xref: /netbsd-src/lib/libc/regex/regexec.c (revision ace896fac114f559f7469472324fbe68bbe378e5)
1 /*	$NetBSD: regexec.c,v 1.9 1997/07/21 14:08:17 jtc 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 1.9 1997/07/21 14:08:17 jtc 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 #include <stdio.h>
61 #include <stdlib.h>
62 #include <string.h>
63 #include <limits.h>
64 #include <ctype.h>
65 #include <regex.h>
66 
67 #ifdef __weak_alias
68 __weak_alias(regexec,_regexec);
69 #endif
70 
71 #include "utils.h"
72 #include "regex2.h"
73 
74 /* macros for manipulating states, small version */
75 #define	states	long
76 #define	states1	states		/* for later use in regexec() decision */
77 #define	CLEAR(v)	((v) = 0)
78 #define	SET0(v, n)	((v) &= ~((unsigned long)1 << (n)))
79 #define	SET1(v, n)	((v) |= (unsigned long)1 << (n))
80 #define	ISSET(v, n)	(((v) & ((unsigned long)1 << (n))) != 0)
81 #define	ASSIGN(d, s)	((d) = (s))
82 #define	EQ(a, b)	((a) == (b))
83 #define	STATEVARS	long dummy	/* dummy version */
84 #define	STATESETUP(m, n)	/* nothing */
85 #define	STATETEARDOWN(m)	/* nothing */
86 #define	SETUP(v)	((v) = 0)
87 #define	onestate	long
88 #define	INIT(o, n)	((o) = (unsigned long)1 << (n))
89 #define	INC(o)	((o) <<= 1)
90 #define	ISSTATEIN(v, o)	(((v) & (o)) != 0)
91 /* some abbreviations; note that some of these know variable names! */
92 /* do "if I'm here, I can also be there" etc without branches */
93 #define	FWD(dst, src, n)	((dst) |= ((unsigned long)(src)&(here)) << (n))
94 #define	BACK(dst, src, n)	((dst) |= ((unsigned long)(src)&(here)) >> (n))
95 #define	ISSETBACK(v, n)	(((v) & ((unsigned long)here >> (n))) != 0)
96 /* function names */
97 #define SNAMES			/* engine.c looks after details */
98 
99 #include "engine.c"
100 
101 /* now undo things */
102 #undef	states
103 #undef	CLEAR
104 #undef	SET0
105 #undef	SET1
106 #undef	ISSET
107 #undef	ASSIGN
108 #undef	EQ
109 #undef	STATEVARS
110 #undef	STATESETUP
111 #undef	STATETEARDOWN
112 #undef	SETUP
113 #undef	onestate
114 #undef	INIT
115 #undef	INC
116 #undef	ISSTATEIN
117 #undef	FWD
118 #undef	BACK
119 #undef	ISSETBACK
120 #undef	SNAMES
121 
122 /* macros for manipulating states, large version */
123 #define	states	char *
124 #define	CLEAR(v)	memset(v, 0, m->g->nstates)
125 #define	SET0(v, n)	((v)[n] = 0)
126 #define	SET1(v, n)	((v)[n] = 1)
127 #define	ISSET(v, n)	((v)[n])
128 #define	ASSIGN(d, s)	memcpy(d, s, m->g->nstates)
129 #define	EQ(a, b)	(memcmp(a, b, m->g->nstates) == 0)
130 #define	STATEVARS	long vn; char *space
131 #define	STATESETUP(m, nv)	{ (m)->space = malloc((nv)*(m)->g->nstates); \
132 				if ((m)->space == NULL) return(REG_ESPACE); \
133 				(m)->vn = 0; }
134 #define	STATETEARDOWN(m)	{ free((m)->space); }
135 #define	SETUP(v)	((v) = &m->space[m->vn++ * m->g->nstates])
136 #define	onestate	long
137 #define	INIT(o, n)	((o) = (n))
138 #define	INC(o)	((o)++)
139 #define	ISSTATEIN(v, o)	((v)[o])
140 /* some abbreviations; note that some of these know variable names! */
141 /* do "if I'm here, I can also be there" etc without branches */
142 #define	FWD(dst, src, n)	((dst)[here+(n)] |= (src)[here])
143 #define	BACK(dst, src, n)	((dst)[here-(n)] |= (src)[here])
144 #define	ISSETBACK(v, n)	((v)[here - (n)])
145 /* function names */
146 #define	LNAMES			/* flag */
147 
148 #include "engine.c"
149 
150 /*
151  - regexec - interface for matching
152  = extern int regexec(const regex_t *, const char *, size_t, \
153  =					regmatch_t [], int);
154  = #define	REG_NOTBOL	00001
155  = #define	REG_NOTEOL	00002
156  = #define	REG_STARTEND	00004
157  = #define	REG_TRACE	00400	// tracing of execution
158  = #define	REG_LARGE	01000	// force large representation
159  = #define	REG_BACKR	02000	// force use of backref code
160  *
161  * We put this here so we can exploit knowledge of the state representation
162  * when choosing which matcher to call.  Also, by this point the matchers
163  * have been prototyped.
164  */
165 int				/* 0 success, REG_NOMATCH failure */
166 regexec(preg, string, nmatch, pmatch, eflags)
167 const regex_t *preg;
168 const char *string;
169 size_t nmatch;
170 regmatch_t pmatch[];
171 int eflags;
172 {
173 	register struct re_guts *g = preg->re_g;
174 #ifdef REDEBUG
175 #	define	GOODFLAGS(f)	(f)
176 #else
177 #	define	GOODFLAGS(f)	((f)&(REG_NOTBOL|REG_NOTEOL|REG_STARTEND))
178 #endif
179 
180 	if (preg->re_magic != MAGIC1 || g->magic != MAGIC2)
181 		return(REG_BADPAT);
182 	assert(!(g->iflags&BAD));
183 	if (g->iflags&BAD)		/* backstop for no-debug case */
184 		return(REG_BADPAT);
185 	eflags = GOODFLAGS(eflags);
186 
187 	if (g->nstates <= CHAR_BIT*sizeof(states1) && !(eflags&REG_LARGE))
188 		return(smatcher(g, (char *)string, nmatch, pmatch, eflags));
189 	else
190 		return(lmatcher(g, (char *)string, nmatch, pmatch, eflags));
191 }
192