regexec.c revision 111010
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 111010 2003-02-16 17:29:11Z nectar $");
45
46/*
47 * the outer shell of regexec()
48 *
49 * This file includes engine.c *twice*, after muchos fiddling with the
50 * macros that code uses.  This lets the same code operate on two different
51 * representations for state sets.
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
61#include "utils.h"
62#include "regex2.h"
63
64static int nope __unused = 0;	/* for use in asserts; shuts lint up */
65
66/* macros for manipulating states, small version */
67#define	states	long
68#define	states1	states		/* for later use in regexec() decision */
69#define	CLEAR(v)	((v) = 0)
70#define	SET0(v, n)	((v) &= ~((unsigned long)1 << (n)))
71#define	SET1(v, n)	((v) |= (unsigned long)1 << (n))
72#define	ISSET(v, n)	(((v) & ((unsigned long)1 << (n))) != 0)
73#define	ASSIGN(d, s)	((d) = (s))
74#define	EQ(a, b)	((a) == (b))
75#define	STATEVARS	long dummy	/* dummy version */
76#define	STATESETUP(m, n)	/* nothing */
77#define	STATETEARDOWN(m)	/* nothing */
78#define	SETUP(v)	((v) = 0)
79#define	onestate	long
80#define	INIT(o, n)	((o) = (unsigned long)1 << (n))
81#define	INC(o)	((o) <<= 1)
82#define	ISSTATEIN(v, o)	(((v) & (o)) != 0)
83/* some abbreviations; note that some of these know variable names! */
84/* do "if I'm here, I can also be there" etc without branches */
85#define	FWD(dst, src, n)	((dst) |= ((unsigned long)(src)&(here)) << (n))
86#define	BACK(dst, src, n)	((dst) |= ((unsigned long)(src)&(here)) >> (n))
87#define	ISSETBACK(v, n)	(((v) & ((unsigned long)here >> (n))) != 0)
88/* function names */
89#define SNAMES			/* engine.c looks after details */
90
91#include "engine.c"
92
93/* now undo things */
94#undef	states
95#undef	CLEAR
96#undef	SET0
97#undef	SET1
98#undef	ISSET
99#undef	ASSIGN
100#undef	EQ
101#undef	STATEVARS
102#undef	STATESETUP
103#undef	STATETEARDOWN
104#undef	SETUP
105#undef	onestate
106#undef	INIT
107#undef	INC
108#undef	ISSTATEIN
109#undef	FWD
110#undef	BACK
111#undef	ISSETBACK
112#undef	SNAMES
113
114/* macros for manipulating states, large version */
115#define	states	char *
116#define	CLEAR(v)	memset(v, 0, m->g->nstates)
117#define	SET0(v, n)	((v)[n] = 0)
118#define	SET1(v, n)	((v)[n] = 1)
119#define	ISSET(v, n)	((v)[n])
120#define	ASSIGN(d, s)	memcpy(d, s, m->g->nstates)
121#define	EQ(a, b)	(memcmp(a, b, m->g->nstates) == 0)
122#define	STATEVARS	long vn; char *space
123#define	STATESETUP(m, nv)	{ (m)->space = malloc((nv)*(m)->g->nstates); \
124				if ((m)->space == NULL) return(REG_ESPACE); \
125				(m)->vn = 0; }
126#define	STATETEARDOWN(m)	{ free((m)->space); }
127#define	SETUP(v)	((v) = &m->space[m->vn++ * m->g->nstates])
128#define	onestate	long
129#define	INIT(o, n)	((o) = (n))
130#define	INC(o)	((o)++)
131#define	ISSTATEIN(v, o)	((v)[o])
132/* some abbreviations; note that some of these know variable names! */
133/* do "if I'm here, I can also be there" etc without branches */
134#define	FWD(dst, src, n)	((dst)[here+(n)] |= (src)[here])
135#define	BACK(dst, src, n)	((dst)[here-(n)] |= (src)[here])
136#define	ISSETBACK(v, n)	((v)[here - (n)])
137/* function names */
138#define	LNAMES			/* flag */
139
140#include "engine.c"
141
142/*
143 - regexec - interface for matching
144 = extern int regexec(const regex_t *, const char *, size_t, \
145 =					regmatch_t [], int);
146 = #define	REG_NOTBOL	00001
147 = #define	REG_NOTEOL	00002
148 = #define	REG_STARTEND	00004
149 = #define	REG_TRACE	00400	// tracing of execution
150 = #define	REG_LARGE	01000	// force large representation
151 = #define	REG_BACKR	02000	// force use of backref code
152 *
153 * We put this here so we can exploit knowledge of the state representation
154 * when choosing which matcher to call.  Also, by this point the matchers
155 * have been prototyped.
156 */
157int				/* 0 success, REG_NOMATCH failure */
158regexec(preg, string, nmatch, pmatch, eflags)
159const regex_t * __restrict preg;
160const char * __restrict string;
161size_t nmatch;
162regmatch_t pmatch[__restrict];
163int eflags;
164{
165	struct re_guts *g = preg->re_g;
166#ifdef REDEBUG
167#	define	GOODFLAGS(f)	(f)
168#else
169#	define	GOODFLAGS(f)	((f)&(REG_NOTBOL|REG_NOTEOL|REG_STARTEND))
170#endif
171
172	if (preg->re_magic != MAGIC1 || g->magic != MAGIC2)
173		return(REG_BADPAT);
174	assert(!(g->iflags&BAD));
175	if (g->iflags&BAD)		/* backstop for no-debug case */
176		return(REG_BADPAT);
177	eflags = GOODFLAGS(eflags);
178
179	if (g->nstates <= CHAR_BIT*sizeof(states1) && !(eflags&REG_LARGE))
180		return(smatcher(g, (char *)string, nmatch, pmatch, eflags));
181	else
182		return(lmatcher(g, (char *)string, nmatch, pmatch, eflags));
183}
184