freebsd-skq/lib/libc/regex/regexec.c
tjr ba689b4043 Make regular expression matching aware of multibyte characters. The general
idea is that we perform multibyte->wide character conversion while parsing
and compiling, then convert byte sequences to wide characters when they're
needed for comparison and stepping through the string during execution.

As with tr(1), the main complication is to efficiently represent sets of
characters in bracket expressions. The old bitmap representation is replaced
by a bitmap for the first 256 characters combined with a vector of individual
wide characters, a vector of character ranges (for [A-Z] etc.), and a vector
of character classes (for [[:alpha:]] etc.).

One other point of interest is that although the Boyer-Moore algorithm had
to be disabled in the general multibyte case, it is still enabled for UTF-8
because of its self-synchronizing nature. This greatly speeds up matching
by reducing the number of multibyte conversions that need to be done.
2004-07-12 07:35:59 +00:00

245 lines
7.5 KiB
C

/*-
* Copyright (c) 1992, 1993, 1994 Henry Spencer.
* Copyright (c) 1992, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Henry Spencer.
*
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*
* @(#)regexec.c 8.3 (Berkeley) 3/20/94
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)regexec.c 8.3 (Berkeley) 3/20/94";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* the outer shell of regexec()
*
* This file includes engine.c three times, after muchos fiddling with the
* macros that code uses. This lets the same code operate on two different
* representations for state sets and characters.
*/
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <ctype.h>
#include <regex.h>
#include <wchar.h>
#include <wctype.h>
#include "utils.h"
#include "regex2.h"
static int nope __unused = 0; /* for use in asserts; shuts lint up */
static __inline size_t
xmbrtowc(wi, s, n, mbs, dummy)
wint_t *wi;
const char *s;
size_t n;
mbstate_t *mbs;
wint_t dummy;
{
size_t nr;
wchar_t wc;
nr = mbrtowc(&wc, s, n, mbs);
if (wi != NULL)
*wi = wc;
if (nr == 0)
return (1);
else if (nr == (size_t)-1 || nr == (size_t)-2) {
memset(mbs, 0, sizeof(*mbs));
if (wi != NULL)
*wi = dummy;
return (1);
} else
return (nr);
}
static __inline size_t
xmbrtowc_dummy(wi, s, n, mbs, dummy)
wint_t *wi;
const char *s;
size_t n __unused;
mbstate_t *mbs __unused;
wint_t dummy __unused;
{
if (wi != NULL)
*wi = (unsigned char)*s;
return (1);
}
/* macros for manipulating states, small version */
#define states long
#define states1 states /* for later use in regexec() decision */
#define CLEAR(v) ((v) = 0)
#define SET0(v, n) ((v) &= ~((unsigned long)1 << (n)))
#define SET1(v, n) ((v) |= (unsigned long)1 << (n))
#define ISSET(v, n) (((v) & ((unsigned long)1 << (n))) != 0)
#define ASSIGN(d, s) ((d) = (s))
#define EQ(a, b) ((a) == (b))
#define STATEVARS long dummy /* dummy version */
#define STATESETUP(m, n) /* nothing */
#define STATETEARDOWN(m) /* nothing */
#define SETUP(v) ((v) = 0)
#define onestate long
#define INIT(o, n) ((o) = (unsigned long)1 << (n))
#define INC(o) ((o) <<= 1)
#define ISSTATEIN(v, o) (((v) & (o)) != 0)
/* some abbreviations; note that some of these know variable names! */
/* do "if I'm here, I can also be there" etc without branches */
#define FWD(dst, src, n) ((dst) |= ((unsigned long)(src)&(here)) << (n))
#define BACK(dst, src, n) ((dst) |= ((unsigned long)(src)&(here)) >> (n))
#define ISSETBACK(v, n) (((v) & ((unsigned long)here >> (n))) != 0)
/* no multibyte support */
#define XMBRTOWC xmbrtowc_dummy
#define ZAPSTATE(mbs) ((void)(mbs))
/* function names */
#define SNAMES /* engine.c looks after details */
#include "engine.c"
/* now undo things */
#undef states
#undef CLEAR
#undef SET0
#undef SET1
#undef ISSET
#undef ASSIGN
#undef EQ
#undef STATEVARS
#undef STATESETUP
#undef STATETEARDOWN
#undef SETUP
#undef onestate
#undef INIT
#undef INC
#undef ISSTATEIN
#undef FWD
#undef BACK
#undef ISSETBACK
#undef SNAMES
#undef XMBRTOWC
#undef ZAPSTATE
/* macros for manipulating states, large version */
#define states char *
#define CLEAR(v) memset(v, 0, m->g->nstates)
#define SET0(v, n) ((v)[n] = 0)
#define SET1(v, n) ((v)[n] = 1)
#define ISSET(v, n) ((v)[n])
#define ASSIGN(d, s) memcpy(d, s, m->g->nstates)
#define EQ(a, b) (memcmp(a, b, m->g->nstates) == 0)
#define STATEVARS long vn; char *space
#define STATESETUP(m, nv) { (m)->space = malloc((nv)*(m)->g->nstates); \
if ((m)->space == NULL) return(REG_ESPACE); \
(m)->vn = 0; }
#define STATETEARDOWN(m) { free((m)->space); }
#define SETUP(v) ((v) = &m->space[m->vn++ * m->g->nstates])
#define onestate long
#define INIT(o, n) ((o) = (n))
#define INC(o) ((o)++)
#define ISSTATEIN(v, o) ((v)[o])
/* some abbreviations; note that some of these know variable names! */
/* do "if I'm here, I can also be there" etc without branches */
#define FWD(dst, src, n) ((dst)[here+(n)] |= (src)[here])
#define BACK(dst, src, n) ((dst)[here-(n)] |= (src)[here])
#define ISSETBACK(v, n) ((v)[here - (n)])
/* no multibyte support */
#define XMBRTOWC xmbrtowc_dummy
#define ZAPSTATE(mbs) ((void)(mbs))
/* function names */
#define LNAMES /* flag */
#include "engine.c"
/* multibyte character & large states version */
#undef LNAMES
#undef XMBRTOWC
#undef ZAPSTATE
#define XMBRTOWC xmbrtowc
#define ZAPSTATE(mbs) memset((mbs), 0, sizeof(*(mbs)))
#define MNAMES
#include "engine.c"
/*
- regexec - interface for matching
= extern int regexec(const regex_t *, const char *, size_t, \
= regmatch_t [], int);
= #define REG_NOTBOL 00001
= #define REG_NOTEOL 00002
= #define REG_STARTEND 00004
= #define REG_TRACE 00400 // tracing of execution
= #define REG_LARGE 01000 // force large representation
= #define REG_BACKR 02000 // force use of backref code
*
* We put this here so we can exploit knowledge of the state representation
* when choosing which matcher to call. Also, by this point the matchers
* have been prototyped.
*/
int /* 0 success, REG_NOMATCH failure */
regexec(preg, string, nmatch, pmatch, eflags)
const regex_t * __restrict preg;
const char * __restrict string;
size_t nmatch;
regmatch_t pmatch[__restrict];
int eflags;
{
struct re_guts *g = preg->re_g;
#ifdef REDEBUG
# define GOODFLAGS(f) (f)
#else
# define GOODFLAGS(f) ((f)&(REG_NOTBOL|REG_NOTEOL|REG_STARTEND))
#endif
if (preg->re_magic != MAGIC1 || g->magic != MAGIC2)
return(REG_BADPAT);
assert(!(g->iflags&BAD));
if (g->iflags&BAD) /* backstop for no-debug case */
return(REG_BADPAT);
eflags = GOODFLAGS(eflags);
if (MB_CUR_MAX > 1)
return(mmatcher(g, (char *)string, nmatch, pmatch, eflags));
else if (g->nstates <= CHAR_BIT*sizeof(states1) && !(eflags&REG_LARGE))
return(smatcher(g, (char *)string, nmatch, pmatch, eflags));
else
return(lmatcher(g, (char *)string, nmatch, pmatch, eflags));
}