indirect.xs

   1 /* This file is part of the indirect Perl module.
   2  * See http://search.cpan.org/dist/indirect/ */
   3
   4 #define PERL_NO_GET_CONTEXT
   5 #include "EXTERN.h"
   6 #include "perl.h"
   7 #include "XSUB.h"
   8
   9 #define __PACKAGE__     "indirect"
  10 #define __PACKAGE_LEN__ (sizeof(__PACKAGE__)-1)
  11
  12 /* --- Compatibility wrappers ---------------------------------------------- */
  13
  14 #ifndef NOOP
  15 # define NOOP
  16 #endif
  17
  18 #ifndef dNOOP
  19 # define dNOOP
  20 #endif
  21
  22 #ifndef Newx
  23 # define Newx(v, n, c) New(0, v, n, c)
  24 #endif
  25
  26 #ifndef SvPV_const
  27 # define SvPV_const SvPV
  28 #endif
  29
  30 #ifndef SvPV_nolen_const
  31 # define SvPV_nolen_const SvPV_nolen
  32 #endif
  33
  34 #ifndef SvPVX_const
  35 # define SvPVX_const SvPVX
  36 #endif
  37
  38 #ifndef SvREFCNT_inc_simple_NN
  39 # define SvREFCNT_inc_simple_NN SvREFCNT_inc
  40 #endif
  41
  42 #ifndef sv_catpvn_nomg
  43 # define sv_catpvn_nomg sv_catpvn
  44 #endif
  45
  46 #ifndef mPUSHp
  47 # define mPUSHp(P, L) PUSHs(sv_2mortal(newSVpvn((P), (L))))
  48 #endif
  49
  50 #ifndef mPUSHu
  51 # define mPUSHu(U) PUSHs(sv_2mortal(newSVuv(U)))
  52 #endif
  53
  54 #ifndef HvNAME_get
  55 # define HvNAME_get(H) HvNAME(H)
  56 #endif
  57
  58 #ifndef HvNAMELEN_get
  59 # define HvNAMELEN_get(H) strlen(HvNAME_get(H))
  60 #endif
  61
  62 #define I_HAS_PERL(R, V, S) (PERL_REVISION > (R) || (PERL_REVISION == (R) && (PERL_VERSION > (V) || (PERL_VERSION == (V) && (PERL_SUBVERSION >= (S))))))
  63
  64 #if I_HAS_PERL(5, 10, 0) || defined(PL_parser)
  65 # ifndef PL_linestr
  66 #  define PL_linestr PL_parser->linestr
  67 # endif
  68 # ifndef PL_bufptr
  69 #  define PL_bufptr PL_parser->bufptr
  70 # endif
  71 # ifndef PL_oldbufptr
  72 #  define PL_oldbufptr PL_parser->oldbufptr
  73 # endif
  74 #else
  75 # ifndef PL_linestr
  76 #  define PL_linestr PL_Ilinestr
  77 # endif
  78 # ifndef PL_bufptr
  79 #  define PL_bufptr PL_Ibufptr
  80 # endif
  81 # ifndef PL_oldbufptr
  82 #  define PL_oldbufptr PL_Ioldbufptr
  83 # endif
  84 #endif
  85
  86 #ifndef I_WORKAROUND_REQUIRE_PROPAGATION
  87 # define I_WORKAROUND_REQUIRE_PROPAGATION !I_HAS_PERL(5, 10, 1)
  88 #endif
  89
  90 /* ... Thread safety and multiplicity ...................................... */
  91
  92 /* Safe unless stated otherwise in Makefile.PL */
  93 #ifndef I_FORKSAFE
  94 # define I_FORKSAFE 1
  95 #endif
  96
  97 #ifndef I_MULTIPLICITY
  98 # if defined(MULTIPLICITY) || defined(PERL_IMPLICIT_CONTEXT)
  99 #  define I_MULTIPLICITY 1
 100 # else
 101 #  define I_MULTIPLICITY 0
 102 # endif
 103 #endif
 104 #if I_MULTIPLICITY && !defined(tTHX)
 105 # define tTHX PerlInterpreter*
 106 #endif
 107
 108 #if I_MULTIPLICITY && defined(USE_ITHREADS) && defined(dMY_CXT) && defined(MY_CXT) && defined(START_MY_CXT) && defined(MY_CXT_INIT) && (defined(MY_CXT_CLONE) || defined(dMY_CXT_SV))
 109 # define I_THREADSAFE 1
 110 # ifndef MY_CXT_CLONE
 111 #  define MY_CXT_CLONE \
 112     dMY_CXT_SV;                                                      \
 113     my_cxt_t *my_cxtp = (my_cxt_t*)SvPVX(newSV(sizeof(my_cxt_t)-1)); \
 114     Copy(INT2PTR(my_cxt_t*, SvUV(my_cxt_sv)), my_cxtp, 1, my_cxt_t); \
 115     sv_setuv(my_cxt_sv, PTR2UV(my_cxtp))
 116 # endif
 117 #else
 118 # define I_THREADSAFE 0
 119 # undef  dMY_CXT
 120 # define dMY_CXT      dNOOP
 121 # undef  MY_CXT
 122 # define MY_CXT       indirect_globaldata
 123 # undef  START_MY_CXT
 124 # define START_MY_CXT STATIC my_cxt_t MY_CXT;
 125 # undef  MY_CXT_INIT
 126 # define MY_CXT_INIT  NOOP
 127 # undef  MY_CXT_CLONE
 128 # define MY_CXT_CLONE NOOP
 129 #endif
 130
 131 /* --- Helpers ------------------------------------------------------------- */
 132
 133 /* ... Thread-safe hints ................................................... */
 134
 135 #if I_WORKAROUND_REQUIRE_PROPAGATION
 136
 137 typedef struct {
 138  SV *code;
 139  IV  require_tag;
 140 } indirect_hint_t;
 141
 142 #define I_HINT_STRUCT 1
 143
 144 #define I_HINT_CODE(H) ((H)->code)
 145
 146 #define I_HINT_FREE(H) {   \
 147  indirect_hint_t *h = (H); \
 148  SvREFCNT_dec(h->code);    \
 149  PerlMemShared_free(h);    \
 150 }
 151
 152 #else  /*  I_WORKAROUND_REQUIRE_PROPAGATION */
 153
 154 typedef SV indirect_hint_t;
 155
 156 #define I_HINT_STRUCT 0
 157
 158 #define I_HINT_CODE(H) (H)
 159
 160 #define I_HINT_FREE(H) SvREFCNT_dec(H);
 161
 162 #endif /* !I_WORKAROUND_REQUIRE_PROPAGATION */
 163
 164 #if I_THREADSAFE
 165
 166 #define PTABLE_NAME        ptable_hints
 167 #define PTABLE_VAL_FREE(V) I_HINT_FREE(V)
 168
 169 #define pPTBL  pTHX
 170 #define pPTBL_ pTHX_
 171 #define aPTBL  aTHX
 172 #define aPTBL_ aTHX_
 173
 174 #include "ptable.h"
 175
 176 #define ptable_hints_store(T, K, V) ptable_hints_store(aTHX_ (T), (K), (V))
 177 #define ptable_hints_free(T)        ptable_hints_free(aTHX_ (T))
 178
 179 #endif /* I_THREADSAFE */
 180
 181 /* Define the op->str ptable here because we need to be able to clean it during
 182  * thread cleanup. */
 183
 184 typedef struct {
 185  char   *buf;
 186  STRLEN  pos;
 187  STRLEN  size;
 188  STRLEN  len;
 189  line_t  line;
 190 } indirect_op_info_t;
 191
 192 #define PTABLE_NAME        ptable
 193 #define PTABLE_VAL_FREE(V) if (V) { Safefree(((indirect_op_info_t *) (V))->buf); Safefree(V); }
 194
 195 #define pPTBL  pTHX
 196 #define pPTBL_ pTHX_
 197 #define aPTBL  aTHX
 198 #define aPTBL_ aTHX_
 199
 200 #include "ptable.h"
 201
 202 #define ptable_store(T, K, V) ptable_store(aTHX_ (T), (K), (V))
 203 #define ptable_delete(T, K)   ptable_delete(aTHX_ (T), (K))
 204 #define ptable_clear(T)       ptable_clear(aTHX_ (T))
 205 #define ptable_free(T)        ptable_free(aTHX_ (T))
 206
 207 #define MY_CXT_KEY __PACKAGE__ "::_guts" XS_VERSION
 208
 209 typedef struct {
 210 #if I_THREADSAFE
 211  ptable *tbl; /* It really is a ptable_hints */
 212  tTHX    owner;
 213 #endif
 214  ptable *map;
 215  SV     *global_code;
 216 } my_cxt_t;
 217
 218 START_MY_CXT
 219
 220 #if I_THREADSAFE
 221
 222 STATIC SV *indirect_clone(pTHX_ SV *sv, tTHX owner) {
 223 #define indirect_clone(S, O) indirect_clone(aTHX_ (S), (O))
 224  CLONE_PARAMS  param;
 225  AV           *stashes = NULL;
 226  SV           *dupsv;
 227
 228  if (!sv)
 229   return NULL;
 230
 231  if (SvTYPE(sv) == SVt_PVHV && HvNAME_get(sv))
 232   stashes = newAV();
 233
 234  param.stashes    = stashes;
 235  param.flags      = 0;
 236  param.proto_perl = owner;
 237
 238  dupsv = sv_dup(sv, &param);
 239
 240  if (stashes) {
 241   av_undef(stashes);
 242   SvREFCNT_dec(stashes);
 243  }
 244
 245  return SvREFCNT_inc(dupsv);
 246 }
 247
 248 STATIC void indirect_ptable_clone(pTHX_ ptable_ent *ent, void *ud_) {
 249  my_cxt_t        *ud = ud_;
 250  indirect_hint_t *h1 = ent->val;
 251  indirect_hint_t *h2;
 252
 253  if (ud->owner == aTHX)
 254   return;
 255
 256 #if I_HINT_STRUCT
 257
 258  h2       = PerlMemShared_malloc(sizeof *h2);
 259  h2->code = indirect_clone(h1->code, ud->owner);
 260 #if I_WORKAROUND_REQUIRE_PROPAGATION
 261  h2->require_tag = PTR2IV(indirect_clone(INT2PTR(SV *, h1->require_tag),
 262                                          ud->owner));
 263 #endif
 264
 265 #else  /*  I_HINT_STRUCT */
 266
 267  h2 = indirect_clone(h1, ud->owner);
 268
 269 #endif /* !I_HINT_STRUCT */
 270
 271  ptable_hints_store(ud->tbl, ent->key, h2);
 272 }
 273
 274 #include "reap.h"
 275
 276 STATIC void indirect_thread_cleanup(pTHX_ void *ud) {
 277  dMY_CXT;
 278
 279  SvREFCNT_dec(MY_CXT.global_code);
 280  ptable_free(MY_CXT.map);
 281  ptable_hints_free(MY_CXT.tbl);
 282 }
 283
 284 #endif /* I_THREADSAFE */
 285
 286 #if I_WORKAROUND_REQUIRE_PROPAGATION
 287 STATIC IV indirect_require_tag(pTHX) {
 288 #define indirect_require_tag() indirect_require_tag(aTHX)
 289  const CV *cv, *outside;
 290
 291  cv = PL_compcv;
 292
 293  if (!cv) {
 294   /* If for some reason the pragma is operational at run-time, try to discover
 295    * the current cv in use. */
 296   const PERL_SI *si;
 297
 298   for (si = PL_curstackinfo; si; si = si->si_prev) {
 299    I32 cxix;
 300
 301    for (cxix = si->si_cxix; cxix >= 0; --cxix) {
 302     const PERL_CONTEXT *cx = si->si_cxstack + cxix;
 303
 304     switch (CxTYPE(cx)) {
 305      case CXt_SUB:
 306      case CXt_FORMAT:
 307       /* The propagation workaround is only needed up to 5.10.0 and at that
 308        * time format and sub contexts were still identical. And even later the
 309        * cv members offsets should have been kept the same. */
 310       cv = cx->blk_sub.cv;
 311       goto get_enclosing_cv;
 312      case CXt_EVAL:
 313       cv = cx->blk_eval.cv;
 314       goto get_enclosing_cv;
 315      default:
 316       break;
 317     }
 318    }
 319   }
 320
 321   cv = PL_main_cv;
 322  }
 323
 324 get_enclosing_cv:
 325  for (outside = CvOUTSIDE(cv); outside; outside = CvOUTSIDE(cv))
 326   cv = outside;
 327
 328  return PTR2IV(cv);
 329 }
 330 #endif /* I_WORKAROUND_REQUIRE_PROPAGATION */
 331
 332 STATIC SV *indirect_tag(pTHX_ SV *value) {
 333 #define indirect_tag(V) indirect_tag(aTHX_ (V))
 334  indirect_hint_t *h;
 335  SV *code = NULL;
 336
 337  if (SvROK(value)) {
 338   value = SvRV(value);
 339   if (SvTYPE(value) >= SVt_PVCV) {
 340    code = value;
 341    SvREFCNT_inc_simple_NN(code);
 342   }
 343  }
 344
 345 #if I_HINT_STRUCT
 346  h = PerlMemShared_malloc(sizeof *h);
 347  h->code        = code;
 348 # if I_WORKAROUND_REQUIRE_PROPAGATION
 349  h->require_tag = indirect_require_tag();
 350 # endif /* I_WORKAROUND_REQUIRE_PROPAGATION */
 351 #else  /*  I_HINT_STRUCT */
 352  h = code;
 353 #endif /* !I_HINT_STRUCT */
 354
 355 #if I_THREADSAFE
 356  {
 357   dMY_CXT;
 358   /* We only need for the key to be an unique tag for looking up the value later
 359    * Allocated memory provides convenient unique identifiers, so that's why we
 360    * use the hint as the key itself. */
 361   ptable_hints_store(MY_CXT.tbl, h, h);
 362  }
 363 #endif /* I_THREADSAFE */
 364
 365  return newSViv(PTR2IV(h));
 366 }
 367
 368 STATIC SV *indirect_detag(pTHX_ const SV *hint) {
 369 #define indirect_detag(H) indirect_detag(aTHX_ (H))
 370  indirect_hint_t *h;
 371 #if I_THREADSAFE || I_WORKAROUND_REQUIRE_PROPAGATION
 372  dMY_CXT;
 373 #endif
 374
 375  h = INT2PTR(indirect_hint_t *, SvIVX(hint));
 376 #if I_THREADSAFE
 377  h = ptable_fetch(MY_CXT.tbl, h);
 378 #endif /* I_THREADSAFE */
 379
 380 #if I_WORKAROUND_REQUIRE_PROPAGATION
 381  if (indirect_require_tag() != h->require_tag)
 382   return MY_CXT.global_code;
 383 #endif /* I_WORKAROUND_REQUIRE_PROPAGATION */
 384
 385  return I_HINT_CODE(h);
 386 }
 387
 388 STATIC U32 indirect_hash = 0;
 389
 390 STATIC SV *indirect_hint(pTHX) {
 391 #define indirect_hint() indirect_hint(aTHX)
 392  SV *hint = NULL;
 393
 394  if (IN_PERL_RUNTIME)
 395   return NULL;
 396
 397 #if I_HAS_PERL(5, 10, 0) || defined(PL_parser)
 398  if (!PL_parser)
 399   return NULL;
 400 #endif
 401
 402 #ifdef cop_hints_fetch_pvn
 403  hint = cop_hints_fetch_pvn(PL_curcop, __PACKAGE__, __PACKAGE_LEN__,
 404                                                               indirect_hash, 0);
 405 #elif I_HAS_PERL(5, 9, 5)
 406  hint = Perl_refcounted_he_fetch(aTHX_ PL_curcop->cop_hints_hash,
 407                                        NULL,
 408                                        __PACKAGE__, __PACKAGE_LEN__,
 409                                        0,
 410                                        indirect_hash);
 411 #else
 412  {
 413   SV **val = hv_fetch(GvHV(PL_hintgv), __PACKAGE__, __PACKAGE_LEN__, 0);
 414   if (val)
 415    hint = *val;
 416  }
 417 #endif
 418
 419  if (hint && SvIOK(hint))
 420   return indirect_detag(hint);
 421  else {
 422   dMY_CXT;
 423   return MY_CXT.global_code;
 424  }
 425 }
 426
 427 /* ... op -> source position ............................................... */
 428
 429 STATIC void indirect_map_store(pTHX_ const OP *o, STRLEN pos, SV *sv, line_t line) {
 430 #define indirect_map_store(O, P, N, L) indirect_map_store(aTHX_ (O), (P), (N), (L))
 431  indirect_op_info_t *oi;
 432  const char *s;
 433  STRLEN len;
 434  dMY_CXT;
 435
 436  if (!(oi = ptable_fetch(MY_CXT.map, o))) {
 437   Newx(oi, 1, indirect_op_info_t);
 438   ptable_store(MY_CXT.map, o, oi);
 439   oi->buf  = NULL;
 440   oi->size = 0;
 441  }
 442
 443  if (sv) {
 444   s = SvPV_const(sv, len);
 445  } else {
 446   s   = "{";
 447   len = 1;
 448  }
 449
 450  if (len > oi->size) {
 451   Safefree(oi->buf);
 452   Newx(oi->buf, len, char);
 453   oi->size = len;
 454  }
 455  Copy(s, oi->buf, len, char);
 456
 457  oi->len  = len;
 458  oi->pos  = pos;
 459  oi->line = line;
 460 }
 461
 462 STATIC const indirect_op_info_t *indirect_map_fetch(pTHX_ const OP *o) {
 463 #define indirect_map_fetch(O) indirect_map_fetch(aTHX_ (O))
 464  dMY_CXT;
 465
 466  return ptable_fetch(MY_CXT.map, o);
 467 }
 468
 469 STATIC void indirect_map_delete(pTHX_ const OP *o) {
 470 #define indirect_map_delete(O) indirect_map_delete(aTHX_ (O))
 471  dMY_CXT;
 472
 473  ptable_delete(MY_CXT.map, o);
 474 }
 475
 476 /* --- Check functions ----------------------------------------------------- */
 477
 478 STATIC int indirect_find(pTHX_ SV *sv, const char *s, STRLEN *pos) {
 479 #define indirect_find(N, S, P) indirect_find(aTHX_ (N), (S), (P))
 480  STRLEN len;
 481  const char *p, *r = SvPV_const(sv, len);
 482
 483  if (len >= 1 && *r == '$') {
 484   ++r;
 485   --len;
 486   s = strchr(s, '$');
 487   if (!s)
 488    return 0;
 489  }
 490
 491  p = s;
 492  while (1) {
 493   p = strstr(p, r);
 494   if (!p)
 495    return 0;
 496   if (!isALNUM(p[len]))
 497    break;
 498   /* p points to a word that has r as prefix, skip the rest of the word */
 499   p += len + 1;
 500   while (isALNUM(*p))
 501    ++p;
 502  }
 503
 504  *pos = p - SvPVX_const(PL_linestr);
 505
 506  return 1;
 507 }
 508
 509 /* ... ck_const ............................................................ */
 510
 511 STATIC OP *(*indirect_old_ck_const)(pTHX_ OP *) = 0;
 512
 513 STATIC OP *indirect_ck_const(pTHX_ OP *o) {
 514  o = indirect_old_ck_const(aTHX_ o);
 515
 516  if (indirect_hint()) {
 517   SV *sv = cSVOPo_sv;
 518
 519   if (SvPOK(sv) && (SvTYPE(sv) >= SVt_PV)) {
 520    STRLEN pos;
 521
 522    if (indirect_find(sv, PL_oldbufptr, &pos)) {
 523     indirect_map_store(o, pos, sv, CopLINE(&PL_compiling));
 524     return o;
 525    }
 526   }
 527  }
 528
 529  indirect_map_delete(o);
 530  return o;
 531 }
 532
 533 /* ... ck_rv2sv ............................................................ */
 534
 535 STATIC OP *(*indirect_old_ck_rv2sv)(pTHX_ OP *) = 0;
 536
 537 STATIC OP *indirect_ck_rv2sv(pTHX_ OP *o) {
 538  if (indirect_hint()) {
 539   OP *op = cUNOPo->op_first;
 540   SV *sv;
 541   const char *name = NULL;
 542   STRLEN pos, len;
 543   OPCODE type = (OPCODE) op->op_type;
 544
 545   switch (type) {
 546    case OP_GV:
 547    case OP_GVSV: {
 548     GV *gv = cGVOPx_gv(op);
 549     name = GvNAME(gv);
 550     len  = GvNAMELEN(gv);
 551     break;
 552    }
 553    default:
 554     if ((PL_opargs[type] & OA_CLASS_MASK) == OA_SVOP) {
 555      SV *nsv = cSVOPx_sv(op);
 556      if (SvPOK(nsv) && (SvTYPE(nsv) >= SVt_PV))
 557       name = SvPV_const(nsv, len);
 558     }
 559   }
 560   if (!name)
 561    goto done;
 562
 563   sv = sv_2mortal(newSVpvn("$", 1));
 564   sv_catpvn_nomg(sv, name, len);
 565   if (!indirect_find(sv, PL_oldbufptr, &pos)) {
 566    /* If it failed, retry without the current stash */
 567    const char *stash = HvNAME_get(PL_curstash);
 568    STRLEN stashlen = HvNAMELEN_get(PL_curstash);
 569
 570    if ((len < stashlen + 2) || strnNE(name, stash, stashlen)
 571        || name[stashlen] != ':' || name[stashlen+1] != ':') {
 572     /* Failed again ? Try to remove main */
 573     stash = "main";
 574     stashlen = 4;
 575     if ((len < stashlen + 2) || strnNE(name, stash, stashlen)
 576         || name[stashlen] != ':' || name[stashlen+1] != ':')
 577      goto done;
 578    }
 579
 580    sv_setpvn(sv, "$", 1);
 581    stashlen += 2;
 582    sv_catpvn_nomg(sv, name + stashlen, len - stashlen);
 583    if (!indirect_find(sv, PL_oldbufptr, &pos))
 584     goto done;
 585   }
 586
 587   o = indirect_old_ck_rv2sv(aTHX_ o);
 588
 589   indirect_map_store(o, pos, sv, CopLINE(&PL_compiling));
 590   return o;
 591  }
 592
 593 done:
 594  o = indirect_old_ck_rv2sv(aTHX_ o);
 595
 596  indirect_map_delete(o);
 597  return o;
 598 }
 599
 600 /* ... ck_padany ........................................................... */
 601
 602 STATIC OP *(*indirect_old_ck_padany)(pTHX_ OP *) = 0;
 603
 604 STATIC OP *indirect_ck_padany(pTHX_ OP *o) {
 605  o = indirect_old_ck_padany(aTHX_ o);
 606
 607  if (indirect_hint()) {
 608   SV *sv;
 609   const char *s = PL_oldbufptr, *t = PL_bufptr - 1;
 610
 611   while (s < t && isSPACE(*s)) ++s;
 612   if (*s == '$' && ++s <= t) {
 613    while (s < t && isSPACE(*s)) ++s;
 614    while (s < t && isSPACE(*t)) --t;
 615    sv = sv_2mortal(newSVpvn("$", 1));
 616    sv_catpvn_nomg(sv, s, t - s + 1);
 617    indirect_map_store(o, s - SvPVX_const(PL_linestr),
 618                          sv, CopLINE(&PL_compiling));
 619    return o;
 620   }
 621  }
 622
 623  indirect_map_delete(o);
 624  return o;
 625 }
 626
 627 /* ... ck_scope ............................................................ */
 628
 629 STATIC OP *(*indirect_old_ck_scope)  (pTHX_ OP *) = 0;
 630 STATIC OP *(*indirect_old_ck_lineseq)(pTHX_ OP *) = 0;
 631
 632 STATIC OP *indirect_ck_scope(pTHX_ OP *o) {
 633  OP *(*old_ck)(pTHX_ OP *) = 0;
 634
 635  switch (o->op_type) {
 636   case OP_SCOPE:   old_ck = indirect_old_ck_scope;   break;
 637   case OP_LINESEQ: old_ck = indirect_old_ck_lineseq; break;
 638  }
 639  o = old_ck(aTHX_ o);
 640
 641  if (indirect_hint()) {
 642   indirect_map_store(o, PL_oldbufptr - SvPVX_const(PL_linestr),
 643                         NULL, CopLINE(&PL_compiling));
 644   return o;
 645  }
 646
 647  indirect_map_delete(o);
 648  return o;
 649 }
 650
 651 /* We don't need to clean the map entries for leave ops because they can only
 652  * be created by mutating from a lineseq. */
 653
 654 /* ... ck_method ........................................................... */
 655
 656 STATIC OP *(*indirect_old_ck_method)(pTHX_ OP *) = 0;
 657
 658 STATIC OP *indirect_ck_method(pTHX_ OP *o) {
 659  if (indirect_hint()) {
 660   OP *op = cUNOPo->op_first;
 661
 662   /* Indirect method call is only possible when the method is a bareword, so
 663    * don't trip up on $obj->$meth. */
 664   if (op && op->op_type == OP_CONST) {
 665    const indirect_op_info_t *oi = indirect_map_fetch(op);
 666    STRLEN pos;
 667    line_t line;
 668    SV *sv;
 669
 670    if (!oi)
 671     goto done;
 672
 673    sv   = sv_2mortal(newSVpvn(oi->buf, oi->len));
 674    pos  = oi->pos;
 675    /* Keep the old line so that we really point to the first line of the
 676     * expression. */
 677    line = oi->line;
 678
 679    o = indirect_old_ck_method(aTHX_ o);
 680    /* o may now be a method_named */
 681
 682    indirect_map_store(o, pos, sv, line);
 683    return o;
 684   }
 685  }
 686
 687 done:
 688  o = indirect_old_ck_method(aTHX_ o);
 689
 690  indirect_map_delete(o);
 691  return o;
 692 }
 693
 694 /* ... ck_method_named ..................................................... */
 695
 696 /* "use foo/no foo" compiles its call to import/unimport directly to a
 697  * method_named op. */
 698
 699 STATIC OP *(*indirect_old_ck_method_named)(pTHX_ OP *) = 0;
 700
 701 STATIC OP *indirect_ck_method_named(pTHX_ OP *o) {
 702  if (indirect_hint()) {
 703   STRLEN pos;
 704   line_t line;
 705   SV *sv;
 706
 707   sv = cSVOPo_sv;
 708   if (!SvPOK(sv) || (SvTYPE(sv) < SVt_PV))
 709    goto done;
 710   sv = sv_mortalcopy(sv);
 711
 712   if (!indirect_find(sv, PL_oldbufptr, &pos))
 713    goto done;
 714   line = CopLINE(&PL_compiling);
 715
 716   o = indirect_old_ck_method_named(aTHX_ o);
 717
 718   indirect_map_store(o, pos, sv, line);
 719   return o;
 720  }
 721
 722 done:
 723  o = indirect_old_ck_method_named(aTHX_ o);
 724
 725  indirect_map_delete(o);
 726  return o;
 727 }
 728
 729 /* ... ck_entersub ......................................................... */
 730
 731 STATIC OP *(*indirect_old_ck_entersub)(pTHX_ OP *) = 0;
 732
 733 STATIC OP *indirect_ck_entersub(pTHX_ OP *o) {
 734  SV *code = indirect_hint();
 735
 736  o = indirect_old_ck_entersub(aTHX_ o);
 737
 738  if (code) {
 739   const indirect_op_info_t *moi, *ooi;
 740   OP     *mop, *oop;
 741   LISTOP *lop;
 742
 743   oop = o;
 744   do {
 745    lop = (LISTOP *) oop;
 746    if (!(lop->op_flags & OPf_KIDS))
 747     goto done;
 748    oop = lop->op_first;
 749   } while (oop->op_type != OP_PUSHMARK);
 750   oop = oop->op_sibling;
 751   mop = lop->op_last;
 752
 753   if (!oop)
 754    goto done;
 755
 756   switch (oop->op_type) {
 757    case OP_CONST:
 758    case OP_RV2SV:
 759    case OP_PADSV:
 760    case OP_SCOPE:
 761    case OP_LEAVE:
 762     break;
 763    default:
 764     goto done;
 765   }
 766
 767   if (mop->op_type == OP_METHOD)
 768    mop = cUNOPx(mop)->op_first;
 769   else if (mop->op_type != OP_METHOD_NAMED)
 770    goto done;
 771
 772   moi = indirect_map_fetch(mop);
 773   if (!moi)
 774    goto done;
 775
 776   ooi = indirect_map_fetch(oop);
 777   if (!ooi)
 778    goto done;
 779
 780   /* When positions are identical, the method and the object must have the
 781    * same name. But it also means that it is an indirect call, as "foo->foo"
 782    * results in different positions. */
 783   if (moi->pos <= ooi->pos) {
 784    SV *file;
 785    dSP;
 786
 787    ENTER;
 788    SAVETMPS;
 789
 790 #ifdef USE_ITHREADS
 791    file = sv_2mortal(newSVpv(CopFILE(&PL_compiling), 0));
 792 #else
 793    file = sv_mortalcopy(CopFILESV(&PL_compiling));
 794 #endif
 795
 796    PUSHMARK(SP);
 797    EXTEND(SP, 4);
 798    mPUSHp(ooi->buf, ooi->len);
 799    mPUSHp(moi->buf, moi->len);
 800    PUSHs(file);
 801    mPUSHu(moi->line);
 802    PUTBACK;
 803
 804    call_sv(code, G_VOID);
 805
 806    PUTBACK;
 807
 808    FREETMPS;
 809    LEAVE;
 810   }
 811  }
 812
 813 done:
 814  return o;
 815 }
 816
 817 STATIC U32 indirect_initialized = 0;
 818
 819 STATIC void indirect_teardown(pTHX_ void *root) {
 820  if (!indirect_initialized)
 821   return;
 822
 823 #if I_MULTIPLICITY
 824  if (aTHX != root)
 825   return;
 826 #endif
 827
 828  {
 829   dMY_CXT;
 830   ptable_free(MY_CXT.map);
 831 #if I_THREADSAFE
 832   ptable_hints_free(MY_CXT.tbl);
 833 #endif
 834  }
 835
 836  PL_check[OP_CONST]           = MEMBER_TO_FPTR(indirect_old_ck_const);
 837  indirect_old_ck_const        = 0;
 838  PL_check[OP_RV2SV]           = MEMBER_TO_FPTR(indirect_old_ck_rv2sv);
 839  indirect_old_ck_rv2sv        = 0;
 840  PL_check[OP_PADANY]          = MEMBER_TO_FPTR(indirect_old_ck_padany);
 841  indirect_old_ck_padany       = 0;
 842  PL_check[OP_SCOPE]           = MEMBER_TO_FPTR(indirect_old_ck_scope);
 843  indirect_old_ck_scope        = 0;
 844  PL_check[OP_LINESEQ]         = MEMBER_TO_FPTR(indirect_old_ck_lineseq);
 845  indirect_old_ck_lineseq      = 0;
 846
 847  PL_check[OP_METHOD]          = MEMBER_TO_FPTR(indirect_old_ck_method);
 848  indirect_old_ck_method       = 0;
 849  PL_check[OP_METHOD_NAMED]    = MEMBER_TO_FPTR(indirect_old_ck_method_named);
 850  indirect_old_ck_method_named = 0;
 851  PL_check[OP_ENTERSUB]        = MEMBER_TO_FPTR(indirect_old_ck_entersub);
 852  indirect_old_ck_entersub     = 0;
 853
 854  indirect_initialized = 0;
 855 }
 856
 857 STATIC void indirect_setup(pTHX) {
 858 #define indirect_setup() indirect_setup(aTHX)
 859  if (indirect_initialized)
 860   return;
 861
 862  {
 863   MY_CXT_INIT;
 864 #if I_THREADSAFE
 865   MY_CXT.tbl         = ptable_new();
 866   MY_CXT.owner       = aTHX;
 867 #endif
 868   MY_CXT.map         = ptable_new();
 869   MY_CXT.global_code = NULL;
 870  }
 871
 872  indirect_old_ck_const        = PL_check[OP_CONST];
 873  PL_check[OP_CONST]           = MEMBER_TO_FPTR(indirect_ck_const);
 874  indirect_old_ck_rv2sv        = PL_check[OP_RV2SV];
 875  PL_check[OP_RV2SV]           = MEMBER_TO_FPTR(indirect_ck_rv2sv);
 876  indirect_old_ck_padany       = PL_check[OP_PADANY];
 877  PL_check[OP_PADANY]          = MEMBER_TO_FPTR(indirect_ck_padany);
 878  indirect_old_ck_scope        = PL_check[OP_SCOPE];
 879  PL_check[OP_SCOPE]           = MEMBER_TO_FPTR(indirect_ck_scope);
 880  indirect_old_ck_lineseq      = PL_check[OP_LINESEQ];
 881  PL_check[OP_LINESEQ]         = MEMBER_TO_FPTR(indirect_ck_scope);
 882
 883  indirect_old_ck_method       = PL_check[OP_METHOD];
 884  PL_check[OP_METHOD]          = MEMBER_TO_FPTR(indirect_ck_method);
 885  indirect_old_ck_method_named = PL_check[OP_METHOD_NAMED];
 886  PL_check[OP_METHOD_NAMED]    = MEMBER_TO_FPTR(indirect_ck_method_named);
 887  indirect_old_ck_entersub     = PL_check[OP_ENTERSUB];
 888  PL_check[OP_ENTERSUB]        = MEMBER_TO_FPTR(indirect_ck_entersub);
 889
 890 #if I_MULTIPLICITY
 891  call_atexit(indirect_teardown, aTHX);
 892 #else
 893  call_atexit(indirect_teardown, NULL);
 894 #endif
 895
 896  indirect_initialized = 1;
 897 }
 898
 899 STATIC U32 indirect_booted = 0;
 900
 901 /* --- XS ------------------------------------------------------------------ */
 902
 903 MODULE = indirect      PACKAGE = indirect
 904
 905 PROTOTYPES: ENABLE
 906
 907 BOOT:
 908 {
 909  if (!indirect_booted++) {
 910   HV *stash;
 911
 912   PERL_HASH(indirect_hash, __PACKAGE__, __PACKAGE_LEN__);
 913
 914   stash = gv_stashpvn(__PACKAGE__, __PACKAGE_LEN__, 1);
 915   newCONSTSUB(stash, "I_THREADSAFE", newSVuv(I_THREADSAFE));
 916   newCONSTSUB(stash, "I_FORKSAFE",   newSVuv(I_FORKSAFE));
 917  }
 918
 919  indirect_setup();
 920 }
 921
 922 #if I_THREADSAFE
 923
 924 void
 925 CLONE(...)
 926 PROTOTYPE: DISABLE
 927 PREINIT:
 928  ptable *t;
 929  SV     *global_code_dup;
 930 PPCODE:
 931  {
 932   my_cxt_t ud;
 933   dMY_CXT;
 934   ud.tbl   = t = ptable_new();
 935   ud.owner = MY_CXT.owner;
 936   ptable_walk(MY_CXT.tbl, indirect_ptable_clone, &ud);
 937   global_code_dup = indirect_clone(MY_CXT.global_code, MY_CXT.owner);
 938  }
 939  {
 940   MY_CXT_CLONE;
 941   MY_CXT.map         = ptable_new();
 942   MY_CXT.tbl         = t;
 943   MY_CXT.owner       = aTHX;
 944   MY_CXT.global_code = global_code_dup;
 945  }
 946  reap(3, indirect_thread_cleanup, NULL);
 947  XSRETURN(0);
 948
 949 #endif
 950
 951 SV *
 952 _tag(SV *value)
 953 PROTOTYPE: $
 954 CODE:
 955  RETVAL = indirect_tag(value);
 956 OUTPUT:
 957  RETVAL
 958
 959 void
 960 _global(SV *code)
 961 PROTOTYPE: $
 962 PPCODE:
 963  if (!SvOK(code))
 964   code = NULL;
 965  else if (SvROK(code))
 966   code = SvRV(code);
 967  {
 968   dMY_CXT;
 969   SvREFCNT_dec(MY_CXT.global_code);
 970   MY_CXT.global_code = SvREFCNT_inc(code);
 971  }
 972  XSRETURN(0);