xref: /netbsd-src/lib/libc/regex/regexec.c (revision 1394f01b4a9e99092957ca5d824d67219565d9b5)
1 /*	$NetBSD: regexec.c,v 1.8 1997/07/13 20:06:00 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 1.8 1997/07/13 20:06:00 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 <sys/types.h>
59 #include <stdio.h>
60 #include <stdlib.h>
61 #include <string.h>
62 #include <limits.h>
63 #include <ctype.h>
64 #include <regex.h>
65 
66 #include "utils.h"
67 #include "regex2.h"
68 
69 /* macros for manipulating states, small version */
70 #define	states	long
71 #define	states1	states		/* for later use in regexec() decision */
72 #define	CLEAR(v)	((v) = 0)
73 #define	SET0(v, n)	((v) &= ~((unsigned long)1 << (n)))
74 #define	SET1(v, n)	((v) |= (unsigned long)1 << (n))
75 #define	ISSET(v, n)	(((v) & ((unsigned long)1 << (n))) != 0)
76 #define	ASSIGN(d, s)	((d) = (s))
77 #define	EQ(a, b)	((a) == (b))
78 #define	STATEVARS	long dummy	/* dummy version */
79 #define	STATESETUP(m, n)	/* nothing */
80 #define	STATETEARDOWN(m)	/* nothing */
81 #define	SETUP(v)	((v) = 0)
82 #define	onestate	long
83 #define	INIT(o, n)	((o) = (unsigned long)1 << (n))
84 #define	INC(o)	((o) <<= 1)
85 #define	ISSTATEIN(v, o)	(((v) & (o)) != 0)
86 /* some abbreviations; note that some of these know variable names! */
87 /* do "if I'm here, I can also be there" etc without branches */
88 #define	FWD(dst, src, n)	((dst) |= ((unsigned long)(src)&(here)) << (n))
89 #define	BACK(dst, src, n)	((dst) |= ((unsigned long)(src)&(here)) >> (n))
90 #define	ISSETBACK(v, n)	(((v) & ((unsigned long)here >> (n))) != 0)
91 /* function names */
92 #define SNAMES			/* engine.c looks after details */
93 
94 #include "engine.c"
95 
96 /* now undo things */
97 #undef	states
98 #undef	CLEAR
99 #undef	SET0
100 #undef	SET1
101 #undef	ISSET
102 #undef	ASSIGN
103 #undef	EQ
104 #undef	STATEVARS
105 #undef	STATESETUP
106 #undef	STATETEARDOWN
107 #undef	SETUP
108 #undef	onestate
109 #undef	INIT
110 #undef	INC
111 #undef	ISSTATEIN
112 #undef	FWD
113 #undef	BACK
114 #undef	ISSETBACK
115 #undef	SNAMES
116 
117 /* macros for manipulating states, large version */
118 #define	states	char *
119 #define	CLEAR(v)	memset(v, 0, m->g->nstates)
120 #define	SET0(v, n)	((v)[n] = 0)
121 #define	SET1(v, n)	((v)[n] = 1)
122 #define	ISSET(v, n)	((v)[n])
123 #define	ASSIGN(d, s)	memcpy(d, s, m->g->nstates)
124 #define	EQ(a, b)	(memcmp(a, b, m->g->nstates) == 0)
125 #define	STATEVARS	long vn; char *space
126 #define	STATESETUP(m, nv)	{ (m)->space = malloc((nv)*(m)->g->nstates); \
127 				if ((m)->space == NULL) return(REG_ESPACE); \
128 				(m)->vn = 0; }
129 #define	STATETEARDOWN(m)	{ free((m)->space); }
130 #define	SETUP(v)	((v) = &m->space[m->vn++ * m->g->nstates])
131 #define	onestate	long
132 #define	INIT(o, n)	((o) = (n))
133 #define	INC(o)	((o)++)
134 #define	ISSTATEIN(v, o)	((v)[o])
135 /* some abbreviations; note that some of these know variable names! */
136 /* do "if I'm here, I can also be there" etc without branches */
137 #define	FWD(dst, src, n)	((dst)[here+(n)] |= (src)[here])
138 #define	BACK(dst, src, n)	((dst)[here-(n)] |= (src)[here])
139 #define	ISSETBACK(v, n)	((v)[here - (n)])
140 /* function names */
141 #define	LNAMES			/* flag */
142 
143 #include "engine.c"
144 
145 /*
146  - regexec - interface for matching
147  = extern int regexec(const regex_t *, const char *, size_t, \
148  =					regmatch_t [], int);
149  = #define	REG_NOTBOL	00001
150  = #define	REG_NOTEOL	00002
151  = #define	REG_STARTEND	00004
152  = #define	REG_TRACE	00400	// tracing of execution
153  = #define	REG_LARGE	01000	// force large representation
154  = #define	REG_BACKR	02000	// force use of backref code
155  *
156  * We put this here so we can exploit knowledge of the state representation
157  * when choosing which matcher to call.  Also, by this point the matchers
158  * have been prototyped.
159  */
160 int				/* 0 success, REG_NOMATCH failure */
161 regexec(preg, string, nmatch, pmatch, eflags)
162 const regex_t *preg;
163 const char *string;
164 size_t nmatch;
165 regmatch_t pmatch[];
166 int eflags;
167 {
168 	register struct re_guts *g = preg->re_g;
169 #ifdef REDEBUG
170 #	define	GOODFLAGS(f)	(f)
171 #else
172 #	define	GOODFLAGS(f)	((f)&(REG_NOTBOL|REG_NOTEOL|REG_STARTEND))
173 #endif
174 
175 	if (preg->re_magic != MAGIC1 || g->magic != MAGIC2)
176 		return(REG_BADPAT);
177 	assert(!(g->iflags&BAD));
178 	if (g->iflags&BAD)		/* backstop for no-debug case */
179 		return(REG_BADPAT);
180 	eflags = GOODFLAGS(eflags);
181 
182 	if (g->nstates <= CHAR_BIT*sizeof(states1) && !(eflags&REG_LARGE))
183 		return(smatcher(g, (char *)string, nmatch, pmatch, eflags));
184 	else
185 		return(lmatcher(g, (char *)string, nmatch, pmatch, eflags));
186 }
187