/*	$OpenBSD: regexec.c,v 1.11 2005/08/05 13:03:00 espie Exp $ */
/*-
 * Copyright (c) 1992, 1993, 1994 Henry Spencer.
 * Copyright (c) 1992, 1993, 1994
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Henry Spencer.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@ (#)regexec.c	8.3 (Berkeley) 3/20/94
 */

/*
 * the outer shell of regexec ()
 *
 * This file includes engine.c *twice*, after muchos fiddling with the
 * macros that code uses.  This lets the same code operate on two different
 * representations for state sets.
 */
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <ctype.h>
#include <r_regex.h>
#include "utils.h"
#include "regex2.h"

/* macros for manipulating states, small version */
#define states long
#define states1 states /* for later use in regexec() decision */
#define CLEAR(v) ((v) = 0)
#define SET0(v, n) ((v) &= ~ ((unsigned long)1 << (n)))
#define SET1(v, n) ((v) |= (unsigned long)1 << (n))
#define ISSET(v, n) (((v) & ((unsigned long)1 << (n))) != 0)
#define ASSIGN(d, s) ((d) = (s))
#define EQ(a, b) ((a) == (b))
#define STATEVARS long dummy /* dummy version */
#define STATESETUP(m, n) /* nothing */
#define STATETEARDOWN(m) /* nothing */
#define SETUP(v) ((v) = 0)
#define onestate long
#define INIT(o, n) ((o) = (unsigned long)1 << (n))
#define INC(o) ((o) <<= 1)
#define ISSTATEIN(v, o) (((v) & (o)) != 0)
/* some abbreviations; note that some of these know variable names! */
/* do "if I'm here, I can also be there" etc without branches */
#define FWD(dst, src, n) ((dst) |= ((unsigned long) (src) & (here)) << (n))
#define BACK(dst, src, n) ((dst) |= ((unsigned long) (src) & (here)) >> (n))
#define ISSETBACK(v, n) (((v) & ((unsigned long)here >> (n))) != 0)
/* function names */
#define SNAMES /* engine.c looks after details */

#include "engine.c"

/* now undo things */
#undef states
#undef CLEAR
#undef SET0
#undef SET1
#undef ISSET
#undef ASSIGN
#undef EQ
#undef STATEVARS
#undef STATESETUP
#undef STATETEARDOWN
#undef SETUP
#undef onestate
#undef INIT
#undef INC
#undef ISSTATEIN
#undef FWD
#undef BACK
#undef ISSETBACK
#undef SNAMES

/* macros for manipulating states, large version */
#define states char *
#define CLEAR(v) memset(v, 0, m->g->nstates)
#define SET0(v, n) ((v)[n] = 0)
#define SET1(v, n) ((v)[n] = 1)
#define ISSET(v, n) ((v)[n])
#define ASSIGN(d, s) memcpy(d, s, m->g->nstates)
#define EQ(a, b) (memcmp (a, b, m->g->nstates) == 0)
#define STATEVARS \
	long vn; \
	char *space
#define STATESETUP(m, nv) \
	{ \
		(m)->space = malloc ((nv) *(m)->g->nstates); \
		if (! (m)->space) \
			return R_REGEX_ESPACE; \
		(m)->vn = 0; \
	}
#define STATETEARDOWN(m) \
	{ free ((m)->space); }
#define SETUP(v) ((v) = &m->space[m->vn++ * m->g->nstates])
#define onestate long
#define INIT(o, n) ((o) = (n))
#define INC(o) ((o)++)
#define ISSTATEIN(v, o) ((v)[o])
/* some abbreviations; note that some of these know variable names! */
/* do "if I'm here, I can also be there" etc without branches */
#define FWD(dst, src, n) ((dst)[here + (n)] |= (src)[here])
#define BACK(dst, src, n) ((dst)[here - (n)] |= (src)[here])
#define ISSETBACK(v, n) ((v)[here - (n)])
/* function names */
#define LNAMES /* flag */

#include "engine.c"

R_API bool r_regex_check(const RRegex *rr, const char *str) {
	return r_regex_exec (rr, str, 0, NULL, 0);
}

/*
- regexec - interface for matching
 *
 * We put this here so we can exploit knowledge of the state representation
 * when choosing which matcher to call.  Also, by this point the matchers
 * have been prototyped.
 */
R_API int r_regex_exec(const RRegex *preg, const char *string, size_t nmatch, RRegexMatch pmatch[], int eflags) {
	if (!preg || !string) {
		return R_REGEX_ASSERT;
	}
	if (((int)nmatch) < 0) {
		return R_REGEX_INVARG;
	}
	struct re_guts *g = preg->re_g;
	if (preg->re_magic != MAGIC1 || g->magic != MAGIC2) {
		return R_REGEX_BADPAT;
	}
	if (g->iflags & BAD) { /* backstop for no-debug case */
		return R_REGEX_BADPAT;
	}
	bool large = eflags & R_REGEX_LARGE;
	eflags &= (R_REGEX_NOTBOL | R_REGEX_NOTEOL | R_REGEX_STARTEND);
	if (g->nstates <= CHAR_BIT * sizeof (states1) && !large) {
		return smatcher (g, (char *)string, nmatch, pmatch, eflags);
	}
	return lmatcher (g, (char *)string, nmatch, pmatch, eflags);
}