xref: /freebsd/contrib/nvi/regex/regexec.c (revision f677a9e2672665f4eb3dd4111c07ee8f1f954262)
1 /*	$NetBSD: regexec.c,v 1.4 2009/10/31 20:11:53 dsl 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 of the University of Toronto.
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	8.2 (Berkeley) 3/16/94
40  */
41 
42 #if defined(LIBC_SCCS) && !defined(lint)
43 static char sccsid[] = "@(#)regexec.c	8.2 (Berkeley) 3/16/94";
44 #endif /* LIBC_SCCS and not lint */
45 
46 /*
47  * the outer shell of regexec()
48  *
49  * This file includes engine.c *twice*, after muchos fiddling with the
50  * macros that code uses.  This lets the same code operate on two different
51  * representations for state sets.
52  */
53 #include <sys/types.h>
54 #include <stdio.h>
55 #include <stdlib.h>
56 #include <string.h>
57 #include <limits.h>
58 #include <ctype.h>
59 #include <regex.h>
60 
61 #include "utils.h"
62 #include "regex2.h"
63 
64 #ifdef notdef
65 static int nope = 0;		/* for use in asserts; shuts lint up */
66 #endif
67 
68 /* macros for manipulating states, small version */
69 #define	states	int
70 #define	states1	int		/* for later use in regexec() decision */
71 #define	CLEAR(v)	((v) = 0)
72 #define	SET0(v, n)	((v) &= ~(1 << (n)))
73 #define	SET1(v, n)	((v) |= 1 << (n))
74 #define	ISSET(v, n)	((v) & (1 << (n)))
75 #define	ASSIGN(d, s)	((d) = (s))
76 #define	EQ(a, b)	((a) == (b))
77 #define	STATEVARS	int dummy	/* dummy version */
78 #define	STATESETUP(m, n)	/* nothing */
79 #define	STATETEARDOWN(m)	/* nothing */
80 #define	SETUP(v)	((v) = 0)
81 #define	onestate	int
82 #define	INIT(o, n)	((o) = (unsigned)1 << (n))
83 #define	INC(o)	((o) <<= 1)
84 #define	ISSTATEIN(v, o)	((v) & (o))
85 /* some abbreviations; note that some of these know variable names! */
86 /* do "if I'm here, I can also be there" etc without branches */
87 #define	FWD(dst, src, n)	((dst) |= ((unsigned)(src)&(here)) << (n))
88 #define	BACK(dst, src, n)	((dst) |= ((unsigned)(src)&(here)) >> (n))
89 #define	ISSETBACK(v, n)	((v) & ((unsigned)here >> (n)))
90 /* function names */
91 #define SNAMES			/* engine.c looks after details */
92 
93 #include "engine.c"
94 
95 /* now undo things */
96 #undef	states
97 #undef	CLEAR
98 #undef	SET0
99 #undef	SET1
100 #undef	ISSET
101 #undef	ASSIGN
102 #undef	EQ
103 #undef	STATEVARS
104 #undef	STATESETUP
105 #undef	STATETEARDOWN
106 #undef	SETUP
107 #undef	onestate
108 #undef	INIT
109 #undef	INC
110 #undef	ISSTATEIN
111 #undef	FWD
112 #undef	BACK
113 #undef	ISSETBACK
114 #undef	SNAMES
115 
116 /* macros for manipulating states, large version */
117 #define	states	char *
118 #define	CLEAR(v)	memset(v, 0, m->g->nstates)
119 #define	SET0(v, n)	((v)[n] = 0)
120 #define	SET1(v, n)	((v)[n] = 1)
121 #define	ISSET(v, n)	((v)[n])
122 #define	ASSIGN(d, s)	memcpy(d, s, m->g->nstates)
123 #define	EQ(a, b)	(memcmp(a, b, m->g->nstates) == 0)
124 #define	STATEVARS	int vn; char *space
125 #define	STATESETUP(m, nv)	{ (m)->space = malloc((nv)*(m)->g->nstates); \
126 				if ((m)->space == NULL) return(REG_ESPACE); \
127 				(m)->vn = 0; }
128 #define	STATETEARDOWN(m)	{ free((m)->space); }
129 #define	SETUP(v)	((v) = &m->space[m->vn++ * m->g->nstates])
130 #define	onestate	int
131 #define	INIT(o, n)	((o) = (n))
132 #define	INC(o)	((o)++)
133 #define	ISSTATEIN(v, o)	((v)[o])
134 /* some abbreviations; note that some of these know variable names! */
135 /* do "if I'm here, I can also be there" etc without branches */
136 #define	FWD(dst, src, n)	((dst)[here+(n)] |= (src)[here])
137 #define	BACK(dst, src, n)	((dst)[here-(n)] |= (src)[here])
138 #define	ISSETBACK(v, n)	((v)[here - (n)])
139 /* function names */
140 #define	LNAMES			/* flag */
141 
142 #include "engine.c"
143 
144 /*
145  - regexec - interface for matching
146  = extern int regexec(const regex_t *, const char *, size_t, \
147  =					regmatch_t [], int);
148  = #define	REG_NOTBOL	00001
149  = #define	REG_NOTEOL	00002
150  = #define	REG_STARTEND	00004
151  = #define	REG_TRACE	00400	// tracing of execution
152  = #define	REG_LARGE	01000	// force large representation
153  = #define	REG_BACKR	02000	// force use of backref code
154  *
155  * We put this here so we can exploit knowledge of the state representation
156  * when choosing which matcher to call.  Also, by this point the matchers
157  * have been prototyped.
158  */
159 int				/* 0 success, REG_NOMATCH failure */
160 regexec(const regex_t *preg, const RCHAR_T *string, size_t nmatch, regmatch_t *pmatch, int eflags)
161 {
162 	register struct re_guts *g = preg->re_g;
163 #ifdef REDEBUG
164 #	define	GOODFLAGS(f)	(f)
165 #else
166 #	define	GOODFLAGS(f)	((f)&(REG_NOTBOL|REG_NOTEOL|REG_STARTEND))
167 #endif
168 
169 	if (preg->re_magic != MAGIC1 || g->magic != MAGIC2)
170 		return(REG_BADPAT);
171 	assert(!(g->iflags&BAD));
172 	if (g->iflags&BAD)		/* backstop for no-debug case */
173 		return(REG_BADPAT);
174 	eflags = GOODFLAGS(eflags);
175 
176 	if (g->nstates <= (int)(CHAR_BIT*sizeof(states1)) && !(eflags&REG_LARGE))
177 		return(smatcher(g, string, nmatch, pmatch, eflags));
178 	else
179 		return(lmatcher(g, string, nmatch, pmatch, eflags));
180 }
181