1/*	$OpenBSD: regexec.c,v 1.11 2005/08/05 13:03:00 espie 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.
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 * the outer shell of regexec()
39 *
40 * This file includes engine.c *twice*, after muchos fiddling with the
41 * macros that code uses.  This lets the same code operate on two different
42 * representations for state sets.
43 */
44#include <sys/types.h>
45#include <stdio.h>
46#include <stdlib.h>
47#include <string.h>
48#include <limits.h>
49#include <ctype.h>
50#include <regex.h>
51
52#include "utils.h"
53#include "regex2.h"
54
55/* macros for manipulating states, small version */
56#define	states	long
57#define	states1	states		/* for later use in regexec() decision */
58#define	CLEAR(v)	((v) = 0)
59#define	SET0(v, n)	((v) &= ~((unsigned long)1 << (n)))
60#define	SET1(v, n)	((v) |= (unsigned long)1 << (n))
61#define	ISSET(v, n)	(((v) & ((unsigned long)1 << (n))) != 0)
62#define	ASSIGN(d, s)	((d) = (s))
63#define	EQ(a, b)	((a) == (b))
64#define	STATEVARS	long dummy	/* dummy version */
65#define	STATESETUP(m, n)	/* nothing */
66#define	STATETEARDOWN(m)	/* nothing */
67#define	SETUP(v)	((v) = 0)
68#define	onestate	long
69#define	INIT(o, n)	((o) = (unsigned long)1 << (n))
70#define	INC(o)		((o) <<= 1)
71#define	ISSTATEIN(v, o)	(((v) & (o)) != 0)
72/* some abbreviations; note that some of these know variable names! */
73/* do "if I'm here, I can also be there" etc without branches */
74#define	FWD(dst, src, n)	((dst) |= ((unsigned long)(src)&(here)) << (n))
75#define	BACK(dst, src, n)	((dst) |= ((unsigned long)(src)&(here)) >> (n))
76#define	ISSETBACK(v, n)		(((v) & ((unsigned long)here >> (n))) != 0)
77/* function names */
78#define SNAMES			/* engine.c looks after details */
79
80#include "engine.c"
81
82/* now undo things */
83#undef	states
84#undef	CLEAR
85#undef	SET0
86#undef	SET1
87#undef	ISSET
88#undef	ASSIGN
89#undef	EQ
90#undef	STATEVARS
91#undef	STATESETUP
92#undef	STATETEARDOWN
93#undef	SETUP
94#undef	onestate
95#undef	INIT
96#undef	INC
97#undef	ISSTATEIN
98#undef	FWD
99#undef	BACK
100#undef	ISSETBACK
101#undef	SNAMES
102
103/* macros for manipulating states, large version */
104#define	states	char *
105#define	CLEAR(v)	memset(v, 0, m->g->nstates)
106#define	SET0(v, n)	((v)[n] = 0)
107#define	SET1(v, n)	((v)[n] = 1)
108#define	ISSET(v, n)	((v)[n])
109#define	ASSIGN(d, s)	memcpy(d, s, m->g->nstates)
110#define	EQ(a, b)	(memcmp(a, b, m->g->nstates) == 0)
111#define	STATEVARS	long vn; char *space
112#define	STATESETUP(m, nv)	{ (m)->space = malloc((nv)*(m)->g->nstates); \
113				if ((m)->space == NULL) return(REG_ESPACE); \
114				(m)->vn = 0; }
115#define	STATETEARDOWN(m)	{ free((m)->space); }
116#define	SETUP(v)	((v) = &m->space[m->vn++ * m->g->nstates])
117#define	onestate	long
118#define	INIT(o, n)	((o) = (n))
119#define	INC(o)	((o)++)
120#define	ISSTATEIN(v, o)	((v)[o])
121/* some abbreviations; note that some of these know variable names! */
122/* do "if I'm here, I can also be there" etc without branches */
123#define	FWD(dst, src, n)	((dst)[here+(n)] |= (src)[here])
124#define	BACK(dst, src, n)	((dst)[here-(n)] |= (src)[here])
125#define	ISSETBACK(v, n)	((v)[here - (n)])
126/* function names */
127#define	LNAMES			/* flag */
128
129#include "engine.c"
130
131/*
132 - regexec - interface for matching
133 *
134 * We put this here so we can exploit knowledge of the state representation
135 * when choosing which matcher to call.  Also, by this point the matchers
136 * have been prototyped.
137 */
138int				/* 0 success, REG_NOMATCH failure */
139regexec(const regex_t *preg, const char *string, size_t nmatch,
140    regmatch_t pmatch[], int eflags)
141{
142	struct re_guts *g = preg->re_g;
143#ifdef REDEBUG
144#	define	GOODFLAGS(f)	(f)
145#else
146#	define	GOODFLAGS(f)	((f)&(REG_NOTBOL|REG_NOTEOL|REG_STARTEND))
147#endif
148
149	if (preg->re_magic != MAGIC1 || g->magic != MAGIC2)
150		return(REG_BADPAT);
151	assert(!(g->iflags&BAD));
152	if (g->iflags&BAD)		/* backstop for no-debug case */
153		return(REG_BADPAT);
154	eflags = GOODFLAGS(eflags);
155
156	if (g->nstates <= (int)(CHAR_BIT*sizeof(states1)) && !(eflags&REG_LARGE))
157		return(smatcher(g, (char *)string, nmatch, pmatch, eflags));
158	else
159		return(lmatcher(g, (char *)string, nmatch, pmatch, eflags));
160}
161