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 STATIC void indirect_thread_cleanup(pTHX_ void *ud) {
 327  dMY_CXT;
 328
 329  SvREFCNT_dec(MY_CXT.global_code);
 330  ptable_free(MY_CXT.map);
 331  ptable_hints_free(MY_CXT.tbl);
 332 }
 333
 334 STATIC int indirect_endav_free(pTHX_ SV *sv, MAGIC *mg) {
 335  SAVEDESTRUCTOR_X(indirect_thread_cleanup, NULL);
 336
 337  return 0;
 338 }
 339
 340 STATIC MGVTBL indirect_endav_vtbl = {
 341  0,
 342  0,
 343  0,
 344  0,
 345  indirect_endav_free
 346 #if MGf_COPY
 347  , 0
 348 #endif
 349 #if MGf_DUP
 350  , 0
 351 #endif
 352 #if MGf_LOCAL
 353  , 0
 354 #endif
 355 };
 356
 357 #endif /* I_THREADSAFE */
 358
 359 #if I_WORKAROUND_REQUIRE_PROPAGATION
 360 STATIC IV indirect_require_tag(pTHX) {
 361 #define indirect_require_tag() indirect_require_tag(aTHX)
 362  const CV *cv, *outside;
 363
 364  cv = PL_compcv;
 365
 366  if (!cv) {
 367   /* If for some reason the pragma is operational at run-time, try to discover
 368    * the current cv in use. */
 369   const PERL_SI *si;
 370
 371   for (si = PL_curstackinfo; si; si = si->si_prev) {
 372    I32 cxix;
 373
 374    for (cxix = si->si_cxix; cxix >= 0; --cxix) {
 375     const PERL_CONTEXT *cx = si->si_cxstack + cxix;
 376
 377     switch (CxTYPE(cx)) {
 378      case CXt_SUB:
 379      case CXt_FORMAT:
 380       /* The propagation workaround is only needed up to 5.10.0 and at that
 381        * time format and sub contexts were still identical. And even later the
 382        * cv members offsets should have been kept the same. */
 383       cv = cx->blk_sub.cv;
 384       goto get_enclosing_cv;
 385      case CXt_EVAL:
 386       cv = cx->blk_eval.cv;
 387       goto get_enclosing_cv;
 388      default:
 389       break;
 390     }
 391    }
 392   }
 393
 394   cv = PL_main_cv;
 395  }
 396
 397 get_enclosing_cv:
 398  for (outside = CvOUTSIDE(cv); outside; outside = CvOUTSIDE(cv))
 399   cv = outside;
 400
 401  return PTR2IV(cv);
 402 }
 403 #endif /* I_WORKAROUND_REQUIRE_PROPAGATION */
 404
 405 STATIC SV *indirect_tag(pTHX_ SV *value) {
 406 #define indirect_tag(V) indirect_tag(aTHX_ (V))
 407  indirect_hint_t *h;
 408  SV *code = NULL;
 409
 410  if (SvROK(value)) {
 411   value = SvRV(value);
 412   if (SvTYPE(value) >= SVt_PVCV) {
 413    code = value;
 414    SvREFCNT_inc_simple_void_NN(code);
 415   }
 416  }
 417
 418 #if I_HINT_STRUCT
 419  h = PerlMemShared_malloc(sizeof *h);
 420  h->code        = code;
 421 # if I_WORKAROUND_REQUIRE_PROPAGATION
 422  h->require_tag = indirect_require_tag();
 423 # endif /* I_WORKAROUND_REQUIRE_PROPAGATION */
 424 #else  /*  I_HINT_STRUCT */
 425  h = code;
 426 #endif /* !I_HINT_STRUCT */
 427
 428 #if I_THREADSAFE
 429  {
 430   dMY_CXT;
 431   /* We only need for the key to be an unique tag for looking up the value later
 432    * Allocated memory provides convenient unique identifiers, so that's why we
 433    * use the hint as the key itself. */
 434   ptable_hints_store(MY_CXT.tbl, h, h);
 435  }
 436 #endif /* I_THREADSAFE */
 437
 438  return newSViv(PTR2IV(h));
 439 }
 440
 441 STATIC SV *indirect_detag(pTHX_ const SV *hint) {
 442 #define indirect_detag(H) indirect_detag(aTHX_ (H))
 443  indirect_hint_t *h;
 444 #if I_THREADSAFE || I_WORKAROUND_REQUIRE_PROPAGATION
 445  dMY_CXT;
 446 #endif
 447
 448  h = INT2PTR(indirect_hint_t *, SvIVX(hint));
 449 #if I_THREADSAFE
 450  h = ptable_fetch(MY_CXT.tbl, h);
 451 #endif /* I_THREADSAFE */
 452
 453 #if I_WORKAROUND_REQUIRE_PROPAGATION
 454  if (indirect_require_tag() != h->require_tag)
 455   return MY_CXT.global_code;
 456 #endif /* I_WORKAROUND_REQUIRE_PROPAGATION */
 457
 458  return I_HINT_CODE(h);
 459 }
 460
 461 STATIC U32 indirect_hash = 0;
 462
 463 STATIC SV *indirect_hint(pTHX) {
 464 #define indirect_hint() indirect_hint(aTHX)
 465  SV *hint = NULL;
 466
 467  if (IN_PERL_RUNTIME)
 468   return NULL;
 469
 470 #if I_HAS_PERL(5, 10, 0) || defined(PL_parser)
 471  if (!PL_parser)
 472   return NULL;
 473 #endif
 474
 475 #ifdef cop_hints_fetch_pvn
 476  hint = cop_hints_fetch_pvn(PL_curcop, __PACKAGE__, __PACKAGE_LEN__,
 477                                                               indirect_hash, 0);
 478 #elif I_HAS_PERL(5, 9, 5)
 479  hint = Perl_refcounted_he_fetch(aTHX_ PL_curcop->cop_hints_hash,
 480                                        NULL,
 481                                        __PACKAGE__, __PACKAGE_LEN__,
 482                                        0,
 483                                        indirect_hash);
 484 #else
 485  {
 486   SV **val = hv_fetch(GvHV(PL_hintgv), __PACKAGE__, __PACKAGE_LEN__, 0);
 487   if (val)
 488    hint = *val;
 489  }
 490 #endif
 491
 492  if (hint && SvIOK(hint))
 493   return indirect_detag(hint);
 494  else {
 495   dMY_CXT;
 496   return MY_CXT.global_code;
 497  }
 498 }
 499
 500 /* ... op -> source position ............................................... */
 501
 502 STATIC void indirect_map_store(pTHX_ const OP *o, STRLEN pos, SV *sv, line_t line) {
 503 #define indirect_map_store(O, P, N, L) indirect_map_store(aTHX_ (O), (P), (N), (L))
 504  indirect_op_info_t *oi;
 505  const char *s;
 506  STRLEN len;
 507  dMY_CXT;
 508
 509  if (!(oi = ptable_fetch(MY_CXT.map, o))) {
 510   Newx(oi, 1, indirect_op_info_t);
 511   ptable_store(MY_CXT.map, o, oi);
 512   oi->buf  = NULL;
 513   oi->size = 0;
 514  }
 515
 516  if (sv) {
 517   s = SvPV_const(sv, len);
 518  } else {
 519   s   = "{";
 520   len = 1;
 521  }
 522
 523  if (len > oi->size) {
 524   Safefree(oi->buf);
 525   Newx(oi->buf, len, char);
 526   oi->size = len;
 527  }
 528  Copy(s, oi->buf, len, char);
 529
 530  oi->len  = len;
 531  oi->pos  = pos;
 532  oi->line = line;
 533 }
 534
 535 STATIC const indirect_op_info_t *indirect_map_fetch(pTHX_ const OP *o) {
 536 #define indirect_map_fetch(O) indirect_map_fetch(aTHX_ (O))
 537  dMY_CXT;
 538
 539  return ptable_fetch(MY_CXT.map, o);
 540 }
 541
 542 STATIC void indirect_map_delete(pTHX_ const OP *o) {
 543 #define indirect_map_delete(O) indirect_map_delete(aTHX_ (O))
 544  dMY_CXT;
 545
 546  ptable_delete(MY_CXT.map, o);
 547 }
 548
 549 /* --- Check functions ----------------------------------------------------- */
 550
 551 STATIC int indirect_find(pTHX_ SV *name_sv, const char *line_bufptr, STRLEN *name_pos) {
 552 #define indirect_find(NSV, LBP, NP) indirect_find(aTHX_ (NSV), (LBP), (NP))
 553  STRLEN      name_len, line_len;
 554  const char *name, *name_end;
 555  const char *line, *line_end;
 556  const char *p;
 557
 558  line     = SvPV_const(PL_linestr, line_len);
 559  line_end = line + line_len;
 560
 561  name = SvPV_const(name_sv, name_len);
 562  if (name_len >= 1 && *name == '$') {
 563   ++name;
 564   --name_len;
 565   while (line_bufptr < line_end && *line_bufptr != '$')
 566    ++line_bufptr;
 567   if (line_bufptr >= line_end)
 568    return 0;
 569  }
 570  name_end = name + name_len;
 571
 572  p = line_bufptr;
 573  while (1) {
 574   p = ninstr(p, line_end, name, name_end);
 575   if (!p)
 576    return 0;
 577   if (!isALNUM(p[name_len]))
 578    break;
 579   /* p points to a word that has name as prefix, skip the rest of the word */
 580   p += name_len + 1;
 581   while (isALNUM(*p))
 582    ++p;
 583  }
 584
 585  *name_pos = p - line;
 586
 587  return 1;
 588 }
 589
 590 /* ... ck_const ............................................................ */
 591
 592 STATIC OP *(*indirect_old_ck_const)(pTHX_ OP *) = 0;
 593
 594 STATIC OP *indirect_ck_const(pTHX_ OP *o) {
 595  o = indirect_old_ck_const(aTHX_ o);
 596
 597  if (indirect_hint()) {
 598   SV *sv = cSVOPo_sv;
 599
 600   if (SvPOK(sv) && (SvTYPE(sv) >= SVt_PV)) {
 601    STRLEN pos;
 602
 603    if (indirect_find(sv, PL_oldbufptr, &pos)) {
 604     STRLEN len;
 605
 606     /* If the constant is equal to the current package name, try to look for
 607      * a "__PACKAGE__" coming before what we got. We only need to check this
 608      * when we already had a match because __PACKAGE__ can only appear in
 609      * direct method calls ("new __PACKAGE__" is a syntax error). */
 610     len = SvCUR(sv);
 611     if (PL_curstash
 612         && len == (STRLEN) HvNAMELEN_get(PL_curstash)
 613         && memcmp(SvPVX(sv), HvNAME_get(PL_curstash), len) == 0) {
 614      STRLEN pos_pkg;
 615      SV    *pkg = sv_newmortal();
 616      sv_setpvn(pkg, "__PACKAGE__", sizeof("__PACKAGE__")-1);
 617
 618      if (indirect_find(pkg, PL_oldbufptr, &pos_pkg) && pos_pkg < pos) {
 619       sv  = pkg;
 620       pos = pos_pkg;
 621      }
 622     }
 623
 624     indirect_map_store(o, pos, sv, CopLINE(&PL_compiling));
 625     return o;
 626    }
 627   }
 628  }
 629
 630  indirect_map_delete(o);
 631  return o;
 632 }
 633
 634 /* ... ck_rv2sv ............................................................ */
 635
 636 STATIC OP *(*indirect_old_ck_rv2sv)(pTHX_ OP *) = 0;
 637
 638 STATIC OP *indirect_ck_rv2sv(pTHX_ OP *o) {
 639  if (indirect_hint()) {
 640   OP *op = cUNOPo->op_first;
 641   SV *sv;
 642   const char *name = NULL;
 643   STRLEN pos, len;
 644   OPCODE type = (OPCODE) op->op_type;
 645
 646   switch (type) {
 647    case OP_GV:
 648    case OP_GVSV: {
 649     GV *gv = cGVOPx_gv(op);
 650     name = GvNAME(gv);
 651     len  = GvNAMELEN(gv);
 652     break;
 653    }
 654    default:
 655     if ((PL_opargs[type] & OA_CLASS_MASK) == OA_SVOP) {
 656      SV *nsv = cSVOPx_sv(op);
 657      if (SvPOK(nsv) && (SvTYPE(nsv) >= SVt_PV))
 658       name = SvPV_const(nsv, len);
 659     }
 660   }
 661   if (!name)
 662    goto done;
 663
 664   sv = sv_2mortal(newSVpvn("$", 1));
 665   sv_catpvn_nomg(sv, name, len);
 666   if (!indirect_find(sv, PL_oldbufptr, &pos)) {
 667    /* If it failed, retry without the current stash */
 668    const char *stash = HvNAME_get(PL_curstash);
 669    STRLEN stashlen = HvNAMELEN_get(PL_curstash);
 670
 671    if ((len < stashlen + 2) || strnNE(name, stash, stashlen)
 672        || name[stashlen] != ':' || name[stashlen+1] != ':') {
 673     /* Failed again ? Try to remove main */
 674     stash = "main";
 675     stashlen = 4;
 676     if ((len < stashlen + 2) || strnNE(name, stash, stashlen)
 677         || name[stashlen] != ':' || name[stashlen+1] != ':')
 678      goto done;
 679    }
 680
 681    sv_setpvn(sv, "$", 1);
 682    stashlen += 2;
 683    sv_catpvn_nomg(sv, name + stashlen, len - stashlen);
 684    if (!indirect_find(sv, PL_oldbufptr, &pos))
 685     goto done;
 686   }
 687
 688   o = indirect_old_ck_rv2sv(aTHX_ o);
 689
 690   indirect_map_store(o, pos, sv, CopLINE(&PL_compiling));
 691   return o;
 692  }
 693
 694 done:
 695  o = indirect_old_ck_rv2sv(aTHX_ o);
 696
 697  indirect_map_delete(o);
 698  return o;
 699 }
 700
 701 /* ... ck_padany ........................................................... */
 702
 703 STATIC OP *(*indirect_old_ck_padany)(pTHX_ OP *) = 0;
 704
 705 STATIC OP *indirect_ck_padany(pTHX_ OP *o) {
 706  o = indirect_old_ck_padany(aTHX_ o);
 707
 708  if (indirect_hint()) {
 709   SV *sv;
 710   const char *s = PL_oldbufptr, *t = PL_bufptr - 1;
 711
 712   while (s < t && isSPACE(*s)) ++s;
 713   if (*s == '$' && ++s <= t) {
 714    while (s < t && isSPACE(*s)) ++s;
 715    while (s < t && isSPACE(*t)) --t;
 716    sv = sv_2mortal(newSVpvn("$", 1));
 717    sv_catpvn_nomg(sv, s, t - s + 1);
 718    indirect_map_store(o, s - SvPVX_const(PL_linestr),
 719                          sv, CopLINE(&PL_compiling));
 720    return o;
 721   }
 722  }
 723
 724  indirect_map_delete(o);
 725  return o;
 726 }
 727
 728 /* ... ck_scope ............................................................ */
 729
 730 STATIC OP *(*indirect_old_ck_scope)  (pTHX_ OP *) = 0;
 731 STATIC OP *(*indirect_old_ck_lineseq)(pTHX_ OP *) = 0;
 732
 733 STATIC OP *indirect_ck_scope(pTHX_ OP *o) {
 734  OP *(*old_ck)(pTHX_ OP *) = 0;
 735
 736  switch (o->op_type) {
 737   case OP_SCOPE:   old_ck = indirect_old_ck_scope;   break;
 738   case OP_LINESEQ: old_ck = indirect_old_ck_lineseq; break;
 739  }
 740  o = old_ck(aTHX_ o);
 741
 742  if (indirect_hint()) {
 743   indirect_map_store(o, PL_oldbufptr - SvPVX_const(PL_linestr),
 744                         NULL, CopLINE(&PL_compiling));
 745   return o;
 746  }
 747
 748  indirect_map_delete(o);
 749  return o;
 750 }
 751
 752 /* We don't need to clean the map entries for leave ops because they can only
 753  * be created by mutating from a lineseq. */
 754
 755 /* ... ck_method ........................................................... */
 756
 757 STATIC OP *(*indirect_old_ck_method)(pTHX_ OP *) = 0;
 758
 759 STATIC OP *indirect_ck_method(pTHX_ OP *o) {
 760  if (indirect_hint()) {
 761   OP *op = cUNOPo->op_first;
 762
 763   /* Indirect method call is only possible when the method is a bareword, so
 764    * don't trip up on $obj->$meth. */
 765   if (op && op->op_type == OP_CONST) {
 766    const indirect_op_info_t *oi = indirect_map_fetch(op);
 767    STRLEN pos;
 768    line_t line;
 769    SV *sv;
 770
 771    if (!oi)
 772     goto done;
 773
 774    sv   = sv_2mortal(newSVpvn(oi->buf, oi->len));
 775    pos  = oi->pos;
 776    /* Keep the old line so that we really point to the first line of the
 777     * expression. */
 778    line = oi->line;
 779
 780    o = indirect_old_ck_method(aTHX_ o);
 781    /* o may now be a method_named */
 782
 783    indirect_map_store(o, pos, sv, line);
 784    return o;
 785   }
 786  }
 787
 788 done:
 789  o = indirect_old_ck_method(aTHX_ o);
 790
 791  indirect_map_delete(o);
 792  return o;
 793 }
 794
 795 /* ... ck_method_named ..................................................... */
 796
 797 /* "use foo/no foo" compiles its call to import/unimport directly to a
 798  * method_named op. */
 799
 800 STATIC OP *(*indirect_old_ck_method_named)(pTHX_ OP *) = 0;
 801
 802 STATIC OP *indirect_ck_method_named(pTHX_ OP *o) {
 803  if (indirect_hint()) {
 804   STRLEN pos;
 805   line_t line;
 806   SV *sv;
 807
 808   sv = cSVOPo_sv;
 809   if (!SvPOK(sv) || (SvTYPE(sv) < SVt_PV))
 810    goto done;
 811   sv = sv_mortalcopy(sv);
 812
 813   if (!indirect_find(sv, PL_oldbufptr, &pos))
 814    goto done;
 815   line = CopLINE(&PL_compiling);
 816
 817   o = indirect_old_ck_method_named(aTHX_ o);
 818
 819   indirect_map_store(o, pos, sv, line);
 820   return o;
 821  }
 822
 823 done:
 824  o = indirect_old_ck_method_named(aTHX_ o);
 825
 826  indirect_map_delete(o);
 827  return o;
 828 }
 829
 830 /* ... ck_entersub ......................................................... */
 831
 832 STATIC OP *(*indirect_old_ck_entersub)(pTHX_ OP *) = 0;
 833
 834 STATIC OP *indirect_ck_entersub(pTHX_ OP *o) {
 835  SV *code = indirect_hint();
 836
 837  o = indirect_old_ck_entersub(aTHX_ o);
 838
 839  if (code) {
 840   const indirect_op_info_t *moi, *ooi;
 841   OP     *mop, *oop;
 842   LISTOP *lop;
 843
 844   oop = o;
 845   do {
 846    lop = (LISTOP *) oop;
 847    if (!(lop->op_flags & OPf_KIDS))
 848     goto done;
 849    oop = lop->op_first;
 850   } while (oop->op_type != OP_PUSHMARK);
 851   oop = OP_SIBLING(oop);
 852   mop = lop->op_last;
 853
 854   if (!oop)
 855    goto done;
 856
 857   switch (oop->op_type) {
 858    case OP_CONST:
 859    case OP_RV2SV:
 860    case OP_PADSV:
 861    case OP_SCOPE:
 862    case OP_LEAVE:
 863     break;
 864    default:
 865     goto done;
 866   }
 867
 868   if (mop->op_type == OP_METHOD)
 869    mop = cUNOPx(mop)->op_first;
 870   else if (mop->op_type != OP_METHOD_NAMED)
 871    goto done;
 872
 873   moi = indirect_map_fetch(mop);
 874   if (!moi)
 875    goto done;
 876
 877   ooi = indirect_map_fetch(oop);
 878   if (!ooi)
 879    goto done;
 880
 881   /* When positions are identical, the method and the object must have the
 882    * same name. But it also means that it is an indirect call, as "foo->foo"
 883    * results in different positions. */
 884   if (   moi->line < ooi->line
 885       || (moi->line == ooi->line && moi->pos <= ooi->pos)) {
 886    SV *file;
 887    dSP;
 888
 889    ENTER;
 890    SAVETMPS;
 891
 892 #ifdef USE_ITHREADS
 893    file = sv_2mortal(newSVpv(CopFILE(&PL_compiling), 0));
 894 #else
 895    file = sv_mortalcopy(CopFILESV(&PL_compiling));
 896 #endif
 897
 898    PUSHMARK(SP);
 899    EXTEND(SP, 4);
 900    mPUSHp(ooi->buf, ooi->len);
 901    mPUSHp(moi->buf, moi->len);
 902    PUSHs(file);
 903    mPUSHu(moi->line);
 904    PUTBACK;
 905
 906    call_sv(code, G_VOID);
 907
 908    PUTBACK;
 909
 910    FREETMPS;
 911    LEAVE;
 912   }
 913  }
 914
 915 done:
 916  return o;
 917 }
 918
 919 STATIC U32 indirect_initialized = 0;
 920
 921 STATIC void indirect_teardown(pTHX_ void *root) {
 922  if (!indirect_initialized)
 923   return;
 924
 925 #if I_MULTIPLICITY
 926  if (aTHX != root)
 927   return;
 928 #endif
 929
 930  {
 931   dMY_CXT;
 932   ptable_free(MY_CXT.map);
 933 #if I_THREADSAFE
 934   ptable_hints_free(MY_CXT.tbl);
 935 #endif
 936  }
 937
 938  indirect_ck_restore(OP_CONST,   &indirect_old_ck_const);
 939  indirect_ck_restore(OP_RV2SV,   &indirect_old_ck_rv2sv);
 940  indirect_ck_restore(OP_PADANY,  &indirect_old_ck_padany);
 941  indirect_ck_restore(OP_SCOPE,   &indirect_old_ck_scope);
 942  indirect_ck_restore(OP_LINESEQ, &indirect_old_ck_lineseq);
 943
 944  indirect_ck_restore(OP_METHOD,       &indirect_old_ck_method);
 945  indirect_ck_restore(OP_METHOD_NAMED, &indirect_old_ck_method_named);
 946  indirect_ck_restore(OP_ENTERSUB,     &indirect_old_ck_entersub);
 947
 948  indirect_initialized = 0;
 949 }
 950
 951 STATIC void indirect_setup(pTHX) {
 952 #define indirect_setup() indirect_setup(aTHX)
 953  if (indirect_initialized)
 954   return;
 955
 956  {
 957   MY_CXT_INIT;
 958 #if I_THREADSAFE
 959   MY_CXT.tbl         = ptable_new();
 960   MY_CXT.owner       = aTHX;
 961 #endif
 962   MY_CXT.map         = ptable_new();
 963   MY_CXT.global_code = NULL;
 964  }
 965
 966  indirect_ck_replace(OP_CONST,   indirect_ck_const,  &indirect_old_ck_const);
 967  indirect_ck_replace(OP_RV2SV,   indirect_ck_rv2sv,  &indirect_old_ck_rv2sv);
 968  indirect_ck_replace(OP_PADANY,  indirect_ck_padany, &indirect_old_ck_padany);
 969  indirect_ck_replace(OP_SCOPE,   indirect_ck_scope,  &indirect_old_ck_scope);
 970  indirect_ck_replace(OP_LINESEQ, indirect_ck_scope,  &indirect_old_ck_lineseq);
 971
 972  indirect_ck_replace(OP_METHOD,       indirect_ck_method,
 973                                       &indirect_old_ck_method);
 974  indirect_ck_replace(OP_METHOD_NAMED, indirect_ck_method_named,
 975                                       &indirect_old_ck_method_named);
 976  indirect_ck_replace(OP_ENTERSUB,     indirect_ck_entersub,
 977                                       &indirect_old_ck_entersub);
 978
 979 #if I_MULTIPLICITY
 980  call_atexit(indirect_teardown, aTHX);
 981 #else
 982  call_atexit(indirect_teardown, NULL);
 983 #endif
 984
 985  indirect_initialized = 1;
 986 }
 987
 988 STATIC U32 indirect_booted = 0;
 989
 990 /* --- XS ------------------------------------------------------------------ */
 991
 992 MODULE = indirect      PACKAGE = indirect
 993
 994 PROTOTYPES: ENABLE
 995
 996 BOOT:
 997 {
 998  if (!indirect_booted++) {
 999   HV *stash;
1000
1001   PERL_HASH(indirect_hash, __PACKAGE__, __PACKAGE_LEN__);
1002
1003   stash = gv_stashpvn(__PACKAGE__, __PACKAGE_LEN__, 1);
1004   newCONSTSUB(stash, "I_THREADSAFE", newSVuv(I_THREADSAFE));
1005   newCONSTSUB(stash, "I_FORKSAFE",   newSVuv(I_FORKSAFE));
1006  }
1007
1008  indirect_setup();
1009 }
1010
1011 #if I_THREADSAFE
1012
1013 void
1014 CLONE(...)
1015 PROTOTYPE: DISABLE
1016 PREINIT:
1017  ptable *t;
1018  SV     *global_code_dup;
1019  GV     *gv;
1020 PPCODE:
1021  {
1022   my_cxt_t ud;
1023   dMY_CXT;
1024   ud.tbl   = t = ptable_new();
1025   ud.owner = MY_CXT.owner;
1026   ptable_walk(MY_CXT.tbl, indirect_ptable_clone, &ud);
1027   global_code_dup = indirect_clone(MY_CXT.global_code, MY_CXT.owner);
1028  }
1029  {
1030   MY_CXT_CLONE;
1031   MY_CXT.map         = ptable_new();
1032   MY_CXT.tbl         = t;
1033   MY_CXT.owner       = aTHX;
1034   MY_CXT.global_code = global_code_dup;
1035  }
1036  gv = gv_fetchpv(__PACKAGE__ "::_THREAD_CLEANUP", 0, SVt_PVCV);
1037  if (gv) {
1038   CV *cv = GvCV(gv);
1039   if (!PL_endav)
1040    PL_endav = newAV();
1041   SvREFCNT_inc(cv);
1042   if (!av_store(PL_endav, av_len(PL_endav) + 1, (SV *) cv))
1043    SvREFCNT_dec(cv);
1044   sv_magicext((SV *) PL_endav, NULL, PERL_MAGIC_ext, &indirect_endav_vtbl, NULL, 0);
1045  }
1046  XSRETURN(0);
1047
1048 void
1049 _THREAD_CLEANUP(...)
1050 PROTOTYPE: DISABLE
1051 PPCODE:
1052  indirect_thread_cleanup(aTHX_ NULL);
1053  XSRETURN(0);
1054
1055 #endif
1056
1057 SV *
1058 _tag(SV *value)
1059 PROTOTYPE: $
1060 CODE:
1061  RETVAL = indirect_tag(value);
1062 OUTPUT:
1063  RETVAL
1064
1065 void
1066 _global(SV *code)
1067 PROTOTYPE: $
1068 PPCODE:
1069  if (!SvOK(code))
1070   code = NULL;
1071  else if (SvROK(code))
1072   code = SvRV(code);
1073  {
1074   dMY_CXT;
1075   SvREFCNT_dec(MY_CXT.global_code);
1076   MY_CXT.global_code = SvREFCNT_inc(code);
1077  }
1078  XSRETURN(0);