xref: /netbsd/lib/libc/regex/regexec.c (revision bf9ec67e)
1 /*	$NetBSD: regexec.c,v 1.16 2001/12/17 16:31:11 christos 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 1.16 2001/12/17 16:31:11 christos 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) \
134     if (((m)->space = malloc((size_t)((nv)*(m)->g->nstates))) == NULL) \
135 	return(REG_ESPACE); \
136     else \
137 	(m)->vn = 0
138 
139 #define	STATETEARDOWN(m)	{ free((m)->space); m->space = NULL; }
140 #define	SETUP(v)	((v) = &m->space[(size_t)(m->vn++ * m->g->nstates)])
141 #define	onestate	int
142 #define	INIT(o, n)	((o) = (n))
143 #define	INC(o)	((o)++)
144 #define	ISSTATEIN(v, o)	((v)[o])
145 /* some abbreviations; note that some of these know variable names! */
146 /* do "if I'm here, I can also be there" etc without branches */
147 #define	FWD(dst, src, n)	((dst)[here+(n)] |= (src)[here])
148 #define	BACK(dst, src, n)	((dst)[here-(n)] |= (src)[here])
149 #define	ISSETBACK(v, n)	((v)[here - (n)])
150 /* function names */
151 #define	LNAMES			/* flag */
152 
153 #include "engine.c"
154 
155 /*
156  - regexec - interface for matching
157  = extern int regexec(const regex_t *, const char *, size_t, \
158  =					regmatch_t [], int);
159  = #define	REG_NOTBOL	00001
160  = #define	REG_NOTEOL	00002
161  = #define	REG_STARTEND	00004
162  = #define	REG_TRACE	00400	// tracing of execution
163  = #define	REG_LARGE	01000	// force large representation
164  = #define	REG_BACKR	02000	// force use of backref code
165  *
166  * We put this here so we can exploit knowledge of the state representation
167  * when choosing which matcher to call.  Also, by this point the matchers
168  * have been prototyped.
169  */
170 int				/* 0 success, REG_NOMATCH failure */
171 regexec(preg, string, nmatch, pmatch, eflags)
172 const regex_t *preg;
173 const char *string;
174 size_t nmatch;
175 regmatch_t pmatch[];
176 int eflags;
177 {
178 	struct re_guts *g = preg->re_g;
179 	char *s;
180 #ifdef REDEBUG
181 #	define	GOODFLAGS(f)	(f)
182 #else
183 #	define	GOODFLAGS(f)	((f)&(REG_NOTBOL|REG_NOTEOL|REG_STARTEND))
184 #endif
185 
186 	_DIAGASSERT(preg != NULL);
187 	_DIAGASSERT(string != NULL);
188 
189 	if (preg->re_magic != MAGIC1 || g->magic != MAGIC2)
190 		return(REG_BADPAT);
191 	assert(!(g->iflags&BAD));
192 	if (g->iflags&BAD)		/* backstop for no-debug case */
193 		return(REG_BADPAT);
194 	eflags = GOODFLAGS(eflags);
195 
196 	/* LINTED we believe that the regex routines do not change the string */
197 	s = (char *)string;
198 
199 	if (g->nstates <= CHAR_BIT*sizeof(states1) && !(eflags&REG_LARGE))
200 		return(smatcher(g, s, nmatch, pmatch, eflags));
201 	else
202 		return(lmatcher(g, s, nmatch, pmatch, eflags));
203 }
204