1268 lines
39 KiB
C
1268 lines
39 KiB
C
/****************************************************************************
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* libs/libc/regex/regexec.c
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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 the
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* documentation and/or other materials provided with the 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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* Included Files
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****************************************************************************/
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#include <stdlib.h>
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#include <string.h>
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#include <wchar.h>
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#include <wctype.h>
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#include <limits.h>
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#include <regex.h>
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#include "tre.h"
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#include <assert.h>
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/****************************************************************************
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* Private Functions
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****************************************************************************/
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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, int *tags, int match_eo);
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/* from tre-match-utils.h
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*/
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#define GET_NEXT_WCHAR() do { \
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prev_c = next_c;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){ ret = REG_NOMATCH;goto error_exit; } \
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else 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) \
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&& (pos > 0 || reg_notbol) \
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&& (prev_c != L'\n' || !reg_newline)) \
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|| ((assertions & ASSERT_AT_EOL) \
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&& (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) \
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&& (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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int *t1, int *t2)
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{
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int i;
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for (i = 0; i < num_tags; i++)
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{
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if (tag_directions[i] == TRE_TAG_MINIMIZE)
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{
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if (t1[i] < t2[i])
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{
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return 1;
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}
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if (t1[i] > t2[i])
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{
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return 0;
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}
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}
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else
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{
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if (t1[i] > t2[i])
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{
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return 1;
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}
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if (t1[i] < t2[i])
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{
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return 0;
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}
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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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{
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while (*classes != (tre_ctype_t)0)
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{
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if ((!icase &&
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tre_isctype(wc,
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*classes)) ||
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(icase &&
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(tre_isctype(tre_toupper(wc),
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*classes) || tre_isctype(tre_tolower(wc),
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*classes))))
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{
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return 1; /* Match. */
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}
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else
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{
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classes++;
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}
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}
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return 0; /* No match. */
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}
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/* from tre-match-parallel.c
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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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*
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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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*
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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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{
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tre_tnfa_transition_t *state;
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int *tags;
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} tre_tnfa_reach_t;
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typedef struct
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{
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int pos;
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int **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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int *match_tags, int eflags,
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int *match_end_ofs)
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{
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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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int pos = -1;
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int 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;
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int i;
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int match_eo = -1; /* end offset of match (-1 if no
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* match found yet) */
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int new_match = 0;
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int *tmp_tags = NULL;
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int *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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{
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num_tags = 0;
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}
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else
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{
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num_tags = tnfa->num_tags;
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}
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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 from the stack frame using alloca()
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* or with malloc() if alloca is unavailable.
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*/
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{
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int tbytes;
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int rbytes;
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int pbytes;
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int xbytes;
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int total_bytes;
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char *tmp_buf;
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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(int) * 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 +
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pbytes;
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/* Allocate the memory. */
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buf = xmalloc((unsigned)total_bytes);
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if (buf == NULL)
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{
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return REG_ESPACE;
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}
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memset(buf, 0, (size_t)total_bytes);
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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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{
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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++)
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{
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reach_pos[i].pos = -1;
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}
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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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{
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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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{
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trans_i = tnfa->initial;
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while (trans_i->state != NULL)
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{
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if (reach_pos[trans_i->state_id].pos < pos)
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{
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if (trans_i->assertions &&
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CHECK_ASSERTIONS(trans_i->assertions))
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{
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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++)
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{
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reach_next_i->tags[i] = -1;
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}
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tag_i = trans_i->tags;
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if (tag_i)
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{
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while (*tag_i >= 0)
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{
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if (*tag_i < num_tags)
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{
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reach_next_i->tags[*tag_i] = pos;
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}
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tag_i++;
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}
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}
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if (reach_next_i->state == tnfa->final)
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{
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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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{
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match_tags[i] = reach_next_i->tags[i];
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}
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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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}
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else
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{
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if (num_tags == 0 || reach_next_i == reach_next)
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{
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/* We have found a match. */
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break;
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}
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}
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/* Check for end of string. */
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if (!next_c)
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{
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break;
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}
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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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*/
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if (tnfa->num_minimals && new_match)
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{
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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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{
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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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{
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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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{
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skip = 1;
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break;
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}
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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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{
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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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{
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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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*/
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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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{
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for (trans_i = reach_i->state; trans_i->state; trans_i++)
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{
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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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{
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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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{
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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++)
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{
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tmp_tags[i] = reach_i->tags[i];
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}
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tag_i = trans_i->tags;
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if (tag_i != NULL)
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{
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while (*tag_i >= 0)
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{
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if (*tag_i < num_tags)
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{
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tmp_tags[*tag_i] = pos;
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}
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|
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tag_i++;
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}
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}
|
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|
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if (reach_pos[trans_i->state_id].pos < pos)
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{
|
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/* Found an unvisited node. */
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|
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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 =
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&reach_next_i->tags;
|
|
|
|
if (reach_next_i->state == tnfa->final &&
|
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(match_eo == -1 ||
|
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(num_tags > 0 &&
|
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reach_next_i->tags[0] <= match_tags[0])))
|
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{
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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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{
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match_tags[i] = reach_next_i->tags[i];
|
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}
|
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}
|
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|
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reach_next_i++;
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}
|
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|
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else
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{
|
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ASSERT(reach_pos[trans_i->state_id].pos == pos);
|
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|
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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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*/
|
|
|
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if (tre_tag_order(num_tags, tnfa->tag_directions,
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tmp_tags,
|
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*reach_pos[trans_i->state_id].tags))
|
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{
|
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/* The new path wins. */
|
|
|
|
tmp_iptr =
|
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*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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{
|
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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] = tmp_tags[i];
|
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}
|
|
}
|
|
|
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tmp_tags = tmp_iptr;
|
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}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
reach_next_i->state = NULL;
|
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}
|
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|
|
*match_end_ofs = match_eo;
|
|
ret = match_eo >= 0 ? REG_OK : REG_NOMATCH;
|
|
error_exit:
|
|
xfree(buf);
|
|
return ret;
|
|
}
|
|
|
|
/* from tre-match-backtrack.c
|
|
*/
|
|
|
|
/* 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.)
|
|
*
|
|
*/
|
|
|
|
typedef struct
|
|
{
|
|
int pos;
|
|
const char *str_byte;
|
|
tre_tnfa_transition_t *state;
|
|
int state_id;
|
|
int next_c;
|
|
int *tags;
|
|
#ifdef TRE_MBSTATE
|
|
mbstate_t mbstate;
|
|
#endif /* TRE_MBSTATE */
|
|
} tre_backtrack_item_t;
|
|
|
|
struct tre_backtrack_struct
|
|
{
|
|
tre_backtrack_item_t item;
|
|
struct tre_backtrack_struct *prev;
|
|
struct tre_backtrack_struct *next;
|
|
};
|
|
|
|
typedef struct tre_backtrack_struct *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) \
|
|
{ \
|
|
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, \
|
|
sizeof(*tags) * tnfa->num_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.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,
|
|
int *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;
|
|
int 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;
|
|
int 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. */
|
|
|
|
int match_eo = -1;
|
|
|
|
/* Tag arrays. */
|
|
|
|
int *next_tags;
|
|
int *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 = xmalloc(sizeof(*tags) * tnfa->num_tags);
|
|
if (!tags)
|
|
{
|
|
ret = REG_ESPACE;
|
|
goto error_exit;
|
|
}
|
|
}
|
|
|
|
if (tnfa->num_submatches)
|
|
{
|
|
pmatch = xmalloc(sizeof(*pmatch) * tnfa->num_submatches);
|
|
if (!pmatch)
|
|
{
|
|
ret = REG_ESPACE;
|
|
goto error_exit;
|
|
}
|
|
}
|
|
|
|
if (tnfa->num_states)
|
|
{
|
|
states_seen = xmalloc(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.
|
|
*/
|
|
|
|
int so;
|
|
int eo;
|
|
int bt = trans_i->u.backref;
|
|
int 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)
|
|
{
|
|
xfree(tags);
|
|
}
|
|
|
|
if (pmatch)
|
|
{
|
|
xfree(pmatch);
|
|
}
|
|
|
|
if (states_seen)
|
|
{
|
|
xfree(states_seen);
|
|
}
|
|
#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, int *tags, int match_eo)
|
|
{
|
|
tre_submatch_data_t *submatch_data;
|
|
unsigned int i;
|
|
unsigned int 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++;
|
|
}
|
|
}
|
|
|
|
/* Wrapper functions for POSIX compatible regexp matching.
|
|
*/
|
|
|
|
int regexec(const regex_t *restrict preg, const char *restrict string,
|
|
size_t nmatch, regmatch_t pmatch[restrict], int eflags)
|
|
{
|
|
tre_tnfa_t *tnfa = (void *)preg->TRE_REGEX_T_FIELD;
|
|
reg_errcode_t status;
|
|
int *tags = NULL;
|
|
int eo;
|
|
|
|
if (tnfa->cflags & REG_NOSUB)
|
|
{
|
|
nmatch = 0;
|
|
}
|
|
|
|
if (tnfa->num_tags > 0 && nmatch > 0)
|
|
{
|
|
tags = xmalloc(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)
|
|
{
|
|
xfree(tags);
|
|
}
|
|
|
|
return status;
|
|
}
|