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)
 117 #  define I_MULTIPLICITY 1
 118 # else
 119 #  define I_MULTIPLICITY 0
 120 # endif
 121 #endif
 122 #if I_MULTIPLICITY
 123 # ifndef PERL_IMPLICIT_CONTEXT
 124 #  error MULTIPLICITY builds must set PERL_IMPLICIT_CONTEXT
 125 # endif
 126 #endif
 127 #if I_MULTIPLICITY && !defined(tTHX)
 128 # define tTHX PerlInterpreter*
 129 #endif
 130
 131 #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))
 132 # define I_THREADSAFE 1
 133 # ifndef MY_CXT_CLONE
 134 #  define MY_CXT_CLONE \
 135     dMY_CXT_SV;                                                      \
 136     my_cxt_t *my_cxtp = (my_cxt_t*)SvPVX(newSV(sizeof(my_cxt_t)-1)); \
 137     Copy(INT2PTR(my_cxt_t*, SvUV(my_cxt_sv)), my_cxtp, 1, my_cxt_t); \
 138     sv_setuv(my_cxt_sv, PTR2UV(my_cxtp))
 139 # endif
 140 #else
 141 # define I_THREADSAFE 0
 142 # undef  dMY_CXT
 143 # define dMY_CXT      dNOOP
 144 # undef  MY_CXT
 145 # define MY_CXT       indirect_globaldata
 146 # undef  START_MY_CXT
 147 # define START_MY_CXT static my_cxt_t MY_CXT;
 148 # undef  MY_CXT_INIT
 149 # define MY_CXT_INIT  NOOP
 150 # undef  MY_CXT_CLONE
 151 # define MY_CXT_CLONE NOOP
 152 #endif
 153
 154 #if I_THREADSAFE
 155 /* We must use preexistent global mutexes or we will never be able to destroy
 156  * them. */
 157 # if I_HAS_PERL(5, 9, 3)
 158 #  define I_LOADED_LOCK   MUTEX_LOCK(&PL_my_ctx_mutex)
 159 #  define I_LOADED_UNLOCK MUTEX_UNLOCK(&PL_my_ctx_mutex)
 160 # else
 161 #  define I_LOADED_LOCK   OP_REFCNT_LOCK
 162 #  define I_LOADED_UNLOCK OP_REFCNT_UNLOCK
 163 # endif
 164 #else
 165 # define I_LOADED_LOCK   NOOP
 166 # define I_LOADED_UNLOCK NOOP
 167 #endif
 168
 169 #if defined(OP_CHECK_MUTEX_LOCK) && defined(OP_CHECK_MUTEX_UNLOCK)
 170 # define I_CHECK_LOCK   OP_CHECK_MUTEX_LOCK
 171 # define I_CHECK_UNLOCK OP_CHECK_MUTEX_UNLOCK
 172 #elif I_HAS_PERL(5, 9, 3)
 173 # define I_CHECK_LOCK   OP_REFCNT_LOCK
 174 # define I_CHECK_UNLOCK OP_REFCNT_UNLOCK
 175 #else
 176 /* Before perl 5.9.3, indirect_ck_*() calls are already protected by the
 177  * I_LOADED mutex, which falls back to the OP_REFCNT mutex. Make sure we don't
 178  * lock it twice. */
 179 # define I_CHECK_LOCK   NOOP
 180 # define I_CHECK_UNLOCK NOOP
 181 #endif
 182
 183 typedef OP *(*indirect_ck_t)(pTHX_ OP *);
 184
 185 #ifdef wrap_op_checker
 186
 187 # define indirect_ck_replace(T, NC, OCP) wrap_op_checker((T), (NC), (OCP))
 188
 189 #else
 190
 191 static void indirect_ck_replace(pTHX_ OPCODE type, indirect_ck_t new_ck, indirect_ck_t *old_ck_p) {
 192 #define indirect_ck_replace(T, NC, OCP) indirect_ck_replace(aTHX_ (T), (NC), (OCP))
 193  I_CHECK_LOCK;
 194  if (!*old_ck_p) {
 195   *old_ck_p      = PL_check[type];
 196   PL_check[type] = new_ck;
 197  }
 198  I_CHECK_UNLOCK;
 199 }
 200
 201 #endif
 202
 203 static void indirect_ck_restore(pTHX_ OPCODE type, indirect_ck_t *old_ck_p) {
 204 #define indirect_ck_restore(T, OCP) indirect_ck_restore(aTHX_ (T), (OCP))
 205  I_CHECK_LOCK;
 206  if (*old_ck_p) {
 207   PL_check[type] = *old_ck_p;
 208   *old_ck_p      = 0;
 209  }
 210  I_CHECK_UNLOCK;
 211 }
 212
 213 /* --- Helpers ------------------------------------------------------------- */
 214
 215 /* ... Check if the module is loaded ....................................... */
 216
 217 static U32 indirect_loaded = 0;
 218
 219 #if I_THREADSAFE
 220
 221 #define PTABLE_NAME        ptable_loaded
 222 #define PTABLE_VAL_FREE(V) NOOP
 223
 224 #include "ptable.h"
 225
 226 #define ptable_loaded_store(T, K, V) ptable_loaded_store(aPTBLMS_ (T), (K), (V))
 227 #define ptable_loaded_delete(T, K)   ptable_loaded_delete(aPTBLMS_ (T), (K))
 228 #define ptable_loaded_free(T)        ptable_loaded_free(aPTBLMS_ (T))
 229
 230 static ptable *indirect_loaded_cxts = NULL;
 231
 232 static int indirect_is_loaded(pTHX_ void *cxt) {
 233 #define indirect_is_loaded(C) indirect_is_loaded(aTHX_ (C))
 234  int res = 0;
 235
 236  I_LOADED_LOCK;
 237  if (indirect_loaded_cxts && ptable_fetch(indirect_loaded_cxts, cxt))
 238   res = 1;
 239  I_LOADED_UNLOCK;
 240
 241  return res;
 242 }
 243
 244 static int indirect_set_loaded_locked(pTHX_ void *cxt) {
 245 #define indirect_set_loaded_locked(C) indirect_set_loaded_locked(aTHX_ (C))
 246  int global_setup = 0;
 247
 248  if (indirect_loaded <= 0) {
 249   assert(!indirect_loaded_cxts);
 250   indirect_loaded_cxts = ptable_new();
 251   global_setup         = 1;
 252  }
 253  ++indirect_loaded;
 254  assert(indirect_loaded_cxts);
 255  ptable_loaded_store(indirect_loaded_cxts, cxt, cxt);
 256
 257  return global_setup;
 258 }
 259
 260 static int indirect_clear_loaded_locked(pTHX_ void *cxt) {
 261 #define indirect_clear_loaded_locked(C) indirect_clear_loaded_locked(aTHX_ (C))
 262  int global_teardown = 0;
 263
 264  if (indirect_loaded > 1) {
 265   assert(indirect_loaded_cxts);
 266   ptable_loaded_delete(indirect_loaded_cxts, cxt);
 267   --indirect_loaded;
 268  } else if (indirect_loaded_cxts) {
 269   ptable_loaded_free(indirect_loaded_cxts);
 270   indirect_loaded_cxts = NULL;
 271   indirect_loaded      = 0;
 272   global_teardown      = 1;
 273  }
 274
 275  return global_teardown;
 276 }
 277
 278 #else
 279
 280 #define indirect_is_loaded(C)           (indirect_loaded > 0)
 281 #define indirect_set_loaded_locked(C)   ((indirect_loaded++ <= 0) ? 1 : 0)
 282 #define indirect_clear_loaded_locked(C) ((--indirect_loaded <= 0) ? 1 : 0)
 283
 284 #endif
 285
 286 /* ... Thread-safe hints ................................................... */
 287
 288 #if I_WORKAROUND_REQUIRE_PROPAGATION
 289
 290 typedef struct {
 291  SV *code;
 292  IV  require_tag;
 293 } indirect_hint_t;
 294
 295 #define I_HINT_STRUCT 1
 296
 297 #define I_HINT_CODE(H) ((H)->code)
 298
 299 #define I_HINT_FREE(H) {   \
 300  indirect_hint_t *h = (H); \
 301  SvREFCNT_dec(h->code);    \
 302  PerlMemShared_free(h);    \
 303 }
 304
 305 #else  /*  I_WORKAROUND_REQUIRE_PROPAGATION */
 306
 307 typedef SV indirect_hint_t;
 308
 309 #define I_HINT_STRUCT 0
 310
 311 #define I_HINT_CODE(H) (H)
 312
 313 #define I_HINT_FREE(H) SvREFCNT_dec(H);
 314
 315 #endif /* !I_WORKAROUND_REQUIRE_PROPAGATION */
 316
 317 #if I_THREADSAFE
 318
 319 #define PTABLE_NAME        ptable_hints
 320 #define PTABLE_VAL_FREE(V) I_HINT_FREE(V)
 321
 322 #define pPTBL  pTHX
 323 #define pPTBL_ pTHX_
 324 #define aPTBL  aTHX
 325 #define aPTBL_ aTHX_
 326
 327 #include "ptable.h"
 328
 329 #define ptable_hints_store(T, K, V) ptable_hints_store(aTHX_ (T), (K), (V))
 330 #define ptable_hints_free(T)        ptable_hints_free(aTHX_ (T))
 331
 332 #endif /* I_THREADSAFE */
 333
 334 /* Define the op->str ptable here because we need to be able to clean it during
 335  * thread cleanup. */
 336
 337 typedef struct {
 338  char   *buf;
 339  STRLEN  pos;
 340  STRLEN  size;
 341  STRLEN  len;
 342  line_t  line;
 343 } indirect_op_info_t;
 344
 345 #define PTABLE_NAME        ptable
 346 #define PTABLE_VAL_FREE(V) if (V) { Safefree(((indirect_op_info_t *) (V))->buf); Safefree(V); }
 347
 348 #define pPTBL  pTHX
 349 #define pPTBL_ pTHX_
 350 #define aPTBL  aTHX
 351 #define aPTBL_ aTHX_
 352
 353 #include "ptable.h"
 354
 355 #define ptable_store(T, K, V) ptable_store(aTHX_ (T), (K), (V))
 356 #define ptable_delete(T, K)   ptable_delete(aTHX_ (T), (K))
 357 #define ptable_clear(T)       ptable_clear(aTHX_ (T))
 358 #define ptable_free(T)        ptable_free(aTHX_ (T))
 359
 360 #define MY_CXT_KEY __PACKAGE__ "::_guts" XS_VERSION
 361
 362 typedef struct {
 363 #if I_THREADSAFE
 364  ptable *tbl; /* It really is a ptable_hints */
 365  tTHX    owner;
 366 #endif
 367  ptable *map;
 368  SV     *global_code;
 369 } my_cxt_t;
 370
 371 START_MY_CXT
 372
 373 #if I_THREADSAFE
 374
 375 typedef struct {
 376  ptable *tbl;
 377 #if I_HAS_PERL(5, 13, 2)
 378  CLONE_PARAMS *params;
 379 #else
 380  CLONE_PARAMS params;
 381 #endif
 382 } indirect_ptable_clone_ud;
 383
 384 #if I_HAS_PERL(5, 13, 2)
 385 # define indirect_ptable_clone_ud_init(U, T, O) \
 386    (U).tbl    = (T); \
 387    (U).params = Perl_clone_params_new((O), aTHX)
 388 # define indirect_ptable_clone_ud_deinit(U) Perl_clone_params_del((U).params)
 389 # define indirect_dup_inc(S, U)             SvREFCNT_inc(sv_dup((S), (U)->params))
 390 #else
 391 # define indirect_ptable_clone_ud_init(U, T, O) \
 392    (U).tbl               = (T);     \
 393    (U).params.stashes    = newAV(); \
 394    (U).params.flags      = 0;       \
 395    (U).params.proto_perl = (O)
 396 # define indirect_ptable_clone_ud_deinit(U) SvREFCNT_dec((U).params.stashes)
 397 # define indirect_dup_inc(S, U)             SvREFCNT_inc(sv_dup((S), &((U)->params)))
 398 #endif
 399
 400 static void indirect_ptable_clone(pTHX_ ptable_ent *ent, void *ud_) {
 401  indirect_ptable_clone_ud *ud = ud_;
 402  indirect_hint_t          *h1 = ent->val;
 403  indirect_hint_t          *h2;
 404
 405 #if I_HINT_STRUCT
 406
 407  h2              = PerlMemShared_malloc(sizeof *h2);
 408  h2->code        = indirect_dup_inc(h1->code, ud);
 409 #if I_WORKAROUND_REQUIRE_PROPAGATION
 410  h2->require_tag = PTR2IV(indirect_dup_inc(INT2PTR(SV *, h1->require_tag), ud));
 411 #endif
 412
 413 #else  /*  I_HINT_STRUCT */
 414
 415  h2 = indirect_dup_inc(h1, ud);
 416
 417 #endif /* !I_HINT_STRUCT */
 418
 419  ptable_hints_store(ud->tbl, ent->key, h2);
 420 }
 421
 422 static void indirect_thread_cleanup(pTHX_ void *ud) {
 423  int global_teardown;
 424  dMY_CXT;
 425
 426  global_teardown = indirect_clear_loaded_locked(&MY_CXT);
 427  assert(!global_teardown);
 428
 429  SvREFCNT_dec(MY_CXT.global_code);
 430  MY_CXT.global_code = NULL;
 431
 432  ptable_free(MY_CXT.map);
 433  MY_CXT.map = NULL;
 434
 435  ptable_hints_free(MY_CXT.tbl);
 436  MY_CXT.tbl = NULL;
 437 }
 438
 439 static int indirect_endav_free(pTHX_ SV *sv, MAGIC *mg) {
 440  SAVEDESTRUCTOR_X(indirect_thread_cleanup, NULL);
 441
 442  return 0;
 443 }
 444
 445 static MGVTBL indirect_endav_vtbl = {
 446  0,
 447  0,
 448  0,
 449  0,
 450  indirect_endav_free
 451 #if MGf_COPY
 452  , 0
 453 #endif
 454 #if MGf_DUP
 455  , 0
 456 #endif
 457 #if MGf_LOCAL
 458  , 0
 459 #endif
 460 };
 461
 462 #endif /* I_THREADSAFE */
 463
 464 #if I_WORKAROUND_REQUIRE_PROPAGATION
 465 static IV indirect_require_tag(pTHX) {
 466 #define indirect_require_tag() indirect_require_tag(aTHX)
 467  const CV *cv, *outside;
 468
 469  cv = PL_compcv;
 470
 471  if (!cv) {
 472   /* If for some reason the pragma is operational at run-time, try to discover
 473    * the current cv in use. */
 474   const PERL_SI *si;
 475
 476   for (si = PL_curstackinfo; si; si = si->si_prev) {
 477    I32 cxix;
 478
 479    for (cxix = si->si_cxix; cxix >= 0; --cxix) {
 480     const PERL_CONTEXT *cx = si->si_cxstack + cxix;
 481
 482     switch (CxTYPE(cx)) {
 483      case CXt_SUB:
 484      case CXt_FORMAT:
 485       /* The propagation workaround is only needed up to 5.10.0 and at that
 486        * time format and sub contexts were still identical. And even later the
 487        * cv members offsets should have been kept the same. */
 488       cv = cx->blk_sub.cv;
 489       goto get_enclosing_cv;
 490      case CXt_EVAL:
 491       cv = cx->blk_eval.cv;
 492       goto get_enclosing_cv;
 493      default:
 494       break;
 495     }
 496    }
 497   }
 498
 499   cv = PL_main_cv;
 500  }
 501
 502 get_enclosing_cv:
 503  for (outside = CvOUTSIDE(cv); outside; outside = CvOUTSIDE(cv))
 504   cv = outside;
 505
 506  return PTR2IV(cv);
 507 }
 508 #endif /* I_WORKAROUND_REQUIRE_PROPAGATION */
 509
 510 static SV *indirect_tag(pTHX_ SV *value) {
 511 #define indirect_tag(V) indirect_tag(aTHX_ (V))
 512  indirect_hint_t *h;
 513  SV              *code = NULL;
 514 #if I_THREADSAFE
 515  dMY_CXT;
 516
 517  if (!MY_CXT.tbl)
 518   return newSViv(0);
 519 #endif /* I_THREADSAFE */
 520
 521  if (SvROK(value)) {
 522   value = SvRV(value);
 523   if (SvTYPE(value) >= SVt_PVCV) {
 524    code = value;
 525    SvREFCNT_inc_simple_void_NN(code);
 526   }
 527  }
 528
 529 #if I_HINT_STRUCT
 530  h = PerlMemShared_malloc(sizeof *h);
 531  h->code        = code;
 532 # if I_WORKAROUND_REQUIRE_PROPAGATION
 533  h->require_tag = indirect_require_tag();
 534 # endif /* I_WORKAROUND_REQUIRE_PROPAGATION */
 535 #else  /*  I_HINT_STRUCT */
 536  h = code;
 537 #endif /* !I_HINT_STRUCT */
 538
 539 #if I_THREADSAFE
 540  /* We only need for the key to be an unique tag for looking up the value later
 541   * Allocated memory provides convenient unique identifiers, so that's why we
 542   * use the hint as the key itself. */
 543  ptable_hints_store(MY_CXT.tbl, h, h);
 544 #endif /* I_THREADSAFE */
 545
 546  return newSViv(PTR2IV(h));
 547 }
 548
 549 static SV *indirect_detag(pTHX_ const SV *hint) {
 550 #define indirect_detag(H) indirect_detag(aTHX_ (H))
 551  indirect_hint_t *h;
 552 #if I_THREADSAFE || I_WORKAROUND_REQUIRE_PROPAGATION
 553  dMY_CXT;
 554 #endif
 555
 556 #if I_THREADSAFE
 557  if (!MY_CXT.tbl)
 558   return NULL;
 559 #endif /* I_THREADSAFE */
 560
 561  h = INT2PTR(indirect_hint_t *, SvIVX(hint));
 562 #if I_THREADSAFE
 563  h = ptable_fetch(MY_CXT.tbl, h);
 564 #endif /* I_THREADSAFE */
 565
 566 #if I_WORKAROUND_REQUIRE_PROPAGATION
 567  if (indirect_require_tag() != h->require_tag)
 568   return MY_CXT.global_code;
 569 #endif /* I_WORKAROUND_REQUIRE_PROPAGATION */
 570
 571  return I_HINT_CODE(h);
 572 }
 573
 574 static VOL U32 indirect_hash = 0;
 575
 576 static SV *indirect_hint(pTHX) {
 577 #define indirect_hint() indirect_hint(aTHX)
 578  SV *hint = NULL;
 579
 580  if (IN_PERL_RUNTIME)
 581   return NULL;
 582
 583 #if I_HAS_PERL(5, 10, 0) || defined(PL_parser)
 584  if (!PL_parser)
 585   return NULL;
 586 #endif
 587
 588 #ifdef cop_hints_fetch_pvn
 589  hint = cop_hints_fetch_pvn(PL_curcop, __PACKAGE__, __PACKAGE_LEN__,
 590                                                               indirect_hash, 0);
 591 #elif I_HAS_PERL(5, 9, 5)
 592  hint = Perl_refcounted_he_fetch(aTHX_ PL_curcop->cop_hints_hash,
 593                                        NULL,
 594                                        __PACKAGE__, __PACKAGE_LEN__,
 595                                        0,
 596                                        indirect_hash);
 597 #else
 598  {
 599   SV **val = hv_fetch(GvHV(PL_hintgv), __PACKAGE__, __PACKAGE_LEN__, 0);
 600   if (val)
 601    hint = *val;
 602  }
 603 #endif
 604
 605  if (hint && SvIOK(hint)) {
 606   return indirect_detag(hint);
 607  } else {
 608   dMY_CXT;
 609   if (indirect_is_loaded(&MY_CXT))
 610    return MY_CXT.global_code;
 611   else
 612    return NULL;
 613  }
 614 }
 615
 616 /* ... op -> source position ............................................... */
 617
 618 static void indirect_map_store(pTHX_ const OP *o, STRLEN pos, SV *sv, line_t line) {
 619 #define indirect_map_store(O, P, N, L) indirect_map_store(aTHX_ (O), (P), (N), (L))
 620  indirect_op_info_t *oi;
 621  const char *s;
 622  STRLEN len;
 623  dMY_CXT;
 624
 625  /* No need to check for MY_CXT.map != NULL because this code path is always
 626   * guarded by indirect_hint(). */
 627
 628  if (!(oi = ptable_fetch(MY_CXT.map, o))) {
 629   Newx(oi, 1, indirect_op_info_t);
 630   ptable_store(MY_CXT.map, o, oi);
 631   oi->buf  = NULL;
 632   oi->size = 0;
 633  }
 634
 635  if (sv) {
 636   s = SvPV_const(sv, len);
 637  } else {
 638   s   = "{";
 639   len = 1;
 640  }
 641
 642  if (len > oi->size) {
 643   Safefree(oi->buf);
 644   Newx(oi->buf, len, char);
 645   oi->size = len;
 646  }
 647  Copy(s, oi->buf, len, char);
 648
 649  oi->len  = len;
 650  oi->pos  = pos;
 651  oi->line = line;
 652 }
 653
 654 static const indirect_op_info_t *indirect_map_fetch(pTHX_ const OP *o) {
 655 #define indirect_map_fetch(O) indirect_map_fetch(aTHX_ (O))
 656  dMY_CXT;
 657
 658  /* No need to check for MY_CXT.map != NULL because this code path is always
 659   * guarded by indirect_hint(). */
 660
 661  return ptable_fetch(MY_CXT.map, o);
 662 }
 663
 664 static void indirect_map_delete(pTHX_ const OP *o) {
 665 #define indirect_map_delete(O) indirect_map_delete(aTHX_ (O))
 666  dMY_CXT;
 667
 668  if (indirect_is_loaded(&MY_CXT) && MY_CXT.map)
 669   ptable_delete(MY_CXT.map, o);
 670 }
 671
 672 /* --- Check functions ----------------------------------------------------- */
 673
 674 static int indirect_find(pTHX_ SV *name_sv, const char *line_bufptr, STRLEN *name_pos) {
 675 #define indirect_find(NSV, LBP, NP) indirect_find(aTHX_ (NSV), (LBP), (NP))
 676  STRLEN      name_len, line_len;
 677  const char *name, *name_end;
 678  const char *line, *line_end;
 679  const char *p;
 680
 681  line     = SvPV_const(PL_linestr, line_len);
 682  line_end = line + line_len;
 683
 684  name = SvPV_const(name_sv, name_len);
 685  if (name_len >= 1 && *name == '$') {
 686   ++name;
 687   --name_len;
 688   while (line_bufptr < line_end && *line_bufptr != '$')
 689    ++line_bufptr;
 690   if (line_bufptr >= line_end)
 691    return 0;
 692  }
 693  name_end = name + name_len;
 694
 695  p = line_bufptr;
 696  while (1) {
 697   p = ninstr(p, line_end, name, name_end);
 698   if (!p)
 699    return 0;
 700   if (!isALNUM(p[name_len]))
 701    break;
 702   /* p points to a word that has name as prefix, skip the rest of the word */
 703   p += name_len + 1;
 704   while (isALNUM(*p))
 705    ++p;
 706  }
 707
 708  *name_pos = p - line;
 709
 710  return 1;
 711 }
 712
 713 /* ... ck_const ............................................................ */
 714
 715 static OP *(*indirect_old_ck_const)(pTHX_ OP *) = 0;
 716
 717 static OP *indirect_ck_const(pTHX_ OP *o) {
 718  o = indirect_old_ck_const(aTHX_ o);
 719
 720  if (indirect_hint()) {
 721   SV *sv = cSVOPo_sv;
 722
 723   if (SvPOK(sv) && (SvTYPE(sv) >= SVt_PV)) {
 724    STRLEN pos;
 725
 726    if (indirect_find(sv, PL_oldbufptr, &pos)) {
 727     STRLEN len;
 728
 729     /* If the constant is equal to the current package name, try to look for
 730      * a "__PACKAGE__" coming before what we got. We only need to check this
 731      * when we already had a match because __PACKAGE__ can only appear in
 732      * direct method calls ("new __PACKAGE__" is a syntax error). */
 733     len = SvCUR(sv);
 734     if (PL_curstash
 735         && len == (STRLEN) HvNAMELEN_get(PL_curstash)
 736         && memcmp(SvPVX(sv), HvNAME_get(PL_curstash), len) == 0) {
 737      STRLEN pos_pkg;
 738      SV    *pkg = sv_newmortal();
 739      sv_setpvn(pkg, "__PACKAGE__", sizeof("__PACKAGE__")-1);
 740
 741      if (indirect_find(pkg, PL_oldbufptr, &pos_pkg) && pos_pkg < pos) {
 742       sv  = pkg;
 743       pos = pos_pkg;
 744      }
 745     }
 746
 747     indirect_map_store(o, pos, sv, CopLINE(&PL_compiling));
 748     return o;
 749    }
 750   }
 751  }
 752
 753  indirect_map_delete(o);
 754  return o;
 755 }
 756
 757 /* ... ck_rv2sv ............................................................ */
 758
 759 static OP *(*indirect_old_ck_rv2sv)(pTHX_ OP *) = 0;
 760
 761 static OP *indirect_ck_rv2sv(pTHX_ OP *o) {
 762  if (indirect_hint()) {
 763   OP *op = cUNOPo->op_first;
 764   SV *sv;
 765   const char *name = NULL;
 766   STRLEN pos, len;
 767   OPCODE type = (OPCODE) op->op_type;
 768
 769   switch (type) {
 770    case OP_GV:
 771    case OP_GVSV: {
 772     GV *gv = cGVOPx_gv(op);
 773     name = GvNAME(gv);
 774     len  = GvNAMELEN(gv);
 775     break;
 776    }
 777    default:
 778     if ((PL_opargs[type] & OA_CLASS_MASK) == OA_SVOP) {
 779      SV *nsv = cSVOPx_sv(op);
 780      if (SvPOK(nsv) && (SvTYPE(nsv) >= SVt_PV))
 781       name = SvPV_const(nsv, len);
 782     }
 783   }
 784   if (!name)
 785    goto done;
 786
 787   sv = sv_2mortal(newSVpvn("$", 1));
 788   sv_catpvn_nomg(sv, name, len);
 789   if (!indirect_find(sv, PL_oldbufptr, &pos)) {
 790    /* If it failed, retry without the current stash */
 791    const char *stash = HvNAME_get(PL_curstash);
 792    STRLEN stashlen = HvNAMELEN_get(PL_curstash);
 793
 794    if ((len < stashlen + 2) || strnNE(name, stash, stashlen)
 795        || name[stashlen] != ':' || name[stashlen+1] != ':') {
 796     /* Failed again ? Try to remove main */
 797     stash = "main";
 798     stashlen = 4;
 799     if ((len < stashlen + 2) || strnNE(name, stash, stashlen)
 800         || name[stashlen] != ':' || name[stashlen+1] != ':')
 801      goto done;
 802    }
 803
 804    sv_setpvn(sv, "$", 1);
 805    stashlen += 2;
 806    sv_catpvn_nomg(sv, name + stashlen, len - stashlen);
 807    if (!indirect_find(sv, PL_oldbufptr, &pos))
 808     goto done;
 809   }
 810
 811   o = indirect_old_ck_rv2sv(aTHX_ o);
 812
 813   indirect_map_store(o, pos, sv, CopLINE(&PL_compiling));
 814   return o;
 815  }
 816
 817 done:
 818  o = indirect_old_ck_rv2sv(aTHX_ o);
 819
 820  indirect_map_delete(o);
 821  return o;
 822 }
 823
 824 /* ... ck_padany ........................................................... */
 825
 826 static OP *(*indirect_old_ck_padany)(pTHX_ OP *) = 0;
 827
 828 static OP *indirect_ck_padany(pTHX_ OP *o) {
 829  o = indirect_old_ck_padany(aTHX_ o);
 830
 831  if (indirect_hint()) {
 832   SV *sv;
 833   const char *s = PL_oldbufptr, *t = PL_bufptr - 1;
 834
 835   while (s < t && isSPACE(*s)) ++s;
 836   if (*s == '$' && ++s <= t) {
 837    while (s < t && isSPACE(*s)) ++s;
 838    while (s < t && isSPACE(*t)) --t;
 839    sv = sv_2mortal(newSVpvn("$", 1));
 840    sv_catpvn_nomg(sv, s, t - s + 1);
 841    indirect_map_store(o, s - SvPVX_const(PL_linestr),
 842                          sv, CopLINE(&PL_compiling));
 843    return o;
 844   }
 845  }
 846
 847  indirect_map_delete(o);
 848  return o;
 849 }
 850
 851 /* ... ck_scope ............................................................ */
 852
 853 static OP *(*indirect_old_ck_scope)  (pTHX_ OP *) = 0;
 854 static OP *(*indirect_old_ck_lineseq)(pTHX_ OP *) = 0;
 855
 856 static OP *indirect_ck_scope(pTHX_ OP *o) {
 857  OP *(*old_ck)(pTHX_ OP *) = 0;
 858
 859  switch (o->op_type) {
 860   case OP_SCOPE:   old_ck = indirect_old_ck_scope;   break;
 861   case OP_LINESEQ: old_ck = indirect_old_ck_lineseq; break;
 862  }
 863  o = old_ck(aTHX_ o);
 864
 865  if (indirect_hint()) {
 866   indirect_map_store(o, PL_oldbufptr - SvPVX_const(PL_linestr),
 867                         NULL, CopLINE(&PL_compiling));
 868   return o;
 869  }
 870
 871  indirect_map_delete(o);
 872  return o;
 873 }
 874
 875 /* We don't need to clean the map entries for leave ops because they can only
 876  * be created by mutating from a lineseq. */
 877
 878 /* ... ck_method ........................................................... */
 879
 880 static OP *(*indirect_old_ck_method)(pTHX_ OP *) = 0;
 881
 882 static OP *indirect_ck_method(pTHX_ OP *o) {
 883  if (indirect_hint()) {
 884   OP *op = cUNOPo->op_first;
 885
 886   /* Indirect method call is only possible when the method is a bareword, so
 887    * don't trip up on $obj->$meth. */
 888   if (op && op->op_type == OP_CONST) {
 889    const indirect_op_info_t *oi = indirect_map_fetch(op);
 890    STRLEN pos;
 891    line_t line;
 892    SV *sv;
 893
 894    if (!oi)
 895     goto done;
 896
 897    sv   = sv_2mortal(newSVpvn(oi->buf, oi->len));
 898    pos  = oi->pos;
 899    /* Keep the old line so that we really point to the first line of the
 900     * expression. */
 901    line = oi->line;
 902
 903    o = indirect_old_ck_method(aTHX_ o);
 904    /* o may now be a method_named */
 905
 906    indirect_map_store(o, pos, sv, line);
 907    return o;
 908   }
 909  }
 910
 911 done:
 912  o = indirect_old_ck_method(aTHX_ o);
 913
 914  indirect_map_delete(o);
 915  return o;
 916 }
 917
 918 /* ... ck_method_named ..................................................... */
 919
 920 /* "use foo/no foo" compiles its call to import/unimport directly to a
 921  * method_named op. */
 922
 923 static OP *(*indirect_old_ck_method_named)(pTHX_ OP *) = 0;
 924
 925 static OP *indirect_ck_method_named(pTHX_ OP *o) {
 926  if (indirect_hint()) {
 927   STRLEN pos;
 928   line_t line;
 929   SV *sv;
 930
 931   sv = cSVOPo_sv;
 932   if (!SvPOK(sv) || (SvTYPE(sv) < SVt_PV))
 933    goto done;
 934   sv = sv_mortalcopy(sv);
 935
 936   if (!indirect_find(sv, PL_oldbufptr, &pos))
 937    goto done;
 938   line = CopLINE(&PL_compiling);
 939
 940   o = indirect_old_ck_method_named(aTHX_ o);
 941
 942   indirect_map_store(o, pos, sv, line);
 943   return o;
 944  }
 945
 946 done:
 947  o = indirect_old_ck_method_named(aTHX_ o);
 948
 949  indirect_map_delete(o);
 950  return o;
 951 }
 952
 953 /* ... ck_entersub ......................................................... */
 954
 955 static OP *(*indirect_old_ck_entersub)(pTHX_ OP *) = 0;
 956
 957 static OP *indirect_ck_entersub(pTHX_ OP *o) {
 958  SV *code = indirect_hint();
 959
 960  o = indirect_old_ck_entersub(aTHX_ o);
 961
 962  if (code) {
 963   const indirect_op_info_t *moi, *ooi;
 964   OP     *mop, *oop;
 965   LISTOP *lop;
 966
 967   oop = o;
 968   do {
 969    lop = (LISTOP *) oop;
 970    if (!(lop->op_flags & OPf_KIDS))
 971     goto done;
 972    oop = lop->op_first;
 973   } while (oop->op_type != OP_PUSHMARK);
 974   oop = OpSIBLING(oop);
 975   mop = lop->op_last;
 976
 977   if (!oop)
 978    goto done;
 979
 980   switch (oop->op_type) {
 981    case OP_CONST:
 982    case OP_RV2SV:
 983    case OP_PADSV:
 984    case OP_SCOPE:
 985    case OP_LEAVE:
 986     break;
 987    default:
 988     goto done;
 989   }
 990
 991   if (mop->op_type == OP_METHOD)
 992    mop = cUNOPx(mop)->op_first;
 993   else if (mop->op_type != OP_METHOD_NAMED)
 994    goto done;
 995
 996   moi = indirect_map_fetch(mop);
 997   if (!moi)
 998    goto done;
 999
1000   ooi = indirect_map_fetch(oop);
1001   if (!ooi)
1002    goto done;
1003
1004   /* When positions are identical, the method and the object must have the
1005    * same name. But it also means that it is an indirect call, as "foo->foo"
1006    * results in different positions. */
1007   if (   moi->line < ooi->line
1008       || (moi->line == ooi->line && moi->pos <= ooi->pos)) {
1009    SV *file;
1010    dSP;
1011
1012    ENTER;
1013    SAVETMPS;
1014
1015 #ifdef USE_ITHREADS
1016    file = sv_2mortal(newSVpv(CopFILE(&PL_compiling), 0));
1017 #else
1018    file = sv_mortalcopy(CopFILESV(&PL_compiling));
1019 #endif
1020
1021    PUSHMARK(SP);
1022    EXTEND(SP, 4);
1023    mPUSHp(ooi->buf, ooi->len);
1024    mPUSHp(moi->buf, moi->len);
1025    PUSHs(file);
1026    mPUSHu(moi->line);
1027    PUTBACK;
1028
1029    call_sv(code, G_VOID);
1030
1031    PUTBACK;
1032
1033    FREETMPS;
1034    LEAVE;
1035   }
1036  }
1037
1038 done:
1039  return o;
1040 }
1041
1042 /* --- Module setup/teardown ----------------------------------------------- */
1043
1044 static void indirect_teardown(pTHX_ void *interp) {
1045  dMY_CXT;
1046
1047 #if I_MULTIPLICITY
1048  if (aTHX != interp)
1049   return;
1050 #endif
1051
1052  I_LOADED_LOCK;
1053
1054  if (indirect_clear_loaded_locked(&MY_CXT)) {
1055   indirect_ck_restore(OP_CONST,   &indirect_old_ck_const);
1056   indirect_ck_restore(OP_RV2SV,   &indirect_old_ck_rv2sv);
1057   indirect_ck_restore(OP_PADANY,  &indirect_old_ck_padany);
1058   indirect_ck_restore(OP_SCOPE,   &indirect_old_ck_scope);
1059   indirect_ck_restore(OP_LINESEQ, &indirect_old_ck_lineseq);
1060
1061   indirect_ck_restore(OP_METHOD,       &indirect_old_ck_method);
1062   indirect_ck_restore(OP_METHOD_NAMED, &indirect_old_ck_method_named);
1063   indirect_ck_restore(OP_ENTERSUB,     &indirect_old_ck_entersub);
1064  }
1065
1066  I_LOADED_UNLOCK;
1067
1068  ptable_free(MY_CXT.map);
1069  MY_CXT.map = NULL;
1070
1071 #if I_THREADSAFE
1072  ptable_hints_free(MY_CXT.tbl);
1073  MY_CXT.tbl = NULL;
1074 #endif
1075
1076  return;
1077 }
1078
1079 static void indirect_setup(pTHX) {
1080 #define indirect_setup() indirect_setup(aTHX)
1081  MY_CXT_INIT; /* Takes/release PL_my_ctx_mutex */
1082
1083  I_LOADED_LOCK;
1084
1085  if (indirect_set_loaded_locked(&MY_CXT)) {
1086   PERL_HASH(indirect_hash, __PACKAGE__, __PACKAGE_LEN__);
1087
1088   indirect_ck_replace(OP_CONST,   indirect_ck_const,  &indirect_old_ck_const);
1089   indirect_ck_replace(OP_RV2SV,   indirect_ck_rv2sv,  &indirect_old_ck_rv2sv);
1090   indirect_ck_replace(OP_PADANY,  indirect_ck_padany, &indirect_old_ck_padany);
1091   indirect_ck_replace(OP_SCOPE,   indirect_ck_scope,  &indirect_old_ck_scope);
1092   indirect_ck_replace(OP_LINESEQ, indirect_ck_scope,  &indirect_old_ck_lineseq);
1093
1094   indirect_ck_replace(OP_METHOD,       indirect_ck_method,
1095                                        &indirect_old_ck_method);
1096   indirect_ck_replace(OP_METHOD_NAMED, indirect_ck_method_named,
1097                                        &indirect_old_ck_method_named);
1098   indirect_ck_replace(OP_ENTERSUB,     indirect_ck_entersub,
1099                                        &indirect_old_ck_entersub);
1100  }
1101
1102  I_LOADED_UNLOCK;
1103
1104  {
1105   HV *stash;
1106
1107   stash = gv_stashpvn(__PACKAGE__, __PACKAGE_LEN__, 1);
1108   newCONSTSUB(stash, "I_THREADSAFE", newSVuv(I_THREADSAFE));
1109   newCONSTSUB(stash, "I_FORKSAFE",   newSVuv(I_FORKSAFE));
1110
1111 #if I_THREADSAFE
1112   MY_CXT.tbl         = ptable_new();
1113   MY_CXT.owner       = aTHX;
1114 #endif
1115
1116   MY_CXT.map         = ptable_new();
1117   MY_CXT.global_code = NULL;
1118  }
1119
1120 #if I_MULTIPLICITY
1121  call_atexit(indirect_teardown, aTHX);
1122 #else
1123  call_atexit(indirect_teardown, NULL);
1124 #endif
1125
1126  return;
1127 }
1128
1129 /* --- XS ------------------------------------------------------------------ */
1130
1131 MODULE = indirect      PACKAGE = indirect
1132
1133 PROTOTYPES: ENABLE
1134
1135 BOOT:
1136 {
1137  indirect_setup();
1138 }
1139
1140 #if I_THREADSAFE
1141
1142 void
1143 CLONE(...)
1144 PROTOTYPE: DISABLE
1145 PREINIT:
1146  ptable *t;
1147  SV     *global_code_dup;
1148  GV     *gv;
1149 PPCODE:
1150  {
1151   indirect_ptable_clone_ud ud;
1152   dMY_CXT;
1153   t = ptable_new();
1154   indirect_ptable_clone_ud_init(ud, t, MY_CXT.owner);
1155   ptable_walk(MY_CXT.tbl, indirect_ptable_clone, &ud);
1156   global_code_dup = indirect_dup_inc(MY_CXT.global_code, &ud);
1157   indirect_ptable_clone_ud_deinit(ud);
1158  }
1159  {
1160   MY_CXT_CLONE;
1161   MY_CXT.map         = ptable_new();
1162   MY_CXT.tbl         = t;
1163   MY_CXT.owner       = aTHX;
1164   MY_CXT.global_code = global_code_dup;
1165   {
1166    int global_setup;
1167    I_LOADED_LOCK;
1168    global_setup = indirect_set_loaded_locked(&MY_CXT);
1169    assert(!global_setup);
1170    I_LOADED_UNLOCK;
1171   }
1172  }
1173  gv = gv_fetchpv(__PACKAGE__ "::_THREAD_CLEANUP", 0, SVt_PVCV);
1174  if (gv) {
1175   CV *cv = GvCV(gv);
1176   if (!PL_endav)
1177    PL_endav = newAV();
1178   SvREFCNT_inc(cv);
1179   if (!av_store(PL_endav, av_len(PL_endav) + 1, (SV *) cv))
1180    SvREFCNT_dec(cv);
1181   sv_magicext((SV *) PL_endav, NULL, PERL_MAGIC_ext, &indirect_endav_vtbl, NULL, 0);
1182  }
1183  XSRETURN(0);
1184
1185 void
1186 _THREAD_CLEANUP(...)
1187 PROTOTYPE: DISABLE
1188 PPCODE:
1189  indirect_thread_cleanup(aTHX_ NULL);
1190  XSRETURN(0);
1191
1192 #endif
1193
1194 SV *
1195 _tag(SV *value)
1196 PROTOTYPE: $
1197 CODE:
1198  RETVAL = indirect_tag(value);
1199 OUTPUT:
1200  RETVAL
1201
1202 void
1203 _global(SV *code)
1204 PROTOTYPE: $
1205 PPCODE:
1206  if (!SvOK(code))
1207   code = NULL;
1208  else if (SvROK(code))
1209   code = SvRV(code);
1210  {
1211   dMY_CXT;
1212   SvREFCNT_dec(MY_CXT.global_code);
1213   MY_CXT.global_code = SvREFCNT_inc(code);
1214  }
1215  XSRETURN(0);