xref: /minix3/external/bsd/nvi/dist/regex/regexec.c (revision 0b98e8aad89f2bd4ba80b523d73cf29e9dd82ce1)
1 /*	$NetBSD: regexec.c,v 1.2 2013/11/22 15:52:06 christos Exp $ */
2 /*-
3  * Copyright (c) 1992, 1993, 1994 Henry Spencer.
4  * Copyright (c) 1992, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Henry Spencer of the University of Toronto.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  *
38  *	@(#)regexec.c	8.2 (Berkeley) 3/16/94
39  */
40 
41 #if defined(LIBC_SCCS) && !defined(lint)
42 static char sccsid[] = "@(#)regexec.c	8.2 (Berkeley) 3/16/94";
43 #endif /* LIBC_SCCS and not lint */
44 
45 /*
46  * the outer shell of regexec()
47  *
48  * This file includes engine.c *twice*, after muchos fiddling with the
49  * macros that code uses.  This lets the same code operate on two different
50  * representations for state sets.
51  */
52 #include <sys/types.h>
53 #include <stdio.h>
54 #include <stdlib.h>
55 #include <string.h>
56 #include <limits.h>
57 #include <ctype.h>
58 #include <regex.h>
59 
60 #include "utils.h"
61 #include "regex2.h"
62 
63 #ifdef notdef
64 static int nope = 0;		/* for use in asserts; shuts lint up */
65 #endif
66 
67 /* macros for manipulating states, small version */
68 #define	states	int
69 #define	states1	int		/* for later use in regexec() decision */
70 #define	CLEAR(v)	((v) = 0)
71 #define	SET0(v, n)	((v) &= ~(1 << (n)))
72 #define	SET1(v, n)	((v) |= 1 << (n))
73 #define	ISSET(v, n)	((v) & (1 << (n)))
74 #define	ASSIGN(d, s)	((d) = (s))
75 #define	EQ(a, b)	((a) == (b))
76 #define	STATEVARS	int dummy	/* dummy version */
77 #define	STATESETUP(m, n)	/* nothing */
78 #define	STATETEARDOWN(m)	/* nothing */
79 #define	SETUP(v)	((v) = 0)
80 #define	onestate	int
81 #define	INIT(o, n)	((o) = (unsigned)1 << (n))
82 #define	INC(o)	((o) <<= 1)
83 #define	ISSTATEIN(v, o)	((v) & (o))
84 /* some abbreviations; note that some of these know variable names! */
85 /* do "if I'm here, I can also be there" etc without branches */
86 #define	FWD(dst, src, n)	((dst) |= ((unsigned)(src)&(here)) << (n))
87 #define	BACK(dst, src, n)	((dst) |= ((unsigned)(src)&(here)) >> (n))
88 #define	ISSETBACK(v, n)	((v) & ((unsigned)here >> (n)))
89 /* function names */
90 #define SNAMES			/* engine.c looks after details */
91 
92 #include "engine.c"
93 
94 /* now undo things */
95 #undef	states
96 #undef	CLEAR
97 #undef	SET0
98 #undef	SET1
99 #undef	ISSET
100 #undef	ASSIGN
101 #undef	EQ
102 #undef	STATEVARS
103 #undef	STATESETUP
104 #undef	STATETEARDOWN
105 #undef	SETUP
106 #undef	onestate
107 #undef	INIT
108 #undef	INC
109 #undef	ISSTATEIN
110 #undef	FWD
111 #undef	BACK
112 #undef	ISSETBACK
113 #undef	SNAMES
114 
115 /* macros for manipulating states, large version */
116 #define	states	char *
117 #define	CLEAR(v)	memset(v, 0, m->g->nstates)
118 #define	SET0(v, n)	((v)[n] = 0)
119 #define	SET1(v, n)	((v)[n] = 1)
120 #define	ISSET(v, n)	((v)[n])
121 #define	ASSIGN(d, s)	memcpy(d, s, m->g->nstates)
122 #define	EQ(a, b)	(memcmp(a, b, m->g->nstates) == 0)
123 #define	STATEVARS	int vn; char *space
124 #define	STATESETUP(m, nv)	{ (m)->space = malloc((nv)*(m)->g->nstates); \
125 				if ((m)->space == NULL) return(REG_ESPACE); \
126 				(m)->vn = 0; }
127 #define	STATETEARDOWN(m)	{ free((m)->space); }
128 #define	SETUP(v)	((v) = &m->space[m->vn++ * m->g->nstates])
129 #define	onestate	int
130 #define	INIT(o, n)	((o) = (n))
131 #define	INC(o)	((o)++)
132 #define	ISSTATEIN(v, o)	((v)[o])
133 /* some abbreviations; note that some of these know variable names! */
134 /* do "if I'm here, I can also be there" etc without branches */
135 #define	FWD(dst, src, n)	((dst)[here+(n)] |= (src)[here])
136 #define	BACK(dst, src, n)	((dst)[here-(n)] |= (src)[here])
137 #define	ISSETBACK(v, n)	((v)[here - (n)])
138 /* function names */
139 #define	LNAMES			/* flag */
140 
141 #include "engine.c"
142 
143 /*
144  - regexec - interface for matching
145  = extern int regexec(const regex_t *, const char *, size_t, \
146  =					regmatch_t [], int);
147  = #define	REG_NOTBOL	00001
148  = #define	REG_NOTEOL	00002
149  = #define	REG_STARTEND	00004
150  = #define	REG_TRACE	00400	// tracing of execution
151  = #define	REG_LARGE	01000	// force large representation
152  = #define	REG_BACKR	02000	// force use of backref code
153  *
154  * We put this here so we can exploit knowledge of the state representation
155  * when choosing which matcher to call.  Also, by this point the matchers
156  * have been prototyped.
157  */
158 int				/* 0 success, REG_NOMATCH failure */
159 regexec(const regex_t *preg, const RCHAR_T *string, size_t nmatch, regmatch_t *pmatch, int eflags)
160 {
161 	register struct re_guts *g = preg->re_g;
162 #ifdef REDEBUG
163 #	define	GOODFLAGS(f)	(f)
164 #else
165 #	define	GOODFLAGS(f)	((f)&(REG_NOTBOL|REG_NOTEOL|REG_STARTEND))
166 #endif
167 
168 	if (preg->re_magic != MAGIC1 || g->magic != MAGIC2)
169 		return(REG_BADPAT);
170 	assert(!(g->iflags&BAD));
171 	if (g->iflags&BAD)		/* backstop for no-debug case */
172 		return(REG_BADPAT);
173 	eflags = GOODFLAGS(eflags);
174 
175 	if (g->nstates <= (int)(CHAR_BIT*sizeof(states1)) && !(eflags&REG_LARGE))
176 		return(smatcher(g, (RCHAR_T *)__UNCONST(string), nmatch, pmatch, eflags));
177 	else
178 		return(lmatcher(g, (RCHAR_T *)__UNCONST(string), nmatch, pmatch, eflags));
179 }
180