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_void_NN
  39 # ifdef SvREFCNT_inc_simple_NN
  40 #  define SvREFCNT_inc_simple_void_NN SvREFCNT_inc_simple_NN
  41 # else
  42 #  define SvREFCNT_inc_simple_void_NN SvREFCNT_inc
  43 # endif
  44 #endif
  45
  46 #ifndef sv_catpvn_nomg
  47 # define sv_catpvn_nomg sv_catpvn
  48 #endif
  49
  50 #ifndef mPUSHp
  51 # define mPUSHp(P, L) PUSHs(sv_2mortal(newSVpvn((P), (L))))
  52 #endif
  53
  54 #ifndef mPUSHu
  55 # define mPUSHu(U) PUSHs(sv_2mortal(newSVuv(U)))
  56 #endif
  57
  58 #ifndef HvNAME_get
  59 # define HvNAME_get(H) HvNAME(H)
  60 #endif
  61
  62 #ifndef HvNAMELEN_get
  63 # define HvNAMELEN_get(H) strlen(HvNAME_get(H))
  64 #endif
  65
  66 #ifndef OP_SIBLING
  67 # define OP_SIBLING(O) ((O)->op_sibling)
  68 #endif
  69
  70 #define I_HAS_PERL(R, V, S) (PERL_REVISION > (R) || (PERL_REVISION == (R) && (PERL_VERSION > (V) || (PERL_VERSION == (V) && (PERL_SUBVERSION >= (S))))))
  71
  72 #if I_HAS_PERL(5, 10, 0) || defined(PL_parser)
  73 # ifndef PL_linestr
  74 #  define PL_linestr PL_parser->linestr
  75 # endif
  76 # ifndef PL_bufptr
  77 #  define PL_bufptr PL_parser->bufptr
  78 # endif
  79 # ifndef PL_oldbufptr
  80 #  define PL_oldbufptr PL_parser->oldbufptr
  81 # endif
  82 # ifndef PL_lex_inwhat
  83 #  define PL_lex_inwhat PL_parser->lex_inwhat
  84 # endif
  85 #else
  86 # ifndef PL_linestr
  87 #  define PL_linestr PL_Ilinestr
  88 # endif
  89 # ifndef PL_bufptr
  90 #  define PL_bufptr PL_Ibufptr
  91 # endif
  92 # ifndef PL_oldbufptr
  93 #  define PL_oldbufptr PL_Ioldbufptr
  94 # endif
  95 # ifndef PL_lex_inwhat
  96 #  define PL_lex_inwhat PL_Ilex_inwhat
  97 # endif
  98 #endif
  99
 100 #ifndef I_WORKAROUND_REQUIRE_PROPAGATION
 101 # define I_WORKAROUND_REQUIRE_PROPAGATION !I_HAS_PERL(5, 10, 1)
 102 #endif
 103
 104 /* ... Thread safety and multiplicity ...................................... */
 105
 106 /* Safe unless stated otherwise in Makefile.PL */
 107 #ifndef I_FORKSAFE
 108 # define I_FORKSAFE 1
 109 #endif
 110
 111 #ifndef I_MULTIPLICITY
 112 # if defined(MULTIPLICITY) || defined(PERL_IMPLICIT_CONTEXT)
 113 #  define I_MULTIPLICITY 1
 114 # else
 115 #  define I_MULTIPLICITY 0
 116 # endif
 117 #endif
 118 #if I_MULTIPLICITY && !defined(tTHX)
 119 # define tTHX PerlInterpreter*
 120 #endif
 121
 122 #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))
 123 # define I_THREADSAFE 1
 124 # ifndef MY_CXT_CLONE
 125 #  define MY_CXT_CLONE \
 126     dMY_CXT_SV;                                                      \
 127     my_cxt_t *my_cxtp = (my_cxt_t*)SvPVX(newSV(sizeof(my_cxt_t)-1)); \
 128     Copy(INT2PTR(my_cxt_t*, SvUV(my_cxt_sv)), my_cxtp, 1, my_cxt_t); \
 129     sv_setuv(my_cxt_sv, PTR2UV(my_cxtp))
 130 # endif
 131 #else
 132 # define I_THREADSAFE 0
 133 # undef  dMY_CXT
 134 # define dMY_CXT      dNOOP
 135 # undef  MY_CXT
 136 # define MY_CXT       indirect_globaldata
 137 # undef  START_MY_CXT
 138 # define START_MY_CXT STATIC my_cxt_t MY_CXT;
 139 # undef  MY_CXT_INIT
 140 # define MY_CXT_INIT  NOOP
 141 # undef  MY_CXT_CLONE
 142 # define MY_CXT_CLONE NOOP
 143 #endif
 144
 145 #if defined(OP_CHECK_MUTEX_LOCK) && defined(OP_CHECK_MUTEX_UNLOCK)
 146 # define I_CHECK_MUTEX_LOCK   OP_CHECK_MUTEX_LOCK
 147 # define I_CHECK_MUTEX_UNLOCK OP_CHECK_MUTEX_UNLOCK
 148 #else
 149 # define I_CHECK_MUTEX_LOCK   OP_REFCNT_LOCK
 150 # define I_CHECK_MUTEX_UNLOCK OP_REFCNT_UNLOCK
 151 #endif
 152
 153 typedef OP *(*indirect_ck_t)(pTHX_ OP *);
 154
 155 #ifdef wrap_op_checker
 156
 157 # define indirect_ck_replace(T, NC, OCP) wrap_op_checker((T), (NC), (OCP))
 158
 159 #else
 160
 161 STATIC void indirect_ck_replace(pTHX_ OPCODE type, indirect_ck_t new_ck, indirect_ck_t *old_ck_p) {
 162 #define indirect_ck_replace(T, NC, OCP) indirect_ck_replace(aTHX_ (T), (NC), (OCP))
 163  I_CHECK_MUTEX_LOCK;
 164  if (!*old_ck_p) {
 165   *old_ck_p      = PL_check[type];
 166   PL_check[type] = new_ck;
 167  }
 168  I_CHECK_MUTEX_UNLOCK;
 169 }
 170
 171 #endif
 172
 173 STATIC void indirect_ck_restore(pTHX_ OPCODE type, indirect_ck_t *old_ck_p) {
 174 #define indirect_ck_restore(T, OCP) indirect_ck_restore(aTHX_ (T), (OCP))
 175  I_CHECK_MUTEX_LOCK;
 176  if (*old_ck_p) {
 177   PL_check[type] = *old_ck_p;
 178   *old_ck_p      = 0;
 179  }
 180  I_CHECK_MUTEX_UNLOCK;
 181 }
 182
 183 /* --- Helpers ------------------------------------------------------------- */
 184
 185 /* ... Thread-safe hints ................................................... */
 186
 187 #if I_WORKAROUND_REQUIRE_PROPAGATION
 188
 189 typedef struct {
 190  SV *code;
 191  IV  require_tag;
 192 } indirect_hint_t;
 193
 194 #define I_HINT_STRUCT 1
 195
 196 #define I_HINT_CODE(H) ((H)->code)
 197
 198 #define I_HINT_FREE(H) {   \
 199  indirect_hint_t *h = (H); \
 200  SvREFCNT_dec(h->code);    \
 201  PerlMemShared_free(h);    \
 202 }
 203
 204 #else  /*  I_WORKAROUND_REQUIRE_PROPAGATION */
 205
 206 typedef SV indirect_hint_t;
 207
 208 #define I_HINT_STRUCT 0
 209
 210 #define I_HINT_CODE(H) (H)
 211
 212 #define I_HINT_FREE(H) SvREFCNT_dec(H);
 213
 214 #endif /* !I_WORKAROUND_REQUIRE_PROPAGATION */
 215
 216 #if I_THREADSAFE
 217
 218 #define PTABLE_NAME        ptable_hints
 219 #define PTABLE_VAL_FREE(V) I_HINT_FREE(V)
 220
 221 #define pPTBL  pTHX
 222 #define pPTBL_ pTHX_
 223 #define aPTBL  aTHX
 224 #define aPTBL_ aTHX_
 225
 226 #include "ptable.h"
 227
 228 #define ptable_hints_store(T, K, V) ptable_hints_store(aTHX_ (T), (K), (V))
 229 #define ptable_hints_free(T)        ptable_hints_free(aTHX_ (T))
 230
 231 #endif /* I_THREADSAFE */
 232
 233 /* Define the op->str ptable here because we need to be able to clean it during
 234  * thread cleanup. */
 235
 236 typedef struct {
 237  char   *buf;
 238  STRLEN  pos;
 239  STRLEN  size;
 240  STRLEN  len;
 241  line_t  line;
 242 } indirect_op_info_t;
 243
 244 #define PTABLE_NAME        ptable
 245 #define PTABLE_VAL_FREE(V) if (V) { Safefree(((indirect_op_info_t *) (V))->buf); Safefree(V); }
 246
 247 #define pPTBL  pTHX
 248 #define pPTBL_ pTHX_
 249 #define aPTBL  aTHX
 250 #define aPTBL_ aTHX_
 251
 252 #include "ptable.h"
 253
 254 #define ptable_store(T, K, V) ptable_store(aTHX_ (T), (K), (V))
 255 #define ptable_delete(T, K)   ptable_delete(aTHX_ (T), (K))
 256 #define ptable_clear(T)       ptable_clear(aTHX_ (T))
 257 #define ptable_free(T)        ptable_free(aTHX_ (T))
 258
 259 #define MY_CXT_KEY __PACKAGE__ "::_guts" XS_VERSION
 260
 261 typedef struct {
 262 #if I_THREADSAFE
 263  ptable *tbl; /* It really is a ptable_hints */
 264  tTHX    owner;
 265 #endif
 266  ptable *map;
 267  SV     *global_code;
 268 } my_cxt_t;
 269
 270 START_MY_CXT
 271
 272 #if I_THREADSAFE
 273
 274 STATIC SV *indirect_clone(pTHX_ SV *sv, tTHX owner) {
 275 #define indirect_clone(S, O) indirect_clone(aTHX_ (S), (O))
 276  CLONE_PARAMS  param;
 277  AV           *stashes = NULL;
 278  SV           *dupsv;
 279
 280  if (!sv)
 281   return NULL;
 282
 283  if (SvTYPE(sv) == SVt_PVHV && HvNAME_get(sv))
 284   stashes = newAV();
 285
 286  param.stashes    = stashes;
 287  param.flags      = 0;
 288  param.proto_perl = owner;
 289
 290  dupsv = sv_dup(sv, &param);
 291
 292  if (stashes) {
 293   av_undef(stashes);
 294   SvREFCNT_dec(stashes);
 295  }
 296
 297  return SvREFCNT_inc(dupsv);
 298 }
 299
 300 STATIC void indirect_ptable_clone(pTHX_ ptable_ent *ent, void *ud_) {
 301  my_cxt_t        *ud = ud_;
 302  indirect_hint_t *h1 = ent->val;
 303  indirect_hint_t *h2;
 304
 305  if (ud->owner == aTHX)
 306   return;
 307
 308 #if I_HINT_STRUCT
 309
 310  h2       = PerlMemShared_malloc(sizeof *h2);
 311  h2->code = indirect_clone(h1->code, ud->owner);
 312 #if I_WORKAROUND_REQUIRE_PROPAGATION
 313  h2->require_tag = PTR2IV(indirect_clone(INT2PTR(SV *, h1->require_tag),
 314                                          ud->owner));
 315 #endif
 316
 317 #else  /*  I_HINT_STRUCT */
 318
 319  h2 = indirect_clone(h1, ud->owner);
 320
 321 #endif /* !I_HINT_STRUCT */
 322
 323  ptable_hints_store(ud->tbl, ent->key, h2);
 324 }
 325
 326 #include "reap.h"
 327
 328 STATIC void indirect_thread_cleanup(pTHX_ void *ud) {
 329  dMY_CXT;
 330
 331  SvREFCNT_dec(MY_CXT.global_code);
 332  ptable_free(MY_CXT.map);
 333  ptable_hints_free(MY_CXT.tbl);
 334 }
 335
 336 #endif /* I_THREADSAFE */
 337
 338 #if I_WORKAROUND_REQUIRE_PROPAGATION
 339 STATIC IV indirect_require_tag(pTHX) {
 340 #define indirect_require_tag() indirect_require_tag(aTHX)
 341  const CV *cv, *outside;
 342
 343  cv = PL_compcv;
 344
 345  if (!cv) {
 346   /* If for some reason the pragma is operational at run-time, try to discover
 347    * the current cv in use. */
 348   const PERL_SI *si;
 349
 350   for (si = PL_curstackinfo; si; si = si->si_prev) {
 351    I32 cxix;
 352
 353    for (cxix = si->si_cxix; cxix >= 0; --cxix) {
 354     const PERL_CONTEXT *cx = si->si_cxstack + cxix;
 355
 356     switch (CxTYPE(cx)) {
 357      case CXt_SUB:
 358      case CXt_FORMAT:
 359       /* The propagation workaround is only needed up to 5.10.0 and at that
 360        * time format and sub contexts were still identical. And even later the
 361        * cv members offsets should have been kept the same. */
 362       cv = cx->blk_sub.cv;
 363       goto get_enclosing_cv;
 364      case CXt_EVAL:
 365       cv = cx->blk_eval.cv;
 366       goto get_enclosing_cv;
 367      default:
 368       break;
 369     }
 370    }
 371   }
 372
 373   cv = PL_main_cv;
 374  }
 375
 376 get_enclosing_cv:
 377  for (outside = CvOUTSIDE(cv); outside; outside = CvOUTSIDE(cv))
 378   cv = outside;
 379
 380  return PTR2IV(cv);
 381 }
 382 #endif /* I_WORKAROUND_REQUIRE_PROPAGATION */
 383
 384 STATIC SV *indirect_tag(pTHX_ SV *value) {
 385 #define indirect_tag(V) indirect_tag(aTHX_ (V))
 386  indirect_hint_t *h;
 387  SV *code = NULL;
 388
 389  if (SvROK(value)) {
 390   value = SvRV(value);
 391   if (SvTYPE(value) >= SVt_PVCV) {
 392    code = value;
 393    SvREFCNT_inc_simple_void_NN(code);
 394   }
 395  }
 396
 397 #if I_HINT_STRUCT
 398  h = PerlMemShared_malloc(sizeof *h);
 399  h->code        = code;
 400 # if I_WORKAROUND_REQUIRE_PROPAGATION
 401  h->require_tag = indirect_require_tag();
 402 # endif /* I_WORKAROUND_REQUIRE_PROPAGATION */
 403 #else  /*  I_HINT_STRUCT */
 404  h = code;
 405 #endif /* !I_HINT_STRUCT */
 406
 407 #if I_THREADSAFE
 408  {
 409   dMY_CXT;
 410   /* We only need for the key to be an unique tag for looking up the value later
 411    * Allocated memory provides convenient unique identifiers, so that's why we
 412    * use the hint as the key itself. */
 413   ptable_hints_store(MY_CXT.tbl, h, h);
 414  }
 415 #endif /* I_THREADSAFE */
 416
 417  return newSViv(PTR2IV(h));
 418 }
 419
 420 STATIC SV *indirect_detag(pTHX_ const SV *hint) {
 421 #define indirect_detag(H) indirect_detag(aTHX_ (H))
 422  indirect_hint_t *h;
 423 #if I_THREADSAFE || I_WORKAROUND_REQUIRE_PROPAGATION
 424  dMY_CXT;
 425 #endif
 426
 427  h = INT2PTR(indirect_hint_t *, SvIVX(hint));
 428 #if I_THREADSAFE
 429  h = ptable_fetch(MY_CXT.tbl, h);
 430 #endif /* I_THREADSAFE */
 431
 432 #if I_WORKAROUND_REQUIRE_PROPAGATION
 433  if (indirect_require_tag() != h->require_tag)
 434   return MY_CXT.global_code;
 435 #endif /* I_WORKAROUND_REQUIRE_PROPAGATION */
 436
 437  return I_HINT_CODE(h);
 438 }
 439
 440 STATIC U32 indirect_hash = 0;
 441
 442 STATIC SV *indirect_hint(pTHX) {
 443 #define indirect_hint() indirect_hint(aTHX)
 444  SV *hint = NULL;
 445
 446  if (IN_PERL_RUNTIME)
 447   return NULL;
 448
 449 #if I_HAS_PERL(5, 10, 0) || defined(PL_parser)
 450  if (!PL_parser)
 451   return NULL;
 452 #endif
 453
 454 #ifdef cop_hints_fetch_pvn
 455  hint = cop_hints_fetch_pvn(PL_curcop, __PACKAGE__, __PACKAGE_LEN__,
 456                                                               indirect_hash, 0);
 457 #elif I_HAS_PERL(5, 9, 5)
 458  hint = Perl_refcounted_he_fetch(aTHX_ PL_curcop->cop_hints_hash,
 459                                        NULL,
 460                                        __PACKAGE__, __PACKAGE_LEN__,
 461                                        0,
 462                                        indirect_hash);
 463 #else
 464  {
 465   SV **val = hv_fetch(GvHV(PL_hintgv), __PACKAGE__, __PACKAGE_LEN__, 0);
 466   if (val)
 467    hint = *val;
 468  }
 469 #endif
 470
 471  if (hint && SvIOK(hint))
 472   return indirect_detag(hint);
 473  else {
 474   dMY_CXT;
 475   return MY_CXT.global_code;
 476  }
 477 }
 478
 479 /* ... op -> source position ............................................... */
 480
 481 STATIC void indirect_map_store(pTHX_ const OP *o, STRLEN pos, SV *sv, line_t line) {
 482 #define indirect_map_store(O, P, N, L) indirect_map_store(aTHX_ (O), (P), (N), (L))
 483  indirect_op_info_t *oi;
 484  const char *s;
 485  STRLEN len;
 486  dMY_CXT;
 487
 488  if (!(oi = ptable_fetch(MY_CXT.map, o))) {
 489   Newx(oi, 1, indirect_op_info_t);
 490   ptable_store(MY_CXT.map, o, oi);
 491   oi->buf  = NULL;
 492   oi->size = 0;
 493  }
 494
 495  if (sv) {
 496   s = SvPV_const(sv, len);
 497  } else {
 498   s   = "{";
 499   len = 1;
 500  }
 501
 502  if (len > oi->size) {
 503   Safefree(oi->buf);
 504   Newx(oi->buf, len, char);
 505   oi->size = len;
 506  }
 507  Copy(s, oi->buf, len, char);
 508
 509  oi->len  = len;
 510  oi->pos  = pos;
 511  oi->line = line;
 512 }
 513
 514 STATIC const indirect_op_info_t *indirect_map_fetch(pTHX_ const OP *o) {
 515 #define indirect_map_fetch(O) indirect_map_fetch(aTHX_ (O))
 516  dMY_CXT;
 517
 518  return ptable_fetch(MY_CXT.map, o);
 519 }
 520
 521 STATIC void indirect_map_delete(pTHX_ const OP *o) {
 522 #define indirect_map_delete(O) indirect_map_delete(aTHX_ (O))
 523  dMY_CXT;
 524
 525  ptable_delete(MY_CXT.map, o);
 526 }
 527
 528 /* --- Check functions ----------------------------------------------------- */
 529
 530 STATIC int indirect_find(pTHX_ SV *name_sv, const char *line_bufptr, STRLEN *name_pos) {
 531 #define indirect_find(NSV, LBP, NP) indirect_find(aTHX_ (NSV), (LBP), (NP))
 532  STRLEN      name_len, line_len;
 533  const char *name, *name_end;
 534  const char *line, *line_end;
 535  const char *p;
 536
 537  line     = SvPV_const(PL_linestr, line_len);
 538  line_end = line + line_len;
 539
 540  name = SvPV_const(name_sv, name_len);
 541  if (name_len >= 1 && *name == '$') {
 542   ++name;
 543   --name_len;
 544   while (line_bufptr < line_end && *line_bufptr != '$')
 545    ++line_bufptr;
 546   if (line_bufptr >= line_end)
 547    return 0;
 548  }
 549  name_end = name + name_len;
 550
 551  p = line_bufptr;
 552  while (1) {
 553   p = ninstr(p, line_end, name, name_end);
 554   if (!p)
 555    return 0;
 556   if (!isALNUM(p[name_len]))
 557    break;
 558   /* p points to a word that has name as prefix, skip the rest of the word */
 559   p += name_len + 1;
 560   while (isALNUM(*p))
 561    ++p;
 562  }
 563
 564  *name_pos = p - line;
 565
 566  return 1;
 567 }
 568
 569 /* ... ck_const ............................................................ */
 570
 571 STATIC OP *(*indirect_old_ck_const)(pTHX_ OP *) = 0;
 572
 573 STATIC OP *indirect_ck_const(pTHX_ OP *o) {
 574  o = indirect_old_ck_const(aTHX_ o);
 575
 576  if (indirect_hint()) {
 577   SV *sv = cSVOPo_sv;
 578
 579   if (SvPOK(sv) && (SvTYPE(sv) >= SVt_PV)) {
 580    STRLEN pos;
 581
 582    if (indirect_find(sv, PL_oldbufptr, &pos)) {
 583     STRLEN len;
 584
 585     /* If the constant is equal to the current package name, try to look for
 586      * a "__PACKAGE__" coming before what we got. We only need to check this
 587      * when we already had a match because __PACKAGE__ can only appear in
 588      * direct method calls ("new __PACKAGE__" is a syntax error). */
 589     len = SvCUR(sv);
 590     if (len == (STRLEN) HvNAMELEN_get(PL_curstash)
 591         && memcmp(SvPVX(sv), HvNAME_get(PL_curstash), len) == 0) {
 592      STRLEN pos_pkg;
 593      SV    *pkg = sv_newmortal();
 594      sv_setpvn(pkg, "__PACKAGE__", sizeof("__PACKAGE__")-1);
 595
 596      if (indirect_find(pkg, PL_oldbufptr, &pos_pkg) && pos_pkg < pos) {
 597       sv  = pkg;
 598       pos = pos_pkg;
 599      }
 600     }
 601
 602     indirect_map_store(o, pos, sv, CopLINE(&PL_compiling));
 603     return o;
 604    }
 605   }
 606  }
 607
 608  indirect_map_delete(o);
 609  return o;
 610 }
 611
 612 /* ... ck_rv2sv ............................................................ */
 613
 614 STATIC OP *(*indirect_old_ck_rv2sv)(pTHX_ OP *) = 0;
 615
 616 STATIC OP *indirect_ck_rv2sv(pTHX_ OP *o) {
 617  if (indirect_hint()) {
 618   OP *op = cUNOPo->op_first;
 619   SV *sv;
 620   const char *name = NULL;
 621   STRLEN pos, len;
 622   OPCODE type = (OPCODE) op->op_type;
 623
 624   switch (type) {
 625    case OP_GV:
 626    case OP_GVSV: {
 627     GV *gv = cGVOPx_gv(op);
 628     name = GvNAME(gv);
 629     len  = GvNAMELEN(gv);
 630     break;
 631    }
 632    default:
 633     if ((PL_opargs[type] & OA_CLASS_MASK) == OA_SVOP) {
 634      SV *nsv = cSVOPx_sv(op);
 635      if (SvPOK(nsv) && (SvTYPE(nsv) >= SVt_PV))
 636       name = SvPV_const(nsv, len);
 637     }
 638   }
 639   if (!name)
 640    goto done;
 641
 642   sv = sv_2mortal(newSVpvn("$", 1));
 643   sv_catpvn_nomg(sv, name, len);
 644   if (!indirect_find(sv, PL_oldbufptr, &pos)) {
 645    /* If it failed, retry without the current stash */
 646    const char *stash = HvNAME_get(PL_curstash);
 647    STRLEN stashlen = HvNAMELEN_get(PL_curstash);
 648
 649    if ((len < stashlen + 2) || strnNE(name, stash, stashlen)
 650        || name[stashlen] != ':' || name[stashlen+1] != ':') {
 651     /* Failed again ? Try to remove main */
 652     stash = "main";
 653     stashlen = 4;
 654     if ((len < stashlen + 2) || strnNE(name, stash, stashlen)
 655         || name[stashlen] != ':' || name[stashlen+1] != ':')
 656      goto done;
 657    }
 658
 659    sv_setpvn(sv, "$", 1);
 660    stashlen += 2;
 661    sv_catpvn_nomg(sv, name + stashlen, len - stashlen);
 662    if (!indirect_find(sv, PL_oldbufptr, &pos))
 663     goto done;
 664   }
 665
 666   o = indirect_old_ck_rv2sv(aTHX_ o);
 667
 668   indirect_map_store(o, pos, sv, CopLINE(&PL_compiling));
 669   return o;
 670  }
 671
 672 done:
 673  o = indirect_old_ck_rv2sv(aTHX_ o);
 674
 675  indirect_map_delete(o);
 676  return o;
 677 }
 678
 679 /* ... ck_padany ........................................................... */
 680
 681 STATIC OP *(*indirect_old_ck_padany)(pTHX_ OP *) = 0;
 682
 683 STATIC OP *indirect_ck_padany(pTHX_ OP *o) {
 684  o = indirect_old_ck_padany(aTHX_ o);
 685
 686  if (indirect_hint()) {
 687   SV *sv;
 688   const char *s = PL_oldbufptr, *t = PL_bufptr - 1;
 689
 690   while (s < t && isSPACE(*s)) ++s;
 691   if (*s == '$' && ++s <= t) {
 692    while (s < t && isSPACE(*s)) ++s;
 693    while (s < t && isSPACE(*t)) --t;
 694    sv = sv_2mortal(newSVpvn("$", 1));
 695    sv_catpvn_nomg(sv, s, t - s + 1);
 696    indirect_map_store(o, s - SvPVX_const(PL_linestr),
 697                          sv, CopLINE(&PL_compiling));
 698    return o;
 699   }
 700  }
 701
 702  indirect_map_delete(o);
 703  return o;
 704 }
 705
 706 /* ... ck_scope ............................................................ */
 707
 708 STATIC OP *(*indirect_old_ck_scope)  (pTHX_ OP *) = 0;
 709 STATIC OP *(*indirect_old_ck_lineseq)(pTHX_ OP *) = 0;
 710
 711 STATIC OP *indirect_ck_scope(pTHX_ OP *o) {
 712  OP *(*old_ck)(pTHX_ OP *) = 0;
 713
 714  switch (o->op_type) {
 715   case OP_SCOPE:   old_ck = indirect_old_ck_scope;   break;
 716   case OP_LINESEQ: old_ck = indirect_old_ck_lineseq; break;
 717  }
 718  o = old_ck(aTHX_ o);
 719
 720  if (indirect_hint()) {
 721   indirect_map_store(o, PL_oldbufptr - SvPVX_const(PL_linestr),
 722                         NULL, CopLINE(&PL_compiling));
 723   return o;
 724  }
 725
 726  indirect_map_delete(o);
 727  return o;
 728 }
 729
 730 /* We don't need to clean the map entries for leave ops because they can only
 731  * be created by mutating from a lineseq. */
 732
 733 /* ... ck_method ........................................................... */
 734
 735 STATIC OP *(*indirect_old_ck_method)(pTHX_ OP *) = 0;
 736
 737 STATIC OP *indirect_ck_method(pTHX_ OP *o) {
 738  if (indirect_hint()) {
 739   OP *op = cUNOPo->op_first;
 740
 741   /* Indirect method call is only possible when the method is a bareword, so
 742    * don't trip up on $obj->$meth. */
 743   if (op && op->op_type == OP_CONST) {
 744    const indirect_op_info_t *oi = indirect_map_fetch(op);
 745    STRLEN pos;
 746    line_t line;
 747    SV *sv;
 748
 749    if (!oi)
 750     goto done;
 751
 752    sv   = sv_2mortal(newSVpvn(oi->buf, oi->len));
 753    pos  = oi->pos;
 754    /* Keep the old line so that we really point to the first line of the
 755     * expression. */
 756    line = oi->line;
 757
 758    o = indirect_old_ck_method(aTHX_ o);
 759    /* o may now be a method_named */
 760
 761    indirect_map_store(o, pos, sv, line);
 762    return o;
 763   }
 764  }
 765
 766 done:
 767  o = indirect_old_ck_method(aTHX_ o);
 768
 769  indirect_map_delete(o);
 770  return o;
 771 }
 772
 773 /* ... ck_method_named ..................................................... */
 774
 775 /* "use foo/no foo" compiles its call to import/unimport directly to a
 776  * method_named op. */
 777
 778 STATIC OP *(*indirect_old_ck_method_named)(pTHX_ OP *) = 0;
 779
 780 STATIC OP *indirect_ck_method_named(pTHX_ OP *o) {
 781  if (indirect_hint()) {
 782   STRLEN pos;
 783   line_t line;
 784   SV *sv;
 785
 786   sv = cSVOPo_sv;
 787   if (!SvPOK(sv) || (SvTYPE(sv) < SVt_PV))
 788    goto done;
 789   sv = sv_mortalcopy(sv);
 790
 791   if (!indirect_find(sv, PL_oldbufptr, &pos))
 792    goto done;
 793   line = CopLINE(&PL_compiling);
 794
 795   o = indirect_old_ck_method_named(aTHX_ o);
 796
 797   indirect_map_store(o, pos, sv, line);
 798   return o;
 799  }
 800
 801 done:
 802  o = indirect_old_ck_method_named(aTHX_ o);
 803
 804  indirect_map_delete(o);
 805  return o;
 806 }
 807
 808 /* ... ck_entersub ......................................................... */
 809
 810 STATIC OP *(*indirect_old_ck_entersub)(pTHX_ OP *) = 0;
 811
 812 STATIC OP *indirect_ck_entersub(pTHX_ OP *o) {
 813  SV *code = indirect_hint();
 814
 815  o = indirect_old_ck_entersub(aTHX_ o);
 816
 817  if (code) {
 818   const indirect_op_info_t *moi, *ooi;
 819   OP     *mop, *oop;
 820   LISTOP *lop;
 821
 822   oop = o;
 823   do {
 824    lop = (LISTOP *) oop;
 825    if (!(lop->op_flags & OPf_KIDS))
 826     goto done;
 827    oop = lop->op_first;
 828   } while (oop->op_type != OP_PUSHMARK);
 829   oop = OP_SIBLING(oop);
 830   mop = lop->op_last;
 831
 832   if (!oop)
 833    goto done;
 834
 835   switch (oop->op_type) {
 836    case OP_CONST:
 837    case OP_RV2SV:
 838    case OP_PADSV:
 839    case OP_SCOPE:
 840    case OP_LEAVE:
 841     break;
 842    default:
 843     goto done;
 844   }
 845
 846   if (mop->op_type == OP_METHOD)
 847    mop = cUNOPx(mop)->op_first;
 848   else if (mop->op_type != OP_METHOD_NAMED)
 849    goto done;
 850
 851   moi = indirect_map_fetch(mop);
 852   if (!moi)
 853    goto done;
 854
 855   ooi = indirect_map_fetch(oop);
 856   if (!ooi)
 857    goto done;
 858
 859   /* When positions are identical, the method and the object must have the
 860    * same name. But it also means that it is an indirect call, as "foo->foo"
 861    * results in different positions. */
 862   if (   moi->line < ooi->line
 863       || (moi->line == ooi->line && moi->pos <= ooi->pos)) {
 864    SV *file;
 865    dSP;
 866
 867    ENTER;
 868    SAVETMPS;
 869
 870 #ifdef USE_ITHREADS
 871    file = sv_2mortal(newSVpv(CopFILE(&PL_compiling), 0));
 872 #else
 873    file = sv_mortalcopy(CopFILESV(&PL_compiling));
 874 #endif
 875
 876    PUSHMARK(SP);
 877    EXTEND(SP, 4);
 878    mPUSHp(ooi->buf, ooi->len);
 879    mPUSHp(moi->buf, moi->len);
 880    PUSHs(file);
 881    mPUSHu(moi->line);
 882    PUTBACK;
 883
 884    call_sv(code, G_VOID);
 885
 886    PUTBACK;
 887
 888    FREETMPS;
 889    LEAVE;
 890   }
 891  }
 892
 893 done:
 894  return o;
 895 }
 896
 897 STATIC U32 indirect_initialized = 0;
 898
 899 STATIC void indirect_teardown(pTHX_ void *root) {
 900  if (!indirect_initialized)
 901   return;
 902
 903 #if I_MULTIPLICITY
 904  if (aTHX != root)
 905   return;
 906 #endif
 907
 908  {
 909   dMY_CXT;
 910   ptable_free(MY_CXT.map);
 911 #if I_THREADSAFE
 912   ptable_hints_free(MY_CXT.tbl);
 913 #endif
 914  }
 915
 916  indirect_ck_restore(OP_CONST,   &indirect_old_ck_const);
 917  indirect_ck_restore(OP_RV2SV,   &indirect_old_ck_rv2sv);
 918  indirect_ck_restore(OP_PADANY,  &indirect_old_ck_padany);
 919  indirect_ck_restore(OP_SCOPE,   &indirect_old_ck_scope);
 920  indirect_ck_restore(OP_LINESEQ, &indirect_old_ck_lineseq);
 921
 922  indirect_ck_restore(OP_METHOD,       &indirect_old_ck_method);
 923  indirect_ck_restore(OP_METHOD_NAMED, &indirect_old_ck_method_named);
 924  indirect_ck_restore(OP_ENTERSUB,     &indirect_old_ck_entersub);
 925
 926  indirect_initialized = 0;
 927 }
 928
 929 STATIC void indirect_setup(pTHX) {
 930 #define indirect_setup() indirect_setup(aTHX)
 931  if (indirect_initialized)
 932   return;
 933
 934  {
 935   MY_CXT_INIT;
 936 #if I_THREADSAFE
 937   MY_CXT.tbl         = ptable_new();
 938   MY_CXT.owner       = aTHX;
 939 #endif
 940   MY_CXT.map         = ptable_new();
 941   MY_CXT.global_code = NULL;
 942  }
 943
 944  indirect_ck_replace(OP_CONST,   indirect_ck_const,  &indirect_old_ck_const);
 945  indirect_ck_replace(OP_RV2SV,   indirect_ck_rv2sv,  &indirect_old_ck_rv2sv);
 946  indirect_ck_replace(OP_PADANY,  indirect_ck_padany, &indirect_old_ck_padany);
 947  indirect_ck_replace(OP_SCOPE,   indirect_ck_scope,  &indirect_old_ck_scope);
 948  indirect_ck_replace(OP_LINESEQ, indirect_ck_scope,  &indirect_old_ck_lineseq);
 949
 950  indirect_ck_replace(OP_METHOD,       indirect_ck_method,
 951                                       &indirect_old_ck_method);
 952  indirect_ck_replace(OP_METHOD_NAMED, indirect_ck_method_named,
 953                                       &indirect_old_ck_method_named);
 954  indirect_ck_replace(OP_ENTERSUB,     indirect_ck_entersub,
 955                                       &indirect_old_ck_entersub);
 956
 957 #if I_MULTIPLICITY
 958  call_atexit(indirect_teardown, aTHX);
 959 #else
 960  call_atexit(indirect_teardown, NULL);
 961 #endif
 962
 963  indirect_initialized = 1;
 964 }
 965
 966 STATIC U32 indirect_booted = 0;
 967
 968 /* --- XS ------------------------------------------------------------------ */
 969
 970 MODULE = indirect      PACKAGE = indirect
 971
 972 PROTOTYPES: ENABLE
 973
 974 BOOT:
 975 {
 976  if (!indirect_booted++) {
 977   HV *stash;
 978
 979   PERL_HASH(indirect_hash, __PACKAGE__, __PACKAGE_LEN__);
 980
 981   stash = gv_stashpvn(__PACKAGE__, __PACKAGE_LEN__, 1);
 982   newCONSTSUB(stash, "I_THREADSAFE", newSVuv(I_THREADSAFE));
 983   newCONSTSUB(stash, "I_FORKSAFE",   newSVuv(I_FORKSAFE));
 984  }
 985
 986  indirect_setup();
 987 }
 988
 989 #if I_THREADSAFE
 990
 991 void
 992 CLONE(...)
 993 PROTOTYPE: DISABLE
 994 PREINIT:
 995  ptable *t;
 996  SV     *global_code_dup;
 997 PPCODE:
 998  {
 999   my_cxt_t ud;
1000   dMY_CXT;
1001   ud.tbl   = t = ptable_new();
1002   ud.owner = MY_CXT.owner;
1003   ptable_walk(MY_CXT.tbl, indirect_ptable_clone, &ud);
1004   global_code_dup = indirect_clone(MY_CXT.global_code, MY_CXT.owner);
1005  }
1006  {
1007   MY_CXT_CLONE;
1008   MY_CXT.map         = ptable_new();
1009   MY_CXT.tbl         = t;
1010   MY_CXT.owner       = aTHX;
1011   MY_CXT.global_code = global_code_dup;
1012  }
1013  reap(3, indirect_thread_cleanup, NULL);
1014  XSRETURN(0);
1015
1016 #endif
1017
1018 SV *
1019 _tag(SV *value)
1020 PROTOTYPE: $
1021 CODE:
1022  RETVAL = indirect_tag(value);
1023 OUTPUT:
1024  RETVAL
1025
1026 void
1027 _global(SV *code)
1028 PROTOTYPE: $
1029 PPCODE:
1030  if (!SvOK(code))
1031   code = NULL;
1032  else if (SvROK(code))
1033   code = SvRV(code);
1034  {
1035   dMY_CXT;
1036   SvREFCNT_dec(MY_CXT.global_code);
1037   MY_CXT.global_code = SvREFCNT_inc(code);
1038  }
1039  XSRETURN(0);