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 OpSIBLING
  67 # ifdef OP_SIBLING
  68 #  define OpSIBLING(O) OP_SIBLING(O)
  69 # else
  70 #  define OpSIBLING(O) ((O)->op_sibling)
  71 # endif
  72 #endif
  73
  74 #define I_HAS_PERL(R, V, S) (PERL_REVISION > (R) || (PERL_REVISION == (R) && (PERL_VERSION > (V) || (PERL_VERSION == (V) && (PERL_SUBVERSION >= (S))))))
  75
  76 #if I_HAS_PERL(5, 10, 0) || defined(PL_parser)
  77 # ifndef PL_linestr
  78 #  define PL_linestr PL_parser->linestr
  79 # endif
  80 # ifndef PL_bufptr
  81 #  define PL_bufptr PL_parser->bufptr
  82 # endif
  83 # ifndef PL_oldbufptr
  84 #  define PL_oldbufptr PL_parser->oldbufptr
  85 # endif
  86 # ifndef PL_lex_inwhat
  87 #  define PL_lex_inwhat PL_parser->lex_inwhat
  88 # endif
  89 #else
  90 # ifndef PL_linestr
  91 #  define PL_linestr PL_Ilinestr
  92 # endif
  93 # ifndef PL_bufptr
  94 #  define PL_bufptr PL_Ibufptr
  95 # endif
  96 # ifndef PL_oldbufptr
  97 #  define PL_oldbufptr PL_Ioldbufptr
  98 # endif
  99 # ifndef PL_lex_inwhat
 100 #  define PL_lex_inwhat PL_Ilex_inwhat
 101 # endif
 102 #endif
 103
 104 #ifndef I_WORKAROUND_REQUIRE_PROPAGATION
 105 # define I_WORKAROUND_REQUIRE_PROPAGATION !I_HAS_PERL(5, 10, 1)
 106 #endif
 107
 108 /* ... Thread safety and multiplicity ...................................... */
 109
 110 /* Safe unless stated otherwise in Makefile.PL */
 111 #ifndef I_FORKSAFE
 112 # define I_FORKSAFE 1
 113 #endif
 114
 115 #ifndef I_MULTIPLICITY
 116 # if defined(MULTIPLICITY) || defined(PERL_IMPLICIT_CONTEXT)
 117 #  define I_MULTIPLICITY 1
 118 # else
 119 #  define I_MULTIPLICITY 0
 120 # endif
 121 #endif
 122 #if I_MULTIPLICITY && !defined(tTHX)
 123 # define tTHX PerlInterpreter*
 124 #endif
 125
 126 #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))
 127 # define I_THREADSAFE 1
 128 # ifndef MY_CXT_CLONE
 129 #  define MY_CXT_CLONE \
 130     dMY_CXT_SV;                                                      \
 131     my_cxt_t *my_cxtp = (my_cxt_t*)SvPVX(newSV(sizeof(my_cxt_t)-1)); \
 132     Copy(INT2PTR(my_cxt_t*, SvUV(my_cxt_sv)), my_cxtp, 1, my_cxt_t); \
 133     sv_setuv(my_cxt_sv, PTR2UV(my_cxtp))
 134 # endif
 135 #else
 136 # define I_THREADSAFE 0
 137 # undef  dMY_CXT
 138 # define dMY_CXT      dNOOP
 139 # undef  MY_CXT
 140 # define MY_CXT       indirect_globaldata
 141 # undef  START_MY_CXT
 142 # define START_MY_CXT static my_cxt_t MY_CXT;
 143 # undef  MY_CXT_INIT
 144 # define MY_CXT_INIT  NOOP
 145 # undef  MY_CXT_CLONE
 146 # define MY_CXT_CLONE NOOP
 147 #endif
 148
 149 #if defined(OP_CHECK_MUTEX_LOCK) && defined(OP_CHECK_MUTEX_UNLOCK)
 150 # define I_CHECK_MUTEX_LOCK   OP_CHECK_MUTEX_LOCK
 151 # define I_CHECK_MUTEX_UNLOCK OP_CHECK_MUTEX_UNLOCK
 152 #else
 153 # define I_CHECK_MUTEX_LOCK   OP_REFCNT_LOCK
 154 # define I_CHECK_MUTEX_UNLOCK OP_REFCNT_UNLOCK
 155 #endif
 156
 157 typedef OP *(*indirect_ck_t)(pTHX_ OP *);
 158
 159 #ifdef wrap_op_checker
 160
 161 # define indirect_ck_replace(T, NC, OCP) wrap_op_checker((T), (NC), (OCP))
 162
 163 #else
 164
 165 static void indirect_ck_replace(pTHX_ OPCODE type, indirect_ck_t new_ck, indirect_ck_t *old_ck_p) {
 166 #define indirect_ck_replace(T, NC, OCP) indirect_ck_replace(aTHX_ (T), (NC), (OCP))
 167  I_CHECK_MUTEX_LOCK;
 168  if (!*old_ck_p) {
 169   *old_ck_p      = PL_check[type];
 170   PL_check[type] = new_ck;
 171  }
 172  I_CHECK_MUTEX_UNLOCK;
 173 }
 174
 175 #endif
 176
 177 static void indirect_ck_restore(pTHX_ OPCODE type, indirect_ck_t *old_ck_p) {
 178 #define indirect_ck_restore(T, OCP) indirect_ck_restore(aTHX_ (T), (OCP))
 179  I_CHECK_MUTEX_LOCK;
 180  if (*old_ck_p) {
 181   PL_check[type] = *old_ck_p;
 182   *old_ck_p      = 0;
 183  }
 184  I_CHECK_MUTEX_UNLOCK;
 185 }
 186
 187 /* --- Helpers ------------------------------------------------------------- */
 188
 189 /* ... Thread-safe hints ................................................... */
 190
 191 #if I_WORKAROUND_REQUIRE_PROPAGATION
 192
 193 typedef struct {
 194  SV *code;
 195  IV  require_tag;
 196 } indirect_hint_t;
 197
 198 #define I_HINT_STRUCT 1
 199
 200 #define I_HINT_CODE(H) ((H)->code)
 201
 202 #define I_HINT_FREE(H) {   \
 203  indirect_hint_t *h = (H); \
 204  SvREFCNT_dec(h->code);    \
 205  PerlMemShared_free(h);    \
 206 }
 207
 208 #else  /*  I_WORKAROUND_REQUIRE_PROPAGATION */
 209
 210 typedef SV indirect_hint_t;
 211
 212 #define I_HINT_STRUCT 0
 213
 214 #define I_HINT_CODE(H) (H)
 215
 216 #define I_HINT_FREE(H) SvREFCNT_dec(H);
 217
 218 #endif /* !I_WORKAROUND_REQUIRE_PROPAGATION */
 219
 220 #if I_THREADSAFE
 221
 222 #define PTABLE_NAME        ptable_hints
 223 #define PTABLE_VAL_FREE(V) I_HINT_FREE(V)
 224
 225 #define pPTBL  pTHX
 226 #define pPTBL_ pTHX_
 227 #define aPTBL  aTHX
 228 #define aPTBL_ aTHX_
 229
 230 #include "ptable.h"
 231
 232 #define ptable_hints_store(T, K, V) ptable_hints_store(aTHX_ (T), (K), (V))
 233 #define ptable_hints_free(T)        ptable_hints_free(aTHX_ (T))
 234
 235 #endif /* I_THREADSAFE */
 236
 237 /* Define the op->str ptable here because we need to be able to clean it during
 238  * thread cleanup. */
 239
 240 typedef struct {
 241  char   *buf;
 242  STRLEN  pos;
 243  STRLEN  size;
 244  STRLEN  len;
 245  line_t  line;
 246 } indirect_op_info_t;
 247
 248 #define PTABLE_NAME        ptable
 249 #define PTABLE_VAL_FREE(V) if (V) { Safefree(((indirect_op_info_t *) (V))->buf); Safefree(V); }
 250
 251 #define pPTBL  pTHX
 252 #define pPTBL_ pTHX_
 253 #define aPTBL  aTHX
 254 #define aPTBL_ aTHX_
 255
 256 #include "ptable.h"
 257
 258 #define ptable_store(T, K, V) ptable_store(aTHX_ (T), (K), (V))
 259 #define ptable_delete(T, K)   ptable_delete(aTHX_ (T), (K))
 260 #define ptable_clear(T)       ptable_clear(aTHX_ (T))
 261 #define ptable_free(T)        ptable_free(aTHX_ (T))
 262
 263 #define MY_CXT_KEY __PACKAGE__ "::_guts" XS_VERSION
 264
 265 typedef struct {
 266 #if I_THREADSAFE
 267  ptable *tbl; /* It really is a ptable_hints */
 268  tTHX    owner;
 269 #endif
 270  ptable *map;
 271  SV     *global_code;
 272 } my_cxt_t;
 273
 274 START_MY_CXT
 275
 276 #if I_THREADSAFE
 277
 278 typedef struct {
 279  ptable *tbl;
 280 #if I_HAS_PERL(5, 13, 2)
 281  CLONE_PARAMS *params;
 282 #else
 283  CLONE_PARAMS params;
 284 #endif
 285 } indirect_ptable_clone_ud;
 286
 287 #if I_HAS_PERL(5, 13, 2)
 288 # define indirect_ptable_clone_ud_init(U, T, O) \
 289    (U).tbl    = (T); \
 290    (U).params = Perl_clone_params_new((O), aTHX)
 291 # define indirect_ptable_clone_ud_deinit(U) Perl_clone_params_del((U).params)
 292 # define indirect_dup_inc(S, U)             SvREFCNT_inc(sv_dup((S), (U)->params))
 293 #else
 294 # define indirect_ptable_clone_ud_init(U, T, O) \
 295    (U).tbl               = (T);     \
 296    (U).params.stashes    = newAV(); \
 297    (U).params.flags      = 0;       \
 298    (U).params.proto_perl = (O)
 299 # define indirect_ptable_clone_ud_deinit(U) SvREFCNT_dec((U).params.stashes)
 300 # define indirect_dup_inc(S, U)             SvREFCNT_inc(sv_dup((S), &((U)->params)))
 301 #endif
 302
 303 static void indirect_ptable_clone(pTHX_ ptable_ent *ent, void *ud_) {
 304  indirect_ptable_clone_ud *ud = ud_;
 305  indirect_hint_t          *h1 = ent->val;
 306  indirect_hint_t          *h2;
 307
 308 #if I_HINT_STRUCT
 309
 310  h2              = PerlMemShared_malloc(sizeof *h2);
 311  h2->code        = indirect_dup_inc(h1->code, ud);
 312 #if I_WORKAROUND_REQUIRE_PROPAGATION
 313  h2->require_tag = PTR2IV(indirect_dup_inc(INT2PTR(SV *, h1->require_tag), ud));
 314 #endif
 315
 316 #else  /*  I_HINT_STRUCT */
 317
 318  h2 = indirect_dup_inc(h1, ud);
 319
 320 #endif /* !I_HINT_STRUCT */
 321
 322  ptable_hints_store(ud->tbl, ent->key, h2);
 323 }
 324
 325 static void indirect_thread_cleanup(pTHX_ void *ud) {
 326  dMY_CXT;
 327
 328  SvREFCNT_dec(MY_CXT.global_code);
 329  MY_CXT.global_code = NULL;
 330  ptable_free(MY_CXT.map);
 331  MY_CXT.map = NULL;
 332  ptable_hints_free(MY_CXT.tbl);
 333  MY_CXT.tbl = NULL;
 334 }
 335
 336 static int indirect_endav_free(pTHX_ SV *sv, MAGIC *mg) {
 337  SAVEDESTRUCTOR_X(indirect_thread_cleanup, NULL);
 338
 339  return 0;
 340 }
 341
 342 static MGVTBL indirect_endav_vtbl = {
 343  0,
 344  0,
 345  0,
 346  0,
 347  indirect_endav_free
 348 #if MGf_COPY
 349  , 0
 350 #endif
 351 #if MGf_DUP
 352  , 0
 353 #endif
 354 #if MGf_LOCAL
 355  , 0
 356 #endif
 357 };
 358
 359 #endif /* I_THREADSAFE */
 360
 361 #if I_WORKAROUND_REQUIRE_PROPAGATION
 362 static IV indirect_require_tag(pTHX) {
 363 #define indirect_require_tag() indirect_require_tag(aTHX)
 364  const CV *cv, *outside;
 365
 366  cv = PL_compcv;
 367
 368  if (!cv) {
 369   /* If for some reason the pragma is operational at run-time, try to discover
 370    * the current cv in use. */
 371   const PERL_SI *si;
 372
 373   for (si = PL_curstackinfo; si; si = si->si_prev) {
 374    I32 cxix;
 375
 376    for (cxix = si->si_cxix; cxix >= 0; --cxix) {
 377     const PERL_CONTEXT *cx = si->si_cxstack + cxix;
 378
 379     switch (CxTYPE(cx)) {
 380      case CXt_SUB:
 381      case CXt_FORMAT:
 382       /* The propagation workaround is only needed up to 5.10.0 and at that
 383        * time format and sub contexts were still identical. And even later the
 384        * cv members offsets should have been kept the same. */
 385       cv = cx->blk_sub.cv;
 386       goto get_enclosing_cv;
 387      case CXt_EVAL:
 388       cv = cx->blk_eval.cv;
 389       goto get_enclosing_cv;
 390      default:
 391       break;
 392     }
 393    }
 394   }
 395
 396   cv = PL_main_cv;
 397  }
 398
 399 get_enclosing_cv:
 400  for (outside = CvOUTSIDE(cv); outside; outside = CvOUTSIDE(cv))
 401   cv = outside;
 402
 403  return PTR2IV(cv);
 404 }
 405 #endif /* I_WORKAROUND_REQUIRE_PROPAGATION */
 406
 407 static SV *indirect_tag(pTHX_ SV *value) {
 408 #define indirect_tag(V) indirect_tag(aTHX_ (V))
 409  indirect_hint_t *h;
 410  SV              *code = NULL;
 411 #if I_THREADSAFE
 412  dMY_CXT;
 413
 414  if (!MY_CXT.tbl)
 415   return newSViv(0);
 416 #endif /* I_THREADSAFE */
 417
 418  if (SvROK(value)) {
 419   value = SvRV(value);
 420   if (SvTYPE(value) >= SVt_PVCV) {
 421    code = value;
 422    SvREFCNT_inc_simple_void_NN(code);
 423   }
 424  }
 425
 426 #if I_HINT_STRUCT
 427  h = PerlMemShared_malloc(sizeof *h);
 428  h->code        = code;
 429 # if I_WORKAROUND_REQUIRE_PROPAGATION
 430  h->require_tag = indirect_require_tag();
 431 # endif /* I_WORKAROUND_REQUIRE_PROPAGATION */
 432 #else  /*  I_HINT_STRUCT */
 433  h = code;
 434 #endif /* !I_HINT_STRUCT */
 435
 436 #if I_THREADSAFE
 437  /* We only need for the key to be an unique tag for looking up the value later
 438   * Allocated memory provides convenient unique identifiers, so that's why we
 439   * use the hint as the key itself. */
 440  ptable_hints_store(MY_CXT.tbl, h, h);
 441 #endif /* I_THREADSAFE */
 442
 443  return newSViv(PTR2IV(h));
 444 }
 445
 446 static SV *indirect_detag(pTHX_ const SV *hint) {
 447 #define indirect_detag(H) indirect_detag(aTHX_ (H))
 448  indirect_hint_t *h;
 449 #if I_THREADSAFE || I_WORKAROUND_REQUIRE_PROPAGATION
 450  dMY_CXT;
 451 #endif
 452
 453 #if I_THREADSAFE
 454  if (!MY_CXT.tbl)
 455   return NULL;
 456 #endif /* I_THREADSAFE */
 457
 458  h = INT2PTR(indirect_hint_t *, SvIVX(hint));
 459 #if I_THREADSAFE
 460  h = ptable_fetch(MY_CXT.tbl, h);
 461 #endif /* I_THREADSAFE */
 462
 463 #if I_WORKAROUND_REQUIRE_PROPAGATION
 464  if (indirect_require_tag() != h->require_tag)
 465   return MY_CXT.global_code;
 466 #endif /* I_WORKAROUND_REQUIRE_PROPAGATION */
 467
 468  return I_HINT_CODE(h);
 469 }
 470
 471 static U32 indirect_hash = 0;
 472
 473 static SV *indirect_hint(pTHX) {
 474 #define indirect_hint() indirect_hint(aTHX)
 475  SV *hint = NULL;
 476
 477  if (IN_PERL_RUNTIME)
 478   return NULL;
 479
 480 #if I_HAS_PERL(5, 10, 0) || defined(PL_parser)
 481  if (!PL_parser)
 482   return NULL;
 483 #endif
 484
 485 #ifdef cop_hints_fetch_pvn
 486  hint = cop_hints_fetch_pvn(PL_curcop, __PACKAGE__, __PACKAGE_LEN__,
 487                                                               indirect_hash, 0);
 488 #elif I_HAS_PERL(5, 9, 5)
 489  hint = Perl_refcounted_he_fetch(aTHX_ PL_curcop->cop_hints_hash,
 490                                        NULL,
 491                                        __PACKAGE__, __PACKAGE_LEN__,
 492                                        0,
 493                                        indirect_hash);
 494 #else
 495  {
 496   SV **val = hv_fetch(GvHV(PL_hintgv), __PACKAGE__, __PACKAGE_LEN__, 0);
 497   if (val)
 498    hint = *val;
 499  }
 500 #endif
 501
 502  if (hint && SvIOK(hint))
 503   return indirect_detag(hint);
 504  else {
 505   dMY_CXT;
 506   return MY_CXT.global_code;
 507  }
 508 }
 509
 510 /* ... op -> source position ............................................... */
 511
 512 static void indirect_map_store(pTHX_ const OP *o, STRLEN pos, SV *sv, line_t line) {
 513 #define indirect_map_store(O, P, N, L) indirect_map_store(aTHX_ (O), (P), (N), (L))
 514  indirect_op_info_t *oi;
 515  const char *s;
 516  STRLEN len;
 517  dMY_CXT;
 518
 519  /* No need to check for MY_CXT.map != NULL because this code path is always
 520   * guarded by indirect_hint(). */
 521
 522  if (!(oi = ptable_fetch(MY_CXT.map, o))) {
 523   Newx(oi, 1, indirect_op_info_t);
 524   ptable_store(MY_CXT.map, o, oi);
 525   oi->buf  = NULL;
 526   oi->size = 0;
 527  }
 528
 529  if (sv) {
 530   s = SvPV_const(sv, len);
 531  } else {
 532   s   = "{";
 533   len = 1;
 534  }
 535
 536  if (len > oi->size) {
 537   Safefree(oi->buf);
 538   Newx(oi->buf, len, char);
 539   oi->size = len;
 540  }
 541  Copy(s, oi->buf, len, char);
 542
 543  oi->len  = len;
 544  oi->pos  = pos;
 545  oi->line = line;
 546 }
 547
 548 static const indirect_op_info_t *indirect_map_fetch(pTHX_ const OP *o) {
 549 #define indirect_map_fetch(O) indirect_map_fetch(aTHX_ (O))
 550  dMY_CXT;
 551
 552  /* No need to check for MY_CXT.map != NULL because this code path is always
 553   * guarded by indirect_hint(). */
 554
 555  return ptable_fetch(MY_CXT.map, o);
 556 }
 557
 558 static void indirect_map_delete(pTHX_ const OP *o) {
 559 #define indirect_map_delete(O) indirect_map_delete(aTHX_ (O))
 560  dMY_CXT;
 561
 562  if (MY_CXT.map)
 563   ptable_delete(MY_CXT.map, o);
 564 }
 565
 566 /* --- Check functions ----------------------------------------------------- */
 567
 568 static int indirect_find(pTHX_ SV *name_sv, const char *line_bufptr, STRLEN *name_pos) {
 569 #define indirect_find(NSV, LBP, NP) indirect_find(aTHX_ (NSV), (LBP), (NP))
 570  STRLEN      name_len, line_len;
 571  const char *name, *name_end;
 572  const char *line, *line_end;
 573  const char *p;
 574
 575  line     = SvPV_const(PL_linestr, line_len);
 576  line_end = line + line_len;
 577
 578  name = SvPV_const(name_sv, name_len);
 579  if (name_len >= 1 && *name == '$') {
 580   ++name;
 581   --name_len;
 582   while (line_bufptr < line_end && *line_bufptr != '$')
 583    ++line_bufptr;
 584   if (line_bufptr >= line_end)
 585    return 0;
 586  }
 587  name_end = name + name_len;
 588
 589  p = line_bufptr;
 590  while (1) {
 591   p = ninstr(p, line_end, name, name_end);
 592   if (!p)
 593    return 0;
 594   if (!isALNUM(p[name_len]))
 595    break;
 596   /* p points to a word that has name as prefix, skip the rest of the word */
 597   p += name_len + 1;
 598   while (isALNUM(*p))
 599    ++p;
 600  }
 601
 602  *name_pos = p - line;
 603
 604  return 1;
 605 }
 606
 607 /* ... ck_const ............................................................ */
 608
 609 static OP *(*indirect_old_ck_const)(pTHX_ OP *) = 0;
 610
 611 static OP *indirect_ck_const(pTHX_ OP *o) {
 612  o = indirect_old_ck_const(aTHX_ o);
 613
 614  if (indirect_hint()) {
 615   SV *sv = cSVOPo_sv;
 616
 617   if (SvPOK(sv) && (SvTYPE(sv) >= SVt_PV)) {
 618    STRLEN pos;
 619
 620    if (indirect_find(sv, PL_oldbufptr, &pos)) {
 621     STRLEN len;
 622
 623     /* If the constant is equal to the current package name, try to look for
 624      * a "__PACKAGE__" coming before what we got. We only need to check this
 625      * when we already had a match because __PACKAGE__ can only appear in
 626      * direct method calls ("new __PACKAGE__" is a syntax error). */
 627     len = SvCUR(sv);
 628     if (PL_curstash
 629         && len == (STRLEN) HvNAMELEN_get(PL_curstash)
 630         && memcmp(SvPVX(sv), HvNAME_get(PL_curstash), len) == 0) {
 631      STRLEN pos_pkg;
 632      SV    *pkg = sv_newmortal();
 633      sv_setpvn(pkg, "__PACKAGE__", sizeof("__PACKAGE__")-1);
 634
 635      if (indirect_find(pkg, PL_oldbufptr, &pos_pkg) && pos_pkg < pos) {
 636       sv  = pkg;
 637       pos = pos_pkg;
 638      }
 639     }
 640
 641     indirect_map_store(o, pos, sv, CopLINE(&PL_compiling));
 642     return o;
 643    }
 644   }
 645  }
 646
 647  indirect_map_delete(o);
 648  return o;
 649 }
 650
 651 /* ... ck_rv2sv ............................................................ */
 652
 653 static OP *(*indirect_old_ck_rv2sv)(pTHX_ OP *) = 0;
 654
 655 static OP *indirect_ck_rv2sv(pTHX_ OP *o) {
 656  if (indirect_hint()) {
 657   OP *op = cUNOPo->op_first;
 658   SV *sv;
 659   const char *name = NULL;
 660   STRLEN pos, len;
 661   OPCODE type = (OPCODE) op->op_type;
 662
 663   switch (type) {
 664    case OP_GV:
 665    case OP_GVSV: {
 666     GV *gv = cGVOPx_gv(op);
 667     name = GvNAME(gv);
 668     len  = GvNAMELEN(gv);
 669     break;
 670    }
 671    default:
 672     if ((PL_opargs[type] & OA_CLASS_MASK) == OA_SVOP) {
 673      SV *nsv = cSVOPx_sv(op);
 674      if (SvPOK(nsv) && (SvTYPE(nsv) >= SVt_PV))
 675       name = SvPV_const(nsv, len);
 676     }
 677   }
 678   if (!name)
 679    goto done;
 680
 681   sv = sv_2mortal(newSVpvn("$", 1));
 682   sv_catpvn_nomg(sv, name, len);
 683   if (!indirect_find(sv, PL_oldbufptr, &pos)) {
 684    /* If it failed, retry without the current stash */
 685    const char *stash = HvNAME_get(PL_curstash);
 686    STRLEN stashlen = HvNAMELEN_get(PL_curstash);
 687
 688    if ((len < stashlen + 2) || strnNE(name, stash, stashlen)
 689        || name[stashlen] != ':' || name[stashlen+1] != ':') {
 690     /* Failed again ? Try to remove main */
 691     stash = "main";
 692     stashlen = 4;
 693     if ((len < stashlen + 2) || strnNE(name, stash, stashlen)
 694         || name[stashlen] != ':' || name[stashlen+1] != ':')
 695      goto done;
 696    }
 697
 698    sv_setpvn(sv, "$", 1);
 699    stashlen += 2;
 700    sv_catpvn_nomg(sv, name + stashlen, len - stashlen);
 701    if (!indirect_find(sv, PL_oldbufptr, &pos))
 702     goto done;
 703   }
 704
 705   o = indirect_old_ck_rv2sv(aTHX_ o);
 706
 707   indirect_map_store(o, pos, sv, CopLINE(&PL_compiling));
 708   return o;
 709  }
 710
 711 done:
 712  o = indirect_old_ck_rv2sv(aTHX_ o);
 713
 714  indirect_map_delete(o);
 715  return o;
 716 }
 717
 718 /* ... ck_padany ........................................................... */
 719
 720 static OP *(*indirect_old_ck_padany)(pTHX_ OP *) = 0;
 721
 722 static OP *indirect_ck_padany(pTHX_ OP *o) {
 723  o = indirect_old_ck_padany(aTHX_ o);
 724
 725  if (indirect_hint()) {
 726   SV *sv;
 727   const char *s = PL_oldbufptr, *t = PL_bufptr - 1;
 728
 729   while (s < t && isSPACE(*s)) ++s;
 730   if (*s == '$' && ++s <= t) {
 731    while (s < t && isSPACE(*s)) ++s;
 732    while (s < t && isSPACE(*t)) --t;
 733    sv = sv_2mortal(newSVpvn("$", 1));
 734    sv_catpvn_nomg(sv, s, t - s + 1);
 735    indirect_map_store(o, s - SvPVX_const(PL_linestr),
 736                          sv, CopLINE(&PL_compiling));
 737    return o;
 738   }
 739  }
 740
 741  indirect_map_delete(o);
 742  return o;
 743 }
 744
 745 /* ... ck_scope ............................................................ */
 746
 747 static OP *(*indirect_old_ck_scope)  (pTHX_ OP *) = 0;
 748 static OP *(*indirect_old_ck_lineseq)(pTHX_ OP *) = 0;
 749
 750 static OP *indirect_ck_scope(pTHX_ OP *o) {
 751  OP *(*old_ck)(pTHX_ OP *) = 0;
 752
 753  switch (o->op_type) {
 754   case OP_SCOPE:   old_ck = indirect_old_ck_scope;   break;
 755   case OP_LINESEQ: old_ck = indirect_old_ck_lineseq; break;
 756  }
 757  o = old_ck(aTHX_ o);
 758
 759  if (indirect_hint()) {
 760   indirect_map_store(o, PL_oldbufptr - SvPVX_const(PL_linestr),
 761                         NULL, CopLINE(&PL_compiling));
 762   return o;
 763  }
 764
 765  indirect_map_delete(o);
 766  return o;
 767 }
 768
 769 /* We don't need to clean the map entries for leave ops because they can only
 770  * be created by mutating from a lineseq. */
 771
 772 /* ... ck_method ........................................................... */
 773
 774 static OP *(*indirect_old_ck_method)(pTHX_ OP *) = 0;
 775
 776 static OP *indirect_ck_method(pTHX_ OP *o) {
 777  if (indirect_hint()) {
 778   OP *op = cUNOPo->op_first;
 779
 780   /* Indirect method call is only possible when the method is a bareword, so
 781    * don't trip up on $obj->$meth. */
 782   if (op && op->op_type == OP_CONST) {
 783    const indirect_op_info_t *oi = indirect_map_fetch(op);
 784    STRLEN pos;
 785    line_t line;
 786    SV *sv;
 787
 788    if (!oi)
 789     goto done;
 790
 791    sv   = sv_2mortal(newSVpvn(oi->buf, oi->len));
 792    pos  = oi->pos;
 793    /* Keep the old line so that we really point to the first line of the
 794     * expression. */
 795    line = oi->line;
 796
 797    o = indirect_old_ck_method(aTHX_ o);
 798    /* o may now be a method_named */
 799
 800    indirect_map_store(o, pos, sv, line);
 801    return o;
 802   }
 803  }
 804
 805 done:
 806  o = indirect_old_ck_method(aTHX_ o);
 807
 808  indirect_map_delete(o);
 809  return o;
 810 }
 811
 812 /* ... ck_method_named ..................................................... */
 813
 814 /* "use foo/no foo" compiles its call to import/unimport directly to a
 815  * method_named op. */
 816
 817 static OP *(*indirect_old_ck_method_named)(pTHX_ OP *) = 0;
 818
 819 static OP *indirect_ck_method_named(pTHX_ OP *o) {
 820  if (indirect_hint()) {
 821   STRLEN pos;
 822   line_t line;
 823   SV *sv;
 824
 825   sv = cSVOPo_sv;
 826   if (!SvPOK(sv) || (SvTYPE(sv) < SVt_PV))
 827    goto done;
 828   sv = sv_mortalcopy(sv);
 829
 830   if (!indirect_find(sv, PL_oldbufptr, &pos))
 831    goto done;
 832   line = CopLINE(&PL_compiling);
 833
 834   o = indirect_old_ck_method_named(aTHX_ o);
 835
 836   indirect_map_store(o, pos, sv, line);
 837   return o;
 838  }
 839
 840 done:
 841  o = indirect_old_ck_method_named(aTHX_ o);
 842
 843  indirect_map_delete(o);
 844  return o;
 845 }
 846
 847 /* ... ck_entersub ......................................................... */
 848
 849 static OP *(*indirect_old_ck_entersub)(pTHX_ OP *) = 0;
 850
 851 static OP *indirect_ck_entersub(pTHX_ OP *o) {
 852  SV *code = indirect_hint();
 853
 854  o = indirect_old_ck_entersub(aTHX_ o);
 855
 856  if (code) {
 857   const indirect_op_info_t *moi, *ooi;
 858   OP     *mop, *oop;
 859   LISTOP *lop;
 860
 861   oop = o;
 862   do {
 863    lop = (LISTOP *) oop;
 864    if (!(lop->op_flags & OPf_KIDS))
 865     goto done;
 866    oop = lop->op_first;
 867   } while (oop->op_type != OP_PUSHMARK);
 868   oop = OpSIBLING(oop);
 869   mop = lop->op_last;
 870
 871   if (!oop)
 872    goto done;
 873
 874   switch (oop->op_type) {
 875    case OP_CONST:
 876    case OP_RV2SV:
 877    case OP_PADSV:
 878    case OP_SCOPE:
 879    case OP_LEAVE:
 880     break;
 881    default:
 882     goto done;
 883   }
 884
 885   if (mop->op_type == OP_METHOD)
 886    mop = cUNOPx(mop)->op_first;
 887   else if (mop->op_type != OP_METHOD_NAMED)
 888    goto done;
 889
 890   moi = indirect_map_fetch(mop);
 891   if (!moi)
 892    goto done;
 893
 894   ooi = indirect_map_fetch(oop);
 895   if (!ooi)
 896    goto done;
 897
 898   /* When positions are identical, the method and the object must have the
 899    * same name. But it also means that it is an indirect call, as "foo->foo"
 900    * results in different positions. */
 901   if (   moi->line < ooi->line
 902       || (moi->line == ooi->line && moi->pos <= ooi->pos)) {
 903    SV *file;
 904    dSP;
 905
 906    ENTER;
 907    SAVETMPS;
 908
 909 #ifdef USE_ITHREADS
 910    file = sv_2mortal(newSVpv(CopFILE(&PL_compiling), 0));
 911 #else
 912    file = sv_mortalcopy(CopFILESV(&PL_compiling));
 913 #endif
 914
 915    PUSHMARK(SP);
 916    EXTEND(SP, 4);
 917    mPUSHp(ooi->buf, ooi->len);
 918    mPUSHp(moi->buf, moi->len);
 919    PUSHs(file);
 920    mPUSHu(moi->line);
 921    PUTBACK;
 922
 923    call_sv(code, G_VOID);
 924
 925    PUTBACK;
 926
 927    FREETMPS;
 928    LEAVE;
 929   }
 930  }
 931
 932 done:
 933  return o;
 934 }
 935
 936 static U32 indirect_initialized = 0;
 937
 938 static void indirect_teardown(pTHX_ void *root) {
 939  if (!indirect_initialized)
 940   return;
 941
 942 #if I_MULTIPLICITY
 943  if (aTHX != root)
 944   return;
 945 #endif
 946
 947  {
 948   dMY_CXT;
 949   ptable_free(MY_CXT.map);
 950   MY_CXT.map = NULL;
 951 #if I_THREADSAFE
 952   ptable_hints_free(MY_CXT.tbl);
 953   MY_CXT.tbl = NULL;
 954 #endif
 955  }
 956
 957  indirect_ck_restore(OP_CONST,   &indirect_old_ck_const);
 958  indirect_ck_restore(OP_RV2SV,   &indirect_old_ck_rv2sv);
 959  indirect_ck_restore(OP_PADANY,  &indirect_old_ck_padany);
 960  indirect_ck_restore(OP_SCOPE,   &indirect_old_ck_scope);
 961  indirect_ck_restore(OP_LINESEQ, &indirect_old_ck_lineseq);
 962
 963  indirect_ck_restore(OP_METHOD,       &indirect_old_ck_method);
 964  indirect_ck_restore(OP_METHOD_NAMED, &indirect_old_ck_method_named);
 965  indirect_ck_restore(OP_ENTERSUB,     &indirect_old_ck_entersub);
 966
 967  indirect_initialized = 0;
 968 }
 969
 970 static void indirect_setup(pTHX) {
 971 #define indirect_setup() indirect_setup(aTHX)
 972  if (indirect_initialized)
 973   return;
 974
 975  {
 976   MY_CXT_INIT;
 977 #if I_THREADSAFE
 978   MY_CXT.tbl         = ptable_new();
 979   MY_CXT.owner       = aTHX;
 980 #endif
 981   MY_CXT.map         = ptable_new();
 982   MY_CXT.global_code = NULL;
 983  }
 984
 985  indirect_ck_replace(OP_CONST,   indirect_ck_const,  &indirect_old_ck_const);
 986  indirect_ck_replace(OP_RV2SV,   indirect_ck_rv2sv,  &indirect_old_ck_rv2sv);
 987  indirect_ck_replace(OP_PADANY,  indirect_ck_padany, &indirect_old_ck_padany);
 988  indirect_ck_replace(OP_SCOPE,   indirect_ck_scope,  &indirect_old_ck_scope);
 989  indirect_ck_replace(OP_LINESEQ, indirect_ck_scope,  &indirect_old_ck_lineseq);
 990
 991  indirect_ck_replace(OP_METHOD,       indirect_ck_method,
 992                                       &indirect_old_ck_method);
 993  indirect_ck_replace(OP_METHOD_NAMED, indirect_ck_method_named,
 994                                       &indirect_old_ck_method_named);
 995  indirect_ck_replace(OP_ENTERSUB,     indirect_ck_entersub,
 996                                       &indirect_old_ck_entersub);
 997
 998 #if I_MULTIPLICITY
 999  call_atexit(indirect_teardown, aTHX);
1000 #else
1001  call_atexit(indirect_teardown, NULL);
1002 #endif
1003
1004  indirect_initialized = 1;
1005 }
1006
1007 static U32 indirect_booted = 0;
1008
1009 /* --- XS ------------------------------------------------------------------ */
1010
1011 MODULE = indirect      PACKAGE = indirect
1012
1013 PROTOTYPES: ENABLE
1014
1015 BOOT:
1016 {
1017  if (!indirect_booted++) {
1018   HV *stash;
1019
1020   PERL_HASH(indirect_hash, __PACKAGE__, __PACKAGE_LEN__);
1021
1022   stash = gv_stashpvn(__PACKAGE__, __PACKAGE_LEN__, 1);
1023   newCONSTSUB(stash, "I_THREADSAFE", newSVuv(I_THREADSAFE));
1024   newCONSTSUB(stash, "I_FORKSAFE",   newSVuv(I_FORKSAFE));
1025  }
1026
1027  indirect_setup();
1028 }
1029
1030 #if I_THREADSAFE
1031
1032 void
1033 CLONE(...)
1034 PROTOTYPE: DISABLE
1035 PREINIT:
1036  ptable *t;
1037  SV     *global_code_dup;
1038  GV     *gv;
1039 PPCODE:
1040  {
1041   indirect_ptable_clone_ud ud;
1042   dMY_CXT;
1043   t = ptable_new();
1044   indirect_ptable_clone_ud_init(ud, t, MY_CXT.owner);
1045   ptable_walk(MY_CXT.tbl, indirect_ptable_clone, &ud);
1046   global_code_dup = indirect_dup_inc(MY_CXT.global_code, &ud);
1047   indirect_ptable_clone_ud_deinit(ud);
1048  }
1049  {
1050   MY_CXT_CLONE;
1051   MY_CXT.map         = ptable_new();
1052   MY_CXT.tbl         = t;
1053   MY_CXT.owner       = aTHX;
1054   MY_CXT.global_code = global_code_dup;
1055  }
1056  gv = gv_fetchpv(__PACKAGE__ "::_THREAD_CLEANUP", 0, SVt_PVCV);
1057  if (gv) {
1058   CV *cv = GvCV(gv);
1059   if (!PL_endav)
1060    PL_endav = newAV();
1061   SvREFCNT_inc(cv);
1062   if (!av_store(PL_endav, av_len(PL_endav) + 1, (SV *) cv))
1063    SvREFCNT_dec(cv);
1064   sv_magicext((SV *) PL_endav, NULL, PERL_MAGIC_ext, &indirect_endav_vtbl, NULL, 0);
1065  }
1066  XSRETURN(0);
1067
1068 void
1069 _THREAD_CLEANUP(...)
1070 PROTOTYPE: DISABLE
1071 PPCODE:
1072  indirect_thread_cleanup(aTHX_ NULL);
1073  XSRETURN(0);
1074
1075 #endif
1076
1077 SV *
1078 _tag(SV *value)
1079 PROTOTYPE: $
1080 CODE:
1081  RETVAL = indirect_tag(value);
1082 OUTPUT:
1083  RETVAL
1084
1085 void
1086 _global(SV *code)
1087 PROTOTYPE: $
1088 PPCODE:
1089  if (!SvOK(code))
1090   code = NULL;
1091  else if (SvROK(code))
1092   code = SvRV(code);
1093  {
1094   dMY_CXT;
1095   SvREFCNT_dec(MY_CXT.global_code);
1096   MY_CXT.global_code = SvREFCNT_inc(code);
1097  }
1098  XSRETURN(0);