XS.xs

   1
   2 #include "EXTERN.h"
   3 #include "perl.h"
   4 #include "XSUB.h"
   5
   6 /* Most of this code is backported from the bleadperl patch's
   7    mro.c, and then modified to work with Class::C3's
   8    internals.
   9 */
  10
  11 AV*
  12 __mro_linear_isa_c3(pTHX_ HV* stash, HV* cache, I32 level)
  13 {
  14     AV* retval;
  15     GV** gvp;
  16     GV* gv;
  17     AV* isa;
  18     const char* stashname;
  19     STRLEN stashname_len;
  20
  21     assert(stash);
  22
  23     stashname = HvNAME(stash);
  24     stashname_len = strlen(stashname);
  25     if (!stashname)
  26       Perl_croak(aTHX_
  27                  "Can't linearize anonymous symbol table");
  28
  29     if (level > 100)
  30         Perl_croak(aTHX_ "Recursive inheritance detected in package '%s'",
  31               stashname);
  32
  33     if(!cache) {
  34         cache = (HV*)sv_2mortal((SV*)newHV());
  35     }
  36     else {
  37         SV** cache_entry = hv_fetch(cache, stashname, stashname_len, 0);
  38         if(cache_entry)
  39             return (AV*)SvREFCNT_inc(*cache_entry);
  40     }
  41
  42     /* not in cache, make a new one */
  43
  44     retval = newAV();
  45     av_push(retval, newSVpvn(stashname, stashname_len)); /* us first */
  46
  47     gvp = (GV**)hv_fetch(stash, "ISA", 3, FALSE);
  48     isa = (gvp && (gv = *gvp) && gv != (GV*)&PL_sv_undef) ? GvAV(gv) : NULL;
  49
  50     if(isa && AvFILLp(isa) >= 0) {
  51         SV** seqs_ptr;
  52         I32 seqs_items;
  53         HV* tails = (HV*)sv_2mortal((SV*)newHV());
  54         AV* seqs = (AV*)sv_2mortal((SV*)newAV());
  55         I32 items = AvFILLp(isa) + 1;
  56         SV** isa_ptr = AvARRAY(isa);
  57         while(items--) {
  58             AV* isa_lin;
  59             SV* isa_item = *isa_ptr++;
  60             HV* isa_item_stash = gv_stashsv(isa_item, 0);
  61             if(!isa_item_stash) {
  62                 isa_lin = newAV();
  63                 av_push(isa_lin, newSVsv(isa_item));
  64             }
  65             else {
  66                 isa_lin = (AV*)sv_2mortal((SV*)__mro_linear_isa_c3(aTHX_ isa_item_stash, cache, level + 1)); /* recursion */
  67             }
  68             av_push(seqs, (SV*)av_make(AvFILLp(isa_lin)+1, AvARRAY(isa_lin)));
  69         }
  70         av_push(seqs, (SV*)av_make(AvFILLp(isa)+1, AvARRAY(isa)));
  71
  72         seqs_ptr = AvARRAY(seqs);
  73         seqs_items = AvFILLp(seqs) + 1;
  74         while(seqs_items--) {
  75             AV* seq = (AV*)*seqs_ptr++;
  76             I32 seq_items = AvFILLp(seq);
  77             if(seq_items > 0) {
  78                 SV** seq_ptr = AvARRAY(seq) + 1;
  79                 while(seq_items--) {
  80                     SV* seqitem = *seq_ptr++;
  81                     HE* he = hv_fetch_ent(tails, seqitem, 0, 0);
  82                     if(!he) {
  83                         hv_store_ent(tails, seqitem, newSViv(1), 0);
  84                     }
  85                     else {
  86                         SV* val = HeVAL(he);
  87                         sv_inc(val);
  88                     }
  89                 }
  90             }
  91         }
  92
  93         while(1) {
  94             SV* seqhead = NULL;
  95             SV* cand = NULL;
  96             SV* winner = NULL;
  97             SV* val;
  98             HE* tail_entry;
  99             AV* seq;
 100             SV** avptr = AvARRAY(seqs);
 101             items = AvFILLp(seqs)+1;
 102             while(items--) {
 103                 SV** svp;
 104                 seq = (AV*)*avptr++;
 105                 if(AvFILLp(seq) < 0) continue;
 106                 svp = av_fetch(seq, 0, 0);
 107                 seqhead = *svp;
 108                 if(!winner) {
 109                     cand = seqhead;
 110                     if((tail_entry = hv_fetch_ent(tails, cand, 0, 0))
 111                        && (val = HeVAL(tail_entry))
 112                        && (SvIVx(val) > 0))
 113                            continue;
 114                     winner = newSVsv(cand);
 115                     av_push(retval, winner);
 116                 }
 117                 if(!sv_cmp(seqhead, winner)) {
 118                     sv_2mortal(av_shift(seq));
 119                     if(AvFILLp(seq) < 0) continue;
 120                     svp = av_fetch(seq, 0, 0);
 121                     seqhead = *svp;
 122                     tail_entry = hv_fetch_ent(tails, seqhead, 0, 0);
 123                     val = HeVAL(tail_entry);
 124                     sv_dec(val);
 125                 }
 126             }
 127             if(!cand) break;
 128             if(!winner) {
 129                 SvREFCNT_dec(retval);
 130                 Perl_croak(aTHX_ "Inconsistent hierarchy during C3 merge of class '%s': "
 131                     "merging failed on parent '%s'", stashname, SvPV_nolen(cand));
 132             }
 133         }
 134     }
 135
 136     SvREADONLY_on(retval);
 137     hv_store(cache, stashname, stashname_len, (SV*)retval, 0);
 138     return (AV*)SvREFCNT_inc(retval);
 139 }
 140
 141 STATIC I32
 142 __dopoptosub_at(const PERL_CONTEXT *cxstk, I32 startingblock) {
 143     I32 i;
 144     for (i = startingblock; i >= 0; i--) {
 145         if(CxTYPE((PERL_CONTEXT*)(&cxstk[i])) == CXt_SUB) return i;
 146     }
 147     return i;
 148 }
 149
 150 STATIC SV*
 151 __nextcan(pTHX_ SV* self, I32 throw_nomethod)
 152 {
 153     register I32 cxix;
 154     register const PERL_CONTEXT *ccstack = cxstack;
 155     const PERL_SI *top_si = PL_curstackinfo;
 156     HV* selfstash;
 157     GV* cvgv;
 158     SV *stashname;
 159     const char *fq_subname;
 160     const char *subname;
 161     STRLEN fq_subname_len;
 162     STRLEN stashname_len;
 163     STRLEN subname_len;
 164     SV* sv;
 165     GV** gvp;
 166     AV* linear_av;
 167     SV** linear_svp;
 168     SV* linear_sv;
 169     HV* cstash;
 170     GV* candidate = NULL;
 171     CV* cand_cv = NULL;
 172     const char *hvname;
 173     I32 items;
 174     HV* nmcache;
 175     HE* cache_entry;
 176     SV* cachekey;
 177
 178     if(sv_isobject(self))
 179         selfstash = SvSTASH(SvRV(self));
 180     else
 181         selfstash = gv_stashsv(self, 0);
 182
 183     assert(selfstash);
 184
 185     hvname = HvNAME(selfstash);
 186     if (!hvname)
 187         croak("Can't use anonymous symbol table for method lookup");
 188
 189     cxix = __dopoptosub_at(cxstack, cxstack_ix);
 190
 191     /* This block finds the contextually-enclosing fully-qualified subname,
 192        much like looking at (caller($i))[3] until you find a real sub that
 193        isn't ANON, etc */
 194     for (;;) {
 195         /* we may be in a higher stacklevel, so dig down deeper */
 196         while (cxix < 0) {
 197             if(top_si->si_type == PERLSI_MAIN)
 198                 croak("next::method/next::can/maybe::next::method must be used in method context");
 199             top_si = top_si->si_prev;
 200             ccstack = top_si->si_cxstack;
 201             cxix = __dopoptosub_at(ccstack, top_si->si_cxix);
 202         }
 203
 204         if(CxTYPE((PERL_CONTEXT*)(&ccstack[cxix])) != CXt_SUB
 205           || (PL_DBsub && GvCV(PL_DBsub) && ccstack[cxix].blk_sub.cv == GvCV(PL_DBsub))) {
 206             cxix = __dopoptosub_at(ccstack, cxix - 1);
 207             continue;
 208         }
 209
 210         {
 211             const I32 dbcxix = __dopoptosub_at(ccstack, cxix - 1);
 212             if (PL_DBsub && GvCV(PL_DBsub) && dbcxix >= 0 && ccstack[dbcxix].blk_sub.cv == GvCV(PL_DBsub)) {
 213                 if(CxTYPE((PERL_CONTEXT*)(&ccstack[dbcxix])) != CXt_SUB) {
 214                     cxix = dbcxix;
 215                     continue;
 216                 }
 217             }
 218         }
 219
 220         cvgv = CvGV(ccstack[cxix].blk_sub.cv);
 221
 222         if(!isGV(cvgv)) {
 223             cxix = __dopoptosub_at(ccstack, cxix - 1);
 224             continue;
 225         }
 226
 227         /* we found a real sub here */
 228         sv = sv_2mortal(newSV(0));
 229
 230         gv_efullname3(sv, cvgv, NULL);
 231
 232         fq_subname = SvPVX(sv);
 233         fq_subname_len = SvCUR(sv);
 234
 235         subname = strrchr(fq_subname, ':');
 236         if(!subname)
 237             croak("next::method/next::can/maybe::next::method cannot find enclosing method");
 238
 239         subname++;
 240         subname_len = fq_subname_len - (subname - fq_subname);
 241         if(subname_len == 8 && strEQ(subname, "__ANON__")) {
 242             cxix = __dopoptosub_at(ccstack, cxix - 1);
 243             continue;
 244         }
 245         break;
 246     }
 247
 248     /* If we made it to here, we found our context */
 249
 250     /* cachekey = "objpkg|context::method::name" */
 251     cachekey = sv_2mortal(newSVpv(hvname, 0));
 252     sv_catpvn(cachekey, "|", 1);
 253     sv_catsv(cachekey, sv);
 254
 255     nmcache = get_hv("next::METHOD_CACHE", 1);
 256     if((cache_entry = hv_fetch_ent(nmcache, cachekey, 0, 0))) {
 257         SV* val = HeVAL(cache_entry);
 258         if(val == &PL_sv_undef) {
 259             if(throw_nomethod)
 260                 croak("No next::method '%s' found for %s", subname, hvname);
 261             return &PL_sv_undef;
 262         }
 263         return SvREFCNT_inc(val);
 264     }
 265
 266     /* beyond here is just for cache misses, so perf isn't as critical */
 267
 268     stashname_len = subname - fq_subname - 2;
 269     stashname = sv_2mortal(newSVpvn(fq_subname, stashname_len));
 270
 271     linear_av = __mro_linear_isa_c3(aTHX_ selfstash, NULL, 0);
 272
 273     linear_svp = AvARRAY(linear_av);
 274     items = AvFILLp(linear_av) + 1;
 275
 276     while (items--) {
 277         linear_sv = *linear_svp++;
 278         assert(linear_sv);
 279         if(sv_eq(linear_sv, stashname))
 280             break;
 281     }
 282
 283     if(items > 0) {
 284         SV* sub_sv = sv_2mortal(newSVpv(subname, subname_len));
 285         HV* cc3_mro = get_hv("Class::C3::MRO", 0);
 286
 287         while (items--) {
 288             linear_sv = *linear_svp++;
 289             assert(linear_sv);
 290
 291             if(cc3_mro) {
 292                 HE* he_cc3_mro_class = hv_fetch_ent(cc3_mro, linear_sv, 0, 0);
 293                 if(he_cc3_mro_class) {
 294                     SV* cc3_mro_class_sv = HeVAL(he_cc3_mro_class);
 295                     if(SvROK(cc3_mro_class_sv)) {
 296                         HV* cc3_mro_class = (HV*)SvRV(cc3_mro_class_sv);
 297                         SV** svp_cc3_mro_class_methods = hv_fetch(cc3_mro_class, "methods", 7, 0);
 298                         if(svp_cc3_mro_class_methods) {
 299                             SV* cc3_mro_class_methods_sv = *svp_cc3_mro_class_methods;
 300                             if(SvROK(cc3_mro_class_methods_sv)) {
 301                                 HV* cc3_mro_class_methods = (HV*)SvRV(cc3_mro_class_methods_sv);
 302                                 if(hv_exists_ent(cc3_mro_class_methods, sub_sv, 0))
 303                                     continue;
 304                             }
 305                         }
 306                     }
 307                 }
 308             }
 309
 310             cstash = gv_stashsv(linear_sv, FALSE);
 311
 312             if (!cstash) {
 313                 if (ckWARN(WARN_MISC))
 314                     Perl_warner(aTHX_ packWARN(WARN_MISC), "Can't locate package %"SVf" for @%s::ISA",
 315                         (void*)linear_sv, hvname);
 316                 continue;
 317             }
 318
 319             assert(cstash);
 320
 321             gvp = (GV**)hv_fetch(cstash, subname, subname_len, 0);
 322             if (!gvp) continue;
 323
 324             candidate = *gvp;
 325             assert(candidate);
 326
 327             if (SvTYPE(candidate) != SVt_PVGV)
 328                 gv_init(candidate, cstash, subname, subname_len, TRUE);
 329             if (SvTYPE(candidate) == SVt_PVGV && (cand_cv = GvCV(candidate)) && !GvCVGEN(candidate)) {
 330                 SvREFCNT_dec(linear_av);
 331                 SvREFCNT_inc((SV*)cand_cv);
 332                 hv_store_ent(nmcache, newSVsv(cachekey), (SV*)cand_cv, 0);
 333                 return (SV*)cand_cv;
 334             }
 335         }
 336     }
 337
 338     SvREFCNT_dec(linear_av);
 339     hv_store_ent(nmcache, newSVsv(cachekey), &PL_sv_undef, 0);
 340     if(throw_nomethod)
 341         croak("No next::method '%s' found for %s", subname, hvname);
 342     return &PL_sv_undef;
 343 }
 344
 345 XS(XS_Class_C3_XS_calculateMRO);
 346 XS(XS_Class_C3_XS_calculateMRO)
 347 {
 348 #ifdef dVAR
 349     dVAR; dXSARGS;
 350 #else
 351     dXSARGS;
 352 #endif
 353
 354     SV* classname;
 355     HV* class_stash;
 356     HV* cache = NULL;
 357     AV* res;
 358     I32 res_items;
 359     I32 ret_items;
 360     SV** res_ptr;
 361
 362     if(items < 1 || items > 2)
 363         croak("Usage: calculateMRO(classname[, cache])");
 364
 365     classname = ST(0);
 366     if(items == 2) cache = (HV*)SvRV(ST(1));
 367
 368     class_stash = gv_stashsv(classname, 0);
 369     if(!class_stash) croak("No such class: '%s'!", SvPV_nolen(classname));
 370
 371     res = __mro_linear_isa_c3(aTHX_ class_stash, cache, 0);
 372
 373     res_items = ret_items = AvFILLp(res) + 1;
 374     res_ptr = AvARRAY(res);
 375
 376     SP -= items;
 377
 378     while(res_items--) {
 379         SV* res_item = *res_ptr++;
 380         XPUSHs(sv_2mortal(newSVsv(res_item)));
 381     }
 382     SvREFCNT_dec(res);
 383
 384     PUTBACK;
 385
 386     return;
 387 }
 388
 389 XS(XS_next_can);
 390 XS(XS_next_can)
 391 {
 392 #ifdef dVAR
 393     dVAR; dXSARGS;
 394 #else
 395     dXSARGS;
 396 #endif
 397
 398     SV* self = ST(0);
 399     SV* methcv = __nextcan(aTHX_ self, 0);
 400
 401     PERL_UNUSED_VAR(items);
 402
 403     if(methcv == &PL_sv_undef) {
 404         ST(0) = &PL_sv_undef;
 405     }
 406     else {
 407         ST(0) = sv_2mortal(newRV_inc(methcv));
 408     }
 409
 410     XSRETURN(1);
 411 }
 412
 413 XS(XS_next_method);
 414 XS(XS_next_method)
 415 {
 416     dMARK;
 417     dAX;
 418     SV* self = ST(0);
 419     SV* methcv = __nextcan(aTHX_ self, 1);
 420
 421     PL_markstack_ptr++;
 422     call_sv(methcv, GIMME_V);
 423 }
 424
 425 XS(XS_maybe_next_method);
 426 XS(XS_maybe_next_method)
 427 {
 428     dMARK;
 429     dAX;
 430     SV* self = ST(0);
 431     SV* methcv = __nextcan(aTHX_ self, 0);
 432
 433     if(methcv == &PL_sv_undef) {
 434         ST(0) = &PL_sv_undef;
 435         XSRETURN(1);
 436     }
 437
 438     PL_markstack_ptr++;
 439     call_sv(methcv, GIMME_V);
 440 }
 441
 442 MODULE = Class::C3::XS  PACKAGE = Class::C3::XS
 443
 444 BOOT:
 445     newXS("Class::C3::XS::calculateMRO", XS_Class_C3_XS_calculateMRO, __FILE__);
 446     newXS("next::can", XS_next_can, __FILE__);
 447     newXS("next::method", XS_next_method, __FILE__);
 448     newXS("maybe::next::method", XS_maybe_next_method, __FILE__);