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 I32 indirect_loaded = 0;
 218
 219 #if I_THREADSAFE
 220
 221 #define PTABLE_NAME        ptable_loaded
 222 #define PTABLE_NEED_DELETE 1
 223 #define PTABLE_NEED_WALK   0
 224
 225 #include "ptable.h"
 226
 227 #define ptable_loaded_store(T, K, V) ptable_loaded_store(aPTBLMS_ (T), (K), (V))
 228 #define ptable_loaded_delete(T, K)   ptable_loaded_delete(aPTBLMS_ (T), (K))
 229 #define ptable_loaded_free(T)        ptable_loaded_free(aPTBLMS_ (T))
 230
 231 static ptable *indirect_loaded_cxts = NULL;
 232
 233 static int indirect_is_loaded(pTHX_ void *cxt) {
 234 #define indirect_is_loaded(C) indirect_is_loaded(aTHX_ (C))
 235  int res = 0;
 236
 237  I_LOADED_LOCK;
 238  if (indirect_loaded_cxts && ptable_fetch(indirect_loaded_cxts, cxt))
 239   res = 1;
 240  I_LOADED_UNLOCK;
 241
 242  return res;
 243 }
 244
 245 static int indirect_set_loaded_locked(pTHX_ void *cxt) {
 246 #define indirect_set_loaded_locked(C) indirect_set_loaded_locked(aTHX_ (C))
 247  int global_setup = 0;
 248
 249  if (indirect_loaded <= 0) {
 250   assert(indirect_loaded == 0);
 251   assert(!indirect_loaded_cxts);
 252   indirect_loaded_cxts = ptable_new();
 253   global_setup         = 1;
 254  }
 255  ++indirect_loaded;
 256  assert(indirect_loaded_cxts);
 257  ptable_loaded_store(indirect_loaded_cxts, cxt, cxt);
 258
 259  return global_setup;
 260 }
 261
 262 static int indirect_clear_loaded_locked(pTHX_ void *cxt) {
 263 #define indirect_clear_loaded_locked(C) indirect_clear_loaded_locked(aTHX_ (C))
 264  int global_teardown = 0;
 265
 266  if (indirect_loaded > 1) {
 267   assert(indirect_loaded_cxts);
 268   ptable_loaded_delete(indirect_loaded_cxts, cxt);
 269   --indirect_loaded;
 270  } else if (indirect_loaded_cxts) {
 271   assert(indirect_loaded == 1);
 272   ptable_loaded_free(indirect_loaded_cxts);
 273   indirect_loaded_cxts = NULL;
 274   indirect_loaded      = 0;
 275   global_teardown      = 1;
 276  }
 277
 278  return global_teardown;
 279 }
 280
 281 #else
 282
 283 #define indirect_is_loaded(C)           (indirect_loaded > 0)
 284 #define indirect_set_loaded_locked(C)   ((indirect_loaded++ <= 0) ? 1 : 0)
 285 #define indirect_clear_loaded_locked(C) ((--indirect_loaded <= 0) ? 1 : 0)
 286
 287 #endif
 288
 289 /* ... Thread-safe hints ................................................... */
 290
 291 #if I_WORKAROUND_REQUIRE_PROPAGATION
 292
 293 typedef struct {
 294  SV *code;
 295  IV  require_tag;
 296 } indirect_hint_t;
 297
 298 #define I_HINT_STRUCT 1
 299
 300 #define I_HINT_CODE(H) ((H)->code)
 301
 302 #define I_HINT_FREE(H) {   \
 303  indirect_hint_t *h = (H); \
 304  SvREFCNT_dec(h->code);    \
 305  PerlMemShared_free(h);    \
 306 }
 307
 308 #else  /*  I_WORKAROUND_REQUIRE_PROPAGATION */
 309
 310 typedef SV indirect_hint_t;
 311
 312 #define I_HINT_STRUCT 0
 313
 314 #define I_HINT_CODE(H) (H)
 315
 316 #define I_HINT_FREE(H) SvREFCNT_dec(H);
 317
 318 #endif /* !I_WORKAROUND_REQUIRE_PROPAGATION */
 319
 320 #if I_THREADSAFE
 321
 322 #define PTABLE_NAME        ptable_hints
 323 #define PTABLE_VAL_FREE(V) I_HINT_FREE(V)
 324 #define PTABLE_NEED_DELETE 0
 325 #define PTABLE_NEED_WALK   1
 326
 327 #define pPTBL  pTHX
 328 #define pPTBL_ pTHX_
 329 #define aPTBL  aTHX
 330 #define aPTBL_ aTHX_
 331
 332 #include "ptable.h"
 333
 334 #define ptable_hints_store(T, K, V) ptable_hints_store(aTHX_ (T), (K), (V))
 335 #define ptable_hints_free(T)        ptable_hints_free(aTHX_ (T))
 336
 337 #endif /* I_THREADSAFE */
 338
 339 /* Define the op->str ptable here because we need to be able to clean it during
 340  * thread cleanup. */
 341
 342 typedef struct {
 343  char   *buf;
 344  STRLEN  pos;
 345  STRLEN  size;
 346  STRLEN  len;
 347  line_t  line;
 348 } indirect_op_info_t;
 349
 350 #define PTABLE_NAME        ptable
 351 #define PTABLE_VAL_FREE(V) if (V) { Safefree(((indirect_op_info_t *) (V))->buf); Safefree(V); }
 352 #define PTABLE_NEED_DELETE 1
 353 #define PTABLE_NEED_WALK   0
 354
 355 #define pPTBL  pTHX
 356 #define pPTBL_ pTHX_
 357 #define aPTBL  aTHX
 358 #define aPTBL_ aTHX_
 359
 360 #include "ptable.h"
 361
 362 #define ptable_store(T, K, V) ptable_store(aTHX_ (T), (K), (V))
 363 #define ptable_delete(T, K)   ptable_delete(aTHX_ (T), (K))
 364 #define ptable_clear(T)       ptable_clear(aTHX_ (T))
 365 #define ptable_free(T)        ptable_free(aTHX_ (T))
 366
 367 #define MY_CXT_KEY __PACKAGE__ "::_guts" XS_VERSION
 368
 369 typedef struct {
 370 #if I_THREADSAFE
 371  ptable *tbl; /* It really is a ptable_hints */
 372  tTHX    owner;
 373 #endif
 374  ptable *map;
 375  SV     *global_code;
 376 } my_cxt_t;
 377
 378 START_MY_CXT
 379
 380 #if I_THREADSAFE
 381
 382 typedef struct {
 383  ptable *tbl;
 384 #if I_HAS_PERL(5, 13, 2)
 385  CLONE_PARAMS *params;
 386 #else
 387  CLONE_PARAMS params;
 388 #endif
 389 } indirect_ptable_clone_ud;
 390
 391 #if I_HAS_PERL(5, 13, 2)
 392 # define indirect_ptable_clone_ud_init(U, T, O) \
 393    (U).tbl    = (T); \
 394    (U).params = Perl_clone_params_new((O), aTHX)
 395 # define indirect_ptable_clone_ud_deinit(U) Perl_clone_params_del((U).params)
 396 # define indirect_dup_inc(S, U)             SvREFCNT_inc(sv_dup((S), (U)->params))
 397 #else
 398 # define indirect_ptable_clone_ud_init(U, T, O) \
 399    (U).tbl               = (T);     \
 400    (U).params.stashes    = newAV(); \
 401    (U).params.flags      = 0;       \
 402    (U).params.proto_perl = (O)
 403 # define indirect_ptable_clone_ud_deinit(U) SvREFCNT_dec((U).params.stashes)
 404 # define indirect_dup_inc(S, U)             SvREFCNT_inc(sv_dup((S), &((U)->params)))
 405 #endif
 406
 407 static void indirect_ptable_clone(pTHX_ ptable_ent *ent, void *ud_) {
 408  indirect_ptable_clone_ud *ud = ud_;
 409  indirect_hint_t          *h1 = ent->val;
 410  indirect_hint_t          *h2;
 411
 412 #if I_HINT_STRUCT
 413
 414  h2              = PerlMemShared_malloc(sizeof *h2);
 415  h2->code        = indirect_dup_inc(h1->code, ud);
 416 #if I_WORKAROUND_REQUIRE_PROPAGATION
 417  h2->require_tag = PTR2IV(indirect_dup_inc(INT2PTR(SV *, h1->require_tag), ud));
 418 #endif
 419
 420 #else  /*  I_HINT_STRUCT */
 421
 422  h2 = indirect_dup_inc(h1, ud);
 423
 424 #endif /* !I_HINT_STRUCT */
 425
 426  ptable_hints_store(ud->tbl, ent->key, h2);
 427 }
 428
 429 #endif /* I_THREADSAFE */
 430
 431 #if I_WORKAROUND_REQUIRE_PROPAGATION
 432
 433 static IV indirect_require_tag(pTHX) {
 434 #define indirect_require_tag() indirect_require_tag(aTHX)
 435  const CV *cv, *outside;
 436
 437  cv = PL_compcv;
 438
 439  if (!cv) {
 440   /* If for some reason the pragma is operational at run-time, try to discover
 441    * the current cv in use. */
 442   const PERL_SI *si;
 443
 444   for (si = PL_curstackinfo; si; si = si->si_prev) {
 445    I32 cxix;
 446
 447    for (cxix = si->si_cxix; cxix >= 0; --cxix) {
 448     const PERL_CONTEXT *cx = si->si_cxstack + cxix;
 449
 450     switch (CxTYPE(cx)) {
 451      case CXt_SUB:
 452      case CXt_FORMAT:
 453       /* The propagation workaround is only needed up to 5.10.0 and at that
 454        * time format and sub contexts were still identical. And even later the
 455        * cv members offsets should have been kept the same. */
 456       cv = cx->blk_sub.cv;
 457       goto get_enclosing_cv;
 458      case CXt_EVAL:
 459       cv = cx->blk_eval.cv;
 460       goto get_enclosing_cv;
 461      default:
 462       break;
 463     }
 464    }
 465   }
 466
 467   cv = PL_main_cv;
 468  }
 469
 470 get_enclosing_cv:
 471  for (outside = CvOUTSIDE(cv); outside; outside = CvOUTSIDE(cv))
 472   cv = outside;
 473
 474  return PTR2IV(cv);
 475 }
 476
 477 #endif /* I_WORKAROUND_REQUIRE_PROPAGATION */
 478
 479 static SV *indirect_tag(pTHX_ SV *value) {
 480 #define indirect_tag(V) indirect_tag(aTHX_ (V))
 481  indirect_hint_t *h;
 482  SV              *code = NULL;
 483 #if I_THREADSAFE
 484  dMY_CXT;
 485
 486  if (!MY_CXT.tbl)
 487   return newSViv(0);
 488 #endif /* I_THREADSAFE */
 489
 490  if (SvROK(value)) {
 491   value = SvRV(value);
 492   if (SvTYPE(value) >= SVt_PVCV) {
 493    code = value;
 494    SvREFCNT_inc_simple_void_NN(code);
 495   }
 496  }
 497
 498 #if I_HINT_STRUCT
 499  h = PerlMemShared_malloc(sizeof *h);
 500  h->code        = code;
 501 # if I_WORKAROUND_REQUIRE_PROPAGATION
 502  h->require_tag = indirect_require_tag();
 503 # endif /* I_WORKAROUND_REQUIRE_PROPAGATION */
 504 #else  /*  I_HINT_STRUCT */
 505  h = code;
 506 #endif /* !I_HINT_STRUCT */
 507
 508 #if I_THREADSAFE
 509  /* We only need for the key to be an unique tag for looking up the value later
 510   * Allocated memory provides convenient unique identifiers, so that's why we
 511   * use the hint as the key itself. */
 512  ptable_hints_store(MY_CXT.tbl, h, h);
 513 #endif /* I_THREADSAFE */
 514
 515  return newSViv(PTR2IV(h));
 516 }
 517
 518 static SV *indirect_detag(pTHX_ const SV *hint) {
 519 #define indirect_detag(H) indirect_detag(aTHX_ (H))
 520  indirect_hint_t *h;
 521 #if I_THREADSAFE || I_WORKAROUND_REQUIRE_PROPAGATION
 522  dMY_CXT;
 523 #endif
 524
 525 #if I_THREADSAFE
 526  if (!MY_CXT.tbl)
 527   return NULL;
 528 #endif /* I_THREADSAFE */
 529
 530  h = INT2PTR(indirect_hint_t *, SvIVX(hint));
 531 #if I_THREADSAFE
 532  h = ptable_fetch(MY_CXT.tbl, h);
 533 #endif /* I_THREADSAFE */
 534
 535 #if I_WORKAROUND_REQUIRE_PROPAGATION
 536  if (indirect_require_tag() != h->require_tag)
 537   return MY_CXT.global_code;
 538 #endif /* I_WORKAROUND_REQUIRE_PROPAGATION */
 539
 540  return I_HINT_CODE(h);
 541 }
 542
 543 static VOL U32 indirect_hash = 0;
 544
 545 static SV *indirect_hint(pTHX) {
 546 #define indirect_hint() indirect_hint(aTHX)
 547  SV *hint = NULL;
 548
 549  if (IN_PERL_RUNTIME)
 550   return NULL;
 551
 552 #if I_HAS_PERL(5, 10, 0) || defined(PL_parser)
 553  if (!PL_parser)
 554   return NULL;
 555 #endif
 556
 557 #ifdef cop_hints_fetch_pvn
 558  hint = cop_hints_fetch_pvn(PL_curcop, __PACKAGE__, __PACKAGE_LEN__,
 559                                                               indirect_hash, 0);
 560 #elif I_HAS_PERL(5, 9, 5)
 561  hint = Perl_refcounted_he_fetch(aTHX_ PL_curcop->cop_hints_hash,
 562                                        NULL,
 563                                        __PACKAGE__, __PACKAGE_LEN__,
 564                                        0,
 565                                        indirect_hash);
 566 #else
 567  {
 568   SV **val = hv_fetch(GvHV(PL_hintgv), __PACKAGE__, __PACKAGE_LEN__, 0);
 569   if (val)
 570    hint = *val;
 571  }
 572 #endif
 573
 574  if (hint && SvIOK(hint)) {
 575   return indirect_detag(hint);
 576  } else {
 577   dMY_CXT;
 578   if (indirect_is_loaded(&MY_CXT))
 579    return MY_CXT.global_code;
 580   else
 581    return NULL;
 582  }
 583 }
 584
 585 /* ... op -> source position ............................................... */
 586
 587 static void indirect_map_store(pTHX_ const OP *o, STRLEN pos, SV *sv, line_t line) {
 588 #define indirect_map_store(O, P, N, L) indirect_map_store(aTHX_ (O), (P), (N), (L))
 589  indirect_op_info_t *oi;
 590  const char *s;
 591  STRLEN len;
 592  dMY_CXT;
 593
 594  /* No need to check for MY_CXT.map != NULL because this code path is always
 595   * guarded by indirect_hint(). */
 596
 597  if (!(oi = ptable_fetch(MY_CXT.map, o))) {
 598   Newx(oi, 1, indirect_op_info_t);
 599   ptable_store(MY_CXT.map, o, oi);
 600   oi->buf  = NULL;
 601   oi->size = 0;
 602  }
 603
 604  if (sv) {
 605   s = SvPV_const(sv, len);
 606  } else {
 607   s   = "{";
 608   len = 1;
 609  }
 610
 611  if (len > oi->size) {
 612   Safefree(oi->buf);
 613   Newx(oi->buf, len, char);
 614   oi->size = len;
 615  }
 616  Copy(s, oi->buf, len, char);
 617
 618  oi->len  = len;
 619  oi->pos  = pos;
 620  oi->line = line;
 621 }
 622
 623 static const indirect_op_info_t *indirect_map_fetch(pTHX_ const OP *o) {
 624 #define indirect_map_fetch(O) indirect_map_fetch(aTHX_ (O))
 625  dMY_CXT;
 626
 627  /* No need to check for MY_CXT.map != NULL because this code path is always
 628   * guarded by indirect_hint(). */
 629
 630  return ptable_fetch(MY_CXT.map, o);
 631 }
 632
 633 static void indirect_map_delete(pTHX_ const OP *o) {
 634 #define indirect_map_delete(O) indirect_map_delete(aTHX_ (O))
 635  dMY_CXT;
 636
 637  if (indirect_is_loaded(&MY_CXT) && MY_CXT.map)
 638   ptable_delete(MY_CXT.map, o);
 639 }
 640
 641 /* --- Safe version of call_sv() ------------------------------------------- */
 642
 643 static I32 indirect_call_sv(pTHX_ SV *sv, I32 flags) {
 644 #define indirect_call_sv(S, F) indirect_call_sv(aTHX_ (S), (F))
 645  I32          ret, cxix;
 646  PERL_CONTEXT saved_cx;
 647  SV          *saved_errsv = NULL;
 648
 649  if (SvTRUE(ERRSV)) {
 650   if (IN_PERL_COMPILETIME && PL_errors)
 651    sv_catsv(PL_errors, ERRSV);
 652   else
 653    saved_errsv = newSVsv(ERRSV);
 654   SvCUR_set(ERRSV, 0);
 655  }
 656
 657  cxix     = (cxstack_ix < cxstack_max) ? (cxstack_ix + 1) : Perl_cxinc(aTHX);
 658  /* The last popped context will be reused by call_sv(), but our callers may
 659   * still need its previous value. Back it up so that it isn't clobbered. */
 660  saved_cx = cxstack[cxix];
 661
 662  ret = call_sv(sv, flags | G_EVAL);
 663
 664  cxstack[cxix] = saved_cx;
 665
 666  if (SvTRUE(ERRSV)) {
 667   /* Discard the old ERRSV, and reuse the variable to temporarily store the
 668    * new one. */
 669   if (saved_errsv)
 670    sv_setsv(saved_errsv, ERRSV);
 671   else
 672    saved_errsv = newSVsv(ERRSV);
 673   SvCUR_set(ERRSV, 0);
 674   /* Immediately flush all errors. */
 675   if (IN_PERL_COMPILETIME) {
 676 #if I_HAS_PERL(5, 10, 0) || defined(PL_parser)
 677    if (PL_parser)
 678     ++PL_parser->error_count;
 679 #elif defined(PL_error_count)
 680    ++PL_error_count;
 681 #else
 682    ++PL_Ierror_count;
 683 #endif
 684    if (PL_errors) {
 685     sv_setsv(ERRSV, PL_errors);
 686     SvCUR_set(PL_errors, 0);
 687    }
 688   }
 689   sv_catsv(ERRSV, saved_errsv);
 690   SvREFCNT_dec(saved_errsv);
 691   croak(NULL);
 692  } else if (saved_errsv) {
 693   /* If IN_PERL_COMPILETIME && PL_errors, then the old ERRSV has already been
 694    * added to PL_errors. Otherwise, just restore it to ERRSV, as if no eval
 695    * block has ever been executed. */
 696   sv_setsv(ERRSV, saved_errsv);
 697   SvREFCNT_dec(saved_errsv);
 698  }
 699
 700  return ret;
 701 }
 702
 703 /* --- Check functions ----------------------------------------------------- */
 704
 705 static int indirect_find(pTHX_ SV *name_sv, const char *line_bufptr, STRLEN *name_pos) {
 706 #define indirect_find(NSV, LBP, NP) indirect_find(aTHX_ (NSV), (LBP), (NP))
 707  STRLEN      name_len, line_len;
 708  const char *name, *name_end;
 709  const char *line, *line_end;
 710  const char *p;
 711
 712  line     = SvPV_const(PL_linestr, line_len);
 713  line_end = line + line_len;
 714
 715  name = SvPV_const(name_sv, name_len);
 716  if (name_len >= 1 && *name == '$') {
 717   ++name;
 718   --name_len;
 719   while (line_bufptr < line_end && *line_bufptr != '$')
 720    ++line_bufptr;
 721   if (line_bufptr >= line_end)
 722    return 0;
 723  }
 724  name_end = name + name_len;
 725
 726  p = line_bufptr;
 727  while (1) {
 728   p = ninstr(p, line_end, name, name_end);
 729   if (!p)
 730    return 0;
 731   if (!isALNUM(p[name_len]))
 732    break;
 733   /* p points to a word that has name as prefix, skip the rest of the word */
 734   p += name_len + 1;
 735   while (isALNUM(*p))
 736    ++p;
 737  }
 738
 739  *name_pos = p - line;
 740
 741  return 1;
 742 }
 743
 744 /* ... ck_const ............................................................ */
 745
 746 static OP *(*indirect_old_ck_const)(pTHX_ OP *) = 0;
 747
 748 static OP *indirect_ck_const(pTHX_ OP *o) {
 749  o = indirect_old_ck_const(aTHX_ o);
 750
 751  if (indirect_hint()) {
 752   SV *sv = cSVOPo_sv;
 753
 754   if (SvPOK(sv) && (SvTYPE(sv) >= SVt_PV)) {
 755    STRLEN pos;
 756
 757    if (indirect_find(sv, PL_oldbufptr, &pos)) {
 758     STRLEN len;
 759
 760     /* If the constant is equal to the current package name, try to look for
 761      * a "__PACKAGE__" coming before what we got. We only need to check this
 762      * when we already had a match because __PACKAGE__ can only appear in
 763      * direct method calls ("new __PACKAGE__" is a syntax error). */
 764     len = SvCUR(sv);
 765     if (PL_curstash
 766         && len == (STRLEN) HvNAMELEN_get(PL_curstash)
 767         && memcmp(SvPVX(sv), HvNAME_get(PL_curstash), len) == 0) {
 768      STRLEN pos_pkg;
 769      SV    *pkg = sv_newmortal();
 770      sv_setpvn(pkg, "__PACKAGE__", sizeof("__PACKAGE__")-1);
 771
 772      if (indirect_find(pkg, PL_oldbufptr, &pos_pkg) && pos_pkg < pos) {
 773       sv  = pkg;
 774       pos = pos_pkg;
 775      }
 776     }
 777
 778     indirect_map_store(o, pos, sv, CopLINE(&PL_compiling));
 779     return o;
 780    }
 781   }
 782  }
 783
 784  indirect_map_delete(o);
 785  return o;
 786 }
 787
 788 /* ... ck_rv2sv ............................................................ */
 789
 790 static OP *(*indirect_old_ck_rv2sv)(pTHX_ OP *) = 0;
 791
 792 static OP *indirect_ck_rv2sv(pTHX_ OP *o) {
 793  if (indirect_hint()) {
 794   OP *op = cUNOPo->op_first;
 795   SV *sv;
 796   const char *name = NULL;
 797   STRLEN pos, len;
 798   OPCODE type = (OPCODE) op->op_type;
 799
 800   switch (type) {
 801    case OP_GV:
 802    case OP_GVSV: {
 803     GV *gv = cGVOPx_gv(op);
 804     name = GvNAME(gv);
 805     len  = GvNAMELEN(gv);
 806     break;
 807    }
 808    default:
 809     if ((PL_opargs[type] & OA_CLASS_MASK) == OA_SVOP) {
 810      SV *nsv = cSVOPx_sv(op);
 811      if (SvPOK(nsv) && (SvTYPE(nsv) >= SVt_PV))
 812       name = SvPV_const(nsv, len);
 813     }
 814   }
 815   if (!name)
 816    goto done;
 817
 818   sv = sv_2mortal(newSVpvn("$", 1));
 819   sv_catpvn_nomg(sv, name, len);
 820   if (!indirect_find(sv, PL_oldbufptr, &pos)) {
 821    /* If it failed, retry without the current stash */
 822    const char *stash = HvNAME_get(PL_curstash);
 823    STRLEN stashlen = HvNAMELEN_get(PL_curstash);
 824
 825    if ((len < stashlen + 2) || strnNE(name, stash, stashlen)
 826        || name[stashlen] != ':' || name[stashlen+1] != ':') {
 827     /* Failed again ? Try to remove main */
 828     stash = "main";
 829     stashlen = 4;
 830     if ((len < stashlen + 2) || strnNE(name, stash, stashlen)
 831         || name[stashlen] != ':' || name[stashlen+1] != ':')
 832      goto done;
 833    }
 834
 835    sv_setpvn(sv, "$", 1);
 836    stashlen += 2;
 837    sv_catpvn_nomg(sv, name + stashlen, len - stashlen);
 838    if (!indirect_find(sv, PL_oldbufptr, &pos))
 839     goto done;
 840   }
 841
 842   o = indirect_old_ck_rv2sv(aTHX_ o);
 843
 844   indirect_map_store(o, pos, sv, CopLINE(&PL_compiling));
 845   return o;
 846  }
 847
 848 done:
 849  o = indirect_old_ck_rv2sv(aTHX_ o);
 850
 851  indirect_map_delete(o);
 852  return o;
 853 }
 854
 855 /* ... ck_padany ........................................................... */
 856
 857 static OP *(*indirect_old_ck_padany)(pTHX_ OP *) = 0;
 858
 859 static OP *indirect_ck_padany(pTHX_ OP *o) {
 860  o = indirect_old_ck_padany(aTHX_ o);
 861
 862  if (indirect_hint()) {
 863   SV *sv;
 864   const char *s = PL_oldbufptr, *t = PL_bufptr - 1;
 865
 866   while (s < t && isSPACE(*s)) ++s;
 867   if (*s == '$' && ++s <= t) {
 868    while (s < t && isSPACE(*s)) ++s;
 869    while (s < t && isSPACE(*t)) --t;
 870    sv = sv_2mortal(newSVpvn("$", 1));
 871    sv_catpvn_nomg(sv, s, t - s + 1);
 872    indirect_map_store(o, s - SvPVX_const(PL_linestr),
 873                          sv, CopLINE(&PL_compiling));
 874    return o;
 875   }
 876  }
 877
 878  indirect_map_delete(o);
 879  return o;
 880 }
 881
 882 /* ... ck_scope ............................................................ */
 883
 884 static OP *(*indirect_old_ck_scope)  (pTHX_ OP *) = 0;
 885 static OP *(*indirect_old_ck_lineseq)(pTHX_ OP *) = 0;
 886
 887 static OP *indirect_ck_scope(pTHX_ OP *o) {
 888  OP *(*old_ck)(pTHX_ OP *) = 0;
 889
 890  switch (o->op_type) {
 891   case OP_SCOPE:   old_ck = indirect_old_ck_scope;   break;
 892   case OP_LINESEQ: old_ck = indirect_old_ck_lineseq; break;
 893  }
 894  o = old_ck(aTHX_ o);
 895
 896  if (indirect_hint()) {
 897   indirect_map_store(o, PL_oldbufptr - SvPVX_const(PL_linestr),
 898                         NULL, CopLINE(&PL_compiling));
 899   return o;
 900  }
 901
 902  indirect_map_delete(o);
 903  return o;
 904 }
 905
 906 /* We don't need to clean the map entries for leave ops because they can only
 907  * be created by mutating from a lineseq. */
 908
 909 /* ... ck_method ........................................................... */
 910
 911 static OP *(*indirect_old_ck_method)(pTHX_ OP *) = 0;
 912
 913 static OP *indirect_ck_method(pTHX_ OP *o) {
 914  if (indirect_hint()) {
 915   OP *op = cUNOPo->op_first;
 916
 917   /* Indirect method call is only possible when the method is a bareword, so
 918    * don't trip up on $obj->$meth. */
 919   if (op && op->op_type == OP_CONST) {
 920    const indirect_op_info_t *oi = indirect_map_fetch(op);
 921    STRLEN pos;
 922    line_t line;
 923    SV *sv;
 924
 925    if (!oi)
 926     goto done;
 927
 928    sv   = sv_2mortal(newSVpvn(oi->buf, oi->len));
 929    pos  = oi->pos;
 930    /* Keep the old line so that we really point to the first line of the
 931     * expression. */
 932    line = oi->line;
 933
 934    o = indirect_old_ck_method(aTHX_ o);
 935    /* o may now be a method_named */
 936
 937    indirect_map_store(o, pos, sv, line);
 938    return o;
 939   }
 940  }
 941
 942 done:
 943  o = indirect_old_ck_method(aTHX_ o);
 944
 945  indirect_map_delete(o);
 946  return o;
 947 }
 948
 949 /* ... ck_method_named ..................................................... */
 950
 951 /* "use foo/no foo" compiles its call to import/unimport directly to a
 952  * method_named op. */
 953
 954 static OP *(*indirect_old_ck_method_named)(pTHX_ OP *) = 0;
 955
 956 static OP *indirect_ck_method_named(pTHX_ OP *o) {
 957  if (indirect_hint()) {
 958   STRLEN pos;
 959   line_t line;
 960   SV *sv;
 961
 962   sv = cSVOPo_sv;
 963   if (!SvPOK(sv) || (SvTYPE(sv) < SVt_PV))
 964    goto done;
 965   sv = sv_mortalcopy(sv);
 966
 967   if (!indirect_find(sv, PL_oldbufptr, &pos))
 968    goto done;
 969   line = CopLINE(&PL_compiling);
 970
 971   o = indirect_old_ck_method_named(aTHX_ o);
 972
 973   indirect_map_store(o, pos, sv, line);
 974   return o;
 975  }
 976
 977 done:
 978  o = indirect_old_ck_method_named(aTHX_ o);
 979
 980  indirect_map_delete(o);
 981  return o;
 982 }
 983
 984 /* ... ck_entersub ......................................................... */
 985
 986 static OP *(*indirect_old_ck_entersub)(pTHX_ OP *) = 0;
 987
 988 static OP *indirect_ck_entersub(pTHX_ OP *o) {
 989  SV *code = indirect_hint();
 990
 991  o = indirect_old_ck_entersub(aTHX_ o);
 992
 993  if (code) {
 994   const indirect_op_info_t *moi, *ooi;
 995   OP     *mop, *oop;
 996   LISTOP *lop;
 997
 998   oop = o;
 999   do {
1000    lop = (LISTOP *) oop;
1001    if (!(lop->op_flags & OPf_KIDS))
1002     goto done;
1003    oop = lop->op_first;
1004   } while (oop->op_type != OP_PUSHMARK);
1005   oop = OpSIBLING(oop);
1006   mop = lop->op_last;
1007
1008   if (!oop)
1009    goto done;
1010
1011   switch (oop->op_type) {
1012    case OP_CONST:
1013    case OP_RV2SV:
1014    case OP_PADSV:
1015    case OP_SCOPE:
1016    case OP_LEAVE:
1017     break;
1018    default:
1019     goto done;
1020   }
1021
1022   if (mop->op_type == OP_METHOD)
1023    mop = cUNOPx(mop)->op_first;
1024   else if (mop->op_type != OP_METHOD_NAMED)
1025    goto done;
1026
1027   moi = indirect_map_fetch(mop);
1028   if (!moi)
1029    goto done;
1030
1031   ooi = indirect_map_fetch(oop);
1032   if (!ooi)
1033    goto done;
1034
1035   /* When positions are identical, the method and the object must have the
1036    * same name. But it also means that it is an indirect call, as "foo->foo"
1037    * results in different positions. */
1038   if (   moi->line < ooi->line
1039       || (moi->line == ooi->line && moi->pos <= ooi->pos)) {
1040    SV *file;
1041    dSP;
1042
1043    ENTER;
1044    SAVETMPS;
1045
1046 #ifdef USE_ITHREADS
1047    file = sv_2mortal(newSVpv(CopFILE(&PL_compiling), 0));
1048 #else
1049    file = sv_mortalcopy(CopFILESV(&PL_compiling));
1050 #endif
1051
1052    PUSHMARK(SP);
1053    EXTEND(SP, 4);
1054    mPUSHp(ooi->buf, ooi->len);
1055    mPUSHp(moi->buf, moi->len);
1056    PUSHs(file);
1057    mPUSHu(moi->line);
1058    PUTBACK;
1059
1060    indirect_call_sv(code, G_VOID);
1061
1062    PUTBACK;
1063
1064    FREETMPS;
1065    LEAVE;
1066   }
1067  }
1068
1069 done:
1070  return o;
1071 }
1072
1073 /* --- Module setup/teardown ----------------------------------------------- */
1074
1075 static void indirect_teardown(pTHX_ void *interp) {
1076  dMY_CXT;
1077
1078  I_LOADED_LOCK;
1079
1080  if (indirect_clear_loaded_locked(&MY_CXT)) {
1081   indirect_ck_restore(OP_CONST,   &indirect_old_ck_const);
1082   indirect_ck_restore(OP_RV2SV,   &indirect_old_ck_rv2sv);
1083   indirect_ck_restore(OP_PADANY,  &indirect_old_ck_padany);
1084   indirect_ck_restore(OP_SCOPE,   &indirect_old_ck_scope);
1085   indirect_ck_restore(OP_LINESEQ, &indirect_old_ck_lineseq);
1086
1087   indirect_ck_restore(OP_METHOD,       &indirect_old_ck_method);
1088   indirect_ck_restore(OP_METHOD_NAMED, &indirect_old_ck_method_named);
1089   indirect_ck_restore(OP_ENTERSUB,     &indirect_old_ck_entersub);
1090  }
1091
1092  I_LOADED_UNLOCK;
1093
1094  SvREFCNT_dec(MY_CXT.global_code);
1095  MY_CXT.global_code = NULL;
1096
1097  ptable_free(MY_CXT.map);
1098  MY_CXT.map = NULL;
1099
1100 #if I_THREADSAFE
1101  ptable_hints_free(MY_CXT.tbl);
1102  MY_CXT.tbl = NULL;
1103 #endif
1104
1105  return;
1106 }
1107
1108 static void indirect_setup(pTHX) {
1109 #define indirect_setup() indirect_setup(aTHX)
1110  MY_CXT_INIT; /* Takes/release PL_my_ctx_mutex */
1111
1112  I_LOADED_LOCK;
1113
1114  if (indirect_set_loaded_locked(&MY_CXT)) {
1115   PERL_HASH(indirect_hash, __PACKAGE__, __PACKAGE_LEN__);
1116
1117   indirect_ck_replace(OP_CONST,   indirect_ck_const,  &indirect_old_ck_const);
1118   indirect_ck_replace(OP_RV2SV,   indirect_ck_rv2sv,  &indirect_old_ck_rv2sv);
1119   indirect_ck_replace(OP_PADANY,  indirect_ck_padany, &indirect_old_ck_padany);
1120   indirect_ck_replace(OP_SCOPE,   indirect_ck_scope,  &indirect_old_ck_scope);
1121   indirect_ck_replace(OP_LINESEQ, indirect_ck_scope,  &indirect_old_ck_lineseq);
1122
1123   indirect_ck_replace(OP_METHOD,       indirect_ck_method,
1124                                        &indirect_old_ck_method);
1125   indirect_ck_replace(OP_METHOD_NAMED, indirect_ck_method_named,
1126                                        &indirect_old_ck_method_named);
1127   indirect_ck_replace(OP_ENTERSUB,     indirect_ck_entersub,
1128                                        &indirect_old_ck_entersub);
1129  }
1130
1131  I_LOADED_UNLOCK;
1132
1133  {
1134   HV *stash;
1135
1136   stash = gv_stashpvn(__PACKAGE__, __PACKAGE_LEN__, 1);
1137   newCONSTSUB(stash, "I_THREADSAFE", newSVuv(I_THREADSAFE));
1138   newCONSTSUB(stash, "I_FORKSAFE",   newSVuv(I_FORKSAFE));
1139
1140 #if I_THREADSAFE
1141   MY_CXT.tbl         = ptable_new();
1142   MY_CXT.owner       = aTHX;
1143 #endif
1144
1145   MY_CXT.map         = ptable_new();
1146   MY_CXT.global_code = NULL;
1147  }
1148
1149  call_atexit(indirect_teardown, NULL);
1150
1151  return;
1152 }
1153
1154 /* --- XS ------------------------------------------------------------------ */
1155
1156 MODULE = indirect      PACKAGE = indirect
1157
1158 PROTOTYPES: ENABLE
1159
1160 BOOT:
1161 {
1162  indirect_setup();
1163 }
1164
1165 #if I_THREADSAFE
1166
1167 void
1168 CLONE(...)
1169 PROTOTYPE: DISABLE
1170 PREINIT:
1171  ptable *t;
1172  SV     *global_code_dup;
1173 PPCODE:
1174  {
1175   indirect_ptable_clone_ud ud;
1176   dMY_CXT;
1177   t = ptable_new();
1178   indirect_ptable_clone_ud_init(ud, t, MY_CXT.owner);
1179   ptable_walk(MY_CXT.tbl, indirect_ptable_clone, &ud);
1180   global_code_dup = indirect_dup_inc(MY_CXT.global_code, &ud);
1181   indirect_ptable_clone_ud_deinit(ud);
1182  }
1183  {
1184   MY_CXT_CLONE;
1185   MY_CXT.map         = ptable_new();
1186   MY_CXT.tbl         = t;
1187   MY_CXT.owner       = aTHX;
1188   MY_CXT.global_code = global_code_dup;
1189   {
1190    int global_setup;
1191    I_LOADED_LOCK;
1192    global_setup = indirect_set_loaded_locked(&MY_CXT);
1193    assert(!global_setup);
1194    I_LOADED_UNLOCK;
1195   }
1196  }
1197  XSRETURN(0);
1198
1199 #endif /* I_THREADSAFE */
1200
1201 SV *
1202 _tag(SV *value)
1203 PROTOTYPE: $
1204 CODE:
1205  RETVAL = indirect_tag(value);
1206 OUTPUT:
1207  RETVAL
1208
1209 void
1210 _global(SV *code)
1211 PROTOTYPE: $
1212 PPCODE:
1213  if (!SvOK(code))
1214   code = NULL;
1215  else if (SvROK(code))
1216   code = SvRV(code);
1217  {
1218   dMY_CXT;
1219   SvREFCNT_dec(MY_CXT.global_code);
1220   MY_CXT.global_code = SvREFCNT_inc(code);
1221  }
1222  XSRETURN(0);