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 typedef struct {
 275  ptable *tbl;
 276 #if I_HAS_PERL(5, 13, 2)
 277  CLONE_PARAMS *params;
 278 #else
 279  CLONE_PARAMS params;
 280 #endif
 281 } indirect_ptable_clone_ud;
 282
 283 #if I_HAS_PERL(5, 13, 2)
 284 # define indirect_ptable_clone_ud_init(U, T, O) \
 285    (U).tbl    = (T); \
 286    (U).params = Perl_clone_params_new((O), aTHX)
 287 # define indirect_ptable_clone_ud_deinit(U) Perl_clone_params_del((U).params)
 288 # define indirect_dup_inc(S, U)             SvREFCNT_inc(sv_dup((S), (U)->params))
 289 #else
 290 # define indirect_ptable_clone_ud_init(U, T, O) \
 291    (U).tbl               = (T);     \
 292    (U).params.stashes    = newAV(); \
 293    (U).params.flags      = 0;       \
 294    (U).params.proto_perl = (O)
 295 # define indirect_ptable_clone_ud_deinit(U) SvREFCNT_dec((U).params.stashes)
 296 # define indirect_dup_inc(S, U)             SvREFCNT_inc(sv_dup((S), &((U)->params)))
 297 #endif
 298
 299 STATIC void indirect_ptable_clone(pTHX_ ptable_ent *ent, void *ud_) {
 300  indirect_ptable_clone_ud *ud = ud_;
 301  indirect_hint_t          *h1 = ent->val;
 302  indirect_hint_t          *h2;
 303
 304 #if I_HINT_STRUCT
 305
 306  h2              = PerlMemShared_malloc(sizeof *h2);
 307  h2->code        = indirect_dup_inc(h1->code, ud);
 308 #if I_WORKAROUND_REQUIRE_PROPAGATION
 309  h2->require_tag = PTR2IV(indirect_dup_inc(INT2PTR(SV *, h1->require_tag), ud));
 310 #endif
 311
 312 #else  /*  I_HINT_STRUCT */
 313
 314  h2 = indirect_dup_inc(h1, ud);
 315
 316 #endif /* !I_HINT_STRUCT */
 317
 318  ptable_hints_store(ud->tbl, ent->key, h2);
 319 }
 320
 321 STATIC void indirect_thread_cleanup(pTHX_ void *ud) {
 322  dMY_CXT;
 323
 324  SvREFCNT_dec(MY_CXT.global_code);
 325  MY_CXT.global_code = NULL;
 326  ptable_free(MY_CXT.map);
 327  MY_CXT.map = NULL;
 328  ptable_hints_free(MY_CXT.tbl);
 329  MY_CXT.tbl = NULL;
 330 }
 331
 332 STATIC int indirect_endav_free(pTHX_ SV *sv, MAGIC *mg) {
 333  SAVEDESTRUCTOR_X(indirect_thread_cleanup, NULL);
 334
 335  return 0;
 336 }
 337
 338 STATIC MGVTBL indirect_endav_vtbl = {
 339  0,
 340  0,
 341  0,
 342  0,
 343  indirect_endav_free
 344 #if MGf_COPY
 345  , 0
 346 #endif
 347 #if MGf_DUP
 348  , 0
 349 #endif
 350 #if MGf_LOCAL
 351  , 0
 352 #endif
 353 };
 354
 355 #endif /* I_THREADSAFE */
 356
 357 #if I_WORKAROUND_REQUIRE_PROPAGATION
 358 STATIC IV indirect_require_tag(pTHX) {
 359 #define indirect_require_tag() indirect_require_tag(aTHX)
 360  const CV *cv, *outside;
 361
 362  cv = PL_compcv;
 363
 364  if (!cv) {
 365   /* If for some reason the pragma is operational at run-time, try to discover
 366    * the current cv in use. */
 367   const PERL_SI *si;
 368
 369   for (si = PL_curstackinfo; si; si = si->si_prev) {
 370    I32 cxix;
 371
 372    for (cxix = si->si_cxix; cxix >= 0; --cxix) {
 373     const PERL_CONTEXT *cx = si->si_cxstack + cxix;
 374
 375     switch (CxTYPE(cx)) {
 376      case CXt_SUB:
 377      case CXt_FORMAT:
 378       /* The propagation workaround is only needed up to 5.10.0 and at that
 379        * time format and sub contexts were still identical. And even later the
 380        * cv members offsets should have been kept the same. */
 381       cv = cx->blk_sub.cv;
 382       goto get_enclosing_cv;
 383      case CXt_EVAL:
 384       cv = cx->blk_eval.cv;
 385       goto get_enclosing_cv;
 386      default:
 387       break;
 388     }
 389    }
 390   }
 391
 392   cv = PL_main_cv;
 393  }
 394
 395 get_enclosing_cv:
 396  for (outside = CvOUTSIDE(cv); outside; outside = CvOUTSIDE(cv))
 397   cv = outside;
 398
 399  return PTR2IV(cv);
 400 }
 401 #endif /* I_WORKAROUND_REQUIRE_PROPAGATION */
 402
 403 STATIC SV *indirect_tag(pTHX_ SV *value) {
 404 #define indirect_tag(V) indirect_tag(aTHX_ (V))
 405  indirect_hint_t *h;
 406  SV *code = NULL;
 407
 408  if (SvROK(value)) {
 409   value = SvRV(value);
 410   if (SvTYPE(value) >= SVt_PVCV) {
 411    code = value;
 412    SvREFCNT_inc_simple_void_NN(code);
 413   }
 414  }
 415
 416 #if I_HINT_STRUCT
 417  h = PerlMemShared_malloc(sizeof *h);
 418  h->code        = code;
 419 # if I_WORKAROUND_REQUIRE_PROPAGATION
 420  h->require_tag = indirect_require_tag();
 421 # endif /* I_WORKAROUND_REQUIRE_PROPAGATION */
 422 #else  /*  I_HINT_STRUCT */
 423  h = code;
 424 #endif /* !I_HINT_STRUCT */
 425
 426 #if I_THREADSAFE
 427  {
 428   dMY_CXT;
 429   /* We only need for the key to be an unique tag for looking up the value later
 430    * Allocated memory provides convenient unique identifiers, so that's why we
 431    * use the hint as the key itself. */
 432   ptable_hints_store(MY_CXT.tbl, h, h);
 433  }
 434 #endif /* I_THREADSAFE */
 435
 436  return newSViv(PTR2IV(h));
 437 }
 438
 439 STATIC SV *indirect_detag(pTHX_ const SV *hint) {
 440 #define indirect_detag(H) indirect_detag(aTHX_ (H))
 441  indirect_hint_t *h;
 442 #if I_THREADSAFE || I_WORKAROUND_REQUIRE_PROPAGATION
 443  dMY_CXT;
 444 #endif
 445
 446  h = INT2PTR(indirect_hint_t *, SvIVX(hint));
 447 #if I_THREADSAFE
 448  h = ptable_fetch(MY_CXT.tbl, h);
 449 #endif /* I_THREADSAFE */
 450
 451 #if I_WORKAROUND_REQUIRE_PROPAGATION
 452  if (indirect_require_tag() != h->require_tag)
 453   return MY_CXT.global_code;
 454 #endif /* I_WORKAROUND_REQUIRE_PROPAGATION */
 455
 456  return I_HINT_CODE(h);
 457 }
 458
 459 STATIC U32 indirect_hash = 0;
 460
 461 STATIC SV *indirect_hint(pTHX) {
 462 #define indirect_hint() indirect_hint(aTHX)
 463  SV *hint = NULL;
 464
 465  if (IN_PERL_RUNTIME)
 466   return NULL;
 467
 468 #if I_HAS_PERL(5, 10, 0) || defined(PL_parser)
 469  if (!PL_parser)
 470   return NULL;
 471 #endif
 472
 473 #ifdef cop_hints_fetch_pvn
 474  hint = cop_hints_fetch_pvn(PL_curcop, __PACKAGE__, __PACKAGE_LEN__,
 475                                                               indirect_hash, 0);
 476 #elif I_HAS_PERL(5, 9, 5)
 477  hint = Perl_refcounted_he_fetch(aTHX_ PL_curcop->cop_hints_hash,
 478                                        NULL,
 479                                        __PACKAGE__, __PACKAGE_LEN__,
 480                                        0,
 481                                        indirect_hash);
 482 #else
 483  {
 484   SV **val = hv_fetch(GvHV(PL_hintgv), __PACKAGE__, __PACKAGE_LEN__, 0);
 485   if (val)
 486    hint = *val;
 487  }
 488 #endif
 489
 490  if (hint && SvIOK(hint))
 491   return indirect_detag(hint);
 492  else {
 493   dMY_CXT;
 494   return MY_CXT.global_code;
 495  }
 496 }
 497
 498 /* ... op -> source position ............................................... */
 499
 500 STATIC void indirect_map_store(pTHX_ const OP *o, STRLEN pos, SV *sv, line_t line) {
 501 #define indirect_map_store(O, P, N, L) indirect_map_store(aTHX_ (O), (P), (N), (L))
 502  indirect_op_info_t *oi;
 503  const char *s;
 504  STRLEN len;
 505  dMY_CXT;
 506
 507  if (!(oi = ptable_fetch(MY_CXT.map, o))) {
 508   Newx(oi, 1, indirect_op_info_t);
 509   ptable_store(MY_CXT.map, o, oi);
 510   oi->buf  = NULL;
 511   oi->size = 0;
 512  }
 513
 514  if (sv) {
 515   s = SvPV_const(sv, len);
 516  } else {
 517   s   = "{";
 518   len = 1;
 519  }
 520
 521  if (len > oi->size) {
 522   Safefree(oi->buf);
 523   Newx(oi->buf, len, char);
 524   oi->size = len;
 525  }
 526  Copy(s, oi->buf, len, char);
 527
 528  oi->len  = len;
 529  oi->pos  = pos;
 530  oi->line = line;
 531 }
 532
 533 STATIC const indirect_op_info_t *indirect_map_fetch(pTHX_ const OP *o) {
 534 #define indirect_map_fetch(O) indirect_map_fetch(aTHX_ (O))
 535  dMY_CXT;
 536
 537  return ptable_fetch(MY_CXT.map, o);
 538 }
 539
 540 STATIC void indirect_map_delete(pTHX_ const OP *o) {
 541 #define indirect_map_delete(O) indirect_map_delete(aTHX_ (O))
 542  dMY_CXT;
 543
 544  ptable_delete(MY_CXT.map, o);
 545 }
 546
 547 /* --- Check functions ----------------------------------------------------- */
 548
 549 STATIC int indirect_find(pTHX_ SV *name_sv, const char *line_bufptr, STRLEN *name_pos) {
 550 #define indirect_find(NSV, LBP, NP) indirect_find(aTHX_ (NSV), (LBP), (NP))
 551  STRLEN      name_len, line_len;
 552  const char *name, *name_end;
 553  const char *line, *line_end;
 554  const char *p;
 555
 556  line     = SvPV_const(PL_linestr, line_len);
 557  line_end = line + line_len;
 558
 559  name = SvPV_const(name_sv, name_len);
 560  if (name_len >= 1 && *name == '$') {
 561   ++name;
 562   --name_len;
 563   while (line_bufptr < line_end && *line_bufptr != '$')
 564    ++line_bufptr;
 565   if (line_bufptr >= line_end)
 566    return 0;
 567  }
 568  name_end = name + name_len;
 569
 570  p = line_bufptr;
 571  while (1) {
 572   p = ninstr(p, line_end, name, name_end);
 573   if (!p)
 574    return 0;
 575   if (!isALNUM(p[name_len]))
 576    break;
 577   /* p points to a word that has name as prefix, skip the rest of the word */
 578   p += name_len + 1;
 579   while (isALNUM(*p))
 580    ++p;
 581  }
 582
 583  *name_pos = p - line;
 584
 585  return 1;
 586 }
 587
 588 /* ... ck_const ............................................................ */
 589
 590 STATIC OP *(*indirect_old_ck_const)(pTHX_ OP *) = 0;
 591
 592 STATIC OP *indirect_ck_const(pTHX_ OP *o) {
 593  o = indirect_old_ck_const(aTHX_ o);
 594
 595  if (indirect_hint()) {
 596   SV *sv = cSVOPo_sv;
 597
 598   if (SvPOK(sv) && (SvTYPE(sv) >= SVt_PV)) {
 599    STRLEN pos;
 600
 601    if (indirect_find(sv, PL_oldbufptr, &pos)) {
 602     STRLEN len;
 603
 604     /* If the constant is equal to the current package name, try to look for
 605      * a "__PACKAGE__" coming before what we got. We only need to check this
 606      * when we already had a match because __PACKAGE__ can only appear in
 607      * direct method calls ("new __PACKAGE__" is a syntax error). */
 608     len = SvCUR(sv);
 609     if (PL_curstash
 610         && len == (STRLEN) HvNAMELEN_get(PL_curstash)
 611         && memcmp(SvPVX(sv), HvNAME_get(PL_curstash), len) == 0) {
 612      STRLEN pos_pkg;
 613      SV    *pkg = sv_newmortal();
 614      sv_setpvn(pkg, "__PACKAGE__", sizeof("__PACKAGE__")-1);
 615
 616      if (indirect_find(pkg, PL_oldbufptr, &pos_pkg) && pos_pkg < pos) {
 617       sv  = pkg;
 618       pos = pos_pkg;
 619      }
 620     }
 621
 622     indirect_map_store(o, pos, sv, CopLINE(&PL_compiling));
 623     return o;
 624    }
 625   }
 626  }
 627
 628  indirect_map_delete(o);
 629  return o;
 630 }
 631
 632 /* ... ck_rv2sv ............................................................ */
 633
 634 STATIC OP *(*indirect_old_ck_rv2sv)(pTHX_ OP *) = 0;
 635
 636 STATIC OP *indirect_ck_rv2sv(pTHX_ OP *o) {
 637  if (indirect_hint()) {
 638   OP *op = cUNOPo->op_first;
 639   SV *sv;
 640   const char *name = NULL;
 641   STRLEN pos, len;
 642   OPCODE type = (OPCODE) op->op_type;
 643
 644   switch (type) {
 645    case OP_GV:
 646    case OP_GVSV: {
 647     GV *gv = cGVOPx_gv(op);
 648     name = GvNAME(gv);
 649     len  = GvNAMELEN(gv);
 650     break;
 651    }
 652    default:
 653     if ((PL_opargs[type] & OA_CLASS_MASK) == OA_SVOP) {
 654      SV *nsv = cSVOPx_sv(op);
 655      if (SvPOK(nsv) && (SvTYPE(nsv) >= SVt_PV))
 656       name = SvPV_const(nsv, len);
 657     }
 658   }
 659   if (!name)
 660    goto done;
 661
 662   sv = sv_2mortal(newSVpvn("$", 1));
 663   sv_catpvn_nomg(sv, name, len);
 664   if (!indirect_find(sv, PL_oldbufptr, &pos)) {
 665    /* If it failed, retry without the current stash */
 666    const char *stash = HvNAME_get(PL_curstash);
 667    STRLEN stashlen = HvNAMELEN_get(PL_curstash);
 668
 669    if ((len < stashlen + 2) || strnNE(name, stash, stashlen)
 670        || name[stashlen] != ':' || name[stashlen+1] != ':') {
 671     /* Failed again ? Try to remove main */
 672     stash = "main";
 673     stashlen = 4;
 674     if ((len < stashlen + 2) || strnNE(name, stash, stashlen)
 675         || name[stashlen] != ':' || name[stashlen+1] != ':')
 676      goto done;
 677    }
 678
 679    sv_setpvn(sv, "$", 1);
 680    stashlen += 2;
 681    sv_catpvn_nomg(sv, name + stashlen, len - stashlen);
 682    if (!indirect_find(sv, PL_oldbufptr, &pos))
 683     goto done;
 684   }
 685
 686   o = indirect_old_ck_rv2sv(aTHX_ o);
 687
 688   indirect_map_store(o, pos, sv, CopLINE(&PL_compiling));
 689   return o;
 690  }
 691
 692 done:
 693  o = indirect_old_ck_rv2sv(aTHX_ o);
 694
 695  indirect_map_delete(o);
 696  return o;
 697 }
 698
 699 /* ... ck_padany ........................................................... */
 700
 701 STATIC OP *(*indirect_old_ck_padany)(pTHX_ OP *) = 0;
 702
 703 STATIC OP *indirect_ck_padany(pTHX_ OP *o) {
 704  o = indirect_old_ck_padany(aTHX_ o);
 705
 706  if (indirect_hint()) {
 707   SV *sv;
 708   const char *s = PL_oldbufptr, *t = PL_bufptr - 1;
 709
 710   while (s < t && isSPACE(*s)) ++s;
 711   if (*s == '$' && ++s <= t) {
 712    while (s < t && isSPACE(*s)) ++s;
 713    while (s < t && isSPACE(*t)) --t;
 714    sv = sv_2mortal(newSVpvn("$", 1));
 715    sv_catpvn_nomg(sv, s, t - s + 1);
 716    indirect_map_store(o, s - SvPVX_const(PL_linestr),
 717                          sv, CopLINE(&PL_compiling));
 718    return o;
 719   }
 720  }
 721
 722  indirect_map_delete(o);
 723  return o;
 724 }
 725
 726 /* ... ck_scope ............................................................ */
 727
 728 STATIC OP *(*indirect_old_ck_scope)  (pTHX_ OP *) = 0;
 729 STATIC OP *(*indirect_old_ck_lineseq)(pTHX_ OP *) = 0;
 730
 731 STATIC OP *indirect_ck_scope(pTHX_ OP *o) {
 732  OP *(*old_ck)(pTHX_ OP *) = 0;
 733
 734  switch (o->op_type) {
 735   case OP_SCOPE:   old_ck = indirect_old_ck_scope;   break;
 736   case OP_LINESEQ: old_ck = indirect_old_ck_lineseq; break;
 737  }
 738  o = old_ck(aTHX_ o);
 739
 740  if (indirect_hint()) {
 741   indirect_map_store(o, PL_oldbufptr - SvPVX_const(PL_linestr),
 742                         NULL, CopLINE(&PL_compiling));
 743   return o;
 744  }
 745
 746  indirect_map_delete(o);
 747  return o;
 748 }
 749
 750 /* We don't need to clean the map entries for leave ops because they can only
 751  * be created by mutating from a lineseq. */
 752
 753 /* ... ck_method ........................................................... */
 754
 755 STATIC OP *(*indirect_old_ck_method)(pTHX_ OP *) = 0;
 756
 757 STATIC OP *indirect_ck_method(pTHX_ OP *o) {
 758  if (indirect_hint()) {
 759   OP *op = cUNOPo->op_first;
 760
 761   /* Indirect method call is only possible when the method is a bareword, so
 762    * don't trip up on $obj->$meth. */
 763   if (op && op->op_type == OP_CONST) {
 764    const indirect_op_info_t *oi = indirect_map_fetch(op);
 765    STRLEN pos;
 766    line_t line;
 767    SV *sv;
 768
 769    if (!oi)
 770     goto done;
 771
 772    sv   = sv_2mortal(newSVpvn(oi->buf, oi->len));
 773    pos  = oi->pos;
 774    /* Keep the old line so that we really point to the first line of the
 775     * expression. */
 776    line = oi->line;
 777
 778    o = indirect_old_ck_method(aTHX_ o);
 779    /* o may now be a method_named */
 780
 781    indirect_map_store(o, pos, sv, line);
 782    return o;
 783   }
 784  }
 785
 786 done:
 787  o = indirect_old_ck_method(aTHX_ o);
 788
 789  indirect_map_delete(o);
 790  return o;
 791 }
 792
 793 /* ... ck_method_named ..................................................... */
 794
 795 /* "use foo/no foo" compiles its call to import/unimport directly to a
 796  * method_named op. */
 797
 798 STATIC OP *(*indirect_old_ck_method_named)(pTHX_ OP *) = 0;
 799
 800 STATIC OP *indirect_ck_method_named(pTHX_ OP *o) {
 801  if (indirect_hint()) {
 802   STRLEN pos;
 803   line_t line;
 804   SV *sv;
 805
 806   sv = cSVOPo_sv;
 807   if (!SvPOK(sv) || (SvTYPE(sv) < SVt_PV))
 808    goto done;
 809   sv = sv_mortalcopy(sv);
 810
 811   if (!indirect_find(sv, PL_oldbufptr, &pos))
 812    goto done;
 813   line = CopLINE(&PL_compiling);
 814
 815   o = indirect_old_ck_method_named(aTHX_ o);
 816
 817   indirect_map_store(o, pos, sv, line);
 818   return o;
 819  }
 820
 821 done:
 822  o = indirect_old_ck_method_named(aTHX_ o);
 823
 824  indirect_map_delete(o);
 825  return o;
 826 }
 827
 828 /* ... ck_entersub ......................................................... */
 829
 830 STATIC OP *(*indirect_old_ck_entersub)(pTHX_ OP *) = 0;
 831
 832 STATIC OP *indirect_ck_entersub(pTHX_ OP *o) {
 833  SV *code = indirect_hint();
 834
 835  o = indirect_old_ck_entersub(aTHX_ o);
 836
 837  if (code) {
 838   const indirect_op_info_t *moi, *ooi;
 839   OP     *mop, *oop;
 840   LISTOP *lop;
 841
 842   oop = o;
 843   do {
 844    lop = (LISTOP *) oop;
 845    if (!(lop->op_flags & OPf_KIDS))
 846     goto done;
 847    oop = lop->op_first;
 848   } while (oop->op_type != OP_PUSHMARK);
 849   oop = OP_SIBLING(oop);
 850   mop = lop->op_last;
 851
 852   if (!oop)
 853    goto done;
 854
 855   switch (oop->op_type) {
 856    case OP_CONST:
 857    case OP_RV2SV:
 858    case OP_PADSV:
 859    case OP_SCOPE:
 860    case OP_LEAVE:
 861     break;
 862    default:
 863     goto done;
 864   }
 865
 866   if (mop->op_type == OP_METHOD)
 867    mop = cUNOPx(mop)->op_first;
 868   else if (mop->op_type != OP_METHOD_NAMED)
 869    goto done;
 870
 871   moi = indirect_map_fetch(mop);
 872   if (!moi)
 873    goto done;
 874
 875   ooi = indirect_map_fetch(oop);
 876   if (!ooi)
 877    goto done;
 878
 879   /* When positions are identical, the method and the object must have the
 880    * same name. But it also means that it is an indirect call, as "foo->foo"
 881    * results in different positions. */
 882   if (   moi->line < ooi->line
 883       || (moi->line == ooi->line && moi->pos <= ooi->pos)) {
 884    SV *file;
 885    dSP;
 886
 887    ENTER;
 888    SAVETMPS;
 889
 890 #ifdef USE_ITHREADS
 891    file = sv_2mortal(newSVpv(CopFILE(&PL_compiling), 0));
 892 #else
 893    file = sv_mortalcopy(CopFILESV(&PL_compiling));
 894 #endif
 895
 896    PUSHMARK(SP);
 897    EXTEND(SP, 4);
 898    mPUSHp(ooi->buf, ooi->len);
 899    mPUSHp(moi->buf, moi->len);
 900    PUSHs(file);
 901    mPUSHu(moi->line);
 902    PUTBACK;
 903
 904    call_sv(code, G_VOID);
 905
 906    PUTBACK;
 907
 908    FREETMPS;
 909    LEAVE;
 910   }
 911  }
 912
 913 done:
 914  return o;
 915 }
 916
 917 STATIC U32 indirect_initialized = 0;
 918
 919 STATIC void indirect_teardown(pTHX_ void *root) {
 920  if (!indirect_initialized)
 921   return;
 922
 923 #if I_MULTIPLICITY
 924  if (aTHX != root)
 925   return;
 926 #endif
 927
 928  {
 929   dMY_CXT;
 930   ptable_free(MY_CXT.map);
 931   MY_CXT.map = NULL;
 932 #if I_THREADSAFE
 933   ptable_hints_free(MY_CXT.tbl);
 934   MY_CXT.tbl = NULL;
 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   indirect_ptable_clone_ud ud;
1023   dMY_CXT;
1024   t = ptable_new();
1025   indirect_ptable_clone_ud_init(ud, t, MY_CXT.owner);
1026   ptable_walk(MY_CXT.tbl, indirect_ptable_clone, &ud);
1027   global_code_dup = indirect_dup_inc(MY_CXT.global_code, &ud);
1028   indirect_ptable_clone_ud_deinit(ud);
1029  }
1030  {
1031   MY_CXT_CLONE;
1032   MY_CXT.map         = ptable_new();
1033   MY_CXT.tbl         = t;
1034   MY_CXT.owner       = aTHX;
1035   MY_CXT.global_code = global_code_dup;
1036  }
1037  gv = gv_fetchpv(__PACKAGE__ "::_THREAD_CLEANUP", 0, SVt_PVCV);
1038  if (gv) {
1039   CV *cv = GvCV(gv);
1040   if (!PL_endav)
1041    PL_endav = newAV();
1042   SvREFCNT_inc(cv);
1043   if (!av_store(PL_endav, av_len(PL_endav) + 1, (SV *) cv))
1044    SvREFCNT_dec(cv);
1045   sv_magicext((SV *) PL_endav, NULL, PERL_MAGIC_ext, &indirect_endav_vtbl, NULL, 0);
1046  }
1047  XSRETURN(0);
1048
1049 void
1050 _THREAD_CLEANUP(...)
1051 PROTOTYPE: DISABLE
1052 PPCODE:
1053  indirect_thread_cleanup(aTHX_ NULL);
1054  XSRETURN(0);
1055
1056 #endif
1057
1058 SV *
1059 _tag(SV *value)
1060 PROTOTYPE: $
1061 CODE:
1062  RETVAL = indirect_tag(value);
1063 OUTPUT:
1064  RETVAL
1065
1066 void
1067 _global(SV *code)
1068 PROTOTYPE: $
1069 PPCODE:
1070  if (!SvOK(code))
1071   code = NULL;
1072  else if (SvROK(code))
1073   code = SvRV(code);
1074  {
1075   dMY_CXT;
1076   SvREFCNT_dec(MY_CXT.global_code);
1077   MY_CXT.global_code = SvREFCNT_inc(code);
1078  }
1079  XSRETURN(0);