regexec.c revision 132019
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)
41static char sccsid[] = "@(#)regexec.c	8.3 (Berkeley) 3/20/94";
42#endif /* LIBC_SCCS and not lint */
43#include <sys/cdefs.h>
44__FBSDID("$FreeBSD: head/lib/libc/regex/regexec.c 132019 2004-07-12 07:35:59Z tjr $");
45
46/*
47 * the outer shell of regexec()
48 *
49 * This file includes engine.c three times, after muchos fiddling with the
50 * macros that code uses.  This lets the same code operate on two different
51 * representations for state sets and characters.
52 */
53#include <sys/types.h>
54#include <stdio.h>
55#include <stdlib.h>
56#include <string.h>
57#include <limits.h>
58#include <ctype.h>
59#include <regex.h>
60#include <wchar.h>
61#include <wctype.h>
62
63#include "utils.h"
64#include "regex2.h"
65
66static int nope __unused = 0;	/* for use in asserts; shuts lint up */
67
68static __inline size_t
69xmbrtowc(wi, s, n, mbs, dummy)
70wint_t *wi;
71const char *s;
72size_t n;
73mbstate_t *mbs;
74wint_t dummy;
75{
76	size_t nr;
77	wchar_t wc;
78
79	nr = mbrtowc(&wc, s, n, mbs);
80	if (wi != NULL)
81		*wi = wc;
82	if (nr == 0)
83		return (1);
84	else if (nr == (size_t)-1 || nr == (size_t)-2) {
85		memset(mbs, 0, sizeof(*mbs));
86		if (wi != NULL)
87			*wi = dummy;
88		return (1);
89	} else
90                return (nr);
91}
92
93static __inline size_t
94xmbrtowc_dummy(wi, s, n, mbs, dummy)
95wint_t *wi;
96const char *s;
97size_t n __unused;
98mbstate_t *mbs __unused;
99wint_t dummy __unused;
100{
101
102	if (wi != NULL)
103		*wi = (unsigned char)*s;
104	return (1);
105}
106
107/* macros for manipulating states, small version */
108#define	states	long
109#define	states1	states		/* for later use in regexec() decision */
110#define	CLEAR(v)	((v) = 0)
111#define	SET0(v, n)	((v) &= ~((unsigned long)1 << (n)))
112#define	SET1(v, n)	((v) |= (unsigned long)1 << (n))
113#define	ISSET(v, n)	(((v) & ((unsigned long)1 << (n))) != 0)
114#define	ASSIGN(d, s)	((d) = (s))
115#define	EQ(a, b)	((a) == (b))
116#define	STATEVARS	long dummy	/* dummy version */
117#define	STATESETUP(m, n)	/* nothing */
118#define	STATETEARDOWN(m)	/* nothing */
119#define	SETUP(v)	((v) = 0)
120#define	onestate	long
121#define	INIT(o, n)	((o) = (unsigned long)1 << (n))
122#define	INC(o)	((o) <<= 1)
123#define	ISSTATEIN(v, o)	(((v) & (o)) != 0)
124/* some abbreviations; note that some of these know variable names! */
125/* do "if I'm here, I can also be there" etc without branches */
126#define	FWD(dst, src, n)	((dst) |= ((unsigned long)(src)&(here)) << (n))
127#define	BACK(dst, src, n)	((dst) |= ((unsigned long)(src)&(here)) >> (n))
128#define	ISSETBACK(v, n)	(((v) & ((unsigned long)here >> (n))) != 0)
129/* no multibyte support */
130#define	XMBRTOWC	xmbrtowc_dummy
131#define	ZAPSTATE(mbs)	((void)(mbs))
132/* function names */
133#define SNAMES			/* engine.c looks after details */
134
135#include "engine.c"
136
137/* now undo things */
138#undef	states
139#undef	CLEAR
140#undef	SET0
141#undef	SET1
142#undef	ISSET
143#undef	ASSIGN
144#undef	EQ
145#undef	STATEVARS
146#undef	STATESETUP
147#undef	STATETEARDOWN
148#undef	SETUP
149#undef	onestate
150#undef	INIT
151#undef	INC
152#undef	ISSTATEIN
153#undef	FWD
154#undef	BACK
155#undef	ISSETBACK
156#undef	SNAMES
157#undef	XMBRTOWC
158#undef	ZAPSTATE
159
160/* macros for manipulating states, large version */
161#define	states	char *
162#define	CLEAR(v)	memset(v, 0, m->g->nstates)
163#define	SET0(v, n)	((v)[n] = 0)
164#define	SET1(v, n)	((v)[n] = 1)
165#define	ISSET(v, n)	((v)[n])
166#define	ASSIGN(d, s)	memcpy(d, s, m->g->nstates)
167#define	EQ(a, b)	(memcmp(a, b, m->g->nstates) == 0)
168#define	STATEVARS	long vn; char *space
169#define	STATESETUP(m, nv)	{ (m)->space = malloc((nv)*(m)->g->nstates); \
170				if ((m)->space == NULL) return(REG_ESPACE); \
171				(m)->vn = 0; }
172#define	STATETEARDOWN(m)	{ free((m)->space); }
173#define	SETUP(v)	((v) = &m->space[m->vn++ * m->g->nstates])
174#define	onestate	long
175#define	INIT(o, n)	((o) = (n))
176#define	INC(o)	((o)++)
177#define	ISSTATEIN(v, o)	((v)[o])
178/* some abbreviations; note that some of these know variable names! */
179/* do "if I'm here, I can also be there" etc without branches */
180#define	FWD(dst, src, n)	((dst)[here+(n)] |= (src)[here])
181#define	BACK(dst, src, n)	((dst)[here-(n)] |= (src)[here])
182#define	ISSETBACK(v, n)	((v)[here - (n)])
183/* no multibyte support */
184#define	XMBRTOWC	xmbrtowc_dummy
185#define	ZAPSTATE(mbs)	((void)(mbs))
186/* function names */
187#define	LNAMES			/* flag */
188
189#include "engine.c"
190
191/* multibyte character & large states version */
192#undef	LNAMES
193#undef	XMBRTOWC
194#undef	ZAPSTATE
195#define	XMBRTOWC	xmbrtowc
196#define	ZAPSTATE(mbs)	memset((mbs), 0, sizeof(*(mbs)))
197#define	MNAMES
198
199#include "engine.c"
200
201/*
202 - regexec - interface for matching
203 = extern int regexec(const regex_t *, const char *, size_t, \
204 =					regmatch_t [], int);
205 = #define	REG_NOTBOL	00001
206 = #define	REG_NOTEOL	00002
207 = #define	REG_STARTEND	00004
208 = #define	REG_TRACE	00400	// tracing of execution
209 = #define	REG_LARGE	01000	// force large representation
210 = #define	REG_BACKR	02000	// force use of backref code
211 *
212 * We put this here so we can exploit knowledge of the state representation
213 * when choosing which matcher to call.  Also, by this point the matchers
214 * have been prototyped.
215 */
216int				/* 0 success, REG_NOMATCH failure */
217regexec(preg, string, nmatch, pmatch, eflags)
218const regex_t * __restrict preg;
219const char * __restrict string;
220size_t nmatch;
221regmatch_t pmatch[__restrict];
222int eflags;
223{
224	struct re_guts *g = preg->re_g;
225#ifdef REDEBUG
226#	define	GOODFLAGS(f)	(f)
227#else
228#	define	GOODFLAGS(f)	((f)&(REG_NOTBOL|REG_NOTEOL|REG_STARTEND))
229#endif
230
231	if (preg->re_magic != MAGIC1 || g->magic != MAGIC2)
232		return(REG_BADPAT);
233	assert(!(g->iflags&BAD));
234	if (g->iflags&BAD)		/* backstop for no-debug case */
235		return(REG_BADPAT);
236	eflags = GOODFLAGS(eflags);
237
238	if (MB_CUR_MAX > 1)
239		return(mmatcher(g, (char *)string, nmatch, pmatch, eflags));
240	else if (g->nstates <= CHAR_BIT*sizeof(states1) && !(eflags&REG_LARGE))
241		return(smatcher(g, (char *)string, nmatch, pmatch, eflags));
242	else
243		return(lmatcher(g, (char *)string, nmatch, pmatch, eflags));
244}
245