Commit | Line | Data |
b2685f0c |
1 | #include "EXTERN.h" |
2 | #include "perl.h" |
3 | #include "XSUB.h" |
4 | |
5 | static AV* |
6 | S_mro_get_linear_isa_c3(pTHX_ HV* stash, U32 level); |
7 | |
8 | static const struct mro_alg c3_alg = |
9 | {S_mro_get_linear_isa_c3, "c3", 2, 0, 0}; |
10 | |
11 | /* |
12 | =for apidoc mro_get_linear_isa_c3 |
13 | |
14 | Returns the C3 linearization of @ISA |
15 | the given stash. The return value is a read-only AV*. |
16 | C<level> should be 0 (it is used internally in this |
17 | function's recursion). |
18 | |
19 | You are responsible for C<SvREFCNT_inc()> on the |
20 | return value if you plan to store it anywhere |
21 | semi-permanently (otherwise it might be deleted |
22 | out from under you the next time the cache is |
23 | invalidated). |
24 | |
25 | =cut |
26 | */ |
27 | |
28 | static AV* |
29 | S_mro_get_linear_isa_c3(pTHX_ HV* stash, U32 level) |
30 | { |
31 | AV* retval; |
32 | GV** gvp; |
33 | GV* gv; |
34 | AV* isa; |
35 | const HEK* stashhek; |
36 | struct mro_meta* meta; |
37 | |
38 | assert(HvAUX(stash)); |
39 | |
40 | stashhek = HvNAME_HEK(stash); |
41 | if (!stashhek) |
42 | Perl_croak(aTHX_ "Can't linearize anonymous symbol table"); |
43 | |
44 | if (level > 100) |
45 | Perl_croak(aTHX_ "Recursive inheritance detected in package '%s'", |
46 | HEK_KEY(stashhek)); |
47 | |
48 | meta = HvMROMETA(stash); |
49 | |
50 | /* return cache if valid */ |
51 | if((retval = MUTABLE_AV(MRO_GET_PRIVATE_DATA(meta, &c3_alg)))) { |
52 | return retval; |
53 | } |
54 | |
55 | /* not in cache, make a new one */ |
56 | |
57 | gvp = (GV**)hv_fetchs(stash, "ISA", FALSE); |
58 | isa = (gvp && (gv = *gvp) && isGV_with_GP(gv)) ? GvAV(gv) : NULL; |
59 | |
60 | /* For a better idea how the rest of this works, see the much clearer |
61 | pure perl version in Algorithm::C3 0.01: |
62 | http://search.cpan.org/src/STEVAN/Algorithm-C3-0.01/lib/Algorithm/C3.pm |
63 | (later versions go about it differently than this code for speed reasons) |
64 | */ |
65 | |
66 | if(isa && AvFILLp(isa) >= 0) { |
67 | SV** seqs_ptr; |
68 | I32 seqs_items; |
69 | HV* const tails = MUTABLE_HV(sv_2mortal(MUTABLE_SV(newHV()))); |
70 | AV *const seqs = MUTABLE_AV(sv_2mortal(MUTABLE_SV(newAV()))); |
71 | I32* heads; |
72 | |
73 | /* This builds @seqs, which is an array of arrays. |
74 | The members of @seqs are the MROs of |
75 | the members of @ISA, followed by @ISA itself. |
76 | */ |
77 | I32 items = AvFILLp(isa) + 1; |
78 | SV** isa_ptr = AvARRAY(isa); |
79 | while(items--) { |
80 | SV* const isa_item = *isa_ptr++; |
81 | HV* const isa_item_stash = gv_stashsv(isa_item, 0); |
82 | if(!isa_item_stash) { |
83 | /* if no stash, make a temporary fake MRO |
84 | containing just itself */ |
85 | AV* const isa_lin = newAV(); |
86 | av_push(isa_lin, newSVsv(isa_item)); |
87 | av_push(seqs, MUTABLE_SV(isa_lin)); |
88 | } |
89 | else { |
90 | /* recursion */ |
91 | AV* const isa_lin |
92 | = S_mro_get_linear_isa_c3(aTHX_ isa_item_stash, level + 1); |
93 | av_push(seqs, SvREFCNT_inc_simple_NN(MUTABLE_SV(isa_lin))); |
94 | } |
95 | } |
96 | av_push(seqs, SvREFCNT_inc_simple_NN(MUTABLE_SV(isa))); |
97 | |
98 | /* This builds "heads", which as an array of integer array |
99 | indices, one per seq, which point at the virtual "head" |
100 | of the seq (initially zero) */ |
101 | Newxz(heads, AvFILLp(seqs)+1, I32); |
102 | |
103 | /* This builds %tails, which has one key for every class |
104 | mentioned in the tail of any sequence in @seqs (tail meaning |
105 | everything after the first class, the "head"). The value |
106 | is how many times this key appears in the tails of @seqs. |
107 | */ |
108 | seqs_ptr = AvARRAY(seqs); |
109 | seqs_items = AvFILLp(seqs) + 1; |
110 | while(seqs_items--) { |
111 | AV *const seq = MUTABLE_AV(*seqs_ptr++); |
112 | I32 seq_items = AvFILLp(seq); |
113 | if(seq_items > 0) { |
114 | SV** seq_ptr = AvARRAY(seq) + 1; |
115 | while(seq_items--) { |
116 | SV* const seqitem = *seq_ptr++; |
117 | /* LVALUE fetch will create a new undefined SV if necessary |
118 | */ |
119 | HE* const he = hv_fetch_ent(tails, seqitem, 1, 0); |
120 | if(he) { |
121 | SV* const val = HeVAL(he); |
122 | /* This will increment undef to 1, which is what we |
123 | want for a newly created entry. */ |
124 | sv_inc(val); |
125 | } |
126 | } |
127 | } |
128 | } |
129 | |
130 | /* Initialize retval to build the return value in */ |
131 | retval = newAV(); |
132 | av_push(retval, newSVhek(stashhek)); /* us first */ |
133 | |
134 | /* This loop won't terminate until we either finish building |
135 | the MRO, or get an exception. */ |
136 | while(1) { |
137 | SV* cand = NULL; |
138 | SV* winner = NULL; |
139 | int s; |
140 | |
141 | /* "foreach $seq (@seqs)" */ |
142 | SV** const avptr = AvARRAY(seqs); |
143 | for(s = 0; s <= AvFILLp(seqs); s++) { |
144 | SV** svp; |
145 | AV * const seq = MUTABLE_AV(avptr[s]); |
146 | SV* seqhead; |
147 | if(!seq) continue; /* skip empty seqs */ |
148 | svp = av_fetch(seq, heads[s], 0); |
149 | seqhead = *svp; /* seqhead = head of this seq */ |
150 | if(!winner) { |
151 | HE* tail_entry; |
152 | SV* val; |
153 | /* if we haven't found a winner for this round yet, |
154 | and this seqhead is not in tails (or the count |
155 | for it in tails has dropped to zero), then this |
156 | seqhead is our new winner, and is added to the |
157 | final MRO immediately */ |
158 | cand = seqhead; |
159 | if((tail_entry = hv_fetch_ent(tails, cand, 0, 0)) |
160 | && (val = HeVAL(tail_entry)) |
161 | && (SvIVX(val) > 0)) |
162 | continue; |
163 | winner = newSVsv(cand); |
164 | av_push(retval, winner); |
165 | /* note however that even when we find a winner, |
166 | we continue looping over @seqs to do housekeeping */ |
167 | } |
168 | if(!sv_cmp(seqhead, winner)) { |
169 | /* Once we have a winner (including the iteration |
170 | where we first found him), inc the head ptr |
171 | for any seq which had the winner as a head, |
172 | NULL out any seq which is now empty, |
173 | and adjust tails for consistency */ |
174 | |
175 | const int new_head = ++heads[s]; |
176 | if(new_head > AvFILLp(seq)) { |
177 | SvREFCNT_dec(avptr[s]); |
178 | avptr[s] = NULL; |
179 | } |
180 | else { |
181 | HE* tail_entry; |
182 | SV* val; |
183 | /* Because we know this new seqhead used to be |
184 | a tail, we can assume it is in tails and has |
185 | a positive value, which we need to dec */ |
186 | svp = av_fetch(seq, new_head, 0); |
187 | seqhead = *svp; |
188 | tail_entry = hv_fetch_ent(tails, seqhead, 0, 0); |
189 | val = HeVAL(tail_entry); |
190 | sv_dec(val); |
191 | } |
192 | } |
193 | } |
194 | |
195 | /* if we found no candidates, we are done building the MRO. |
196 | !cand means no seqs have any entries left to check */ |
197 | if(!cand) { |
198 | Safefree(heads); |
199 | break; |
200 | } |
201 | |
202 | /* If we had candidates, but nobody won, then the @ISA |
203 | hierarchy is not C3-incompatible */ |
204 | if(!winner) { |
205 | /* we have to do some cleanup before we croak */ |
206 | |
207 | SvREFCNT_dec(retval); |
208 | Safefree(heads); |
209 | |
210 | Perl_croak(aTHX_ "Inconsistent hierarchy during C3 merge of class '%s': " |
211 | "merging failed on parent '%"SVf"'", HEK_KEY(stashhek), SVfARG(cand)); |
212 | } |
213 | } |
214 | } |
215 | else { /* @ISA was undefined or empty */ |
216 | /* build a retval containing only ourselves */ |
217 | retval = newAV(); |
218 | av_push(retval, newSVhek(stashhek)); |
219 | } |
220 | |
221 | /* we don't want anyone modifying the cache entry but us, |
222 | and we do so by replacing it completely */ |
223 | SvREADONLY_on(retval); |
224 | |
225 | return MUTABLE_AV(Perl_mro_set_private_data(aTHX_ meta, &c3_alg, |
226 | MUTABLE_SV(retval))); |
227 | return retval; |
228 | } |
229 | |
230 | |
231 | /* These two are static helpers for next::method and friends, |
232 | and re-implement a bunch of the code from pp_caller() in |
233 | a more efficient manner for this particular usage. |
234 | */ |
235 | |
236 | static I32 |
237 | __dopoptosub_at(const PERL_CONTEXT *cxstk, I32 startingblock) { |
238 | I32 i; |
239 | for (i = startingblock; i >= 0; i--) { |
240 | if(CxTYPE((PERL_CONTEXT*)(&cxstk[i])) == CXt_SUB) return i; |
241 | } |
242 | return i; |
243 | } |
244 | |
1e9bd118 |
245 | MODULE = mro PACKAGE = mro PREFIX = mro_ |
b2685f0c |
246 | |
247 | void |
1e9bd118 |
248 | mro_get_linear_isa(...) |
249 | PROTOTYPE: $;$ |
250 | PREINIT: |
251 | AV* RETVAL; |
252 | HV* class_stash; |
253 | SV* classname; |
254 | PPCODE: |
255 | if(items < 1 || items > 2) |
256 | croak_xs_usage(cv, "classname [, type ]"); |
257 | |
258 | classname = ST(0); |
259 | class_stash = gv_stashsv(classname, 0); |
260 | |
261 | if(!class_stash) { |
262 | /* No stash exists yet, give them just the classname */ |
263 | AV* isalin = newAV(); |
264 | av_push(isalin, newSVsv(classname)); |
265 | ST(0) = sv_2mortal(newRV_noinc(MUTABLE_SV(isalin))); |
266 | XSRETURN(1); |
267 | } |
268 | else if(items > 1) { |
269 | const struct mro_alg *const algo = Perl_mro_get_from_name(aTHX_ ST(1)); |
270 | if (!algo) |
271 | Perl_croak(aTHX_ "Invalid mro name: '%"SVf"'", ST(1)); |
272 | RETVAL = algo->resolve(aTHX_ class_stash, 0); |
273 | } |
274 | else { |
275 | RETVAL = mro_get_linear_isa(class_stash); |
276 | } |
277 | ST(0) = newRV_inc(MUTABLE_SV(RETVAL)); |
278 | sv_2mortal(ST(0)); |
279 | XSRETURN(1); |
280 | |
281 | void |
282 | mro_set_mro(...) |
283 | PROTOTYPE: $$ |
284 | PREINIT: |
285 | SV* classname; |
286 | const struct mro_alg *which; |
287 | HV* class_stash; |
288 | struct mro_meta* meta; |
289 | PPCODE: |
290 | if (items != 2) |
291 | croak_xs_usage(cv, "classname, type"); |
292 | |
293 | classname = ST(0); |
294 | class_stash = gv_stashsv(classname, GV_ADD); |
295 | if(!class_stash) Perl_croak(aTHX_ "Cannot create class: '%"SVf"'!", SVfARG(classname)); |
296 | meta = HvMROMETA(class_stash); |
297 | |
298 | Perl_mro_set_mro(aTHX_ meta, ST(1)); |
299 | |
300 | XSRETURN_EMPTY; |
301 | |
302 | void |
303 | mro_get_mro(...) |
304 | PROTOTYPE: $ |
305 | PREINIT: |
306 | SV* classname; |
307 | HV* class_stash; |
308 | PPCODE: |
309 | if (items != 1) |
310 | croak_xs_usage(cv, "classname"); |
311 | |
312 | classname = ST(0); |
313 | class_stash = gv_stashsv(classname, 0); |
314 | |
315 | ST(0) = sv_2mortal(newSVpv(class_stash |
316 | ? HvMROMETA(class_stash)->mro_which->name |
317 | : "dfs", 0)); |
318 | XSRETURN(1); |
319 | |
320 | void |
321 | mro_get_isarev(...) |
322 | PROTOTYPE: $ |
323 | PREINIT: |
324 | SV* classname; |
325 | HE* he; |
326 | HV* isarev; |
327 | AV* ret_array; |
328 | PPCODE: |
329 | if (items != 1) |
330 | croak_xs_usage(cv, "classname"); |
331 | |
332 | classname = ST(0); |
333 | |
334 | he = hv_fetch_ent(PL_isarev, classname, 0, 0); |
335 | isarev = he ? MUTABLE_HV(HeVAL(he)) : NULL; |
336 | |
337 | ret_array = newAV(); |
338 | if(isarev) { |
339 | HE* iter; |
340 | hv_iterinit(isarev); |
341 | while((iter = hv_iternext(isarev))) |
342 | av_push(ret_array, newSVsv(hv_iterkeysv(iter))); |
343 | } |
344 | mXPUSHs(newRV_noinc(MUTABLE_SV(ret_array))); |
345 | |
346 | PUTBACK; |
347 | |
348 | void |
349 | mro_is_universal(...) |
350 | PROTOTYPE: $ |
351 | PREINIT: |
352 | SV* classname; |
353 | HV* isarev; |
354 | char* classname_pv; |
355 | STRLEN classname_len; |
356 | HE* he; |
357 | PPCODE: |
358 | if (items != 1) |
359 | croak_xs_usage(cv, "classname"); |
360 | |
361 | classname = ST(0); |
362 | |
363 | classname_pv = SvPV(classname,classname_len); |
364 | |
365 | he = hv_fetch_ent(PL_isarev, classname, 0, 0); |
366 | isarev = he ? MUTABLE_HV(HeVAL(he)) : NULL; |
367 | |
368 | if((classname_len == 9 && strEQ(classname_pv, "UNIVERSAL")) |
369 | || (isarev && hv_exists(isarev, "UNIVERSAL", 9))) |
370 | XSRETURN_YES; |
371 | else |
372 | XSRETURN_NO; |
373 | |
374 | |
375 | void |
376 | mro_invalidate_method_caches(...) |
377 | PROTOTYPE: |
378 | PPCODE: |
379 | if (items != 0) |
380 | croak_xs_usage(cv, ""); |
381 | |
382 | PL_sub_generation++; |
383 | |
384 | XSRETURN_EMPTY; |
385 | |
386 | void |
387 | mro_get_pkg_gen(...) |
388 | PROTOTYPE: $ |
389 | PREINIT: |
390 | SV* classname; |
391 | HV* class_stash; |
392 | PPCODE: |
393 | if(items != 1) |
394 | croak_xs_usage(cv, "classname"); |
395 | |
396 | classname = ST(0); |
397 | |
398 | class_stash = gv_stashsv(classname, 0); |
399 | |
400 | mXPUSHi(class_stash ? HvMROMETA(class_stash)->pkg_gen : 0); |
401 | |
402 | PUTBACK; |
403 | |
404 | void |
405 | mro__nextcan(...) |
b2685f0c |
406 | PREINIT: |
407 | SV* self = ST(0); |
408 | const I32 throw_nomethod = SvIVX(ST(1)); |
409 | register I32 cxix = cxstack_ix; |
410 | register const PERL_CONTEXT *ccstack = cxstack; |
411 | const PERL_SI *top_si = PL_curstackinfo; |
412 | HV* selfstash; |
413 | SV *stashname; |
414 | const char *fq_subname; |
415 | const char *subname; |
416 | STRLEN stashname_len; |
417 | STRLEN subname_len; |
418 | SV* sv; |
419 | GV** gvp; |
420 | AV* linear_av; |
421 | SV** linear_svp; |
422 | const char *hvname; |
423 | I32 entries; |
424 | struct mro_meta* selfmeta; |
425 | HV* nmcache; |
426 | I32 i; |
427 | PPCODE: |
428 | PERL_UNUSED_ARG(cv); |
429 | |
430 | if(sv_isobject(self)) |
431 | selfstash = SvSTASH(SvRV(self)); |
432 | else |
433 | selfstash = gv_stashsv(self, GV_ADD); |
434 | |
435 | assert(selfstash); |
436 | |
437 | hvname = HvNAME_get(selfstash); |
438 | if (!hvname) |
439 | Perl_croak(aTHX_ "Can't use anonymous symbol table for method lookup"); |
440 | |
441 | /* This block finds the contextually-enclosing fully-qualified subname, |
442 | much like looking at (caller($i))[3] until you find a real sub that |
443 | isn't ANON, etc (also skips over pureperl next::method, etc) */ |
444 | for(i = 0; i < 2; i++) { |
445 | cxix = __dopoptosub_at(ccstack, cxix); |
446 | for (;;) { |
447 | GV* cvgv; |
448 | STRLEN fq_subname_len; |
449 | |
450 | /* we may be in a higher stacklevel, so dig down deeper */ |
451 | while (cxix < 0) { |
452 | if(top_si->si_type == PERLSI_MAIN) |
453 | Perl_croak(aTHX_ "next::method/next::can/maybe::next::method must be used in method context"); |
454 | top_si = top_si->si_prev; |
455 | ccstack = top_si->si_cxstack; |
456 | cxix = __dopoptosub_at(ccstack, top_si->si_cxix); |
457 | } |
458 | |
459 | if(CxTYPE((PERL_CONTEXT*)(&ccstack[cxix])) != CXt_SUB |
460 | || (PL_DBsub && GvCV(PL_DBsub) && ccstack[cxix].blk_sub.cv == GvCV(PL_DBsub))) { |
461 | cxix = __dopoptosub_at(ccstack, cxix - 1); |
462 | continue; |
463 | } |
464 | |
465 | { |
466 | const I32 dbcxix = __dopoptosub_at(ccstack, cxix - 1); |
467 | if (PL_DBsub && GvCV(PL_DBsub) && dbcxix >= 0 && ccstack[dbcxix].blk_sub.cv == GvCV(PL_DBsub)) { |
468 | if(CxTYPE((PERL_CONTEXT*)(&ccstack[dbcxix])) != CXt_SUB) { |
469 | cxix = dbcxix; |
470 | continue; |
471 | } |
472 | } |
473 | } |
474 | |
475 | cvgv = CvGV(ccstack[cxix].blk_sub.cv); |
476 | |
477 | if(!isGV(cvgv)) { |
478 | cxix = __dopoptosub_at(ccstack, cxix - 1); |
479 | continue; |
480 | } |
481 | |
482 | /* we found a real sub here */ |
483 | sv = sv_2mortal(newSV(0)); |
484 | |
485 | gv_efullname3(sv, cvgv, NULL); |
486 | |
487 | fq_subname = SvPVX(sv); |
488 | fq_subname_len = SvCUR(sv); |
489 | |
490 | subname = strrchr(fq_subname, ':'); |
491 | if(!subname) |
492 | Perl_croak(aTHX_ "next::method/next::can/maybe::next::method cannot find enclosing method"); |
493 | |
494 | subname++; |
495 | subname_len = fq_subname_len - (subname - fq_subname); |
496 | if(subname_len == 8 && strEQ(subname, "__ANON__")) { |
497 | cxix = __dopoptosub_at(ccstack, cxix - 1); |
498 | continue; |
499 | } |
500 | break; |
501 | } |
502 | cxix--; |
503 | } |
504 | |
505 | /* If we made it to here, we found our context */ |
506 | |
507 | /* Initialize the next::method cache for this stash |
508 | if necessary */ |
509 | selfmeta = HvMROMETA(selfstash); |
510 | if(!(nmcache = selfmeta->mro_nextmethod)) { |
511 | nmcache = selfmeta->mro_nextmethod = newHV(); |
512 | } |
513 | else { /* Use the cached coderef if it exists */ |
514 | HE* cache_entry = hv_fetch_ent(nmcache, sv, 0, 0); |
515 | if (cache_entry) { |
516 | SV* const val = HeVAL(cache_entry); |
517 | if(val == &PL_sv_undef) { |
518 | if(throw_nomethod) |
519 | Perl_croak(aTHX_ "No next::method '%s' found for %s", subname, hvname); |
520 | XSRETURN_EMPTY; |
521 | } |
522 | mXPUSHs(newRV_inc(val)); |
523 | XSRETURN(1); |
524 | } |
525 | } |
526 | |
527 | /* beyond here is just for cache misses, so perf isn't as critical */ |
528 | |
529 | stashname_len = subname - fq_subname - 2; |
530 | stashname = newSVpvn_flags(fq_subname, stashname_len, SVs_TEMP); |
531 | |
532 | /* has ourselves at the top of the list */ |
533 | linear_av = S_mro_get_linear_isa_c3(aTHX_ selfstash, 0); |
534 | |
535 | linear_svp = AvARRAY(linear_av); |
536 | entries = AvFILLp(linear_av) + 1; |
537 | |
538 | /* Walk down our MRO, skipping everything up |
539 | to the contextually enclosing class */ |
540 | while (entries--) { |
541 | SV * const linear_sv = *linear_svp++; |
542 | assert(linear_sv); |
543 | if(sv_eq(linear_sv, stashname)) |
544 | break; |
545 | } |
546 | |
547 | /* Now search the remainder of the MRO for the |
548 | same method name as the contextually enclosing |
549 | method */ |
550 | if(entries > 0) { |
551 | while (entries--) { |
552 | SV * const linear_sv = *linear_svp++; |
553 | HV* curstash; |
554 | GV* candidate; |
555 | CV* cand_cv; |
556 | |
557 | assert(linear_sv); |
558 | curstash = gv_stashsv(linear_sv, FALSE); |
559 | |
560 | if (!curstash) { |
561 | if (ckWARN(WARN_SYNTAX)) |
562 | Perl_warner(aTHX_ packWARN(WARN_SYNTAX), "Can't locate package %"SVf" for @%s::ISA", |
563 | (void*)linear_sv, hvname); |
564 | continue; |
565 | } |
566 | |
567 | assert(curstash); |
568 | |
569 | gvp = (GV**)hv_fetch(curstash, subname, subname_len, 0); |
570 | if (!gvp) continue; |
571 | |
572 | candidate = *gvp; |
573 | assert(candidate); |
574 | |
575 | if (SvTYPE(candidate) != SVt_PVGV) |
576 | gv_init(candidate, curstash, subname, subname_len, TRUE); |
577 | |
578 | /* Notably, we only look for real entries, not method cache |
579 | entries, because in C3 the method cache of a parent is not |
580 | valid for the child */ |
581 | if (SvTYPE(candidate) == SVt_PVGV && (cand_cv = GvCV(candidate)) && !GvCVGEN(candidate)) { |
582 | SvREFCNT_inc_simple_void_NN(MUTABLE_SV(cand_cv)); |
583 | (void)hv_store_ent(nmcache, newSVsv(sv), MUTABLE_SV(cand_cv), 0); |
584 | mXPUSHs(newRV_inc(MUTABLE_SV(cand_cv))); |
585 | XSRETURN(1); |
586 | } |
587 | } |
588 | } |
589 | |
590 | (void)hv_store_ent(nmcache, newSVsv(sv), &PL_sv_undef, 0); |
591 | if(throw_nomethod) |
592 | Perl_croak(aTHX_ "No next::method '%s' found for %s", subname, hvname); |
593 | XSRETURN_EMPTY; |
594 | |
595 | BOOT: |
596 | Perl_mro_register(aTHX_ &c3_alg); |