = HvNAMELEN_get(class_stash); |
960 | svp = hv_fetch(PL_isarev, stashname, stashname_len, 0); |
961 | isarev = svp ? (HV*)*svp : NULL; |
962 | if(isarev) { |
e1a479c5 |
963 | HE* iter; |
964 | hv_iterinit(isarev); |
965 | while((iter = hv_iternext(isarev))) |
966 | XPUSHs(hv_iterkeysv(iter)); |
967 | } |
968 | |
969 | PUTBACK; |
970 | return; |
971 | } |
972 | |
973 | XS(XS_mro_is_universal) |
974 | { |
975 | dVAR; |
976 | dXSARGS; |
977 | SV* classname; |
978 | HV* class_stash; |
dd69841b |
979 | HV* isarev; |
980 | char* stashname; |
981 | STRLEN stashname_len; |
982 | SV** svp; |
e1a479c5 |
983 | |
984 | PERL_UNUSED_ARG(cv); |
985 | |
986 | if (items != 1) |
dd69841b |
987 | Perl_croak(aTHX_ "Usage: mro::is_universal(classname)"); |
e1a479c5 |
988 | |
989 | classname = ST(0); |
990 | class_stash = gv_stashsv(classname, 0); |
991 | if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname)); |
992 | |
dd69841b |
993 | stashname = HvNAME_get(class_stash); |
994 | stashname_len = HvNAMELEN_get(class_stash); |
995 | |
996 | svp = hv_fetch(PL_isarev, stashname, stashname_len, 0); |
997 | isarev = svp ? (HV*)*svp : NULL; |
998 | |
999 | if((stashname_len == 9 && strEQ(stashname, "UNIVERSAL")) |
1000 | || (isarev && hv_exists(isarev, "UNIVERSAL", 9))) |
9edc5bb8 |
1001 | XSRETURN_YES; |
1002 | else |
1003 | XSRETURN_NO; |
e1a479c5 |
1004 | } |
1005 | |
c5860d66 |
1006 | XS(XS_mro_invalidate_method_caches) |
e1a479c5 |
1007 | { |
1008 | dVAR; |
1009 | dXSARGS; |
1010 | |
1011 | PERL_UNUSED_ARG(cv); |
1012 | |
1013 | if (items != 0) |
1014 | Perl_croak(aTHX_ "Usage: mro::invalidate_all_method_caches()"); |
1015 | |
1016 | PL_sub_generation++; |
1017 | |
1018 | XSRETURN_EMPTY; |
1019 | } |
1020 | |
e1a479c5 |
1021 | XS(XS_mro_method_changed_in) |
1022 | { |
1023 | dVAR; |
1024 | dXSARGS; |
1025 | SV* classname; |
1026 | HV* class_stash; |
1027 | |
1028 | PERL_UNUSED_ARG(cv); |
1029 | |
1030 | if(items != 1) |
1031 | Perl_croak(aTHX_ "Usage: mro::method_changed_in(classname)"); |
1032 | |
1033 | classname = ST(0); |
1034 | |
1035 | class_stash = gv_stashsv(classname, 0); |
1036 | if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname)); |
1037 | |
1038 | mro_method_changed_in(class_stash); |
1039 | |
1040 | XSRETURN_EMPTY; |
1041 | } |
1042 | |
1043 | XS(XS_next_can) |
1044 | { |
1045 | dVAR; |
1046 | dXSARGS; |
1047 | SV* self = ST(0); |
1048 | SV* methcv = __nextcan(aTHX_ self, 0); |
1049 | |
1050 | PERL_UNUSED_ARG(cv); |
1051 | PERL_UNUSED_VAR(items); |
1052 | |
1053 | if(methcv == &PL_sv_undef) { |
1054 | ST(0) = &PL_sv_undef; |
1055 | } |
1056 | else { |
1057 | ST(0) = sv_2mortal(newRV_inc(methcv)); |
1058 | } |
1059 | |
1060 | XSRETURN(1); |
1061 | } |
1062 | |
1063 | XS(XS_next_method) |
1064 | { |
1065 | dMARK; |
1066 | dAX; |
1067 | SV* self = ST(0); |
1068 | SV* methcv = __nextcan(aTHX_ self, 1); |
1069 | |
1070 | PERL_UNUSED_ARG(cv); |
1071 | |
1072 | PL_markstack_ptr++; |
1073 | call_sv(methcv, GIMME_V); |
1074 | } |
1075 | |
1076 | XS(XS_maybe_next_method) |
1077 | { |
1078 | dMARK; |
1079 | dAX; |
1080 | SV* self = ST(0); |
1081 | SV* methcv = __nextcan(aTHX_ self, 0); |
1082 | |
1083 | PERL_UNUSED_ARG(cv); |
1084 | |
1085 | if(methcv == &PL_sv_undef) { |
1086 | ST(0) = &PL_sv_undef; |
1087 | XSRETURN(1); |
1088 | } |
1089 | |
1090 | PL_markstack_ptr++; |
1091 | call_sv(methcv, GIMME_V); |
1092 | } |
1093 | |
1094 | /* |
1095 | * Local variables: |
1096 | * c-indentation-style: bsd |
1097 | * c-basic-offset: 4 |
1098 | * indent-tabs-mode: t |
1099 | * End: |
1100 | * |
1101 | * ex: set ts=8 sts=4 sw=4 noet: |
1102 | */ |