xref: /minix3/lib/libc/regex/regexec.c (revision 9a21d1a2fdca366d7697d6ecbfe4ed6d5851f9c7)
1 /*-
2  * Copyright (c) 1992, 1993, 1994 Henry Spencer.
3  * Copyright (c) 1992, 1993, 1994
4  *	The Regents of the University of California.  All rights reserved.
5  *
6  * This code is derived from software contributed to Berkeley by
7  * Henry Spencer.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *	This product includes software developed by the University of
20  *	California, Berkeley and its contributors.
21  * 4. Neither the name of the University nor the names of its contributors
22  *    may be used to endorse or promote products derived from this software
23  *    without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  *
37  *	@(#)regexec.c	8.3 (Berkeley) 3/20/94
38  */
39 
40 #if defined(LIBC_SCCS) && !defined(lint)
41 static char sccsid[] = "@(#)regexec.c	8.3 (Berkeley) 3/20/94";
42 #endif /* LIBC_SCCS and not lint */
43 
44 /*
45  * the outer shell of regexec()
46  *
47  * This file includes engine.c *twice*, after muchos fiddling with the
48  * macros that code uses.  This lets the same code operate on two different
49  * representations for state sets.
50  */
51 #include <sys/types.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <string.h>
55 #include <limits.h>
56 #include <unistd.h>
57 #ifdef __minix_vmd
58 #include <bsd/asciictype.h>
59 #else
60 #include <ctype.h>
61 #endif
62 #include <regex.h>
63 
64 #include "utils.h"
65 #include "regex2.h"
66 
67 static int nope = 0;		/* for use in asserts; shuts lint up */
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) &= ~(1 << (n)))
74 #define	SET1(v, n)	((v) |= 1 << (n))
75 #define	ISSET(v, n)	((v) & (1 << (n)))
76 #define	ASSIGN(d, s)	((d) = (s))
77 #define	EQ(a, b)	((a) == (b))
78 #define	STATEVARS	int dummy	/* dummy version */
79 #define	STATESETUP(m, n)	/* nothing */
80 #define	STATETEARDOWN(m)	/* nothing */
81 #define	SETUP(v)	((v) = 0)
82 #define	onestate	int
83 #define	INIT(o, n)	((o) = (unsigned)1 << (n))
84 #define	INC(o)	((o) <<= 1)
85 #define	ISSTATEIN(v, o)	((v) & (o))
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)(src)&(here)) << (n))
89 #define	BACK(dst, src, n)	((dst) |= ((unsigned)(src)&(here)) >> (n))
90 #define	ISSETBACK(v, n)	((v) & ((unsigned)here >> (n)))
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	int 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	int
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 
188 /*
189  * $PchId: regexec.c,v 1.2 1996/03/12 19:10:15 philip Exp $
190  */
191