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  STRLEN  pos;
 186  STRLEN  size;
 187  STRLEN  len;
 188  char   *buf;
 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 #ifdef cop_hints_fetch_pvn
 398  hint = cop_hints_fetch_pvn(PL_curcop, __PACKAGE__, __PACKAGE_LEN__,
 399                                                               indirect_hash, 0);
 400 #elif I_HAS_PERL(5, 9, 5)
 401  hint = Perl_refcounted_he_fetch(aTHX_ PL_curcop->cop_hints_hash,
 402                                        NULL,
 403                                        __PACKAGE__, __PACKAGE_LEN__,
 404                                        0,
 405                                        indirect_hash);
 406 #else
 407  {
 408   SV **val = hv_fetch(GvHV(PL_hintgv), __PACKAGE__, __PACKAGE_LEN__, 0);
 409   if (val)
 410    hint = *val;
 411  }
 412 #endif
 413
 414  if (hint && SvIOK(hint))
 415   return indirect_detag(hint);
 416  else {
 417   dMY_CXT;
 418   return MY_CXT.global_code;
 419  }
 420 }
 421
 422 /* ... op -> source position ............................................... */
 423
 424 STATIC void indirect_map_store(pTHX_ const OP *o, STRLEN pos, SV *sv, line_t line) {
 425 #define indirect_map_store(O, P, N, L) indirect_map_store(aTHX_ (O), (P), (N), (L))
 426  indirect_op_info_t *oi;
 427  const char *s;
 428  STRLEN len;
 429  dMY_CXT;
 430
 431  if (!(oi = ptable_fetch(MY_CXT.map, o))) {
 432   Newx(oi, 1, indirect_op_info_t);
 433   ptable_store(MY_CXT.map, o, oi);
 434   oi->buf  = NULL;
 435   oi->size = 0;
 436  }
 437
 438  if (sv) {
 439   s = SvPV_const(sv, len);
 440  } else {
 441   s   = "{";
 442   len = 1;
 443  }
 444
 445  if (len > oi->size) {
 446   Safefree(oi->buf);
 447   Newx(oi->buf, len, char);
 448   oi->size = len;
 449  }
 450  Copy(s, oi->buf, len, char);
 451
 452  oi->len  = len;
 453  oi->pos  = pos;
 454  oi->line = line;
 455 }
 456
 457 STATIC const indirect_op_info_t *indirect_map_fetch(pTHX_ const OP *o) {
 458 #define indirect_map_fetch(O) indirect_map_fetch(aTHX_ (O))
 459  dMY_CXT;
 460
 461  return ptable_fetch(MY_CXT.map, o);
 462 }
 463
 464 STATIC void indirect_map_delete(pTHX_ const OP *o) {
 465 #define indirect_map_delete(O) indirect_map_delete(aTHX_ (O))
 466  dMY_CXT;
 467
 468  ptable_delete(MY_CXT.map, o);
 469 }
 470
 471 /* --- Check functions ----------------------------------------------------- */
 472
 473 STATIC int indirect_find(pTHX_ SV *sv, const char *s, STRLEN *pos) {
 474 #define indirect_find(N, S, P) indirect_find(aTHX_ (N), (S), (P))
 475  STRLEN len;
 476  const char *p, *r = SvPV_const(sv, len);
 477
 478  if (len >= 1 && *r == '$') {
 479   ++r;
 480   --len;
 481   s = strchr(s, '$');
 482   if (!s)
 483    return 0;
 484  }
 485
 486  p = s;
 487  while (1) {
 488   p = strstr(p, r);
 489   if (!p)
 490    return 0;
 491   if (!isALNUM(p[len]))
 492    break;
 493   /* p points to a word that has r as prefix, skip the rest of the word */
 494   p += len + 1;
 495   while (isALNUM(*p))
 496    ++p;
 497  }
 498
 499  *pos = p - SvPVX_const(PL_linestr);
 500
 501  return 1;
 502 }
 503
 504 /* ... ck_const ............................................................ */
 505
 506 STATIC OP *(*indirect_old_ck_const)(pTHX_ OP *) = 0;
 507
 508 STATIC OP *indirect_ck_const(pTHX_ OP *o) {
 509  o = indirect_old_ck_const(aTHX_ o);
 510
 511  if (indirect_hint()) {
 512   SV *sv = cSVOPo_sv;
 513
 514   if (SvPOK(sv) && (SvTYPE(sv) >= SVt_PV)) {
 515    STRLEN pos;
 516
 517    if (indirect_find(sv, PL_oldbufptr, &pos)) {
 518     indirect_map_store(o, pos, sv, CopLINE(&PL_compiling));
 519     return o;
 520    }
 521   }
 522  }
 523
 524  indirect_map_delete(o);
 525  return o;
 526 }
 527
 528 /* ... ck_rv2sv ............................................................ */
 529
 530 STATIC OP *(*indirect_old_ck_rv2sv)(pTHX_ OP *) = 0;
 531
 532 STATIC OP *indirect_ck_rv2sv(pTHX_ OP *o) {
 533  if (indirect_hint()) {
 534   OP *op = cUNOPo->op_first;
 535   SV *sv;
 536   const char *name = NULL;
 537   STRLEN pos, len;
 538   OPCODE type = (OPCODE) op->op_type;
 539
 540   switch (type) {
 541    case OP_GV:
 542    case OP_GVSV: {
 543     GV *gv = cGVOPx_gv(op);
 544     name = GvNAME(gv);
 545     len  = GvNAMELEN(gv);
 546     break;
 547    }
 548    default:
 549     if ((PL_opargs[type] & OA_CLASS_MASK) == OA_SVOP) {
 550      SV *nsv = cSVOPx_sv(op);
 551      if (SvPOK(nsv) && (SvTYPE(nsv) >= SVt_PV))
 552       name = SvPV_const(nsv, len);
 553     }
 554   }
 555   if (!name)
 556    goto done;
 557
 558   sv = sv_2mortal(newSVpvn("$", 1));
 559   sv_catpvn_nomg(sv, name, len);
 560   if (!indirect_find(sv, PL_oldbufptr, &pos)) {
 561    /* If it failed, retry without the current stash */
 562    const char *stash = HvNAME_get(PL_curstash);
 563    STRLEN stashlen = HvNAMELEN_get(PL_curstash);
 564
 565    if ((len < stashlen + 2) || strnNE(name, stash, stashlen)
 566        || name[stashlen] != ':' || name[stashlen+1] != ':') {
 567     /* Failed again ? Try to remove main */
 568     stash = "main";
 569     stashlen = 4;
 570     if ((len < stashlen + 2) || strnNE(name, stash, stashlen)
 571         || name[stashlen] != ':' || name[stashlen+1] != ':')
 572      goto done;
 573    }
 574
 575    sv_setpvn(sv, "$", 1);
 576    stashlen += 2;
 577    sv_catpvn_nomg(sv, name + stashlen, len - stashlen);
 578    if (!indirect_find(sv, PL_oldbufptr, &pos))
 579     goto done;
 580   }
 581
 582   o = indirect_old_ck_rv2sv(aTHX_ o);
 583
 584   indirect_map_store(o, pos, sv, CopLINE(&PL_compiling));
 585   return o;
 586  }
 587
 588 done:
 589  o = indirect_old_ck_rv2sv(aTHX_ o);
 590
 591  indirect_map_delete(o);
 592  return o;
 593 }
 594
 595 /* ... ck_padany ........................................................... */
 596
 597 STATIC OP *(*indirect_old_ck_padany)(pTHX_ OP *) = 0;
 598
 599 STATIC OP *indirect_ck_padany(pTHX_ OP *o) {
 600  o = indirect_old_ck_padany(aTHX_ o);
 601
 602  if (indirect_hint()) {
 603   SV *sv;
 604   const char *s = PL_oldbufptr, *t = PL_bufptr - 1;
 605
 606   while (s < t && isSPACE(*s)) ++s;
 607   if (*s == '$' && ++s <= t) {
 608    while (s < t && isSPACE(*s)) ++s;
 609    while (s < t && isSPACE(*t)) --t;
 610    sv = sv_2mortal(newSVpvn("$", 1));
 611    sv_catpvn_nomg(sv, s, t - s + 1);
 612    indirect_map_store(o, s - SvPVX_const(PL_linestr),
 613                          sv, CopLINE(&PL_compiling));
 614    return o;
 615   }
 616  }
 617
 618  indirect_map_delete(o);
 619  return o;
 620 }
 621
 622 /* ... ck_scope ............................................................ */
 623
 624 STATIC OP *(*indirect_old_ck_scope)  (pTHX_ OP *) = 0;
 625 STATIC OP *(*indirect_old_ck_lineseq)(pTHX_ OP *) = 0;
 626
 627 STATIC OP *indirect_ck_scope(pTHX_ OP *o) {
 628  OP *(*old_ck)(pTHX_ OP *) = 0;
 629
 630  switch (o->op_type) {
 631   case OP_SCOPE:   old_ck = indirect_old_ck_scope;   break;
 632   case OP_LINESEQ: old_ck = indirect_old_ck_lineseq; break;
 633  }
 634  o = old_ck(aTHX_ o);
 635
 636  if (indirect_hint()) {
 637   indirect_map_store(o, PL_oldbufptr - SvPVX_const(PL_linestr),
 638                         NULL, CopLINE(&PL_compiling));
 639   return o;
 640  }
 641
 642  indirect_map_delete(o);
 643  return o;
 644 }
 645
 646 /* We don't need to clean the map entries for leave ops because they can only
 647  * be created by mutating from a lineseq. */
 648
 649 /* ... ck_method ........................................................... */
 650
 651 STATIC OP *(*indirect_old_ck_method)(pTHX_ OP *) = 0;
 652
 653 STATIC OP *indirect_ck_method(pTHX_ OP *o) {
 654  if (indirect_hint()) {
 655   OP *op = cUNOPo->op_first;
 656
 657   /* Indirect method call is only possible when the method is a bareword, so
 658    * don't trip up on $obj->$meth. */
 659   if (op && op->op_type == OP_CONST) {
 660    const indirect_op_info_t *oi = indirect_map_fetch(op);
 661    STRLEN pos;
 662    line_t line;
 663    SV *sv;
 664
 665    if (!oi)
 666     goto done;
 667
 668    sv   = sv_2mortal(newSVpvn(oi->buf, oi->len));
 669    pos  = oi->pos;
 670    /* Keep the old line so that we really point to the first line of the
 671     * expression. */
 672    line = oi->line;
 673
 674    o = indirect_old_ck_method(aTHX_ o);
 675    /* o may now be a method_named */
 676
 677    indirect_map_store(o, pos, sv, line);
 678    return o;
 679   }
 680  }
 681
 682 done:
 683  o = indirect_old_ck_method(aTHX_ o);
 684
 685  indirect_map_delete(o);
 686  return o;
 687 }
 688
 689 /* ... ck_method_named ..................................................... */
 690
 691 /* "use foo/no foo" compiles its call to import/unimport directly to a
 692  * method_named op. */
 693
 694 STATIC OP *(*indirect_old_ck_method_named)(pTHX_ OP *) = 0;
 695
 696 STATIC OP *indirect_ck_method_named(pTHX_ OP *o) {
 697  if (indirect_hint()) {
 698   STRLEN pos;
 699   line_t line;
 700   SV *sv;
 701
 702   sv = cSVOPo_sv;
 703   if (!SvPOK(sv) || (SvTYPE(sv) < SVt_PV))
 704    goto done;
 705   sv = sv_mortalcopy(sv);
 706
 707   if (!indirect_find(sv, PL_oldbufptr, &pos))
 708    goto done;
 709   line = CopLINE(&PL_compiling);
 710
 711   o = indirect_old_ck_method_named(aTHX_ o);
 712
 713   indirect_map_store(o, pos, sv, line);
 714   return o;
 715  }
 716
 717 done:
 718  o = indirect_old_ck_method_named(aTHX_ o);
 719
 720  indirect_map_delete(o);
 721  return o;
 722 }
 723
 724 /* ... ck_entersub ......................................................... */
 725
 726 STATIC OP *(*indirect_old_ck_entersub)(pTHX_ OP *) = 0;
 727
 728 STATIC OP *indirect_ck_entersub(pTHX_ OP *o) {
 729  SV *code = indirect_hint();
 730
 731  o = indirect_old_ck_entersub(aTHX_ o);
 732
 733  if (code) {
 734   const indirect_op_info_t *moi, *ooi;
 735   OP     *mop, *oop;
 736   LISTOP *lop;
 737
 738   oop = o;
 739   do {
 740    lop = (LISTOP *) oop;
 741    if (!(lop->op_flags & OPf_KIDS))
 742     goto done;
 743    oop = lop->op_first;
 744   } while (oop->op_type != OP_PUSHMARK);
 745   oop = oop->op_sibling;
 746   mop = lop->op_last;
 747
 748   if (!oop)
 749    goto done;
 750
 751   switch (oop->op_type) {
 752    case OP_CONST:
 753    case OP_RV2SV:
 754    case OP_PADSV:
 755    case OP_SCOPE:
 756    case OP_LEAVE:
 757     break;
 758    default:
 759     goto done;
 760   }
 761
 762   if (mop->op_type == OP_METHOD)
 763    mop = cUNOPx(mop)->op_first;
 764   else if (mop->op_type != OP_METHOD_NAMED)
 765    goto done;
 766
 767   moi = indirect_map_fetch(mop);
 768   if (!moi)
 769    goto done;
 770
 771   ooi = indirect_map_fetch(oop);
 772   if (!ooi)
 773    goto done;
 774
 775   /* When positions are identical, the method and the object must have the
 776    * same name. But it also means that it is an indirect call, as "foo->foo"
 777    * results in different positions. */
 778   if (moi->pos <= ooi->pos) {
 779    SV *file;
 780    dSP;
 781
 782    ENTER;
 783    SAVETMPS;
 784
 785 #ifdef USE_ITHREADS
 786    file = sv_2mortal(newSVpv(CopFILE(&PL_compiling), 0));
 787 #else
 788    file = sv_mortalcopy(CopFILESV(&PL_compiling));
 789 #endif
 790
 791    PUSHMARK(SP);
 792    EXTEND(SP, 4);
 793    mPUSHp(ooi->buf, ooi->len);
 794    mPUSHp(moi->buf, moi->len);
 795    PUSHs(file);
 796    mPUSHu(moi->line);
 797    PUTBACK;
 798
 799    call_sv(code, G_VOID);
 800
 801    PUTBACK;
 802
 803    FREETMPS;
 804    LEAVE;
 805   }
 806  }
 807
 808 done:
 809  return o;
 810 }
 811
 812 STATIC U32 indirect_initialized = 0;
 813
 814 STATIC void indirect_teardown(pTHX_ void *root) {
 815  if (!indirect_initialized)
 816   return;
 817
 818 #if I_MULTIPLICITY
 819  if (aTHX != root)
 820   return;
 821 #endif
 822
 823  {
 824   dMY_CXT;
 825   ptable_free(MY_CXT.map);
 826 #if I_THREADSAFE
 827   ptable_hints_free(MY_CXT.tbl);
 828 #endif
 829  }
 830
 831  PL_check[OP_CONST]           = MEMBER_TO_FPTR(indirect_old_ck_const);
 832  indirect_old_ck_const        = 0;
 833  PL_check[OP_RV2SV]           = MEMBER_TO_FPTR(indirect_old_ck_rv2sv);
 834  indirect_old_ck_rv2sv        = 0;
 835  PL_check[OP_PADANY]          = MEMBER_TO_FPTR(indirect_old_ck_padany);
 836  indirect_old_ck_padany       = 0;
 837  PL_check[OP_SCOPE]           = MEMBER_TO_FPTR(indirect_old_ck_scope);
 838  indirect_old_ck_scope        = 0;
 839  PL_check[OP_LINESEQ]         = MEMBER_TO_FPTR(indirect_old_ck_lineseq);
 840  indirect_old_ck_lineseq      = 0;
 841
 842  PL_check[OP_METHOD]          = MEMBER_TO_FPTR(indirect_old_ck_method);
 843  indirect_old_ck_method       = 0;
 844  PL_check[OP_METHOD_NAMED]    = MEMBER_TO_FPTR(indirect_old_ck_method_named);
 845  indirect_old_ck_method_named = 0;
 846  PL_check[OP_ENTERSUB]        = MEMBER_TO_FPTR(indirect_old_ck_entersub);
 847  indirect_old_ck_entersub     = 0;
 848
 849  indirect_initialized = 0;
 850 }
 851
 852 STATIC void indirect_setup(pTHX) {
 853 #define indirect_setup() indirect_setup(aTHX)
 854  if (indirect_initialized)
 855   return;
 856
 857  {
 858   MY_CXT_INIT;
 859 #if I_THREADSAFE
 860   MY_CXT.tbl         = ptable_new();
 861   MY_CXT.owner       = aTHX;
 862 #endif
 863   MY_CXT.map         = ptable_new();
 864   MY_CXT.global_code = NULL;
 865  }
 866
 867  indirect_old_ck_const        = PL_check[OP_CONST];
 868  PL_check[OP_CONST]           = MEMBER_TO_FPTR(indirect_ck_const);
 869  indirect_old_ck_rv2sv        = PL_check[OP_RV2SV];
 870  PL_check[OP_RV2SV]           = MEMBER_TO_FPTR(indirect_ck_rv2sv);
 871  indirect_old_ck_padany       = PL_check[OP_PADANY];
 872  PL_check[OP_PADANY]          = MEMBER_TO_FPTR(indirect_ck_padany);
 873  indirect_old_ck_scope        = PL_check[OP_SCOPE];
 874  PL_check[OP_SCOPE]           = MEMBER_TO_FPTR(indirect_ck_scope);
 875  indirect_old_ck_lineseq      = PL_check[OP_LINESEQ];
 876  PL_check[OP_LINESEQ]         = MEMBER_TO_FPTR(indirect_ck_scope);
 877
 878  indirect_old_ck_method       = PL_check[OP_METHOD];
 879  PL_check[OP_METHOD]          = MEMBER_TO_FPTR(indirect_ck_method);
 880  indirect_old_ck_method_named = PL_check[OP_METHOD_NAMED];
 881  PL_check[OP_METHOD_NAMED]    = MEMBER_TO_FPTR(indirect_ck_method_named);
 882  indirect_old_ck_entersub     = PL_check[OP_ENTERSUB];
 883  PL_check[OP_ENTERSUB]        = MEMBER_TO_FPTR(indirect_ck_entersub);
 884
 885 #if I_MULTIPLICITY
 886  call_atexit(indirect_teardown, aTHX);
 887 #else
 888  call_atexit(indirect_teardown, NULL);
 889 #endif
 890
 891  indirect_initialized = 1;
 892 }
 893
 894 STATIC U32 indirect_booted = 0;
 895
 896 /* --- XS ------------------------------------------------------------------ */
 897
 898 MODULE = indirect      PACKAGE = indirect
 899
 900 PROTOTYPES: ENABLE
 901
 902 BOOT:
 903 {
 904  if (!indirect_booted++) {
 905   HV *stash;
 906
 907   PERL_HASH(indirect_hash, __PACKAGE__, __PACKAGE_LEN__);
 908
 909   stash = gv_stashpvn(__PACKAGE__, __PACKAGE_LEN__, 1);
 910   newCONSTSUB(stash, "I_THREADSAFE", newSVuv(I_THREADSAFE));
 911   newCONSTSUB(stash, "I_FORKSAFE",   newSVuv(I_FORKSAFE));
 912  }
 913
 914  indirect_setup();
 915 }
 916
 917 #if I_THREADSAFE
 918
 919 void
 920 CLONE(...)
 921 PROTOTYPE: DISABLE
 922 PREINIT:
 923  ptable *t;
 924  SV     *global_code_dup;
 925 PPCODE:
 926  {
 927   my_cxt_t ud;
 928   dMY_CXT;
 929   ud.tbl   = t = ptable_new();
 930   ud.owner = MY_CXT.owner;
 931   ptable_walk(MY_CXT.tbl, indirect_ptable_clone, &ud);
 932   global_code_dup = indirect_clone(MY_CXT.global_code, MY_CXT.owner);
 933  }
 934  {
 935   MY_CXT_CLONE;
 936   MY_CXT.map         = ptable_new();
 937   MY_CXT.tbl         = t;
 938   MY_CXT.owner       = aTHX;
 939   MY_CXT.global_code = global_code_dup;
 940  }
 941  reap(3, indirect_thread_cleanup, NULL);
 942  XSRETURN(0);
 943
 944 #endif
 945
 946 SV *
 947 _tag(SV *value)
 948 PROTOTYPE: $
 949 CODE:
 950  RETVAL = indirect_tag(value);
 951 OUTPUT:
 952  RETVAL
 953
 954 void
 955 _global(SV *code)
 956 PROTOTYPE: $
 957 PPCODE:
 958  if (!SvOK(code))
 959   code = NULL;
 960  else if (SvROK(code))
 961   code = SvRV(code);
 962  {
 963   dMY_CXT;
 964   SvREFCNT_dec(MY_CXT.global_code);
 965   MY_CXT.global_code = SvREFCNT_inc(code);
 966  }
 967  XSRETURN(0);