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freebsd-dev/usr.bin/grep/regex/tre-fastmatch.c
Dimitry Andric 00f060000f Fix a segfault in bsdgrep when parsing the invalid extended regexps "?" 
or "+" (these are invalid, because there is no preceding operand).

When bsdgrep attempts to emulate GNU grep in discarding and ignoring the
invalid ? or + operators, some later logic in tre_compile_fast() goes
beyond the end of the buffer, leading to a crash.

Fix this by bailing out, and reporting a bad pattern instead.

Reported by:	Steve Kargl
MFC after:	1 week
2016-08-02 20:25:22 +00:00

1043 lines
28 KiB
C
Raw Blame History

/* $FreeBSD$ */
/*-
* Copyright (c) 1999 James Howard and Dag-Erling Coïdan Smørgrav
* Copyright (C) 2008-2011 Gabor Kovesdan <gabor@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "glue.h"
#include <ctype.h>
#include <limits.h>
#include <regex.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#ifdef TRE_WCHAR
#include <wchar.h>
#include <wctype.h>
#endif
#include "hashtable.h"
#include "tre-fastmatch.h"
#include "xmalloc.h"
static int fastcmp(const fastmatch_t *fg, const void *data,
tre_str_type_t type);
/*
* Clean up if pattern compilation fails.
*/
#define FAIL_COMP(errcode) \
{ \
if (fg->pattern) \
xfree(fg->pattern); \
if (fg->wpattern) \
xfree(fg->wpattern); \
if (fg->qsBc_table) \
hashtable_free(fg->qsBc_table); \
fg = NULL; \
return errcode; \
}
/*
* Skips n characters in the input string and assigns the start
* address to startptr. Note: as per IEEE Std 1003.1-2008
* matching is based on bit pattern not character representations
* so we can handle MB strings as byte sequences just like
* SB strings.
*/
#define SKIP_CHARS(n) \
switch (type) \
{ \
case STR_WIDE: \
startptr = str_wide + n; \
break; \
default: \
startptr = str_byte + n; \
}
/*
* Converts the wide string pattern to SB/MB string and stores
* it in fg->pattern. Sets fg->len to the byte length of the
* converted string.
*/
#define STORE_MBS_PAT \
{ \
size_t siz; \
\
siz = wcstombs(NULL, fg->wpattern, 0); \
if (siz == (size_t)-1) \
return REG_BADPAT; \
fg->len = siz; \
fg->pattern = xmalloc(siz + 1); \
if (fg->pattern == NULL) \
return REG_ESPACE; \
wcstombs(fg->pattern, fg->wpattern, siz); \
fg->pattern[siz] = '\0'; \
} \
#define IS_OUT_OF_BOUNDS \
((!fg->reversed \
? ((type == STR_WIDE) ? ((j + fg->wlen) > len) \
: ((j + fg->len) > len)) \
: (j < 0)))
/*
* Checks whether the new position after shifting in the input string
* is out of the bounds and break out from the loop if so.
*/
#define CHECKBOUNDS \
if (IS_OUT_OF_BOUNDS) \
break; \
/*
* Shifts in the input string after a mismatch. The position of the
* mismatch is stored in the mismatch variable.
*/
#define SHIFT \
CHECKBOUNDS; \
\
{ \
int r = -1; \
unsigned int bc = 0, gs = 0, ts; \
\
switch (type) \
{ \
case STR_WIDE: \
if (!fg->hasdot) \
{ \
if (u != 0 && (unsigned)mismatch == fg->wlen - 1 - shift) \
mismatch -= u; \
v = fg->wlen - 1 - mismatch; \
r = hashtable_get(fg->qsBc_table, \
&str_wide[!fg->reversed ? (size_t)j + fg->wlen \
: (size_t)j - 1], &bc); \
gs = fg->bmGs[mismatch]; \
} \
bc = (r == HASH_OK) ? bc : fg->defBc; \
DPRINT(("tre_fast_match: mismatch on character" CHF ", " \
"BC %d, GS %d\n", \
((const tre_char_t *)startptr)[mismatch + 1], \
bc, gs)); \
break; \
default: \
if (!fg->hasdot) \
{ \
if (u != 0 && (unsigned)mismatch == fg->len - 1 - shift) \
mismatch -= u; \
v = fg->len - 1 - mismatch; \
gs = fg->sbmGs[mismatch]; \
} \
bc = fg->qsBc[((const unsigned char *)str_byte) \
[!fg->reversed ? (size_t)j + fg->len \
: (size_t)j - 1]]; \
DPRINT(("tre_fast_match: mismatch on character %c, " \
"BC %d, GS %d\n", \
((const unsigned char *)startptr)[mismatch + 1], \
bc, gs)); \
} \
if (fg->hasdot) \
shift = bc; \
else \
{ \
ts = (u >= v) ? (u - v) : 0; \
shift = MAX(ts, bc); \
shift = MAX(shift, gs); \
if (shift == gs) \
u = MIN((type == STR_WIDE ? fg->wlen : fg->len) - shift, v); \
else \
{ \
if (ts < bc) \
shift = MAX(shift, u + 1); \
u = 0; \
} \
} \
DPRINT(("tre_fast_match: shifting %u characters\n", shift)); \
j = !fg->reversed ? j + shift : j - shift; \
}
/*
* Normal Quick Search would require a shift based on the position the
* next character after the comparison is within the pattern. With
* wildcards, the position of the last dot effects the maximum shift
* distance.
* The closer to the end the wild card is the slower the search.
*
* Examples:
* Pattern Max shift
* ------- ---------
* this 5
* .his 4
* t.is 3
* th.s 2
* thi. 1
*/
/*
* Fills in the bad character shift array for SB/MB strings.
*/
#define FILL_QSBC \
if (fg->reversed) \
{ \
_FILL_QSBC_REVERSED \
} \
else \
{ \
_FILL_QSBC \
}
#define _FILL_QSBC \
for (unsigned int i = 0; i <= UCHAR_MAX; i++) \
fg->qsBc[i] = fg->len - hasdot; \
for (unsigned int i = hasdot + 1; i < fg->len; i++) \
{ \
fg->qsBc[(unsigned char)fg->pattern[i]] = fg->len - i; \
DPRINT(("BC shift for char %c is %zu\n", fg->pattern[i], \
fg->len - i)); \
if (fg->icase) \
{ \
char c = islower((unsigned char)fg->pattern[i]) ? \
toupper((unsigned char)fg->pattern[i]) : \
tolower((unsigned char)fg->pattern[i]); \
fg->qsBc[(unsigned char)c] = fg->len - i; \
DPRINT(("BC shift for char %c is %zu\n", c, fg->len - i)); \
} \
}
#define _FILL_QSBC_REVERSED \
for (unsigned int i = 0; i <= UCHAR_MAX; i++) \
fg->qsBc[i] = firstdot + 1; \
for (int i = firstdot - 1; i >= 0; i--) \
{ \
fg->qsBc[(unsigned char)fg->pattern[i]] = i + 1; \
DPRINT(("Reverse BC shift for char %c is %d\n", fg->pattern[i], \
i + 1)); \
if (fg->icase) \
{ \
char c = islower((unsigned char)fg->pattern[i]) ? \
toupper((unsigned char)fg->pattern[i]) : \
tolower((unsigned char)fg->pattern[i]); \
fg->qsBc[(unsigned char)c] = i + 1; \
DPRINT(("Reverse BC shift for char %c is %d\n", c, i + 1)); \
} \
}
/*
* Fills in the bad character shifts into a hastable for wide strings.
* With wide characters it is not possible any more to use a normal
* array because there are too many characters and we could not
* provide enough memory. Fortunately, we only have to store distinct
* values for so many characters as the number of distinct characters
* in the pattern, so we can store them in a hashtable and store a
* default shift value for the rest.
*/
#define FILL_QSBC_WIDE \
if (fg->reversed) \
{ \
_FILL_QSBC_WIDE_REVERSED \
} \
else \
{ \
_FILL_QSBC_WIDE \
}
#define _FILL_QSBC_WIDE \
/* Adjust the shift based on location of the last dot ('.'). */ \
fg->defBc = fg->wlen - whasdot; \
\
/* Preprocess pattern. */ \
fg->qsBc_table = hashtable_init(fg->wlen * (fg->icase ? 8 : 4), \
sizeof(tre_char_t), sizeof(int)); \
if (!fg->qsBc_table) \
FAIL_COMP(REG_ESPACE); \
for (unsigned int i = whasdot + 1; i < fg->wlen; i++) \
{ \
int k = fg->wlen - i; \
int r; \
\
r = hashtable_put(fg->qsBc_table, &fg->wpattern[i], &k); \
if ((r == HASH_FAIL) || (r == HASH_FULL)) \
FAIL_COMP(REG_ESPACE); \
DPRINT(("BC shift for wide char " CHF " is %d\n", fg->wpattern[i],\
k)); \
if (fg->icase) \
{ \
tre_char_t wc = iswlower(fg->wpattern[i]) ? \
towupper(fg->wpattern[i]) : towlower(fg->wpattern[i]); \
r = hashtable_put(fg->qsBc_table, &wc, &k); \
if ((r == HASH_FAIL) || (r == HASH_FULL)) \
FAIL_COMP(REG_ESPACE); \
DPRINT(("BC shift for wide char " CHF " is %d\n", wc, k)); \
} \
}
#define _FILL_QSBC_WIDE_REVERSED \
/* Adjust the shift based on location of the last dot ('.'). */ \
fg->defBc = (size_t)wfirstdot; \
\
/* Preprocess pattern. */ \
fg->qsBc_table = hashtable_init(fg->wlen * (fg->icase ? 8 : 4), \
sizeof(tre_char_t), sizeof(int)); \
if (!fg->qsBc_table) \
FAIL_COMP(REG_ESPACE); \
for (int i = wfirstdot - 1; i >= 0; i--) \
{ \
int k = i + 1; \
int r; \
\
r = hashtable_put(fg->qsBc_table, &fg->wpattern[i], &k); \
if ((r == HASH_FAIL) || (r == HASH_FULL)) \
FAIL_COMP(REG_ESPACE); \
DPRINT(("Reverse BC shift for wide char " CHF " is %d\n", \
fg->wpattern[i], k)); \
if (fg->icase) \
{ \
tre_char_t wc = iswlower(fg->wpattern[i]) ? \
towupper(fg->wpattern[i]) : towlower(fg->wpattern[i]); \
r = hashtable_put(fg->qsBc_table, &wc, &k); \
if ((r == HASH_FAIL) || (r == HASH_FULL)) \
FAIL_COMP(REG_ESPACE); \
DPRINT(("Reverse BC shift for wide char " CHF " is %d\n", wc, \
k)); \
} \
}
#ifdef _GREP_DEBUG
#define DPRINT_BMGS(len, fmt_str, sh) \
for (unsigned int i = 0; i < len; i++) \
DPRINT((fmt_str, i, sh[i]));
#else
#define DPRINT_BMGS(len, fmt_str, sh) \
do { } while(/*CONSTCOND*/0)
#endif
/*
* Fills in the good suffix table for SB/MB strings.
*/
#define FILL_BMGS \
if (!fg->hasdot) \
{ \
fg->sbmGs = xmalloc(fg->len * sizeof(int)); \
if (!fg->sbmGs) \
return REG_ESPACE; \
if (fg->len == 1) \
fg->sbmGs[0] = 1; \
else \
_FILL_BMGS(fg->sbmGs, fg->pattern, fg->len, false); \
DPRINT_BMGS(fg->len, "GS shift for pos %d is %d\n", fg->sbmGs); \
}
/*
* Fills in the good suffix table for wide strings.
*/
#define FILL_BMGS_WIDE \
if (!fg->hasdot) \
{ \
fg->bmGs = xmalloc(fg->wlen * sizeof(int)); \
if (!fg->bmGs) \
return REG_ESPACE; \
if (fg->wlen == 1) \
fg->bmGs[0] = 1; \
else \
_FILL_BMGS(fg->bmGs, fg->wpattern, fg->wlen, true); \
DPRINT_BMGS(fg->wlen, "GS shift (wide) for pos %d is %d\n", \
fg->bmGs); \
}
#define _FILL_BMGS(arr, pat, plen, wide) \
{ \
char *p; \
tre_char_t *wp; \
\
if (wide) \
{ \
if (fg->icase) \
{ \
wp = xmalloc(plen * sizeof(tre_char_t)); \
if (wp == NULL) \
return REG_ESPACE; \
for (unsigned int i = 0; i < plen; i++) \
wp[i] = towlower(pat[i]); \
_CALC_BMGS(arr, wp, plen); \
xfree(wp); \
} \
else \
_CALC_BMGS(arr, pat, plen); \
} \
else \
{ \
if (fg->icase) \
{ \
p = xmalloc(plen); \
if (p == NULL) \
return REG_ESPACE; \
for (unsigned int i = 0; i < plen; i++) \
p[i] = tolower((unsigned char)pat[i]); \
_CALC_BMGS(arr, p, plen); \
xfree(p); \
} \
else \
_CALC_BMGS(arr, pat, plen); \
} \
}
#define _CALC_BMGS(arr, pat, plen) \
{ \
int f = 0, g; \
\
int *suff = xmalloc(plen * sizeof(int)); \
if (suff == NULL) \
return REG_ESPACE; \
\
suff[plen - 1] = plen; \
g = plen - 1; \
for (int i = plen - 2; i >= 0; i--) \
{ \
if (i > g && suff[i + plen - 1 - f] < i - g) \
suff[i] = suff[i + plen - 1 - f]; \
else \
{ \
if (i < g) \
g = i; \
f = i; \
while (g >= 0 && pat[g] == pat[g + plen - 1 - f]) \
g--; \
suff[i] = f - g; \
} \
} \
\
for (unsigned int i = 0; i < plen; i++) \
arr[i] = plen; \
g = 0; \
for (int i = plen - 1; i >= 0; i--) \
if (suff[i] == i + 1) \
for(; (unsigned long)g < plen - 1 - i; g++) \
if (arr[g] == plen) \
arr[g] = plen - 1 - i; \
for (unsigned int i = 0; i <= plen - 2; i++) \
arr[plen - 1 - suff[i]] = plen - 1 - i; \
\
xfree(suff); \
}
/*
* Copies the pattern pat having length n to p and stores
* the size in l.
*/
#define SAVE_PATTERN(src, srclen, dst, dstlen) \
dstlen = srclen; \
dst = xmalloc((dstlen + 1) * sizeof(tre_char_t)); \
if (dst == NULL) \
return REG_ESPACE; \
if (dstlen > 0) \
memcpy(dst, src, dstlen * sizeof(tre_char_t)); \
dst[dstlen] = TRE_CHAR('\0');
/*
* Initializes pattern compiling.
*/
#define INIT_COMP \
/* Initialize. */ \
memset(fg, 0, sizeof(*fg)); \
fg->icase = (cflags & REG_ICASE); \
fg->word = (cflags & REG_WORD); \
fg->newline = (cflags & REG_NEWLINE); \
fg->nosub = (cflags & REG_NOSUB); \
\
/* Cannot handle REG_ICASE with MB string */ \
if (fg->icase && (TRE_MB_CUR_MAX > 1) && n > 0) \
{ \
DPRINT(("Cannot use fast matcher for MBS with REG_ICASE\n")); \
return REG_BADPAT; \
}
/*
* Checks whether we have a 0-length pattern that will match
* anything. If literal is set to false, the EOL anchor is also
* taken into account.
*/
#define CHECK_MATCHALL(literal) \
if (!literal && n == 1 && pat[0] == TRE_CHAR('$')) \
{ \
n--; \
fg->eol = true; \
} \
\
if (n == 0) \
{ \
fg->matchall = true; \
fg->pattern = xmalloc(sizeof(char)); \
if (!fg->pattern) \
FAIL_COMP(REG_ESPACE); \
fg->pattern[0] = '\0'; \
fg->wpattern = xmalloc(sizeof(tre_char_t)); \
if (!fg->wpattern) \
FAIL_COMP(REG_ESPACE); \
fg->wpattern[0] = TRE_CHAR('\0'); \
DPRINT(("Matching every input\n")); \
return REG_OK; \
}
/*
* Returns: REG_OK on success, error code otherwise
*/
int
tre_compile_literal(fastmatch_t *fg, const tre_char_t *pat, size_t n,
int cflags)
{
size_t hasdot = 0, whasdot = 0;
ssize_t firstdot = -1, wfirstdot = -1;
INIT_COMP;
CHECK_MATCHALL(true);
/* Cannot handle word boundaries with MB string */
if (fg->word && (TRE_MB_CUR_MAX > 1))
return REG_BADPAT;
#ifdef TRE_WCHAR
SAVE_PATTERN(pat, n, fg->wpattern, fg->wlen);
STORE_MBS_PAT;
#else
SAVE_PATTERN(pat, n, fg->pattern, fg->len);
#endif
DPRINT(("tre_compile_literal: pattern: %s, len %zu, icase: %c, word: %c, "
"newline %c\n", fg->pattern, fg->len, fg->icase ? 'y' : 'n',
fg->word ? 'y' : 'n', fg->newline ? 'y' : 'n'));
FILL_QSBC;
FILL_BMGS;
#ifdef TRE_WCHAR
FILL_QSBC_WIDE;
FILL_BMGS_WIDE;
#endif
return REG_OK;
}
/*
* Returns: REG_OK on success, error code otherwise
*/
int
tre_compile_fast(fastmatch_t *fg, const tre_char_t *pat, size_t n,
int cflags)
{
tre_char_t *tmp;
size_t pos = 0, hasdot = 0, whasdot = 0;
ssize_t firstdot = -1, wfirstdot = -1;
bool escaped = false;
bool *_escmap = NULL;
INIT_COMP;
/* Remove beginning-of-line character ('^'). */
if (pat[0] == TRE_CHAR('^'))
{
fg->bol = true;
n--;
pat++;
}
CHECK_MATCHALL(false);
/* Handle word-boundary matching when GNU extensions are enabled */
if ((cflags & REG_GNU) && (n >= 14) &&
(memcmp(pat, TRE_CHAR("[[:<:]]"), 7 * sizeof(tre_char_t)) == 0) &&
(memcmp(pat + n - 7, TRE_CHAR("[[:>:]]"),
7 * sizeof(tre_char_t)) == 0))
{
n -= 14;
pat += 7;
fg->word = true;
}
/* Cannot handle word boundaries with MB string */
if (fg->word && (TRE_MB_CUR_MAX > 1))
return REG_BADPAT;
tmp = xmalloc((n + 1) * sizeof(tre_char_t));
if (tmp == NULL)
return REG_ESPACE;
/* Copies the char into the stored pattern and skips to the next char. */
#define STORE_CHAR \
do \
{ \
tmp[pos++] = pat[i]; \
escaped = false; \
continue; \
} while (0)
/* Traverse the input pattern for processing */
for (unsigned int i = 0; i < n; i++)
{
switch (pat[i])
{
case TRE_CHAR('\\'):
if (escaped)
STORE_CHAR;
else if (i == n - 1)
goto badpat;
else
escaped = true;
continue;
case TRE_CHAR('['):
if (escaped)
STORE_CHAR;
else
goto badpat;
continue;
case TRE_CHAR('*'):
if (escaped || (!(cflags & REG_EXTENDED) && (i == 0)))
STORE_CHAR;
else
goto badpat;
continue;
case TRE_CHAR('+'):
case TRE_CHAR('?'):
if ((cflags & REG_EXTENDED) && (i == 0))
goto badpat;
else if ((cflags & REG_EXTENDED) ^ !escaped)
STORE_CHAR;
else
goto badpat;
continue;
case TRE_CHAR('.'):
if (escaped)
{
if (!_escmap)
_escmap = xmalloc(n * sizeof(bool));
if (!_escmap)
{
xfree(tmp);
return REG_ESPACE;
}
_escmap[i] = true;
STORE_CHAR;
}
else
{
whasdot = i;
if (wfirstdot == -1)
wfirstdot = i;
STORE_CHAR;
}
continue;
case TRE_CHAR('^'):
STORE_CHAR;
continue;
case TRE_CHAR('$'):
if (!escaped && (i == n - 1))
fg->eol = true;
else
STORE_CHAR;
continue;
case TRE_CHAR('('):
if ((cflags & REG_EXTENDED) ^ escaped)
goto badpat;
else
STORE_CHAR;
continue;
case TRE_CHAR('{'):
if (!(cflags & REG_EXTENDED) ^ escaped)
STORE_CHAR;
else if (!(cflags & REG_EXTENDED) && (i == 0))
STORE_CHAR;
else if ((cflags & REG_EXTENDED) && (i == 0))
continue;
else
goto badpat;
continue;
case TRE_CHAR('|'):
if ((cflags & REG_EXTENDED) ^ escaped)
goto badpat;
else
STORE_CHAR;
continue;
default:
if (escaped)
goto badpat;
else
STORE_CHAR;
continue;
}
continue;
badpat:
xfree(tmp);
DPRINT(("tre_compile_fast: compilation of pattern failed, falling"
"back to NFA\n"));
return REG_BADPAT;
}
fg->hasdot = wfirstdot > -1;
/*
* The pattern has been processed and copied to tmp as a literal string
* with escapes, anchors (^$) and the word boundary match character
* classes stripped out.
*/
#ifdef TRE_WCHAR
SAVE_PATTERN(tmp, pos, fg->wpattern, fg->wlen);
fg->wescmap = _escmap;
STORE_MBS_PAT;
/*
* The position of dots and escaped dots is different in the MB string
* than in to the wide string so traverse the converted string, as well,
* to store these positions.
*/
if (fg->hasdot || (fg->wescmap != NULL))
{
if (fg->wescmap != NULL)
{
fg->escmap = xmalloc(fg->len * sizeof(bool));
if (!fg->escmap)
{
tre_free_fast(fg);
return REG_ESPACE;
}
}
escaped = false;
for (unsigned int i = 0; i < fg->len; i++)
if (fg->pattern[i] == '\\')
escaped = !escaped;
else if (fg->pattern[i] == '.' && fg->escmap && escaped)
{
fg->escmap[i] = true;
escaped = false;
}
else if (fg->pattern[i] == '.' && !escaped)
{
hasdot = i;
if (firstdot == -1)
firstdot = i;
}
else
escaped = false;
}
#else
SAVE_PATTERN(tmp, pos, fg->pattern, fg->len);
fg->escmap = _escmap;
#endif
xfree(tmp);
DPRINT(("tre_compile_fast: pattern: %s, len %zu, bol %c, eol %c, "
"icase: %c, word: %c, newline %c\n", fg->pattern, fg->len,
fg->bol ? 'y' : 'n', fg->eol ? 'y' : 'n',
fg->icase ? 'y' : 'n', fg->word ? 'y' : 'n',
fg->newline ? 'y' : 'n'));
/* Check whether reverse QS algorithm is more efficient */
if ((wfirstdot > -1) && (fg->wlen - whasdot + 1 < (size_t)wfirstdot) &&
fg->nosub)
{
fg->reversed = true;
DPRINT(("tre_compile_fast: using reverse QS algorithm\n"));
}
FILL_QSBC;
FILL_BMGS;
#ifdef TRE_WCHAR
FILL_QSBC_WIDE;
FILL_BMGS_WIDE;
#endif
return REG_OK;
}
#define _SHIFT_ONE \
{ \
shift = 1; \
j = !fg->reversed ? j + shift : j - shift; \
continue; \
}
#define _BBOUND_COND \
((type == STR_WIDE) ? \
((j == 0) || !(tre_isalnum(str_wide[j - 1]) || \
(str_wide[j - 1] == TRE_CHAR('_')))) : \
((j == 0) || !(tre_isalnum(str_byte[j - 1]) || \
(str_byte[j - 1] == '_'))))
#define _EBOUND_COND \
((type == STR_WIDE) ? \
((j + fg->wlen == len) || !(tre_isalnum(str_wide[j + fg->wlen]) || \
(str_wide[j + fg->wlen] == TRE_CHAR('_')))) : \
((j + fg->len == len) || !(tre_isalnum(str_byte[j + fg->len]) || \
(str_byte[j + fg->len] == '_'))))
/*
* Condition to check whether the match on position j is on a
* word boundary.
*/
#define IS_ON_WORD_BOUNDARY \
(_BBOUND_COND && _EBOUND_COND)
/*
* Checks word boundary and shifts one if match is not on a
* boundary.
*/
#define CHECK_WORD_BOUNDARY \
if (!IS_ON_WORD_BOUNDARY) \
_SHIFT_ONE;
#define _BOL_COND \
((j == 0) || ((type == STR_WIDE) ? (str_wide[j - 1] == TRE_CHAR('\n'))\
: (str_byte[j - 1] == '\n')))
/*
* Checks BOL anchor and shifts one if match is not on a
* boundary.
*/
#define CHECK_BOL_ANCHOR \
if (!_BOL_COND) \
_SHIFT_ONE;
#define _EOL_COND \
((type == STR_WIDE) \
? ((j + fg->wlen == len) || \
(str_wide[j + fg->wlen] == TRE_CHAR('\n'))) \
: ((j + fg->len == len) || (str_byte[j + fg->wlen] == '\n')))
/*
* Checks EOL anchor and shifts one if match is not on a
* boundary.
*/
#define CHECK_EOL_ANCHOR \
if (!_EOL_COND) \
_SHIFT_ONE;
/*
* Executes matching of the precompiled pattern on the input string.
* Returns REG_OK or REG_NOMATCH depending on if we find a match or not.
*/
int
tre_match_fast(const fastmatch_t *fg, const void *data, size_t len,
tre_str_type_t type, int nmatch, regmatch_t pmatch[], int eflags)
{
unsigned int shift, u = 0, v = 0;
ssize_t j = 0;
int ret = REG_NOMATCH;
int mismatch;
const char *str_byte = data;
const void *startptr = NULL;
const tre_char_t *str_wide = data;
/* Calculate length if unspecified. */
if (len == (size_t)-1)
switch (type)
{
case STR_WIDE:
len = tre_strlen(str_wide);
break;
default:
len = strlen(str_byte);
break;
}
/* Shortcut for empty pattern */
if (fg->matchall)
{
if (!fg->nosub && nmatch >= 1)
{
pmatch[0].rm_so = 0;
pmatch[0].rm_eo = len;
}
if (fg->bol && fg->eol)
return (len == 0) ? REG_OK : REG_NOMATCH;
else
return REG_OK;
}
/* No point in going farther if we do not have enough data. */
switch (type)
{
case STR_WIDE:
if (len < fg->wlen)
return ret;
shift = fg->wlen;
break;
default:
if (len < fg->len)
return ret;
shift = fg->len;
}
/*
* REG_NOTBOL means not anchoring ^ to the beginning of the line, so we
* can shift one because there can't be a match at the beginning.
*/
if (fg->bol && (eflags & REG_NOTBOL))
j = 1;
/*
* Like above, we cannot have a match at the very end when anchoring to
* the end and REG_NOTEOL is specified.
*/
if (fg->eol && (eflags & REG_NOTEOL))
len--;
if (fg->reversed)
j = len - (type == STR_WIDE ? fg->wlen : fg->len);
/* Only try once at the beginning or ending of the line. */
if ((fg->bol || fg->eol) && !fg->newline && !(eflags & REG_NOTBOL) &&
!(eflags & REG_NOTEOL))
{
/* Simple text comparison. */
if (!((fg->bol && fg->eol) &&
(type == STR_WIDE ? (len != fg->wlen) : (len != fg->len))))
{
/* Determine where in data to start search at. */
j = fg->eol ? len - (type == STR_WIDE ? fg->wlen : fg->len) : 0;
SKIP_CHARS(j);
mismatch = fastcmp(fg, startptr, type);
if (mismatch == REG_OK)
{
if (fg->word && !IS_ON_WORD_BOUNDARY)
return ret;
if (!fg->nosub && nmatch >= 1)
{
pmatch[0].rm_so = j;
pmatch[0].rm_eo = j + (type == STR_WIDE ? fg->wlen : fg->len);
}
return REG_OK;
}
}
}
else
{
/* Quick Search / Turbo Boyer-Moore algorithm. */
do
{
SKIP_CHARS(j);
mismatch = fastcmp(fg, startptr, type);
if (mismatch == REG_OK)
{
if (fg->word)
CHECK_WORD_BOUNDARY;
if (fg->bol)
CHECK_BOL_ANCHOR;
if (fg->eol)
CHECK_EOL_ANCHOR;
if (!fg->nosub && nmatch >= 1)
{
pmatch[0].rm_so = j;
pmatch[0].rm_eo = j + ((type == STR_WIDE) ? fg->wlen : fg->len);
}
return REG_OK;
}
else if (mismatch > 0)
return mismatch;
mismatch = -mismatch - 1;
SHIFT;
} while (!IS_OUT_OF_BOUNDS);
}
return ret;
}
/*
* Frees the resources that were allocated when the pattern was compiled.
*/
void
tre_free_fast(fastmatch_t *fg)
{
DPRINT(("tre_fast_free: freeing structures for pattern %s\n",
fg->pattern));
#ifdef TRE_WCHAR
hashtable_free(fg->qsBc_table);
if (!fg->hasdot)
xfree(fg->bmGs);
if (fg->wescmap)
xfree(fg->wescmap);
xfree(fg->wpattern);
#endif
if (!fg->hasdot)
xfree(fg->sbmGs);
if (fg->escmap)
xfree(fg->escmap);
xfree(fg->pattern);
}
/*
* Returns: -(i + 1) on failure (position that it failed with minus sign)
* error code on error
* REG_OK on success
*/
static inline int
fastcmp(const fastmatch_t *fg, const void *data, tre_str_type_t type)
{
const char *str_byte = data;
const char *pat_byte = fg->pattern;
const tre_char_t *str_wide = data;
const tre_char_t *pat_wide = fg->wpattern;
const bool *escmap = (type == STR_WIDE) ? fg->wescmap : fg->escmap;
size_t len = (type == STR_WIDE) ? fg->wlen : fg->len;
int ret = REG_OK;
/* Compare the pattern and the input char-by-char from the last position. */
for (int i = len - 1; i >= 0; i--) {
switch (type)
{
case STR_WIDE:
/* Check dot */
if (fg->hasdot && pat_wide[i] == TRE_CHAR('.') &&
(!escmap || !escmap[i]) &&
(!fg->newline || (str_wide[i] != TRE_CHAR('\n'))))
continue;
/* Compare */
if (fg->icase ? (towlower(pat_wide[i]) == towlower(str_wide[i]))
: (pat_wide[i] == str_wide[i]))
continue;
break;
default:
/* Check dot */
if (fg->hasdot && pat_byte[i] == '.' &&
(!escmap || !escmap[i]) &&
(!fg->newline || (str_byte[i] != '\n')))
continue;
/* Compare */
if (fg->icase ? (tolower((unsigned char)pat_byte[i]) == tolower((unsigned char)str_byte[i]))
: (pat_byte[i] == str_byte[i]))
continue;
}
DPRINT(("fastcmp: mismatch at position %d\n", i));
ret = -(i + 1);
break;
}
return ret;
}
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