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