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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 | /* tre-match-backtrack.c - TRE backtracking regex matching engine This software is released under a BSD-style license. See the file LICENSE for details and copyright. */ /* This matcher is for regexps that use back referencing. Regexp matching with back referencing is an NP-complete problem on the number of back references. The easiest way to match them is to use a backtracking routine which basically goes through all possible paths in the TNFA and chooses the one which results in the best (leftmost and longest) match. This can be spectacularly expensive and may run out of stack space, but there really is no better known generic algorithm. Quoting Henry Spencer from comp.compilers: <URL: http://compilers.iecc.com/comparch/article/93-03-102> POSIX.2 REs require longest match, which is really exciting to implement since the obsolete ("basic") variant also includes \<digit>. I haven't found a better way of tackling this than doing a preliminary match using a DFA (or simulation) on a modified RE that just replicates subREs for \<digit>, and then doing a backtracking match to determine whether the subRE matches were right. This can be rather slow, but I console myself with the thought that people who use \<digit> deserve very slow execution. (Pun unintentional but very appropriate.) */ #ifdef HAVE_CONFIG_H #include <config.h> #endif /* HAVE_CONFIG_H */ /* Unset TRE_USE_ALLOCA to avoid using the stack to hold all the state info while running */ #undef TRE_USE_ALLOCA #ifdef TRE_USE_ALLOCA /* AIX requires this to be the first thing in the file. */ #ifndef __GNUC__ # if HAVE_ALLOCA_H # include <alloca.h> # else # ifdef _AIX #pragma alloca # else # ifndef alloca /* predefined by HP cc +Olibcalls */ char *alloca (); # endif # endif # endif #endif #endif /* TRE_USE_ALLOCA */ #include <assert.h> #include <stdlib.h> #include <string.h> #ifdef HAVE_WCHAR_H #include <wchar.h> #endif /* HAVE_WCHAR_H */ #ifdef HAVE_WCTYPE_H #include <wctype.h> #endif /* HAVE_WCTYPE_H */ #ifndef TRE_WCHAR #include <ctype.h> #endif /* !TRE_WCHAR */ #ifdef HAVE_MALLOC_H #include <malloc.h> #endif /* HAVE_MALLOC_H */ #include "tre-internal.h" #include "tre-mem.h" #include "tre-match-utils.h" #include "tre.h" #include "xmalloc.h" typedef struct { int pos; unsigned int pos_add_next; const char *str_byte; #ifdef TRE_WCHAR const wchar_t *str_wide; #endif /* TRE_WCHAR */ tre_tnfa_transition_t *state; int state_id; int next_c; tre_tag_t *tags; #ifdef TRE_MBSTATE mbstate_t mbstate; #endif /* TRE_MBSTATE */ } tre_backtrack_item_t; typedef struct tre_backtrack_struct { tre_backtrack_item_t item; struct tre_backtrack_struct *prev; struct tre_backtrack_struct *next; } *tre_backtrack_t; #ifdef TRE_WCHAR #define BT_STACK_WIDE_IN(_str_wide) stack->item.str_wide = (_str_wide) #define BT_STACK_WIDE_OUT (str_wide) = stack->item.str_wide #else /* !TRE_WCHAR */ #define BT_STACK_WIDE_IN(_str_wide) #define BT_STACK_WIDE_OUT #endif /* !TRE_WCHAR */ #ifdef TRE_MBSTATE #define BT_STACK_MBSTATE_IN stack->item.mbstate = (mbstate) #define BT_STACK_MBSTATE_OUT (mbstate) = stack->item.mbstate #else /* !TRE_MBSTATE */ #define BT_STACK_MBSTATE_IN #define BT_STACK_MBSTATE_OUT #endif /* !TRE_MBSTATE */ #ifdef TRE_USE_ALLOCA #define tre_bt_mem_new tre_mem_newa #define tre_bt_mem_alloc tre_mem_alloca #define tre_bt_mem_destroy(obj) do { } while (0) #else /* !TRE_USE_ALLOCA */ #define tre_bt_mem_new tre_mem_new #define tre_bt_mem_alloc tre_mem_alloc #define tre_bt_mem_destroy tre_mem_destroy #endif /* !TRE_USE_ALLOCA */ #define BT_STACK_PUSH(_pos, _pos_add_next, _str_byte, _str_wide, _state, _state_id, _next_c, _tags, _mbstate) \ do \ { \ if (!stack->next) \ { \ tre_backtrack_t s; \ s = tre_bt_mem_alloc(mem, sizeof(*s)); \ if (!s) \ { \ tre_bt_mem_destroy(mem); \ if (tags) \ xfree(tags); \ if (pmatch) \ xfree(pmatch); \ if (states_seen) \ xfree(states_seen); \ return REG_ESPACE; \ } \ s->prev = stack; \ s->next = NULL; \ s->item.tags = tre_bt_mem_alloc(mem, \ num_tags * sizeof(*tags)); \ if (!s->item.tags) \ { \ tre_bt_mem_destroy(mem); \ if (tags) \ xfree(tags); \ if (pmatch) \ xfree(pmatch); \ if (states_seen) \ xfree(states_seen); \ return REG_ESPACE; \ } \ stack->next = s; \ stack = s; \ } \ else \ stack = stack->next; \ stack->item.pos = (_pos); \ stack->item.pos_add_next = (_pos_add_next); \ stack->item.str_byte = (_str_byte); \ BT_STACK_WIDE_IN(_str_wide); \ stack->item.state = (_state); \ stack->item.state_id = (_state_id); \ stack->item.next_c = (_next_c); \ memcpy(stack->item.tags, (_tags), num_tags * sizeof(*(_tags))); \ BT_STACK_MBSTATE_IN; \ } \ while (/*CONSTCOND*/0) #ifdef TRE_STR_USER #define BT_STACK_POP() \ do \ { \ assert(stack->prev); \ pos = stack->item.pos; \ pos_add_next = stack->item.pos_add_next; \ if (type == STR_USER) \ str_source->rewind(pos + pos_add_next, str_source->context); \ str_byte = stack->item.str_byte; \ BT_STACK_WIDE_OUT; \ state = stack->item.state; \ next_c = stack->item.next_c; \ memcpy(tags, stack->item.tags, num_tags * sizeof(*tags)); \ BT_STACK_MBSTATE_OUT; \ stack = stack->prev; \ } \ while (/*CONSTCOND*/0) #else /* !TRE_STR_USER */ #define BT_STACK_POP() \ do \ { \ assert(stack->prev); \ pos = stack->item.pos; \ pos_add_next = stack->item.pos_add_next; \ str_byte = stack->item.str_byte; \ BT_STACK_WIDE_OUT; \ state = stack->item.state; \ next_c = stack->item.next_c; \ memcpy(tags, stack->item.tags, num_tags * sizeof(*tags)); \ BT_STACK_MBSTATE_OUT; \ stack = stack->prev; \ } \ while (/*CONSTCOND*/0) #endif /* !TRE_STR_USER */ #undef MIN #define MIN(a, b) ((a) <= (b) ? (a) : (b)) reg_errcode_t tre_tnfa_run_backtrack(const tre_tnfa_t *tnfa, const void *string, int len, tre_str_type_t type, tre_tag_t *match_tags, int eflags, int *match_end_ofs) { /* State variables required by GET_NEXT_WCHAR. */ tre_char_t prev_c = 0, next_c = 0; const char *str_byte = string; int pos = 0; unsigned int pos_add_next = 1; #ifdef TRE_WCHAR const wchar_t *str_wide = string; #ifdef TRE_MBSTATE mbstate_t mbstate; #endif /* TRE_MBSTATE */ #endif /* TRE_WCHAR */ int reg_notbol = eflags & REG_NOTBOL; int reg_noteol = eflags & REG_NOTEOL; int reg_newline = tnfa->cflags & REG_NEWLINE; #ifdef TRE_STR_USER int str_user_end = 0; #endif /* TRE_STR_USER */ int i; /* These are used to remember the necessary values of the above variables to return to the position where the current search started from. */ int next_c_start; const char *str_byte_start; int pos_start = -1; #ifdef TRE_WCHAR const wchar_t *str_wide_start; #endif /* TRE_WCHAR */ #ifdef TRE_MBSTATE mbstate_t mbstate_start; #endif /* TRE_MBSTATE */ /* End offset of best match so far, or -1 if no match found yet. */ int match_eo = -1; /* Tag arrays. */ int *next_tags; tre_tag_t *tags = NULL; /* Current TNFA state. */ tre_tnfa_transition_t *state; int *states_seen = NULL; /* Memory allocator to for allocating the backtracking stack. */ tre_mem_t mem = tre_bt_mem_new(); /* The backtracking stack. */ tre_backtrack_t stack; tre_tnfa_transition_t *trans_i; regmatch_t *pmatch = NULL; reg_errcode_t ret; int num_tags = tnfa->num_tags; int touch = 1; char *buf = NULL; int tbytes; #ifdef TRE_MBSTATE memset(&mbstate, '\0', sizeof(mbstate)); #endif /* TRE_MBSTATE */ if (!mem) return REG_ESPACE; stack = tre_bt_mem_alloc(mem, sizeof(*stack)); if (!stack) { ret = REG_ESPACE; goto error_exit; } stack->prev = NULL; stack->next = NULL; DPRINT(("tnfa_execute_backtrack, input type %d\n", type)); DPRINT(("len = %d\n", len)); { int pbytes, sbytes, total_bytes; char *tmp_buf; /* Compute the length of the block we need. */ tbytes = sizeof(*tags) * num_tags; pbytes = sizeof(*pmatch) * tnfa->num_submatches; sbytes = sizeof(*states_seen) * tnfa->num_states; total_bytes = (sizeof(long) - 1) * 2 /* for alignment paddings */ + tbytes + pbytes + sbytes; DPRINT(("tre_tnfa_run_backtrack, allocate %d bytes\n", total_bytes)); /* Allocate the memory. */ #ifdef TRE_USE_ALLOCA buf = alloca(total_bytes); #else /* !TRE_USE_ALLOCA */ buf = xmalloc((unsigned)total_bytes); #endif /* !TRE_USE_ALLOCA */ if (buf == NULL) return REG_ESPACE; /* Get the various pointers within tmp_buf (properly aligned). */ tags = (void *)buf; tmp_buf = buf + tbytes; tmp_buf += ALIGN(tmp_buf, long); pmatch = (void *)tmp_buf; tmp_buf += pbytes; tmp_buf += ALIGN(tmp_buf, long); states_seen = (void *)tmp_buf; } retry: { memset(tags, 0, num_tags * sizeof(*tags)); if (match_tags) memset(match_tags, 0, num_tags * sizeof(*match_tags)); for (i = 0; i < tnfa->num_states; i++) states_seen[i] = 0; } state = NULL; pos = pos_start; #ifdef TRE_STR_USER if (type == STR_USER) str_source->rewind(pos + pos_add_next, str_source->context); #endif /* TRE_STR_USER */ GET_NEXT_WCHAR(); pos_start = pos; next_c_start = next_c; str_byte_start = str_byte; #ifdef TRE_WCHAR str_wide_start = str_wide; #endif /* TRE_WCHAR */ #ifdef TRE_MBSTATE mbstate_start = mbstate; #endif /* TRE_MBSTATE */ /* Handle initial states. */ next_tags = NULL; for (trans_i = tnfa->initial; trans_i->state; trans_i++) { DPRINT(("> init %p, prev_c %lc\n", trans_i->state, (tre_cint_t)prev_c)); if (trans_i->assertions && CHECK_ASSERTIONS(trans_i->assertions)) { DPRINT(("assert failed\n")); continue; } if (state == NULL) { /* Start from this state. */ state = trans_i->state; next_tags = trans_i->tags; } else { /* Backtrack to this state. */ DPRINT(("saving state %d for backtracking\n", trans_i->state_id)); BT_STACK_PUSH(pos, pos_add_next, str_byte, str_wide, trans_i->state, trans_i->state_id, next_c, tags, mbstate); { int *tmp = trans_i->tags; if (tmp) { while (*tmp >= 0) tre_tag_set(stack->item.tags, *tmp++, pos, touch); touch++; } } } } if (next_tags) { for (; *next_tags >= 0; next_tags++) tre_tag_set(tags, *next_tags, pos, touch); touch++; } DPRINT(("entering match loop, pos %d, str_byte %p\n", pos, str_byte)); DPRINT(("pos:chr/code | state and tags\n")); DPRINT(("-------------+------------------------------------------------\n")); if (state == NULL) goto backtrack; while (/*CONSTCOND*/1) { tre_tnfa_transition_t *next_state; int empty_br_match; DPRINT(("start loop\n")); if (match_eo >= 0 && tnfa->num_minimals) { int skip = 0; #ifdef TRE_DEBUG DPRINT(("Checking minimal conditions: match_eo=%d match_tags=", match_eo)); tre_print_tags(match_tags, tnfa->num_tags); DPRINT(("\n")); #endif /* TRE_DEBUG */ for (i = 0; tnfa->minimal_tags[i] >= 0; i += 2) { int end = tnfa->minimal_tags[i]; int start = tnfa->minimal_tags[i + 1]; DPRINT((" Minimal start %d, end %d\n", start, end)); if (tre_minimal_tag_order(start, end, match_tags, tags) > 0) { skip = 1; break; } } if (!skip) { #ifdef TRE_DEBUG DPRINT((" Keeping tags=")); tre_print_tags(tags, tnfa->num_tags); DPRINT(("\n")); #endif /* TRE_DEBUG */ } else { #ifdef TRE_DEBUG DPRINT((" Throwing out tags=")); tre_print_tags(tags, tnfa->num_tags); DPRINT(("\n")); #endif /* TRE_DEBUG */ goto backtrack; } } if (state == tnfa->final) { DPRINT((" match found, match_eo=%d pos=%d\n", match_eo, pos)); if (match_eo >= 0 && tnfa->num_minimals) { int compare = 0; #ifdef TRE_DEBUG DPRINT(("Checking minimal conditions: match_eo=%d " "match_tags=", match_eo)); tre_print_tags(match_tags, tnfa->num_tags); DPRINT(("\n")); #endif /* TRE_DEBUG */ for (i = 0; tnfa->minimal_tags[i] >= 0; i += 2) { int end = tnfa->minimal_tags[i]; int start = tnfa->minimal_tags[i + 1]; DPRINT((" Minimal start %d, end %d\n", start, end)); if ((compare = tre_minimal_tag_order(start, end, match_tags, tags)) != 0) break; } if (compare > 0) { #ifdef TRE_DEBUG DPRINT((" Throwing out new match, tags=")); tre_print_tags(tags, tnfa->num_tags); DPRINT(("\n")); #endif /* TRE_DEBUG */ goto backtrack; } else if (compare < 0) { #ifdef TRE_DEBUG DPRINT((" Throwing out old match, tags=")); tre_print_tags(match_tags, tnfa->num_tags); DPRINT(("\n")); #endif /* TRE_DEBUG */ match_eo = -1; } } if (match_eo < pos || (match_eo == pos && match_tags && tre_tag_order(tnfa->num_tags, tnfa->tag_directions, tags, match_tags))) { /* This match wins the previous match. */ #ifdef TRE_DEBUG DPRINT((" win previous tags=")); tre_print_tags(tags, tnfa->num_tags); DPRINT(("\n")); #endif /* TRE_DEBUG */ match_eo = pos; if (match_tags) memcpy(match_tags, tags, num_tags * sizeof(*tags)); } /* Our TNFAs never have transitions leaving from the final state, so we jump right to backtracking. */ goto backtrack; } #ifdef TRE_DEBUG DPRINT(("%3d:%2lc/%05d | %p ", pos, (tre_cint_t)next_c, (int)next_c, state)); tre_print_tags(tags, tnfa->num_tags); DPRINT(("\n")); #endif /* TRE_DEBUG */ /* Go to the next character in the input string. */ empty_br_match = 0; trans_i = state; if (trans_i->state && trans_i->assertions & ASSERT_BACKREF) { /* This is a back reference state. All transitions leaving from this state have the same back reference "assertion". Instead of reading the next character, we match the back reference. */ int so, eo, bt = trans_i->u.backref; int bt_len; int result; DPRINT((" should match back reference %d\n", bt)); /* Get the substring we need to match against. Remember to turn off REG_NOSUB temporarily. */ ret = tre_fill_pmatch(bt + 1, pmatch, tnfa->cflags & ~REG_NOSUB, tnfa, tags, pos); if (ret != REG_OK) goto error_exit; so = pmatch[bt].rm_so; eo = pmatch[bt].rm_eo; bt_len = eo - so; #ifdef TRE_DEBUG { int slen; if (len < 0) slen = bt_len; else slen = MIN(bt_len, len - pos); if (type == STR_BYTE) { DPRINT((" substring (len %d) is [%d, %d]: '%.*s'\n", bt_len, so, eo, bt_len, (char*)string + so)); DPRINT((" current string is '%.*s'\n", slen, str_byte - 1)); } #ifdef TRE_WCHAR else if (type == STR_WIDE) { DPRINT((" substring (len %d) is [%d, %d]: '%.*" STRF "'\n", bt_len, so, eo, bt_len, (wchar_t*)string + so)); DPRINT((" current string is '%.*" STRF "'\n", slen, str_wide - 1)); } #endif /* TRE_WCHAR */ } #endif if (so < 0) { result = 1; /* Back reference of nomatch doesn't match */ } else if (len < 0) { #ifdef TRE_STR_USER if (type == STR_USER) result = str_source->compare((unsigned)so, (unsigned)pos, (unsigned)bt_len, str_source->context); else #endif /* TRE_STR_USER */ #ifdef TRE_WCHAR if (type == STR_WIDE) result = wcsncmp((const wchar_t*)string + so, str_wide - 1, (size_t)bt_len); else #endif /* TRE_WCHAR */ result = strncmp((const char*)string + so, str_byte - 1, (size_t)bt_len); } else if (len - pos < bt_len) result = 1; #ifdef TRE_WCHAR else if (type == STR_WIDE) result = wmemcmp((const wchar_t*)string + so, str_wide - 1, (size_t)bt_len); #endif /* TRE_WCHAR */ else result = memcmp((const char*)string + so, str_byte - 1, (size_t)bt_len); if (result == 0) { /* Back reference matched. Check for infinite loop. */ if (bt_len == 0) empty_br_match = 1; if (empty_br_match && states_seen[trans_i->state_id]) { DPRINT((" avoid loop\n")); goto backtrack; } states_seen[trans_i->state_id] = empty_br_match; /* Advance in input string and resync `prev_c', `next_c' and pos. */ DPRINT((" back reference matched\n")); str_byte += bt_len - 1; #ifdef TRE_WCHAR str_wide += bt_len - 1; #endif /* TRE_WCHAR */ pos += bt_len - 1; GET_NEXT_WCHAR(); DPRINT((" pos now %d\n", pos)); } else { DPRINT((" back reference did not match\n")); goto backtrack; } } else { /* Check for end of string. */ if (len < 0) { #ifdef TRE_STR_USER if (type == STR_USER) { if (str_user_end) goto backtrack; } else #endif /* TRE_STR_USER */ if (next_c == L'\0') goto backtrack; } else { if (pos >= len) goto backtrack; } /* Read the next character. */ GET_NEXT_WCHAR(); } next_state = NULL; for (trans_i = state; trans_i->state; trans_i++) { DPRINT((" transition %d-%d (%c-%c) %d to %d\n", trans_i->code_min, trans_i->code_max, trans_i->code_min, trans_i->code_max, trans_i->assertions, trans_i->state_id)); if (trans_i->code_min <= (tre_cint_t)prev_c && trans_i->code_max >= (tre_cint_t)prev_c) { if (trans_i->assertions && (CHECK_ASSERTIONS(trans_i->assertions) || CHECK_CHAR_CLASSES(trans_i, tnfa, eflags))) { DPRINT((" assertion failed\n")); continue; } if (next_state == NULL) { /* First matching transition. */ DPRINT((" Next state is %d\n", trans_i->state_id)); next_state = trans_i->state; next_tags = trans_i->tags; } else { /* Second matching transition. We may need to backtrack here to take this transition instead of the first one, so we push this transition in the backtracking stack so we can jump back here if needed. */ DPRINT((" saving state %d for backtracking\n", trans_i->state_id)); BT_STACK_PUSH(pos, pos_add_next, str_byte, str_wide, trans_i->state, trans_i->state_id, next_c, tags, mbstate); { int *tmp; for (tmp = trans_i->tags; tmp && *tmp >= 0; tmp++) tre_tag_set(stack->item.tags, *tmp, pos, touch); touch++; } #if 0 /* XXX - it's important not to look at all transitions here to keep the stack small! */ break; #endif } } } if (next_state != NULL) { /* Matching transitions were found. Take the first one. */ state = next_state; /* Update the tag values. */ if (next_tags) { while (*next_tags >= 0) tre_tag_set(tags, *next_tags++, pos, touch); touch++; } } else { backtrack: /* A matching transition was not found. Try to backtrack. */ if (stack->prev) { DPRINT((" backtracking\n")); if (stack->item.state->assertions & ASSERT_BACKREF) { DPRINT((" states_seen[%d] = 0\n", stack->item.state_id)); states_seen[stack->item.state_id] = 0; } BT_STACK_POP(); } else if (match_eo < 0) { /* Try starting from a later position in the input string. */ /* Check for end of string. */ if (pos == pos_start) { if (len < 0) { if (next_c == L'\0') { DPRINT(("end of string.\n")); break; } } else { if (pos >= len) { DPRINT(("end of string.\n")); break; } } } DPRINT(("restarting from next start position\n")); next_c = next_c_start; #ifdef TRE_MBSTATE mbstate = mbstate_start; #endif /* TRE_MBSTATE */ str_byte = str_byte_start; #ifdef TRE_WCHAR str_wide = str_wide_start; #endif /* TRE_WCHAR */ goto retry; } else { DPRINT(("finished\n")); break; } } } ret = match_eo >= 0 ? REG_OK : REG_NOMATCH; *match_end_ofs = match_eo; error_exit: tre_bt_mem_destroy(mem); #ifndef TRE_USE_ALLOCA if (buf) xfree(buf); #endif /* !TRE_USE_ALLOCA */ return ret; } |