1 /*	$OpenBSD: regexec.c,v 1.11 2005/08/05 13:03:00 espie Exp $ */
2 /*-
3  * Copyright (c) 1992, 1993, 1994 Henry Spencer.
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  * the outer shell of regexec()
39  *
40  * This file includes engine.c *twice*, after muchos fiddling with the
41  * macros that code uses.  This lets the same code operate on two different
42  * representations for state sets.
43  */
44 #include <sys/types.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include <limits.h>
49 #include <ctype.h>
50 #include "./regex.h"
51 
52 #include "utils.h"
53 #include "./regex2.h"
54 
55 /* macros for manipulating states, small version */
56 #define	states	long
57 #define	states1	states		/* for later use in regexec() decision */
58 #define	CLEAR(v)	((v) = 0)
59 #define	SET0(v, n)	((v) &= ~((unsigned long)1 << (n)))
60 #define	SET1(v, n)	((v) |= (unsigned long)1 << (n))
61 #define	ISSET(v, n)	(((v) & ((unsigned long)1 << (n))) != 0)
62 #define	ASSIGN(d, s)	((d) = (s))
63 #define	EQ(a, b)	((a) == (b))
64 #define	STATEVARS	long dummy	/* dummy version */
65 #define	STATESETUP(m, n)	/* nothing */
66 #define	STATETEARDOWN(m)	/* nothing */
67 #define	SETUP(v)	((v) = 0)
68 #define	onestate	long
69 #define	INIT(o, n)	((o) = (unsigned long)1 << (n))
70 #define	INC(o)		((o) <<= 1)
71 #define	ISSTATEIN(v, o)	(((v) & (o)) != 0)
72 /* some abbreviations; note that some of these know variable names! */
73 /* do "if I'm here, I can also be there" etc without branches */
74 #define	FWD(dst, src, n)	((dst) |= ((unsigned long)(src)&(here)) << (n))
75 #define	BACK(dst, src, n)	((dst) |= ((unsigned long)(src)&(here)) >> (n))
76 #define	ISSETBACK(v, n)		(((v) & ((unsigned long)here >> (n))) != 0)
77 /* function names */
78 #define SNAMES			/* engine.c looks after details */
79 
80 #include "engine.c"
81 
82 /* now undo things */
83 #undef	states
84 #undef	CLEAR
85 #undef	SET0
86 #undef	SET1
87 #undef	ISSET
88 #undef	ASSIGN
89 #undef	EQ
90 #undef	STATEVARS
91 #undef	STATESETUP
92 #undef	STATETEARDOWN
93 #undef	SETUP
94 #undef	onestate
95 #undef	INIT
96 #undef	INC
97 #undef	ISSTATEIN
98 #undef	FWD
99 #undef	BACK
100 #undef	ISSETBACK
101 #undef	SNAMES
102 
103 /* macros for manipulating states, large version */
104 #define	states	char *
105 #define	CLEAR(v)	memset(v, 0, m->g->nstates)
106 #define	SET0(v, n)	((v)[n] = 0)
107 #define	SET1(v, n)	((v)[n] = 1)
108 #define	ISSET(v, n)	((v)[n])
109 #define	ASSIGN(d, s)	memcpy(d, s, m->g->nstates)
110 #define	EQ(a, b)	(memcmp(a, b, m->g->nstates) == 0)
111 #define	STATEVARS	long vn; char *space
112 #define	STATESETUP(m, nv)	{ (m)->space = (char*)malloc((nv)*(m)->g->nstates); \
113 				if ((m)->space == NULL) return(REG_ESPACE); \
114 				(m)->vn = 0; }
115 #define	STATETEARDOWN(m)	{ free((m)->space); }
116 #define	SETUP(v)	((v) = &m->space[m->vn++ * m->g->nstates])
117 #define	onestate	long
118 #define	INIT(o, n)	((o) = (n))
119 #define	INC(o)	((o)++)
120 #define	ISSTATEIN(v, o)	((v)[o])
121 /* some abbreviations; note that some of these know variable names! */
122 /* do "if I'm here, I can also be there" etc without branches */
123 #define	FWD(dst, src, n)	((dst)[here+(n)] |= (src)[here])
124 #define	BACK(dst, src, n)	((dst)[here-(n)] |= (src)[here])
125 #define	ISSETBACK(v, n)	((v)[here - (n)])
126 /* function names */
127 #define	LNAMES			/* flag */
128 
129 #include "engine.c"
130 
131 /*
132  - regexec - interface for matching
133  *
134  * We put this here so we can exploit knowledge of the state representation
135  * when choosing which matcher to call.  Also, by this point the matchers
136  * have been prototyped.
137  */
138 int				/* 0 success, REG_NOMATCH failure */
regexec(const regex_t * preg,const char * string,size_t nmatch,regmatch_t pmatch[],int eflags)139 regexec(const regex_t *preg, const char *string, size_t nmatch,
140     regmatch_t pmatch[], int eflags)
141 {
142 	struct re_guts *g = preg->re_g;
143 #ifdef REDEBUG
144 #	define	GOODFLAGS(f)	(f)
145 #else
146 #	define	GOODFLAGS(f)	((f)&(REG_NOTBOL|REG_NOTEOL|REG_STARTEND))
147 #endif
148 
149 	if (preg->re_magic != MAGIC1 || g->magic != MAGIC2)
150 		return(REG_BADPAT);
151 	assert(!(g->iflags&BAD));
152 	if (g->iflags&BAD)		/* backstop for no-debug case */
153 		return(REG_BADPAT);
154 	eflags = GOODFLAGS(eflags);
155 
156 	if (g->nstates <= (int)(CHAR_BIT*sizeof(states1)) && !(eflags&REG_LARGE))
157 		return(smatcher(g, (char *)string, nmatch, pmatch, eflags));
158 	else
159 		return(lmatcher(g, (char *)string, nmatch, pmatch, eflags));
160 }
161