/*	$NetBSD: regexec.c,v 1.22 2012/03/13 21:13:43 christos Exp $	*/

/*-
 * 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
 */

/*-
 * Copyright (c) 1992, 1993, 1994 Henry Spencer.
 *
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. 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
 */

#include <sys/cdefs.h>

/*
 * the outer shell of regexec()
 *
 * This file includes engine.h *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 <assert.h>
#include <ctype.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <regex.h>

#include "utils.h"
#include "regex2.h"

/* macros for manipulating states, small version */
#define states unsigned long
#define states1 unsigned long /* 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 int dummy /* dummy version */
#define STATESETUP(m, n)    /* nothing */
#define STATETEARDOWN(m)    /* nothing */
#define SETUP(v) ((v) = 0)
#define onestate unsigned 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.h looks after details */

#include "engine.h"

/* 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, (size_t)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, (size_t)m->g->nstates)
#define EQ(a, b) (memcmp(a, b, (size_t)m->g->nstates) == 0)
#define STATEVARS                                                              \
  int vn;                                                                      \
  char *space
#define STATESETUP(m, nv)                                                      \
  if (((m)->space = malloc((size_t)((nv) * (m)->g->nstates))) == NULL)         \
    return (REG_ESPACE);                                                       \
  else                                                                         \
    (m)->vn = 0

#define STATETEARDOWN(m)                                                       \
  {                                                                            \
    free((m)->space);                                                          \
    m->space = NULL;                                                           \
  }
#define SETUP(v) ((v) = &m->space[(size_t)(m->vn++ * m->g->nstates)])
#define onestate int
#define INIT(o, n) ((o) = (int)(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.h"

/*
 - regexec - interface for matching
 = extern int regexec(const regex_t *, const char *, size_t, \
 =					regmatch_t [], int);
 = #define	REG_NOTBOL	00001
 = #define	REG_NOTEOL	00002
 = #define	REG_STARTEND	00004
 = #define	REG_TRACE	00400	// tracing of execution
 = #define	REG_LARGE	01000	// force large representation
 = #define	REG_BACKR	02000	// force use of backref code
 *
 * 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.
 */
int /* 0 success, REG_NOMATCH failure */
regexec(const regex_t *preg, const char *string, size_t nmatch,
        regmatch_t pmatch[], int eflags) {
  struct re_guts *g = preg->re_g;
  char *s;
#ifdef REDEBUG
#define GOODFLAGS(f) (f)
#else
#define GOODFLAGS(f) ((f) & (REG_NOTBOL | REG_NOTEOL | REG_STARTEND))
#endif

  _DIAGASSERT(preg != NULL);
  _DIAGASSERT(string != NULL);

  if (preg->re_magic != MAGIC1 || g->magic != MAGIC2)
    return (REG_BADPAT);
  assert(!(g->iflags & BAD));
  if (g->iflags & BAD) /* backstop for no-debug case */
    return (REG_BADPAT);
  eflags = GOODFLAGS(eflags);

  s = __UNCONST(string);

  if (g->nstates <= (sopno)(CHAR_BIT * sizeof(states1)) &&
      !(eflags & REG_LARGE))
    return (smatcher(g, s, nmatch, pmatch, eflags));
  else
    return (lmatcher(g, s, nmatch, pmatch, eflags));
}
