900 lines
35 KiB
C
900 lines
35 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
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╚──────────────────────────────────────────────────────────────────────────────╝
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│ │
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│ regexec.c - TRE POSIX compatible matching functions (and more). │
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│ │
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│ Copyright (c) 2001-2009 Ville Laurikari <vl@iki.fi> │
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│ All rights reserved. │
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│ │
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│ Redistribution and use in source and binary forms, with or without │
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│ modification, are permitted provided that the following conditions │
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│ are met: │
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│ │
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│ 1. Redistributions of source code must retain the above copyright │
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│ notice, this list of conditions and the following disclaimer. │
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│ │
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│ 2. Redistributions in binary form must reproduce the above copyright │
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│ notice, this list of conditions and the following disclaimer in │
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│ the documentation and/or other materials provided with the │
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│ distribution. │
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│ │
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│ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS │
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│ ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT │
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│ LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR │
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│ A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT │
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│ HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, │
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│ SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT │
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│ LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, │
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│ DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY │
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│ THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT │
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│ (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE │
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│ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. │
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│ │
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│──────────────────────────────────────────────────────────────────────────────│
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│ │
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│ Musl Libc │
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│ Copyright © 2005-2014 Rich Felker, et al. │
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│ │
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│ Permission is hereby granted, free of charge, to any person obtaining │
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│ a copy of this software and associated documentation files (the │
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│ "Software"), to deal in the Software without restriction, including │
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│ without limitation the rights to use, copy, modify, merge, publish, │
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│ distribute, sublicense, and/or sell copies of the Software, and to │
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│ permit persons to whom the Software is furnished to do so, subject to │
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│ the following conditions: │
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│ │
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│ The above copyright notice and this permission notice shall be │
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│ included in all copies or substantial portions of the Software. │
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│ │
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│ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, │
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│ EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF │
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│ MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. │
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│ IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY │
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│ CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, │
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│ TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE │
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│ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. │
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│ │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/limits.h"
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#include "third_party/regex/tre.inc"
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static void tre_fill_pmatch(size_t nmatch, regmatch_t pmatch[], int cflags,
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const tre_tnfa_t *tnfa, regoff_t *tags,
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regoff_t match_eo);
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/***********************************************************************
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from tre-match-utils.h
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***********************************************************************/
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#define GET_NEXT_WCHAR() \
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do { \
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prev_c = next_c; \
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pos += pos_add_next; \
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if ((pos_add_next = mbtowc(&next_c, str_byte, MB_LEN_MAX)) <= 0) { \
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if (pos_add_next < 0) { \
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ret = REG_NOMATCH; \
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goto error_exit; \
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} else \
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pos_add_next++; \
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} \
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str_byte += pos_add_next; \
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} while (0)
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#define IS_WORD_CHAR(c) ((c) == L'_' || tre_isalnum(c))
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#define CHECK_ASSERTIONS(assertions) \
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(((assertions & ASSERT_AT_BOL) && (pos > 0 || reg_notbol) && \
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(prev_c != L'\n' || !reg_newline)) || \
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((assertions & ASSERT_AT_EOL) && (next_c != L'\0' || reg_noteol) && \
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(next_c != L'\n' || !reg_newline)) || \
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((assertions & ASSERT_AT_BOW) && \
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(IS_WORD_CHAR(prev_c) || !IS_WORD_CHAR(next_c))) || \
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((assertions & ASSERT_AT_EOW) && \
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(!IS_WORD_CHAR(prev_c) || IS_WORD_CHAR(next_c))) || \
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((assertions & ASSERT_AT_WB) && \
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(pos != 0 && next_c != L'\0' && \
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IS_WORD_CHAR(prev_c) == IS_WORD_CHAR(next_c))) || \
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((assertions & ASSERT_AT_WB_NEG) && \
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(pos == 0 || next_c == L'\0' || \
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IS_WORD_CHAR(prev_c) != IS_WORD_CHAR(next_c))))
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#define CHECK_CHAR_CLASSES(trans_i, tnfa, eflags) \
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(((trans_i->assertions & ASSERT_CHAR_CLASS) && \
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!(tnfa->cflags & REG_ICASE) && \
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!tre_isctype((tre_cint_t)prev_c, trans_i->u.class)) || \
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((trans_i->assertions & ASSERT_CHAR_CLASS) && (tnfa->cflags & REG_ICASE) && \
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!tre_isctype(tre_tolower((tre_cint_t)prev_c), trans_i->u.class) && \
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!tre_isctype(tre_toupper((tre_cint_t)prev_c), trans_i->u.class)) || \
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((trans_i->assertions & ASSERT_CHAR_CLASS_NEG) && \
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tre_neg_char_classes_match(trans_i->neg_classes, (tre_cint_t)prev_c, \
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tnfa->cflags & REG_ICASE)))
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/* Returns 1 if `t1' wins `t2', 0 otherwise. */
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static int tre_tag_order(int num_tags, tre_tag_direction_t *tag_directions,
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regoff_t *t1, regoff_t *t2) {
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int i;
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for (i = 0; i < num_tags; i++) {
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if (tag_directions[i] == TRE_TAG_MINIMIZE) {
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if (t1[i] < t2[i]) return 1;
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if (t1[i] > t2[i]) return 0;
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} else {
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if (t1[i] > t2[i]) return 1;
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if (t1[i] < t2[i]) return 0;
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}
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}
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/* assert(0);*/
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return 0;
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}
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static int tre_neg_char_classes_match(tre_ctype_t *classes, tre_cint_t wc,
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int icase) {
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while (*classes != (tre_ctype_t)0)
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if ((!icase && tre_isctype(wc, *classes)) ||
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(icase && (tre_isctype(tre_toupper(wc), *classes) ||
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tre_isctype(tre_tolower(wc), *classes))))
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return 1; /* Match. */
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else
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classes++;
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return 0; /* No match. */
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}
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/***********************************************************************
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from tre-match-parallel.c
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***********************************************************************/
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/*
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This algorithm searches for matches basically by reading characters
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in the searched string one by one, starting at the beginning. All
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matching paths in the TNFA are traversed in parallel. When two or
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more paths reach the same state, exactly one is chosen according to
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tag ordering rules; if returning submatches is not required it does
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not matter which path is chosen.
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The worst case time required for finding the leftmost and longest
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match, or determining that there is no match, is always linearly
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dependent on the length of the text being searched.
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This algorithm cannot handle TNFAs with back referencing nodes.
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See `tre-match-backtrack.c'.
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*/
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typedef struct {
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tre_tnfa_transition_t *state;
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regoff_t *tags;
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} tre_tnfa_reach_t;
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typedef struct {
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regoff_t pos;
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regoff_t **tags;
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} tre_reach_pos_t;
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static reg_errcode_t tre_tnfa_run_parallel(const tre_tnfa_t *tnfa,
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const void *string,
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regoff_t *match_tags, int eflags,
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regoff_t *match_end_ofs) {
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/* State variables required by GET_NEXT_WCHAR. */
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tre_char_t prev_c = 0, next_c = 0;
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const char *str_byte = string;
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regoff_t pos = -1;
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regoff_t pos_add_next = 1;
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#ifdef TRE_MBSTATE
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mbstate_t mbstate;
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#endif /* TRE_MBSTATE */
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int reg_notbol = eflags & REG_NOTBOL;
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int reg_noteol = eflags & REG_NOTEOL;
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int reg_newline = tnfa->cflags & REG_NEWLINE;
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reg_errcode_t ret;
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char *buf;
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tre_tnfa_transition_t *trans_i;
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tre_tnfa_reach_t *reach, *reach_next, *reach_i, *reach_next_i;
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tre_reach_pos_t *reach_pos;
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int *tag_i;
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int num_tags, i;
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regoff_t match_eo = -1; /* end offset of match (-1 if no match found yet) */
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int new_match = 0;
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regoff_t *tmp_tags = NULL;
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regoff_t *tmp_iptr;
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#ifdef TRE_MBSTATE
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memset(&mbstate, '\0', sizeof(mbstate));
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#endif /* TRE_MBSTATE */
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if (!match_tags)
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num_tags = 0;
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else
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num_tags = tnfa->num_tags;
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/* Allocate memory for temporary data required for matching. This needs to
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be done for every matching operation to be thread safe. This allocates
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everything in a single large block with calloc(). */
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{
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size_t tbytes, rbytes, pbytes, xbytes, total_bytes;
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char *tmp_buf;
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/* Ensure that tbytes and xbytes*num_states cannot overflow, and that
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* they don't contribute more than 1/8 of SIZE_MAX to total_bytes. */
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if (num_tags > SIZE_MAX / (8 * sizeof(regoff_t) * tnfa->num_states))
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return REG_ESPACE;
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/* Likewise check rbytes. */
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if (tnfa->num_states + 1 > SIZE_MAX / (8 * sizeof(*reach_next)))
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return REG_ESPACE;
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/* Likewise check pbytes. */
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if (tnfa->num_states > SIZE_MAX / (8 * sizeof(*reach_pos)))
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return REG_ESPACE;
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/* Compute the length of the block we need. */
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tbytes = sizeof(*tmp_tags) * num_tags;
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rbytes = sizeof(*reach_next) * (tnfa->num_states + 1);
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pbytes = sizeof(*reach_pos) * tnfa->num_states;
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xbytes = sizeof(regoff_t) * num_tags;
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total_bytes = (sizeof(long) - 1) * 4 /* for alignment paddings */
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+ (rbytes + xbytes * tnfa->num_states) * 2 + tbytes + pbytes;
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/* Allocate the memory. */
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buf = calloc(total_bytes, 1);
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if (buf == NULL) return REG_ESPACE;
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/* Get the various pointers within tmp_buf (properly aligned). */
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tmp_tags = (void *)buf;
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tmp_buf = buf + tbytes;
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tmp_buf += ALIGN(tmp_buf, long);
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reach_next = (void *)tmp_buf;
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tmp_buf += rbytes;
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tmp_buf += ALIGN(tmp_buf, long);
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reach = (void *)tmp_buf;
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tmp_buf += rbytes;
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tmp_buf += ALIGN(tmp_buf, long);
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reach_pos = (void *)tmp_buf;
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tmp_buf += pbytes;
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tmp_buf += ALIGN(tmp_buf, long);
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for (i = 0; i < tnfa->num_states; i++) {
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reach[i].tags = (void *)tmp_buf;
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tmp_buf += xbytes;
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reach_next[i].tags = (void *)tmp_buf;
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tmp_buf += xbytes;
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}
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}
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for (i = 0; i < tnfa->num_states; i++) reach_pos[i].pos = -1;
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GET_NEXT_WCHAR();
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pos = 0;
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reach_next_i = reach_next;
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while (1) {
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/* If no match found yet, add the initial states to `reach_next'. */
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if (match_eo < 0) {
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trans_i = tnfa->initial;
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while (trans_i->state != NULL) {
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if (reach_pos[trans_i->state_id].pos < pos) {
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if (trans_i->assertions && CHECK_ASSERTIONS(trans_i->assertions)) {
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trans_i++;
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continue;
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}
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reach_next_i->state = trans_i->state;
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for (i = 0; i < num_tags; i++) reach_next_i->tags[i] = -1;
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tag_i = trans_i->tags;
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if (tag_i)
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while (*tag_i >= 0) {
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if (*tag_i < num_tags) reach_next_i->tags[*tag_i] = pos;
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tag_i++;
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}
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if (reach_next_i->state == tnfa->final) {
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match_eo = pos;
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new_match = 1;
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for (i = 0; i < num_tags; i++)
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match_tags[i] = reach_next_i->tags[i];
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}
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reach_pos[trans_i->state_id].pos = pos;
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reach_pos[trans_i->state_id].tags = &reach_next_i->tags;
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reach_next_i++;
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}
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trans_i++;
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}
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reach_next_i->state = NULL;
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} else {
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if (num_tags == 0 || reach_next_i == reach_next)
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/* We have found a match. */
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break;
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}
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/* Check for end of string. */
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if (!next_c) break;
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GET_NEXT_WCHAR();
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/* Swap `reach' and `reach_next'. */
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reach_i = reach;
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reach = reach_next;
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reach_next = reach_i;
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/* For each state in `reach', weed out states that don't fulfill the
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minimal matching conditions. */
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if (tnfa->num_minimals && new_match) {
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new_match = 0;
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reach_next_i = reach_next;
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for (reach_i = reach; reach_i->state; reach_i++) {
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int skip = 0;
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for (i = 0; tnfa->minimal_tags[i] >= 0; i += 2) {
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int end = tnfa->minimal_tags[i];
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int start = tnfa->minimal_tags[i + 1];
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if (end >= num_tags) {
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skip = 1;
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break;
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} else if (reach_i->tags[start] == match_tags[start] &&
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reach_i->tags[end] < match_tags[end]) {
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skip = 1;
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break;
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}
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}
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if (!skip) {
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reach_next_i->state = reach_i->state;
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tmp_iptr = reach_next_i->tags;
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reach_next_i->tags = reach_i->tags;
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reach_i->tags = tmp_iptr;
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reach_next_i++;
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}
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}
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reach_next_i->state = NULL;
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/* Swap `reach' and `reach_next'. */
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reach_i = reach;
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reach = reach_next;
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reach_next = reach_i;
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}
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/* For each state in `reach' see if there is a transition leaving with
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the current input symbol to a state not yet in `reach_next', and
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add the destination states to `reach_next'. */
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reach_next_i = reach_next;
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for (reach_i = reach; reach_i->state; reach_i++) {
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for (trans_i = reach_i->state; trans_i->state; trans_i++) {
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/* Does this transition match the input symbol? */
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if (trans_i->code_min <= (tre_cint_t)prev_c &&
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trans_i->code_max >= (tre_cint_t)prev_c) {
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if (trans_i->assertions &&
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(CHECK_ASSERTIONS(trans_i->assertions) ||
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CHECK_CHAR_CLASSES(trans_i, tnfa, eflags))) {
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continue;
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}
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/* Compute the tags after this transition. */
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for (i = 0; i < num_tags; i++) tmp_tags[i] = reach_i->tags[i];
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tag_i = trans_i->tags;
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if (tag_i != NULL)
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while (*tag_i >= 0) {
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if (*tag_i < num_tags) tmp_tags[*tag_i] = pos;
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tag_i++;
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}
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if (reach_pos[trans_i->state_id].pos < pos) {
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/* Found an unvisited node. */
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reach_next_i->state = trans_i->state;
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tmp_iptr = reach_next_i->tags;
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reach_next_i->tags = tmp_tags;
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tmp_tags = tmp_iptr;
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reach_pos[trans_i->state_id].pos = pos;
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reach_pos[trans_i->state_id].tags = &reach_next_i->tags;
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if (reach_next_i->state == tnfa->final &&
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(match_eo == -1 ||
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(num_tags > 0 && reach_next_i->tags[0] <= match_tags[0]))) {
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match_eo = pos;
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new_match = 1;
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for (i = 0; i < num_tags; i++)
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match_tags[i] = reach_next_i->tags[i];
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}
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reach_next_i++;
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} else {
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assert(reach_pos[trans_i->state_id].pos == pos);
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/* Another path has also reached this state. We choose
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the winner by examining the tag values for both
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paths. */
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if (tre_tag_order(num_tags, tnfa->tag_directions, tmp_tags,
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*reach_pos[trans_i->state_id].tags)) {
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/* The new path wins. */
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tmp_iptr = *reach_pos[trans_i->state_id].tags;
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*reach_pos[trans_i->state_id].tags = tmp_tags;
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if (trans_i->state == tnfa->final) {
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match_eo = pos;
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new_match = 1;
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for (i = 0; i < num_tags; i++) match_tags[i] = tmp_tags[i];
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}
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tmp_tags = tmp_iptr;
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}
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}
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}
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}
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}
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reach_next_i->state = NULL;
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}
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*match_end_ofs = match_eo;
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ret = match_eo >= 0 ? REG_OK : REG_NOMATCH;
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error_exit:
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free(buf), buf = NULL;
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return ret;
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}
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/***********************************************************************
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from tre-match-backtrack.c
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***********************************************************************/
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/*
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This matcher is for regexps that use back referencing. Regexp matching
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with back referencing is an NP-complete problem on the number of back
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references. The easiest way to match them is to use a backtracking
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routine which basically goes through all possible paths in the TNFA
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and chooses the one which results in the best (leftmost and longest)
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match. This can be spectacularly expensive and may run out of stack
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space, but there really is no better known generic algorithm. Quoting
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Henry Spencer from comp.compilers:
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<URL: http://compilers.iecc.com/comparch/article/93-03-102>
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POSIX.2 REs require longest match, which is really exciting to
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implement since the obsolete ("basic") variant also includes
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\<digit>. I haven't found a better way of tackling this than doing
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a preliminary match using a DFA (or simulation) on a modified RE
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that just replicates subREs for \<digit>, and then doing a
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|
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.)
|
|
|
|
*/
|
|
|
|
typedef struct {
|
|
regoff_t pos;
|
|
const char *str_byte;
|
|
tre_tnfa_transition_t *state;
|
|
int state_id;
|
|
int next_c;
|
|
regoff_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_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 */
|
|
|
|
#define tre_bt_mem_new tre_mem_new
|
|
#define tre_bt_mem_alloc tre_mem_alloc
|
|
#define tre_bt_mem_destroy tre_mem_destroy
|
|
|
|
#define BT_STACK_PUSH(_pos, _str_byte, _str_wide, _state, _state_id, _next_c, \
|
|
_tags, _mbstate) \
|
|
do { \
|
|
int i; \
|
|
if (!stack->next) { \
|
|
tre_backtrack_t s; \
|
|
s = tre_bt_mem_alloc(mem, sizeof(*s)); \
|
|
if (!s) { \
|
|
tre_bt_mem_destroy(mem); \
|
|
if (tags) free(tags), tags = NULL; \
|
|
if (pmatch) free(pmatch), pmatch = NULL; \
|
|
if (states_seen) free(states_seen), states_seen = NULL; \
|
|
return REG_ESPACE; \
|
|
} \
|
|
s->prev = stack; \
|
|
s->next = NULL; \
|
|
s->item.tags = tre_bt_mem_alloc(mem, sizeof(*tags) * tnfa->num_tags); \
|
|
if (!s->item.tags) { \
|
|
tre_bt_mem_destroy(mem); \
|
|
if (tags) free(tags), tags = NULL; \
|
|
if (pmatch) free(pmatch), pmatch = NULL; \
|
|
if (states_seen) free(states_seen), states_seen = NULL; \
|
|
return REG_ESPACE; \
|
|
} \
|
|
stack->next = s; \
|
|
stack = s; \
|
|
} else \
|
|
stack = stack->next; \
|
|
stack->item.pos = (_pos); \
|
|
stack->item.str_byte = (_str_byte); \
|
|
stack->item.state = (_state); \
|
|
stack->item.state_id = (_state_id); \
|
|
stack->item.next_c = (_next_c); \
|
|
for (i = 0; i < tnfa->num_tags; i++) stack->item.tags[i] = (_tags)[i]; \
|
|
BT_STACK_MBSTATE_IN; \
|
|
} while (0)
|
|
|
|
#define BT_STACK_POP() \
|
|
do { \
|
|
int i; \
|
|
assert(stack->prev); \
|
|
pos = stack->item.pos; \
|
|
str_byte = stack->item.str_byte; \
|
|
state = stack->item.state; \
|
|
next_c = stack->item.next_c; \
|
|
for (i = 0; i < tnfa->num_tags; i++) tags[i] = stack->item.tags[i]; \
|
|
BT_STACK_MBSTATE_OUT; \
|
|
stack = stack->prev; \
|
|
} while (0)
|
|
|
|
#undef MIN
|
|
#define MIN(a, b) ((a) <= (b) ? (a) : (b))
|
|
|
|
static reg_errcode_t tre_tnfa_run_backtrack(const tre_tnfa_t *tnfa,
|
|
const void *string,
|
|
regoff_t *match_tags, int eflags,
|
|
regoff_t *match_end_ofs) {
|
|
/* State variables required by GET_NEXT_WCHAR. */
|
|
tre_char_t prev_c = 0, next_c = 0;
|
|
const char *str_byte = string;
|
|
regoff_t pos = 0;
|
|
regoff_t pos_add_next = 1;
|
|
#ifdef TRE_MBSTATE
|
|
mbstate_t mbstate;
|
|
#endif /* TRE_MBSTATE */
|
|
int reg_notbol = eflags & REG_NOTBOL;
|
|
int reg_noteol = eflags & REG_NOTEOL;
|
|
int reg_newline = tnfa->cflags & REG_NEWLINE;
|
|
|
|
/* 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;
|
|
regoff_t pos_start = -1;
|
|
#ifdef TRE_MBSTATE
|
|
mbstate_t mbstate_start;
|
|
#endif /* TRE_MBSTATE */
|
|
|
|
/* End offset of best match so far, or -1 if no match found yet. */
|
|
regoff_t match_eo = -1;
|
|
/* Tag arrays. */
|
|
int *next_tags;
|
|
regoff_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;
|
|
int ret;
|
|
|
|
#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;
|
|
|
|
if (tnfa->num_tags) {
|
|
tags = malloc(sizeof(*tags) * tnfa->num_tags);
|
|
if (!tags) {
|
|
ret = REG_ESPACE;
|
|
goto error_exit;
|
|
}
|
|
}
|
|
if (tnfa->num_submatches) {
|
|
pmatch = malloc(sizeof(*pmatch) * tnfa->num_submatches);
|
|
if (!pmatch) {
|
|
ret = REG_ESPACE;
|
|
goto error_exit;
|
|
}
|
|
}
|
|
if (tnfa->num_states) {
|
|
states_seen = malloc(sizeof(*states_seen) * tnfa->num_states);
|
|
if (!states_seen) {
|
|
ret = REG_ESPACE;
|
|
goto error_exit;
|
|
}
|
|
}
|
|
|
|
retry : {
|
|
int i;
|
|
for (i = 0; i < tnfa->num_tags; i++) {
|
|
tags[i] = -1;
|
|
if (match_tags) match_tags[i] = -1;
|
|
}
|
|
for (i = 0; i < tnfa->num_states; i++) states_seen[i] = 0;
|
|
}
|
|
|
|
state = NULL;
|
|
pos = pos_start;
|
|
GET_NEXT_WCHAR();
|
|
pos_start = pos;
|
|
next_c_start = next_c;
|
|
str_byte_start = str_byte;
|
|
#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++) {
|
|
if (trans_i->assertions && CHECK_ASSERTIONS(trans_i->assertions)) {
|
|
continue;
|
|
}
|
|
if (state == NULL) {
|
|
/* Start from this state. */
|
|
state = trans_i->state;
|
|
next_tags = trans_i->tags;
|
|
} else {
|
|
/* Backtrack to this state. */
|
|
BT_STACK_PUSH(pos, str_byte, 0, trans_i->state, trans_i->state_id, next_c,
|
|
tags, mbstate);
|
|
{
|
|
int *tmp = trans_i->tags;
|
|
if (tmp)
|
|
while (*tmp >= 0) stack->item.tags[*tmp++] = pos;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (next_tags)
|
|
for (; *next_tags >= 0; next_tags++) tags[*next_tags] = pos;
|
|
|
|
if (state == NULL) goto backtrack;
|
|
|
|
while (1) {
|
|
tre_tnfa_transition_t *next_state;
|
|
int empty_br_match;
|
|
|
|
if (state == tnfa->final) {
|
|
if (match_eo < pos || (match_eo == pos && match_tags &&
|
|
tre_tag_order(tnfa->num_tags, tnfa->tag_directions,
|
|
tags, match_tags))) {
|
|
int i;
|
|
/* This match wins the previous match. */
|
|
match_eo = pos;
|
|
if (match_tags)
|
|
for (i = 0; i < tnfa->num_tags; i++) match_tags[i] = tags[i];
|
|
}
|
|
/* Our TNFAs never have transitions leaving from the final state,
|
|
so we jump right to backtracking. */
|
|
goto backtrack;
|
|
}
|
|
|
|
/* 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. */
|
|
regoff_t so, eo;
|
|
int bt = trans_i->u.backref;
|
|
regoff_t bt_len;
|
|
int result;
|
|
|
|
/* Get the substring we need to match against. Remember to
|
|
turn off REG_NOSUB temporarily. */
|
|
tre_fill_pmatch(bt + 1, pmatch, tnfa->cflags & ~REG_NOSUB, tnfa, tags,
|
|
pos);
|
|
so = pmatch[bt].rm_so;
|
|
eo = pmatch[bt].rm_eo;
|
|
bt_len = eo - so;
|
|
|
|
result = strncmp((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]) {
|
|
goto backtrack;
|
|
}
|
|
|
|
states_seen[trans_i->state_id] = empty_br_match;
|
|
|
|
/* Advance in input string and resync `prev_c', `next_c'
|
|
and pos. */
|
|
str_byte += bt_len - 1;
|
|
pos += bt_len - 1;
|
|
GET_NEXT_WCHAR();
|
|
} else {
|
|
goto backtrack;
|
|
}
|
|
} else {
|
|
/* Check for end of string. */
|
|
if (next_c == L'\0') goto backtrack;
|
|
|
|
/* Read the next character. */
|
|
GET_NEXT_WCHAR();
|
|
}
|
|
|
|
next_state = NULL;
|
|
for (trans_i = state; trans_i->state; trans_i++) {
|
|
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))) {
|
|
continue;
|
|
}
|
|
|
|
if (next_state == NULL) {
|
|
/* First matching transition. */
|
|
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. */
|
|
BT_STACK_PUSH(pos, str_byte, 0, trans_i->state, trans_i->state_id,
|
|
next_c, tags, mbstate);
|
|
{
|
|
int *tmp;
|
|
for (tmp = trans_i->tags; tmp && *tmp >= 0; tmp++)
|
|
stack->item.tags[*tmp] = pos;
|
|
}
|
|
#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) tags[*next_tags++] = pos;
|
|
} else {
|
|
backtrack:
|
|
/* A matching transition was not found. Try to backtrack. */
|
|
if (stack->prev) {
|
|
if (stack->item.state->assertions & ASSERT_BACKREF) {
|
|
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 (next_c == L'\0') {
|
|
break;
|
|
}
|
|
next_c = next_c_start;
|
|
#ifdef TRE_MBSTATE
|
|
mbstate = mbstate_start;
|
|
#endif /* TRE_MBSTATE */
|
|
str_byte = str_byte_start;
|
|
goto retry;
|
|
} else {
|
|
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 (tags) free(tags), tags = NULL;
|
|
if (pmatch) free(pmatch), pmatch = NULL;
|
|
if (states_seen) free(states_seen), states_seen = NULL;
|
|
#endif /* !TRE_USE_ALLOCA */
|
|
|
|
return ret;
|
|
}
|
|
|
|
/***********************************************************************
|
|
from regexec.c
|
|
***********************************************************************/
|
|
|
|
/* Fills the POSIX.2 regmatch_t array according to the TNFA tag and match
|
|
endpoint values. */
|
|
static void tre_fill_pmatch(size_t nmatch, regmatch_t pmatch[], int cflags,
|
|
const tre_tnfa_t *tnfa, regoff_t *tags,
|
|
regoff_t match_eo) {
|
|
tre_submatch_data_t *submatch_data;
|
|
unsigned int i, j;
|
|
int *parents;
|
|
|
|
i = 0;
|
|
if (match_eo >= 0 && !(cflags & REG_NOSUB)) {
|
|
/* Construct submatch offsets from the tags. */
|
|
submatch_data = tnfa->submatch_data;
|
|
while (i < tnfa->num_submatches && i < nmatch) {
|
|
if (submatch_data[i].so_tag == tnfa->end_tag)
|
|
pmatch[i].rm_so = match_eo;
|
|
else
|
|
pmatch[i].rm_so = tags[submatch_data[i].so_tag];
|
|
|
|
if (submatch_data[i].eo_tag == tnfa->end_tag)
|
|
pmatch[i].rm_eo = match_eo;
|
|
else
|
|
pmatch[i].rm_eo = tags[submatch_data[i].eo_tag];
|
|
|
|
/* If either of the endpoints were not used, this submatch
|
|
was not part of the match. */
|
|
if (pmatch[i].rm_so == -1 || pmatch[i].rm_eo == -1)
|
|
pmatch[i].rm_so = pmatch[i].rm_eo = -1;
|
|
|
|
i++;
|
|
}
|
|
/* Reset all submatches that are not within all of their parent
|
|
submatches. */
|
|
i = 0;
|
|
while (i < tnfa->num_submatches && i < nmatch) {
|
|
if (pmatch[i].rm_eo == -1) assert(pmatch[i].rm_so == -1);
|
|
assert(pmatch[i].rm_so <= pmatch[i].rm_eo);
|
|
|
|
parents = submatch_data[i].parents;
|
|
if (parents != NULL)
|
|
for (j = 0; parents[j] >= 0; j++) {
|
|
if (pmatch[i].rm_so < pmatch[parents[j]].rm_so ||
|
|
pmatch[i].rm_eo > pmatch[parents[j]].rm_eo)
|
|
pmatch[i].rm_so = pmatch[i].rm_eo = -1;
|
|
}
|
|
i++;
|
|
}
|
|
}
|
|
|
|
while (i < nmatch) {
|
|
pmatch[i].rm_so = -1;
|
|
pmatch[i].rm_eo = -1;
|
|
i++;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Executes regular expression.
|
|
*
|
|
* @param preg is state object previously made by regcomp()
|
|
* @param eflags can have REG_NOTBOL, REG_NOTEOL
|
|
* @return 0 or REG_NOMATCH
|
|
*/
|
|
int regexec(const regex_t *preg, const char *string, size_t nmatch,
|
|
regmatch_t pmatch[nmatch], int eflags) {
|
|
tre_tnfa_t *tnfa = (void *)preg->TRE_REGEX_T_FIELD;
|
|
reg_errcode_t status;
|
|
regoff_t *tags = NULL, eo;
|
|
if (tnfa->cflags & REG_NOSUB) nmatch = 0;
|
|
if (tnfa->num_tags > 0 && nmatch > 0) {
|
|
tags = malloc(sizeof(*tags) * tnfa->num_tags);
|
|
if (tags == NULL) return REG_ESPACE;
|
|
}
|
|
/* Dispatch to the appropriate matcher. */
|
|
if (tnfa->have_backrefs) {
|
|
/* The regex has back references, use the backtracking matcher. */
|
|
status = tre_tnfa_run_backtrack(tnfa, string, tags, eflags, &eo);
|
|
} else {
|
|
/* Exact matching, no back references, use the parallel matcher. */
|
|
status = tre_tnfa_run_parallel(tnfa, string, tags, eflags, &eo);
|
|
}
|
|
if (status == REG_OK) /* A match was found, so fill the submatch registers. */
|
|
tre_fill_pmatch(nmatch, pmatch, tnfa->cflags, tnfa, tags, eo);
|
|
if (tags) free(tags), tags = NULL;
|
|
return status;
|
|
}
|