xref: /netbsd-src/lib/libc/regex/regexec.c (revision b48252f3655d61e52b0915f9a89e514d7be3ff24)
1 /*	$NetBSD: regexec.c,v 1.13 1999/09/16 11:45:21 lukem 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 1.13 1999/09/16 11:45:21 lukem 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 #ifdef _DIAGNOSTIC
186 	if (preg == NULL || string == NULL)
187 		return (REG_INVARG);
188 #endif
189 
190 	if (preg->re_magic != MAGIC1 || g->magic != MAGIC2)
191 		return(REG_BADPAT);
192 	assert(!(g->iflags&BAD));
193 	if (g->iflags&BAD)		/* backstop for no-debug case */
194 		return(REG_BADPAT);
195 	eflags = GOODFLAGS(eflags);
196 
197 	/* LINTED we believe that the regex routines do not change the string */
198 	s = (char *)string;
199 
200 	if (g->nstates <= CHAR_BIT*sizeof(states1) && !(eflags&REG_LARGE))
201 		return(smatcher(g, s, nmatch, pmatch, eflags));
202 	else
203 		return(lmatcher(g, s, nmatch, pmatch, eflags));
204 }
205