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regexec.c revision 1.15
      1 /*	$NetBSD: regexec.c,v 1.15 2000/01/22 22:19:17 mycroft Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1992, 1993, 1994 Henry Spencer.
      5  * Copyright (c) 1992, 1993, 1994
      6  *	The Regents of the University of California.  All rights reserved.
      7  *
      8  * This code is derived from software contributed to Berkeley by
      9  * Henry Spencer.
     10  *
     11  * Redistribution and use in source and binary forms, with or without
     12  * modification, are permitted provided that the following conditions
     13  * are met:
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions and the following disclaimer.
     16  * 2. Redistributions in binary form must reproduce the above copyright
     17  *    notice, this list of conditions and the following disclaimer in the
     18  *    documentation and/or other materials provided with the distribution.
     19  * 3. All advertising materials mentioning features or use of this software
     20  *    must display the following acknowledgement:
     21  *	This product includes software developed by the University of
     22  *	California, Berkeley and its contributors.
     23  * 4. Neither the name of the University nor the names of its contributors
     24  *    may be used to endorse or promote products derived from this software
     25  *    without specific prior written permission.
     26  *
     27  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     37  * SUCH DAMAGE.
     38  *
     39  *	@(#)regexec.c	8.3 (Berkeley) 3/20/94
     40  */
     41 
     42 #include <sys/cdefs.h>
     43 #if defined(LIBC_SCCS) && !defined(lint)
     44 #if 0
     45 static char sccsid[] = "@(#)regexec.c	8.3 (Berkeley) 3/20/94";
     46 #else
     47 __RCSID("$NetBSD: regexec.c,v 1.15 2000/01/22 22:19:17 mycroft Exp $");
     48 #endif
     49 #endif /* LIBC_SCCS and not lint */
     50 
     51 /*
     52  * the outer shell of regexec()
     53  *
     54  * This file includes engine.c *twice*, after muchos fiddling with the
     55  * macros that code uses.  This lets the same code operate on two different
     56  * representations for state sets.
     57  */
     58 #include "namespace.h"
     59 #include <sys/types.h>
     60 
     61 #include <assert.h>
     62 #include <ctype.h>
     63 #include <limits.h>
     64 #include <regex.h>
     65 #include <stdio.h>
     66 #include <stdlib.h>
     67 #include <string.h>
     68 
     69 #ifdef __weak_alias
     70 __weak_alias(regexec,_regexec)
     71 #endif
     72 
     73 #include "utils.h"
     74 #include "regex2.h"
     75 
     76 /* macros for manipulating states, small version */
     77 #define	states	unsigned long
     78 #define	states1	unsigned long	/* for later use in regexec() decision */
     79 #define	CLEAR(v)	((v) = 0)
     80 #define	SET0(v, n)	((v) &= ~((unsigned long)1 << (n)))
     81 #define	SET1(v, n)	((v) |= (unsigned long)1 << (n))
     82 #define	ISSET(v, n)	(((v) & ((unsigned long)1 << (n))) != 0)
     83 #define	ASSIGN(d, s)	((d) = (s))
     84 #define	EQ(a, b)	((a) == (b))
     85 #define	STATEVARS	int dummy	/* dummy version */
     86 #define	STATESETUP(m, n)	/* nothing */
     87 #define	STATETEARDOWN(m)	/* nothing */
     88 #define	SETUP(v)	((v) = 0)
     89 #define	onestate	unsigned long
     90 #define	INIT(o, n)	((o) = (unsigned long)1 << (n))
     91 #define	INC(o)	((o) <<= 1)
     92 #define	ISSTATEIN(v, o)	(((v) & (o)) != 0)
     93 /* some abbreviations; note that some of these know variable names! */
     94 /* do "if I'm here, I can also be there" etc without branches */
     95 #define	FWD(dst, src, n)	((dst) |= ((unsigned long)(src)&(here)) << (n))
     96 #define	BACK(dst, src, n)	((dst) |= ((unsigned long)(src)&(here)) >> (n))
     97 #define	ISSETBACK(v, n)	(((v) & ((unsigned long)here >> (n))) != 0)
     98 /* function names */
     99 #define SNAMES			/* engine.c looks after details */
    100 
    101 #include "engine.c"
    102 
    103 /* now undo things */
    104 #undef	states
    105 #undef	CLEAR
    106 #undef	SET0
    107 #undef	SET1
    108 #undef	ISSET
    109 #undef	ASSIGN
    110 #undef	EQ
    111 #undef	STATEVARS
    112 #undef	STATESETUP
    113 #undef	STATETEARDOWN
    114 #undef	SETUP
    115 #undef	onestate
    116 #undef	INIT
    117 #undef	INC
    118 #undef	ISSTATEIN
    119 #undef	FWD
    120 #undef	BACK
    121 #undef	ISSETBACK
    122 #undef	SNAMES
    123 
    124 /* macros for manipulating states, large version */
    125 #define	states	char *
    126 #define	CLEAR(v)	memset(v, 0, (size_t)m->g->nstates)
    127 #define	SET0(v, n)	((v)[n] = 0)
    128 #define	SET1(v, n)	((v)[n] = 1)
    129 #define	ISSET(v, n)	((v)[n])
    130 #define	ASSIGN(d, s)	memcpy(d, s, (size_t)m->g->nstates)
    131 #define	EQ(a, b)	(memcmp(a, b, (size_t)m->g->nstates) == 0)
    132 #define	STATEVARS	int vn; char *space
    133 #define	STATESETUP(m, nv) { (m)->space = malloc((size_t)((nv)*(m)->g->nstates)); \
    134 				if ((m)->space == NULL) return(REG_ESPACE); \
    135 				(m)->vn = 0; }
    136 #define	STATETEARDOWN(m)	{ free((m)->space); }
    137 #define	SETUP(v)	((v) = &m->space[(size_t)(m->vn++ * m->g->nstates)])
    138 #define	onestate	int
    139 #define	INIT(o, n)	((o) = (n))
    140 #define	INC(o)	((o)++)
    141 #define	ISSTATEIN(v, o)	((v)[o])
    142 /* some abbreviations; note that some of these know variable names! */
    143 /* do "if I'm here, I can also be there" etc without branches */
    144 #define	FWD(dst, src, n)	((dst)[here+(n)] |= (src)[here])
    145 #define	BACK(dst, src, n)	((dst)[here-(n)] |= (src)[here])
    146 #define	ISSETBACK(v, n)	((v)[here - (n)])
    147 /* function names */
    148 #define	LNAMES			/* flag */
    149 
    150 #include "engine.c"
    151 
    152 /*
    153  - regexec - interface for matching
    154  = extern int regexec(const regex_t *, const char *, size_t, \
    155  =					regmatch_t [], int);
    156  = #define	REG_NOTBOL	00001
    157  = #define	REG_NOTEOL	00002
    158  = #define	REG_STARTEND	00004
    159  = #define	REG_TRACE	00400	// tracing of execution
    160  = #define	REG_LARGE	01000	// force large representation
    161  = #define	REG_BACKR	02000	// force use of backref code
    162  *
    163  * We put this here so we can exploit knowledge of the state representation
    164  * when choosing which matcher to call.  Also, by this point the matchers
    165  * have been prototyped.
    166  */
    167 int				/* 0 success, REG_NOMATCH failure */
    168 regexec(preg, string, nmatch, pmatch, eflags)
    169 const regex_t *preg;
    170 const char *string;
    171 size_t nmatch;
    172 regmatch_t pmatch[];
    173 int eflags;
    174 {
    175 	struct re_guts *g = preg->re_g;
    176 	char *s;
    177 #ifdef REDEBUG
    178 #	define	GOODFLAGS(f)	(f)
    179 #else
    180 #	define	GOODFLAGS(f)	((f)&(REG_NOTBOL|REG_NOTEOL|REG_STARTEND))
    181 #endif
    182 
    183 	_DIAGASSERT(preg != NULL);
    184 	_DIAGASSERT(string != NULL);
    185 
    186 	if (preg->re_magic != MAGIC1 || g->magic != MAGIC2)
    187 		return(REG_BADPAT);
    188 	assert(!(g->iflags&BAD));
    189 	if (g->iflags&BAD)		/* backstop for no-debug case */
    190 		return(REG_BADPAT);
    191 	eflags = GOODFLAGS(eflags);
    192 
    193 	/* LINTED we believe that the regex routines do not change the string */
    194 	s = (char *)string;
    195 
    196 	if (g->nstates <= CHAR_BIT*sizeof(states1) && !(eflags&REG_LARGE))
    197 		return(smatcher(g, s, nmatch, pmatch, eflags));
    198 	else
    199 		return(lmatcher(g, s, nmatch, pmatch, eflags));
    200 }
    201