/*  $OpenBSD: regexec.c,v 1.14 2018/07/11 12:38:46 martijn 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 "others.h"

#include "regex.h"

#include "utils.h"

#include "regex2.h"

/* macros for manipulating states, small version */

#define states  long

#define states1 long    /* for later use in cli_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 = cli_max_malloc((nv)*(m)->g->nstates); \

        if ((m)->space == NULL) return(REG_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"

/*

 - 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.

 */

int       /* 0 success, REG_NOMATCH failure */

cli_regexec(const regex_t *preg, const char *string, size_t nmatch,

    regmatch_t pmatch[], int eflags)

{

  struct re_guts *g = preg->re_g;

#ifdef REDEBUG

# define  GOODFLAGS(f)  (f)

#else

# define  GOODFLAGS(f)  ((f)&(REG_NOTBOL|REG_NOTEOL|REG_STARTEND))

#endif

  if (preg->re_magic != MAGIC1 || g->magic != MAGIC2)

    return(REG_BADPAT);

  assert(!(g->iflags&REGEX_BAD));

  if (g->iflags&REGEX_BAD)   /* backstop for no-debug case */

    return(REG_BADPAT);

  eflags = GOODFLAGS(eflags);

  if ((unsigned long)g->nstates <= CHAR_BIT*sizeof(states1) && !(eflags&REG_LARGE))

    return(smatcher(g, string, nmatch, pmatch, eflags));

  else

    return(lmatcher(g, string, nmatch, pmatch, eflags));

}