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