1/*	$NetBSD: regexec.c,v 1.22 2012/03/13 21:13:43 christos Exp $	*/
2
3/*-
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.
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. Neither the name of the University nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 *	@(#)regexec.c	8.3 (Berkeley) 3/20/94
35 */
36
37/*-
38 * Copyright (c) 1992, 1993, 1994 Henry Spencer.
39 *
40 * This code is derived from software contributed to Berkeley by
41 * Henry Spencer.
42 *
43 * Redistribution and use in source and binary forms, with or without
44 * modification, are permitted provided that the following conditions
45 * are met:
46 * 1. Redistributions of source code must retain the above copyright
47 *    notice, this list of conditions and the following disclaimer.
48 * 2. Redistributions in binary form must reproduce the above copyright
49 *    notice, this list of conditions and the following disclaimer in the
50 *    documentation and/or other materials provided with the distribution.
51 * 3. All advertising materials mentioning features or use of this software
52 *    must display the following acknowledgement:
53 *	This product includes software developed by the University of
54 *	California, Berkeley and its contributors.
55 * 4. Neither the name of the University nor the names of its contributors
56 *    may be used to endorse or promote products derived from this software
57 *    without specific prior written permission.
58 *
59 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
60 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
61 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
62 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
63 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
64 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
65 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
66 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
67 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
68 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
69 * SUCH DAMAGE.
70 *
71 *	@(#)regexec.c	8.3 (Berkeley) 3/20/94
72 */
73
74#include <sys/cdefs.h>
75#if defined(LIBC_SCCS) && !defined(lint)
76#if 0
77static char sccsid[] = "@(#)regexec.c	8.3 (Berkeley) 3/20/94";
78#else
79__RCSID("$NetBSD: regexec.c,v 1.22 2012/03/13 21:13:43 christos Exp $");
80#endif
81#endif /* LIBC_SCCS and not lint */
82
83/*
84 * the outer shell of regexec()
85 *
86 * This file includes engine.c *twice*, after muchos fiddling with the
87 * macros that code uses.  This lets the same code operate on two different
88 * representations for state sets.
89 */
90#include "namespace.h"
91#include <sys/types.h>
92
93#include <assert.h>
94#include <ctype.h>
95#include <limits.h>
96#include <stdio.h>
97#include <stdlib.h>
98#include <string.h>
99#include <regex.h>
100
101#ifdef __weak_alias
102__weak_alias(regexec,_regexec)
103#endif
104
105#include "utils.h"
106#include "regex2.h"
107
108/* macros for manipulating states, small version */
109#define	states	unsigned long
110#define	states1	unsigned long	/* for later use in regexec() decision */
111#define	CLEAR(v)	((v) = 0)
112#define	SET0(v, n)	((v) &= ~((unsigned long)1 << (n)))
113#define	SET1(v, n)	((v) |= (unsigned long)1 << (n))
114#define	ISSET(v, n)	(((v) & ((unsigned long)1 << (n))) != 0)
115#define	ASSIGN(d, s)	((d) = (s))
116#define	EQ(a, b)	((a) == (b))
117#define	STATEVARS	int dummy	/* dummy version */
118#define	STATESETUP(m, n)	/* nothing */
119#define	STATETEARDOWN(m)	/* nothing */
120#define	SETUP(v)	((v) = 0)
121#define	onestate	unsigned long
122#define	INIT(o, n)	((o) = (unsigned long)1 << (n))
123#define	INC(o)	((o) <<= 1)
124#define	ISSTATEIN(v, o)	(((v) & (o)) != 0)
125/* some abbreviations; note that some of these know variable names! */
126/* do "if I'm here, I can also be there" etc without branches */
127#define	FWD(dst, src, n)	((dst) |= ((unsigned long)(src)&(here)) << (n))
128#define	BACK(dst, src, n)	((dst) |= ((unsigned long)(src)&(here)) >> (n))
129#define	ISSETBACK(v, n)	(((v) & ((unsigned long)here >> (n))) != 0)
130/* function names */
131#define SNAMES			/* engine.c looks after details */
132
133#include "engine.c"
134
135/* now undo things */
136#undef	states
137#undef	CLEAR
138#undef	SET0
139#undef	SET1
140#undef	ISSET
141#undef	ASSIGN
142#undef	EQ
143#undef	STATEVARS
144#undef	STATESETUP
145#undef	STATETEARDOWN
146#undef	SETUP
147#undef	onestate
148#undef	INIT
149#undef	INC
150#undef	ISSTATEIN
151#undef	FWD
152#undef	BACK
153#undef	ISSETBACK
154#undef	SNAMES
155
156/* macros for manipulating states, large version */
157#define	states	char *
158#define	CLEAR(v)	memset(v, 0, (size_t)m->g->nstates)
159#define	SET0(v, n)	((v)[n] = 0)
160#define	SET1(v, n)	((v)[n] = 1)
161#define	ISSET(v, n)	((v)[n])
162#define	ASSIGN(d, s)	memcpy(d, s, (size_t)m->g->nstates)
163#define	EQ(a, b)	(memcmp(a, b, (size_t)m->g->nstates) == 0)
164#define	STATEVARS	int vn; char *space
165#define	STATESETUP(m, nv) \
166    if (((m)->space = malloc((size_t)((nv)*(m)->g->nstates))) == NULL) \
167	return(REG_ESPACE); \
168    else \
169	(m)->vn = 0
170
171#define	STATETEARDOWN(m)	{ free((m)->space); m->space = NULL; }
172#define	SETUP(v)	((v) = &m->space[(size_t)(m->vn++ * m->g->nstates)])
173#define	onestate	int
174#define	INIT(o, n)	((o) = (int)(n))
175#define	INC(o)	((o)++)
176#define	ISSTATEIN(v, o)	((v)[o])
177/* some abbreviations; note that some of these know variable names! */
178/* do "if I'm here, I can also be there" etc without branches */
179#define	FWD(dst, src, n)	((dst)[here+(n)] |= (src)[here])
180#define	BACK(dst, src, n)	((dst)[here-(n)] |= (src)[here])
181#define	ISSETBACK(v, n)	((v)[here - (n)])
182/* function names */
183#define	LNAMES			/* flag */
184
185#include "engine.c"
186
187/*
188 - regexec - interface for matching
189 = extern int regexec(const regex_t *, const char *, size_t, \
190 =					regmatch_t [], int);
191 = #define	REG_NOTBOL	00001
192 = #define	REG_NOTEOL	00002
193 = #define	REG_STARTEND	00004
194 = #define	REG_TRACE	00400	// tracing of execution
195 = #define	REG_LARGE	01000	// force large representation
196 = #define	REG_BACKR	02000	// force use of backref code
197 *
198 * We put this here so we can exploit knowledge of the state representation
199 * when choosing which matcher to call.  Also, by this point the matchers
200 * have been prototyped.
201 */
202int				/* 0 success, REG_NOMATCH failure */
203regexec(
204    const regex_t *preg,
205    const char *string,
206    size_t nmatch,
207    regmatch_t pmatch[],
208    int eflags)
209{
210	struct re_guts *g = preg->re_g;
211	char *s;
212#ifdef REDEBUG
213#	define	GOODFLAGS(f)	(f)
214#else
215#	define	GOODFLAGS(f)	((f)&(REG_NOTBOL|REG_NOTEOL|REG_STARTEND))
216#endif
217
218	_DIAGASSERT(preg != NULL);
219	_DIAGASSERT(string != NULL);
220
221	if (preg->re_magic != MAGIC1 || g->magic != MAGIC2)
222		return(REG_BADPAT);
223	assert(!(g->iflags&BAD));
224	if (g->iflags&BAD)		/* backstop for no-debug case */
225		return(REG_BADPAT);
226	eflags = GOODFLAGS(eflags);
227
228	s = __UNCONST(string);
229
230	if (g->nstates <= (sopno)(CHAR_BIT*sizeof(states1)) && !(eflags&REG_LARGE))
231		return(smatcher(g, s, nmatch, pmatch, eflags));
232	else
233		return(lmatcher(g, s, nmatch, pmatch, eflags));
234}
235