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e1a479c5 BB |
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 RGS |
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 BB |
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 BB |
30 | |
31 | assert(stash); | |
32 | assert(HvAUX(stash)); | |
33 | assert(!(HvAUX(stash)->xhv_mro_meta)); | |
183086be | 34 | Newxz(newmeta, 1, struct mro_meta); |
9fe4aecf RGS |
35 | HvAUX(stash)->xhv_mro_meta = newmeta; |
36 | newmeta->sub_generation = 1; | |
e1a479c5 BB |
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 BB |
57 | struct mro_meta* newmeta; |
58 | ||
59 | assert(smeta); | |
60 | ||
33e12d9d NC |
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 BB |
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 RGS |
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 BB |
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 BB |
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 RGS |
121 | |
122 | /* return cache if valid */ | |
e1a479c5 | 123 | if((retval = meta->mro_linear_dfs)) { |
e1a479c5 BB |
124 | return retval; |
125 | } | |
126 | ||
127 | /* not in cache, make a new one */ | |
1c908217 | 128 | |
e1a479c5 BB |
129 | retval = newAV(); |
130 | av_push(retval, newSVpv(stashname, 0)); /* add ourselves at the top */ | |
131 | ||
1c908217 | 132 | /* fetch our @ISA */ |
e1a479c5 BB |
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 RGS |
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 NC |
144 | SV **svp = AvARRAY(av); |
145 | I32 items = AvFILLp(av) + 1; | |
1c908217 RGS |
146 | |
147 | /* foreach(@ISA) */ | |
e1a479c5 BB |
148 | while (items--) { |
149 | SV* const sv = *svp++; | |
150 | HV* const basestash = gv_stashsv(sv, 0); | |
ffd8da72 NC |
151 | SV *const *subrv_p; |
152 | I32 subrv_items; | |
e1a479c5 BB |
153 | |
154 | if (!basestash) { | |
1c908217 RGS |
155 | /* if no stash exists for this @ISA member, |
156 | simply add it to the MRO and move on */ | |
ffd8da72 NC |
157 | subrv_p = &sv; |
158 | subrv_items = 1; | |
e1a479c5 BB |
159 | } |
160 | else { | |
1c908217 RGS |
161 | /* otherwise, recurse into ourselves for the MRO |
162 | of this @ISA member, and append their MRO to ours */ | |
ffd8da72 NC |
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 BB |
175 | } |
176 | } | |
177 | } | |
178 | ||
1c908217 RGS |
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 BB |
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 RGS |
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 BB |
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 RGS |
229 | |
230 | /* return cache if valid */ | |
e1a479c5 | 231 | if((retval = meta->mro_linear_c3)) { |
e1a479c5 BB |
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 RGS |
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 | */ | |
e1a479c5 BB |
248 | if(isa && AvFILLp(isa) >= 0) { |
249 | SV** seqs_ptr; | |
250 | I32 seqs_items; | |
251 | HV* tails = (HV*)sv_2mortal((SV*)newHV()); | |
252 | AV* seqs = (AV*)sv_2mortal((SV*)newAV()); | |
253 | I32 items = AvFILLp(isa) + 1; | |
254 | SV** isa_ptr = AvARRAY(isa); | |
255 | while(items--) { | |
256 | AV* isa_lin; | |
257 | SV* isa_item = *isa_ptr++; | |
258 | HV* isa_item_stash = gv_stashsv(isa_item, 0); | |
259 | if(!isa_item_stash) { | |
260 | isa_lin = newAV(); | |
261 | av_push(isa_lin, newSVsv(isa_item)); | |
262 | } | |
263 | else { | |
264 | isa_lin = mro_get_linear_isa_c3(isa_item_stash, level + 1); /* recursion */ | |
265 | } | |
266 | av_push(seqs, (SV*)av_make(AvFILLp(isa_lin)+1, AvARRAY(isa_lin))); | |
267 | } | |
268 | av_push(seqs, (SV*)av_make(AvFILLp(isa)+1, AvARRAY(isa))); | |
269 | ||
270 | seqs_ptr = AvARRAY(seqs); | |
271 | seqs_items = AvFILLp(seqs) + 1; | |
272 | while(seqs_items--) { | |
273 | AV* seq = (AV*)*seqs_ptr++; | |
274 | I32 seq_items = AvFILLp(seq); | |
275 | if(seq_items > 0) { | |
276 | SV** seq_ptr = AvARRAY(seq) + 1; | |
277 | while(seq_items--) { | |
278 | SV* seqitem = *seq_ptr++; | |
279 | HE* he = hv_fetch_ent(tails, seqitem, 0, 0); | |
280 | if(!he) { | |
281 | hv_store_ent(tails, seqitem, newSViv(1), 0); | |
282 | } | |
283 | else { | |
284 | SV* val = HeVAL(he); | |
285 | sv_inc(val); | |
286 | } | |
287 | } | |
288 | } | |
289 | } | |
290 | ||
291 | while(1) { | |
292 | SV* seqhead = NULL; | |
293 | SV* cand = NULL; | |
294 | SV* winner = NULL; | |
295 | SV* val; | |
296 | HE* tail_entry; | |
297 | AV* seq; | |
298 | SV** avptr = AvARRAY(seqs); | |
299 | items = AvFILLp(seqs)+1; | |
300 | while(items--) { | |
301 | SV** svp; | |
302 | seq = (AV*)*avptr++; | |
303 | if(AvFILLp(seq) < 0) continue; | |
304 | svp = av_fetch(seq, 0, 0); | |
305 | seqhead = *svp; | |
306 | if(!winner) { | |
307 | cand = seqhead; | |
308 | if((tail_entry = hv_fetch_ent(tails, cand, 0, 0)) | |
309 | && (val = HeVAL(tail_entry)) | |
25270bc0 | 310 | && (SvIVX(val) > 0)) |
e1a479c5 BB |
311 | continue; |
312 | winner = newSVsv(cand); | |
313 | av_push(retval, winner); | |
314 | } | |
315 | if(!sv_cmp(seqhead, winner)) { | |
316 | ||
317 | /* this is basically shift(@seq) in void context */ | |
318 | SvREFCNT_dec(*AvARRAY(seq)); | |
319 | *AvARRAY(seq) = &PL_sv_undef; | |
320 | AvARRAY(seq) = AvARRAY(seq) + 1; | |
321 | AvMAX(seq)--; | |
322 | AvFILLp(seq)--; | |
323 | ||
324 | if(AvFILLp(seq) < 0) continue; | |
325 | svp = av_fetch(seq, 0, 0); | |
326 | seqhead = *svp; | |
327 | tail_entry = hv_fetch_ent(tails, seqhead, 0, 0); | |
328 | val = HeVAL(tail_entry); | |
329 | sv_dec(val); | |
330 | } | |
331 | } | |
332 | if(!cand) break; | |
333 | if(!winner) { | |
334 | SvREFCNT_dec(retval); | |
335 | Perl_croak(aTHX_ "Inconsistent hierarchy during C3 merge of class '%s': " | |
336 | "merging failed on parent '%"SVf"'", stashname, SVfARG(cand)); | |
337 | } | |
338 | } | |
339 | } | |
340 | ||
1c908217 RGS |
341 | /* we don't want anyone modifying the cache entry but us, |
342 | and we do so by replacing it completely */ | |
e1a479c5 | 343 | SvREADONLY_on(retval); |
1c908217 | 344 | |
e1a479c5 BB |
345 | meta->mro_linear_c3 = retval; |
346 | return retval; | |
347 | } | |
348 | ||
349 | /* | |
350 | =for apidoc mro_get_linear_isa | |
351 | ||
352 | Returns either C<mro_get_linear_isa_c3> or | |
353 | C<mro_get_linear_isa_dfs> for the given stash, | |
354 | dependant upon which MRO is in effect | |
355 | for that stash. The return value is a | |
356 | read-only AV*. | |
357 | ||
1c908217 RGS |
358 | You are responsible for C<SvREFCNT_inc()> on the |
359 | return value if you plan to store it anywhere | |
360 | semi-permanently (otherwise it might be deleted | |
361 | out from under you the next time the cache is | |
362 | invalidated). | |
363 | ||
e1a479c5 BB |
364 | =cut |
365 | */ | |
366 | AV* | |
367 | Perl_mro_get_linear_isa(pTHX_ HV *stash) | |
368 | { | |
369 | struct mro_meta* meta; | |
370 | assert(stash); | |
371 | assert(HvAUX(stash)); | |
372 | ||
373 | meta = HvMROMETA(stash); | |
374 | if(meta->mro_which == MRO_DFS) { | |
375 | return mro_get_linear_isa_dfs(stash, 0); | |
376 | } else if(meta->mro_which == MRO_C3) { | |
377 | return mro_get_linear_isa_c3(stash, 0); | |
378 | } else { | |
14f97ce6 | 379 | Perl_croak(aTHX_ "panic: invalid MRO!"); |
e1a479c5 BB |
380 | } |
381 | } | |
382 | ||
383 | /* | |
384 | =for apidoc mro_isa_changed_in | |
385 | ||
1c908217 | 386 | Takes the necessary steps (cache invalidations, mostly) |
e1a479c5 BB |
387 | when the @ISA of the given package has changed. Invoked |
388 | by the C<setisa> magic, should not need to invoke directly. | |
389 | ||
390 | =cut | |
391 | */ | |
392 | void | |
393 | Perl_mro_isa_changed_in(pTHX_ HV* stash) | |
394 | { | |
395 | dVAR; | |
396 | HV* isarev; | |
397 | AV* linear_mro; | |
398 | HE* iter; | |
399 | SV** svp; | |
400 | I32 items; | |
401 | struct mro_meta* meta; | |
402 | char* stashname; | |
403 | ||
404 | stashname = HvNAME_get(stash); | |
405 | ||
406 | /* wipe out the cached linearizations for this stash */ | |
407 | meta = HvMROMETA(stash); | |
408 | SvREFCNT_dec((SV*)meta->mro_linear_dfs); | |
409 | SvREFCNT_dec((SV*)meta->mro_linear_c3); | |
410 | meta->mro_linear_dfs = NULL; | |
411 | meta->mro_linear_c3 = NULL; | |
412 | ||
413 | /* Wipe the global method cache if this package | |
414 | is UNIVERSAL or one of its parents */ | |
415 | if(meta->is_universal) | |
416 | PL_sub_generation++; | |
417 | ||
418 | /* Wipe the local method cache otherwise */ | |
419 | else | |
420 | meta->sub_generation++; | |
421 | ||
422 | /* wipe next::method cache too */ | |
423 | if(meta->mro_nextmethod) hv_clear(meta->mro_nextmethod); | |
424 | ||
425 | /* Iterate the isarev (classes that are our children), | |
426 | wiping out their linearization and method caches */ | |
427 | if((isarev = meta->mro_isarev)) { | |
428 | hv_iterinit(isarev); | |
429 | while((iter = hv_iternext(isarev))) { | |
430 | SV* revkey = hv_iterkeysv(iter); | |
431 | HV* revstash = gv_stashsv(revkey, 0); | |
432 | struct mro_meta* revmeta = HvMROMETA(revstash); | |
433 | SvREFCNT_dec((SV*)revmeta->mro_linear_dfs); | |
434 | SvREFCNT_dec((SV*)revmeta->mro_linear_c3); | |
435 | revmeta->mro_linear_dfs = NULL; | |
436 | revmeta->mro_linear_c3 = NULL; | |
437 | if(!meta->is_universal) | |
438 | revmeta->sub_generation++; | |
439 | if(revmeta->mro_nextmethod) | |
440 | hv_clear(revmeta->mro_nextmethod); | |
441 | } | |
442 | } | |
443 | ||
1c908217 RGS |
444 | /* Now iterate our MRO (parents), and do a few things: |
445 | 1) instantiate with the "fake" flag if they don't exist | |
446 | 2) flag them as universal if we are universal | |
447 | 3) Add everything from our isarev to their isarev | |
448 | */ | |
449 | ||
450 | /* We're starting at the 2nd element, skipping ourselves here */ | |
e1a479c5 BB |
451 | linear_mro = mro_get_linear_isa(stash); |
452 | svp = AvARRAY(linear_mro) + 1; | |
453 | items = AvFILLp(linear_mro); | |
1c908217 | 454 | |
e1a479c5 BB |
455 | while (items--) { |
456 | SV* const sv = *svp++; | |
457 | struct mro_meta* mrometa; | |
458 | HV* mroisarev; | |
459 | ||
460 | HV* mrostash = gv_stashsv(sv, 0); | |
461 | if(!mrostash) { | |
462 | mrostash = gv_stashsv(sv, GV_ADD); | |
463 | /* | |
464 | We created the package on the fly, so | |
465 | that we could store isarev information. | |
466 | This flag lets gv_fetchmeth know about it, | |
467 | so that it can still generate the very useful | |
468 | "Can't locate package Foo for @Bar::ISA" warning. | |
469 | */ | |
470 | HvMROMETA(mrostash)->fake = 1; | |
471 | } | |
472 | ||
473 | mrometa = HvMROMETA(mrostash); | |
474 | mroisarev = mrometa->mro_isarev; | |
475 | ||
476 | /* is_universal is viral */ | |
477 | if(meta->is_universal) | |
478 | mrometa->is_universal = 1; | |
479 | ||
480 | if(!mroisarev) | |
481 | mroisarev = mrometa->mro_isarev = newHV(); | |
482 | ||
25270bc0 NC |
483 | /* This hash only ever contains PL_sv_yes. Storing it over itself is |
484 | almost as cheap as calling hv_exists, so on aggregate we expect to | |
485 | save time by not making two calls to the common HV code for the | |
486 | case where it doesn't exist. */ | |
487 | ||
488 | hv_store(mroisarev, stashname, strlen(stashname), &PL_sv_yes, 0); | |
e1a479c5 BB |
489 | |
490 | if(isarev) { | |
491 | hv_iterinit(isarev); | |
492 | while((iter = hv_iternext(isarev))) { | |
493 | SV* revkey = hv_iterkeysv(iter); | |
25270bc0 | 494 | hv_store_ent(mroisarev, revkey, &PL_sv_yes, 0); |
e1a479c5 BB |
495 | } |
496 | } | |
497 | } | |
498 | } | |
499 | ||
500 | /* | |
501 | =for apidoc mro_method_changed_in | |
502 | ||
503 | Like C<mro_isa_changed_in>, but invalidates method | |
504 | caching on any child classes of the given stash, so | |
505 | that they might notice the changes in this one. | |
506 | ||
507 | Ideally, all instances of C<PL_sub_generation++> in | |
508 | the perl source should be replaced by calls to this. | |
509 | Some already are, but some are more difficult to | |
510 | replace. | |
511 | ||
512 | Perl has always had problems with method caches | |
513 | getting out of sync when one directly manipulates | |
514 | stashes via things like C<%{Foo::} = %{Bar::}> or | |
515 | C<${Foo::}{bar} = ...> or the equivalent. If | |
516 | you do this in core or XS code, call this afterwards | |
517 | on the destination stash to get things back in sync. | |
518 | ||
519 | If you're doing such a thing from pure perl, use | |
520 | C<mro::method_changed_in(classname)>, which | |
521 | just calls this. | |
522 | ||
523 | =cut | |
524 | */ | |
525 | void | |
526 | Perl_mro_method_changed_in(pTHX_ HV *stash) | |
527 | { | |
528 | struct mro_meta* meta = HvMROMETA(stash); | |
529 | HV* isarev; | |
530 | HE* iter; | |
531 | ||
532 | /* If stash is UNIVERSAL, or one of UNIVERSAL's parents, | |
533 | invalidate all method caches globally */ | |
534 | if(meta->is_universal) { | |
535 | PL_sub_generation++; | |
536 | return; | |
537 | } | |
538 | ||
539 | /* else, invalidate the method caches of all child classes, | |
540 | but not itself */ | |
541 | if((isarev = meta->mro_isarev)) { | |
542 | hv_iterinit(isarev); | |
543 | while((iter = hv_iternext(isarev))) { | |
544 | SV* revkey = hv_iterkeysv(iter); | |
545 | HV* revstash = gv_stashsv(revkey, 0); | |
546 | struct mro_meta* mrometa = HvMROMETA(revstash); | |
547 | mrometa->sub_generation++; | |
548 | if(mrometa->mro_nextmethod) | |
549 | hv_clear(mrometa->mro_nextmethod); | |
550 | } | |
551 | } | |
552 | } | |
553 | ||
554 | /* These two are static helpers for next::method and friends, | |
555 | and re-implement a bunch of the code from pp_caller() in | |
556 | a more efficient manner for this particular usage. | |
557 | */ | |
558 | ||
559 | STATIC I32 | |
560 | __dopoptosub_at(const PERL_CONTEXT *cxstk, I32 startingblock) { | |
561 | I32 i; | |
562 | for (i = startingblock; i >= 0; i--) { | |
563 | if(CxTYPE((PERL_CONTEXT*)(&cxstk[i])) == CXt_SUB) return i; | |
564 | } | |
565 | return i; | |
566 | } | |
567 | ||
568 | STATIC SV* | |
569 | __nextcan(pTHX_ SV* self, I32 throw_nomethod) | |
570 | { | |
571 | register I32 cxix; | |
572 | register const PERL_CONTEXT *ccstack = cxstack; | |
573 | const PERL_SI *top_si = PL_curstackinfo; | |
574 | HV* selfstash; | |
575 | GV* cvgv; | |
576 | SV *stashname; | |
577 | const char *fq_subname; | |
578 | const char *subname; | |
579 | STRLEN fq_subname_len; | |
580 | STRLEN stashname_len; | |
581 | STRLEN subname_len; | |
582 | SV* sv; | |
583 | GV** gvp; | |
584 | AV* linear_av; | |
585 | SV** linear_svp; | |
586 | SV* linear_sv; | |
587 | HV* curstash; | |
588 | GV* candidate = NULL; | |
589 | CV* cand_cv = NULL; | |
590 | const char *hvname; | |
591 | I32 items; | |
592 | struct mro_meta* selfmeta; | |
593 | HV* nmcache; | |
594 | HE* cache_entry; | |
595 | ||
596 | if(sv_isobject(self)) | |
597 | selfstash = SvSTASH(SvRV(self)); | |
598 | else | |
599 | selfstash = gv_stashsv(self, 0); | |
600 | ||
601 | assert(selfstash); | |
602 | ||
603 | hvname = HvNAME_get(selfstash); | |
604 | if (!hvname) | |
605 | Perl_croak(aTHX_ "Can't use anonymous symbol table for method lookup"); | |
606 | ||
607 | cxix = __dopoptosub_at(cxstack, cxstack_ix); | |
608 | ||
609 | /* This block finds the contextually-enclosing fully-qualified subname, | |
610 | much like looking at (caller($i))[3] until you find a real sub that | |
611 | isn't ANON, etc */ | |
612 | for (;;) { | |
613 | /* we may be in a higher stacklevel, so dig down deeper */ | |
614 | while (cxix < 0) { | |
615 | if(top_si->si_type == PERLSI_MAIN) | |
616 | Perl_croak(aTHX_ "next::method/next::can/maybe::next::method must be used in method context"); | |
617 | top_si = top_si->si_prev; | |
618 | ccstack = top_si->si_cxstack; | |
619 | cxix = __dopoptosub_at(ccstack, top_si->si_cxix); | |
620 | } | |
621 | ||
622 | if(CxTYPE((PERL_CONTEXT*)(&ccstack[cxix])) != CXt_SUB | |
623 | || (PL_DBsub && GvCV(PL_DBsub) && ccstack[cxix].blk_sub.cv == GvCV(PL_DBsub))) { | |
624 | cxix = __dopoptosub_at(ccstack, cxix - 1); | |
625 | continue; | |
626 | } | |
627 | ||
628 | { | |
629 | const I32 dbcxix = __dopoptosub_at(ccstack, cxix - 1); | |
630 | if (PL_DBsub && GvCV(PL_DBsub) && dbcxix >= 0 && ccstack[dbcxix].blk_sub.cv == GvCV(PL_DBsub)) { | |
631 | if(CxTYPE((PERL_CONTEXT*)(&ccstack[dbcxix])) != CXt_SUB) { | |
632 | cxix = dbcxix; | |
633 | continue; | |
634 | } | |
635 | } | |
636 | } | |
637 | ||
638 | cvgv = CvGV(ccstack[cxix].blk_sub.cv); | |
639 | ||
640 | if(!isGV(cvgv)) { | |
641 | cxix = __dopoptosub_at(ccstack, cxix - 1); | |
642 | continue; | |
643 | } | |
644 | ||
645 | /* we found a real sub here */ | |
646 | sv = sv_2mortal(newSV(0)); | |
647 | ||
648 | gv_efullname3(sv, cvgv, NULL); | |
649 | ||
650 | fq_subname = SvPVX(sv); | |
651 | fq_subname_len = SvCUR(sv); | |
652 | ||
653 | subname = strrchr(fq_subname, ':'); | |
654 | if(!subname) | |
655 | Perl_croak(aTHX_ "next::method/next::can/maybe::next::method cannot find enclosing method"); | |
656 | ||
657 | subname++; | |
658 | subname_len = fq_subname_len - (subname - fq_subname); | |
659 | if(subname_len == 8 && strEQ(subname, "__ANON__")) { | |
660 | cxix = __dopoptosub_at(ccstack, cxix - 1); | |
661 | continue; | |
662 | } | |
663 | break; | |
664 | } | |
665 | ||
666 | /* If we made it to here, we found our context */ | |
667 | ||
1c908217 RGS |
668 | /* Initialize the next::method cache for this stash |
669 | if necessary */ | |
e1a479c5 BB |
670 | selfmeta = HvMROMETA(selfstash); |
671 | if(!(nmcache = selfmeta->mro_nextmethod)) { | |
672 | nmcache = selfmeta->mro_nextmethod = newHV(); | |
673 | } | |
674 | ||
1c908217 | 675 | /* Use the cached coderef if it exists */ |
640da897 | 676 | else if((cache_entry = hv_fetch_ent(nmcache, sv, 0, 0))) { |
e1a479c5 BB |
677 | SV* val = HeVAL(cache_entry); |
678 | if(val == &PL_sv_undef) { | |
679 | if(throw_nomethod) | |
680 | Perl_croak(aTHX_ "No next::method '%s' found for %s", subname, hvname); | |
681 | } | |
682 | return val; | |
683 | } | |
684 | ||
685 | /* beyond here is just for cache misses, so perf isn't as critical */ | |
686 | ||
687 | stashname_len = subname - fq_subname - 2; | |
688 | stashname = sv_2mortal(newSVpvn(fq_subname, stashname_len)); | |
689 | ||
690 | linear_av = mro_get_linear_isa_c3(selfstash, 0); /* has ourselves at the top of the list */ | |
691 | ||
692 | linear_svp = AvARRAY(linear_av); | |
693 | items = AvFILLp(linear_av) + 1; | |
694 | ||
1c908217 RGS |
695 | /* Walk down our MRO, skipping everything up |
696 | to the contextually enclosing class */ | |
e1a479c5 BB |
697 | while (items--) { |
698 | linear_sv = *linear_svp++; | |
699 | assert(linear_sv); | |
700 | if(sv_eq(linear_sv, stashname)) | |
701 | break; | |
702 | } | |
703 | ||
1c908217 RGS |
704 | /* Now search the remainder of the MRO for the |
705 | same method name as the contextually enclosing | |
706 | method */ | |
e1a479c5 BB |
707 | if(items > 0) { |
708 | while (items--) { | |
709 | linear_sv = *linear_svp++; | |
710 | assert(linear_sv); | |
711 | curstash = gv_stashsv(linear_sv, FALSE); | |
712 | ||
713 | if (!curstash || (HvMROMETA(curstash)->fake && !HvFILL(curstash))) { | |
b0c482e3 RGS |
714 | if (ckWARN(WARN_SYNTAX)) |
715 | Perl_warner(aTHX_ packWARN(WARN_SYNTAX), "Can't locate package %"SVf" for @%s::ISA", | |
e1a479c5 BB |
716 | (void*)linear_sv, hvname); |
717 | continue; | |
718 | } | |
719 | ||
720 | assert(curstash); | |
721 | ||
722 | gvp = (GV**)hv_fetch(curstash, subname, subname_len, 0); | |
723 | if (!gvp) continue; | |
724 | ||
725 | candidate = *gvp; | |
726 | assert(candidate); | |
727 | ||
728 | if (SvTYPE(candidate) != SVt_PVGV) | |
729 | gv_init(candidate, curstash, subname, subname_len, TRUE); | |
1c908217 RGS |
730 | |
731 | /* Notably, we only look for real entries, not method cache | |
732 | entries, because in C3 the method cache of a parent is not | |
733 | valid for the child */ | |
e1a479c5 BB |
734 | if (SvTYPE(candidate) == SVt_PVGV && (cand_cv = GvCV(candidate)) && !GvCVGEN(candidate)) { |
735 | SvREFCNT_inc_simple_void_NN((SV*)cand_cv); | |
736 | hv_store_ent(nmcache, newSVsv(sv), (SV*)cand_cv, 0); | |
737 | return (SV*)cand_cv; | |
738 | } | |
739 | } | |
740 | } | |
741 | ||
742 | hv_store_ent(nmcache, newSVsv(sv), &PL_sv_undef, 0); | |
743 | if(throw_nomethod) | |
744 | Perl_croak(aTHX_ "No next::method '%s' found for %s", subname, hvname); | |
745 | return &PL_sv_undef; | |
746 | } | |
747 | ||
748 | #include "XSUB.h" | |
749 | ||
750 | XS(XS_mro_get_linear_isa); | |
751 | XS(XS_mro_set_mro); | |
752 | XS(XS_mro_get_mro); | |
753 | XS(XS_mro_get_isarev); | |
754 | XS(XS_mro_is_universal); | |
c5860d66 CB |
755 | XS(XS_mro_get_global_sub_gen); |
756 | XS(XS_mro_invalidate_method_caches); | |
e1a479c5 BB |
757 | XS(XS_mro_get_sub_generation); |
758 | XS(XS_mro_method_changed_in); | |
759 | XS(XS_next_can); | |
760 | XS(XS_next_method); | |
761 | XS(XS_maybe_next_method); | |
762 | ||
763 | void | |
764 | Perl_boot_core_mro(pTHX) | |
765 | { | |
766 | dVAR; | |
767 | static const char file[] = __FILE__; | |
768 | ||
769 | newXSproto("mro::get_linear_isa", XS_mro_get_linear_isa, file, "$;$"); | |
770 | newXSproto("mro::set_mro", XS_mro_set_mro, file, "$$"); | |
771 | newXSproto("mro::get_mro", XS_mro_get_mro, file, "$"); | |
772 | newXSproto("mro::get_isarev", XS_mro_get_isarev, file, "$"); | |
773 | newXSproto("mro::is_universal", XS_mro_is_universal, file, "$"); | |
c5860d66 CB |
774 | newXSproto("mro::get_global_sub_generation", XS_mro_get_global_sub_gen, file, ""); |
775 | newXSproto("mro::invalidate_all_method_caches", XS_mro_invalidate_method_caches, file, ""); | |
e1a479c5 BB |
776 | newXSproto("mro::get_sub_generation", XS_mro_get_sub_generation, file, "$"); |
777 | newXSproto("mro::method_changed_in", XS_mro_method_changed_in, file, "$"); | |
778 | newXS("next::can", XS_next_can, file); | |
779 | newXS("next::method", XS_next_method, file); | |
780 | newXS("maybe::next::method", XS_maybe_next_method, file); | |
781 | } | |
782 | ||
783 | XS(XS_mro_get_linear_isa) { | |
784 | dVAR; | |
785 | dXSARGS; | |
786 | AV* RETVAL; | |
787 | HV* class_stash; | |
788 | SV* classname; | |
789 | ||
790 | PERL_UNUSED_ARG(cv); | |
791 | ||
792 | if(items < 1 || items > 2) | |
793 | Perl_croak(aTHX_ "Usage: mro::get_linear_isa(classname [, type ])"); | |
794 | ||
795 | classname = ST(0); | |
796 | class_stash = gv_stashsv(classname, 0); | |
797 | if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname)); | |
798 | ||
799 | if(items > 1) { | |
800 | char* which = SvPV_nolen(ST(1)); | |
801 | if(strEQ(which, "dfs")) | |
802 | RETVAL = mro_get_linear_isa_dfs(class_stash, 0); | |
803 | else if(strEQ(which, "c3")) | |
804 | RETVAL = mro_get_linear_isa_c3(class_stash, 0); | |
805 | else | |
806 | Perl_croak(aTHX_ "Invalid mro name: '%s'", which); | |
807 | } | |
808 | else { | |
809 | RETVAL = mro_get_linear_isa(class_stash); | |
810 | } | |
811 | ||
812 | ST(0) = newRV_inc((SV*)RETVAL); | |
813 | sv_2mortal(ST(0)); | |
814 | XSRETURN(1); | |
815 | } | |
816 | ||
817 | XS(XS_mro_set_mro) | |
818 | { | |
819 | dVAR; | |
820 | dXSARGS; | |
821 | SV* classname; | |
822 | char* whichstr; | |
823 | mro_alg which; | |
824 | HV* class_stash; | |
825 | struct mro_meta* meta; | |
826 | ||
827 | PERL_UNUSED_ARG(cv); | |
828 | ||
829 | if (items != 2) | |
830 | Perl_croak(aTHX_ "Usage: mro::set_mro(classname, type)"); | |
831 | ||
832 | classname = ST(0); | |
833 | whichstr = SvPV_nolen(ST(1)); | |
834 | class_stash = gv_stashsv(classname, GV_ADD); | |
835 | if(!class_stash) Perl_croak(aTHX_ "Cannot create class: '%"SVf"'!", SVfARG(classname)); | |
836 | meta = HvMROMETA(class_stash); | |
837 | ||
838 | if(strEQ(whichstr, "dfs")) | |
839 | which = MRO_DFS; | |
840 | else if(strEQ(whichstr, "c3")) | |
841 | which = MRO_C3; | |
842 | else | |
843 | Perl_croak(aTHX_ "Invalid mro name: '%s'", whichstr); | |
844 | ||
845 | if(meta->mro_which != which) { | |
846 | meta->mro_which = which; | |
847 | /* Only affects local method cache, not | |
848 | even child classes */ | |
849 | meta->sub_generation++; | |
850 | if(meta->mro_nextmethod) | |
851 | hv_clear(meta->mro_nextmethod); | |
852 | } | |
853 | ||
854 | XSRETURN_EMPTY; | |
855 | } | |
856 | ||
857 | ||
858 | XS(XS_mro_get_mro) | |
859 | { | |
860 | dVAR; | |
861 | dXSARGS; | |
862 | SV* classname; | |
863 | HV* class_stash; | |
864 | struct mro_meta* meta; | |
865 | ||
866 | PERL_UNUSED_ARG(cv); | |
867 | ||
868 | if (items != 1) | |
869 | Perl_croak(aTHX_ "Usage: mro::get_mro(classname)"); | |
870 | ||
871 | classname = ST(0); | |
872 | class_stash = gv_stashsv(classname, 0); | |
873 | if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname)); | |
874 | meta = HvMROMETA(class_stash); | |
875 | ||
876 | if(meta->mro_which == MRO_DFS) | |
877 | ST(0) = sv_2mortal(newSVpvn("dfs", 3)); | |
878 | else | |
879 | ST(0) = sv_2mortal(newSVpvn("c3", 2)); | |
880 | ||
881 | XSRETURN(1); | |
882 | } | |
883 | ||
884 | XS(XS_mro_get_isarev) | |
885 | { | |
886 | dVAR; | |
887 | dXSARGS; | |
888 | SV* classname; | |
889 | HV* class_stash; | |
890 | HV* isarev; | |
891 | ||
892 | PERL_UNUSED_ARG(cv); | |
893 | ||
894 | if (items != 1) | |
895 | Perl_croak(aTHX_ "Usage: mro::get_isarev(classname)"); | |
896 | ||
897 | classname = ST(0); | |
898 | ||
899 | class_stash = gv_stashsv(classname, 0); | |
900 | if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname)); | |
901 | ||
902 | SP -= items; | |
903 | ||
904 | if((isarev = HvMROMETA(class_stash)->mro_isarev)) { | |
905 | HE* iter; | |
906 | hv_iterinit(isarev); | |
907 | while((iter = hv_iternext(isarev))) | |
908 | XPUSHs(hv_iterkeysv(iter)); | |
909 | } | |
910 | ||
911 | PUTBACK; | |
912 | return; | |
913 | } | |
914 | ||
915 | XS(XS_mro_is_universal) | |
916 | { | |
917 | dVAR; | |
918 | dXSARGS; | |
919 | SV* classname; | |
920 | HV* class_stash; | |
921 | ||
922 | PERL_UNUSED_ARG(cv); | |
923 | ||
924 | if (items != 1) | |
925 | Perl_croak(aTHX_ "Usage: mro::get_mro(classname)"); | |
926 | ||
927 | classname = ST(0); | |
928 | class_stash = gv_stashsv(classname, 0); | |
929 | if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname)); | |
930 | ||
9edc5bb8 RGS |
931 | if (HvMROMETA(class_stash)->is_universal) |
932 | XSRETURN_YES; | |
933 | else | |
934 | XSRETURN_NO; | |
e1a479c5 BB |
935 | } |
936 | ||
c5860d66 | 937 | XS(XS_mro_get_global_sub_gen) |
e1a479c5 BB |
938 | { |
939 | dVAR; | |
940 | dXSARGS; | |
941 | ||
942 | PERL_UNUSED_ARG(cv); | |
943 | ||
944 | if (items != 0) | |
945 | Perl_croak(aTHX_ "Usage: mro::get_global_sub_generation()"); | |
946 | ||
947 | ST(0) = sv_2mortal(newSViv(PL_sub_generation)); | |
948 | XSRETURN(1); | |
949 | } | |
950 | ||
c5860d66 | 951 | XS(XS_mro_invalidate_method_caches) |
e1a479c5 BB |
952 | { |
953 | dVAR; | |
954 | dXSARGS; | |
955 | ||
956 | PERL_UNUSED_ARG(cv); | |
957 | ||
958 | if (items != 0) | |
959 | Perl_croak(aTHX_ "Usage: mro::invalidate_all_method_caches()"); | |
960 | ||
961 | PL_sub_generation++; | |
962 | ||
963 | XSRETURN_EMPTY; | |
964 | } | |
965 | ||
966 | XS(XS_mro_get_sub_generation) | |
967 | { | |
968 | dVAR; | |
969 | dXSARGS; | |
970 | SV* classname; | |
971 | HV* class_stash; | |
972 | ||
973 | PERL_UNUSED_ARG(cv); | |
974 | ||
975 | if(items != 1) | |
976 | Perl_croak(aTHX_ "Usage: mro::get_sub_generation(classname)"); | |
977 | ||
978 | classname = ST(0); | |
979 | class_stash = gv_stashsv(classname, 0); | |
980 | if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname)); | |
981 | ||
982 | ST(0) = sv_2mortal(newSViv(HvMROMETA(class_stash)->sub_generation)); | |
983 | XSRETURN(1); | |
984 | } | |
985 | ||
986 | XS(XS_mro_method_changed_in) | |
987 | { | |
988 | dVAR; | |
989 | dXSARGS; | |
990 | SV* classname; | |
991 | HV* class_stash; | |
992 | ||
993 | PERL_UNUSED_ARG(cv); | |
994 | ||
995 | if(items != 1) | |
996 | Perl_croak(aTHX_ "Usage: mro::method_changed_in(classname)"); | |
997 | ||
998 | classname = ST(0); | |
999 | ||
1000 | class_stash = gv_stashsv(classname, 0); | |
1001 | if(!class_stash) Perl_croak(aTHX_ "No such class: '%"SVf"'!", SVfARG(classname)); | |
1002 | ||
1003 | mro_method_changed_in(class_stash); | |
1004 | ||
1005 | XSRETURN_EMPTY; | |
1006 | } | |
1007 | ||
1008 | XS(XS_next_can) | |
1009 | { | |
1010 | dVAR; | |
1011 | dXSARGS; | |
1012 | SV* self = ST(0); | |
1013 | SV* methcv = __nextcan(aTHX_ self, 0); | |
1014 | ||
1015 | PERL_UNUSED_ARG(cv); | |
1016 | PERL_UNUSED_VAR(items); | |
1017 | ||
1018 | if(methcv == &PL_sv_undef) { | |
1019 | ST(0) = &PL_sv_undef; | |
1020 | } | |
1021 | else { | |
1022 | ST(0) = sv_2mortal(newRV_inc(methcv)); | |
1023 | } | |
1024 | ||
1025 | XSRETURN(1); | |
1026 | } | |
1027 | ||
1028 | XS(XS_next_method) | |
1029 | { | |
1030 | dMARK; | |
1031 | dAX; | |
1032 | SV* self = ST(0); | |
1033 | SV* methcv = __nextcan(aTHX_ self, 1); | |
1034 | ||
1035 | PERL_UNUSED_ARG(cv); | |
1036 | ||
1037 | PL_markstack_ptr++; | |
1038 | call_sv(methcv, GIMME_V); | |
1039 | } | |
1040 | ||
1041 | XS(XS_maybe_next_method) | |
1042 | { | |
1043 | dMARK; | |
1044 | dAX; | |
1045 | SV* self = ST(0); | |
1046 | SV* methcv = __nextcan(aTHX_ self, 0); | |
1047 | ||
1048 | PERL_UNUSED_ARG(cv); | |
1049 | ||
1050 | if(methcv == &PL_sv_undef) { | |
1051 | ST(0) = &PL_sv_undef; | |
1052 | XSRETURN(1); | |
1053 | } | |
1054 | ||
1055 | PL_markstack_ptr++; | |
1056 | call_sv(methcv, GIMME_V); | |
1057 | } | |
1058 | ||
1059 | /* | |
1060 | * Local variables: | |
1061 | * c-indentation-style: bsd | |
1062 | * c-basic-offset: 4 | |
1063 | * indent-tabs-mode: t | |
1064 | * End: | |
1065 | * | |
1066 | * ex: set ts=8 sts=4 sw=4 noet: | |
1067 | */ |