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      1 /*	$NetBSD: regexec.c,v 1.22 2012/03/13 21:13:43 christos Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1992, 1993, 1994
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * This code is derived from software contributed to Berkeley by
      8  * Henry Spencer.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. Neither the name of the University nor the names of its contributors
     19  *    may be used to endorse or promote products derived from this software
     20  *    without specific prior written permission.
     21  *
     22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     32  * SUCH DAMAGE.
     33  *
     34  *	@(#)regexec.c	8.3 (Berkeley) 3/20/94
     35  */
     36 
     37 /*-
     38  * Copyright (c) 1992, 1993, 1994 Henry Spencer.
     39  *
     40  * This code is derived from software contributed to Berkeley by
     41  * Henry Spencer.
     42  *
     43  * Redistribution and use in source and binary forms, with or without
     44  * modification, are permitted provided that the following conditions
     45  * are met:
     46  * 1. Redistributions of source code must retain the above copyright
     47  *    notice, this list of conditions and the following disclaimer.
     48  * 2. Redistributions in binary form must reproduce the above copyright
     49  *    notice, this list of conditions and the following disclaimer in the
     50  *    documentation and/or other materials provided with the distribution.
     51  * 3. All advertising materials mentioning features or use of this software
     52  *    must display the following acknowledgement:
     53  *	This product includes software developed by the University of
     54  *	California, Berkeley and its contributors.
     55  * 4. Neither the name of the University nor the names of its contributors
     56  *    may be used to endorse or promote products derived from this software
     57  *    without specific prior written permission.
     58  *
     59  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     60  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     61  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     62  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     63  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     64  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     65  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     66  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     67  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     68  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     69  * SUCH DAMAGE.
     70  *
     71  *	@(#)regexec.c	8.3 (Berkeley) 3/20/94
     72  */
     73 
     74 #include <sys/cdefs.h>
     75 #if defined(LIBC_SCCS) && !defined(lint)
     76 #if 0
     77 static char sccsid[] = "@(#)regexec.c	8.3 (Berkeley) 3/20/94";
     78 #else
     79 __RCSID("$NetBSD: regexec.c,v 1.22 2012/03/13 21:13:43 christos Exp $");
     80 #endif
     81 #endif /* LIBC_SCCS and not lint */
     82 
     83 /*
     84  * the outer shell of regexec()
     85  *
     86  * This file includes engine.c *twice*, after muchos fiddling with the
     87  * macros that code uses.  This lets the same code operate on two different
     88  * representations for state sets.
     89  */
     90 #include "namespace.h"
     91 #include <sys/types.h>
     92 
     93 #include <assert.h>
     94 #include <ctype.h>
     95 #include <limits.h>
     96 #include <stdio.h>
     97 #include <stdlib.h>
     98 #include <string.h>
     99 #include <regex.h>
    100 
    101 #ifdef __weak_alias
    102 __weak_alias(regexec,_regexec)
    103 #endif
    104 
    105 #include "utils.h"
    106 #include "regex2.h"
    107 
    108 /* macros for manipulating states, small version */
    109 #define	states	unsigned long
    110 #define	states1	unsigned long	/* for later use in regexec() decision */
    111 #define	CLEAR(v)	((v) = 0)
    112 #define	SET0(v, n)	((v) &= ~((unsigned long)1 << (n)))
    113 #define	SET1(v, n)	((v) |= (unsigned long)1 << (n))
    114 #define	ISSET(v, n)	(((v) & ((unsigned long)1 << (n))) != 0)
    115 #define	ASSIGN(d, s)	((d) = (s))
    116 #define	EQ(a, b)	((a) == (b))
    117 #define	STATEVARS	int dummy	/* dummy version */
    118 #define	STATESETUP(m, n)	/* nothing */
    119 #define	STATETEARDOWN(m)	/* nothing */
    120 #define	SETUP(v)	((v) = 0)
    121 #define	onestate	unsigned long
    122 #define	INIT(o, n)	((o) = (unsigned long)1 << (n))
    123 #define	INC(o)	((o) <<= 1)
    124 #define	ISSTATEIN(v, o)	(((v) & (o)) != 0)
    125 /* some abbreviations; note that some of these know variable names! */
    126 /* do "if I'm here, I can also be there" etc without branches */
    127 #define	FWD(dst, src, n)	((dst) |= ((unsigned long)(src)&(here)) << (n))
    128 #define	BACK(dst, src, n)	((dst) |= ((unsigned long)(src)&(here)) >> (n))
    129 #define	ISSETBACK(v, n)	(((v) & ((unsigned long)here >> (n))) != 0)
    130 /* function names */
    131 #define SNAMES			/* engine.c looks after details */
    132 
    133 #include "engine.c"
    134 
    135 /* now undo things */
    136 #undef	states
    137 #undef	CLEAR
    138 #undef	SET0
    139 #undef	SET1
    140 #undef	ISSET
    141 #undef	ASSIGN
    142 #undef	EQ
    143 #undef	STATEVARS
    144 #undef	STATESETUP
    145 #undef	STATETEARDOWN
    146 #undef	SETUP
    147 #undef	onestate
    148 #undef	INIT
    149 #undef	INC
    150 #undef	ISSTATEIN
    151 #undef	FWD
    152 #undef	BACK
    153 #undef	ISSETBACK
    154 #undef	SNAMES
    155 
    156 /* macros for manipulating states, large version */
    157 #define	states	char *
    158 #define	CLEAR(v)	memset(v, 0, (size_t)m->g->nstates)
    159 #define	SET0(v, n)	((v)[n] = 0)
    160 #define	SET1(v, n)	((v)[n] = 1)
    161 #define	ISSET(v, n)	((v)[n])
    162 #define	ASSIGN(d, s)	memcpy(d, s, (size_t)m->g->nstates)
    163 #define	EQ(a, b)	(memcmp(a, b, (size_t)m->g->nstates) == 0)
    164 #define	STATEVARS	int vn; char *space
    165 #define	STATESETUP(m, nv) \
    166     if (((m)->space = malloc((size_t)((nv)*(m)->g->nstates))) == NULL) \
    167 	return(REG_ESPACE); \
    168     else \
    169 	(m)->vn = 0
    170 
    171 #define	STATETEARDOWN(m)	{ free((m)->space); m->space = NULL; }
    172 #define	SETUP(v)	((v) = &m->space[(size_t)(m->vn++ * m->g->nstates)])
    173 #define	onestate	int
    174 #define	INIT(o, n)	((o) = (int)(n))
    175 #define	INC(o)	((o)++)
    176 #define	ISSTATEIN(v, o)	((v)[o])
    177 /* some abbreviations; note that some of these know variable names! */
    178 /* do "if I'm here, I can also be there" etc without branches */
    179 #define	FWD(dst, src, n)	((dst)[here+(n)] |= (src)[here])
    180 #define	BACK(dst, src, n)	((dst)[here-(n)] |= (src)[here])
    181 #define	ISSETBACK(v, n)	((v)[here - (n)])
    182 /* function names */
    183 #define	LNAMES			/* flag */
    184 
    185 #include "engine.c"
    186 
    187 /*
    188  - regexec - interface for matching
    189  = extern int regexec(const regex_t *, const char *, size_t, \
    190  =					regmatch_t [], int);
    191  = #define	REG_NOTBOL	00001
    192  = #define	REG_NOTEOL	00002
    193  = #define	REG_STARTEND	00004
    194  = #define	REG_TRACE	00400	// tracing of execution
    195  = #define	REG_LARGE	01000	// force large representation
    196  = #define	REG_BACKR	02000	// force use of backref code
    197  *
    198  * We put this here so we can exploit knowledge of the state representation
    199  * when choosing which matcher to call.  Also, by this point the matchers
    200  * have been prototyped.
    201  */
    202 int				/* 0 success, REG_NOMATCH failure */
    203 regexec(
    204     const regex_t *preg,
    205     const char *string,
    206     size_t nmatch,
    207     regmatch_t pmatch[],
    208     int eflags)
    209 {
    210 	struct re_guts *g = preg->re_g;
    211 	char *s;
    212 #ifdef REDEBUG
    213 #	define	GOODFLAGS(f)	(f)
    214 #else
    215 #	define	GOODFLAGS(f)	((f)&(REG_NOTBOL|REG_NOTEOL|REG_STARTEND))
    216 #endif
    217 
    218 	_DIAGASSERT(preg != NULL);
    219 	_DIAGASSERT(string != NULL);
    220 
    221 	if (preg->re_magic != MAGIC1 || g->magic != MAGIC2)
    222 		return(REG_BADPAT);
    223 	assert(!(g->iflags&BAD));
    224 	if (g->iflags&BAD)		/* backstop for no-debug case */
    225 		return(REG_BADPAT);
    226 	eflags = GOODFLAGS(eflags);
    227 
    228 	s = __UNCONST(string);
    229 
    230 	if (g->nstates <= (sopno)(CHAR_BIT*sizeof(states1)) && !(eflags&REG_LARGE))
    231 		return(smatcher(g, s, nmatch, pmatch, eflags));
    232 	else
    233 		return(lmatcher(g, s, nmatch, pmatch, eflags));
    234 }
    235