regexec.c

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/*-
 * This code is derived from OpenBSD's libc/regex, original license follows:
 *
 * 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 llvm_regexec()
 *
 * This file includes engine.inc *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 "regex_impl.h"

#include "regutils.h"
#include "regex2.h"

/* macros for manipulating states, small version */
/* FIXME: 'states' is assumed as 'long' on small version. */
#define states1 long    /* for later use in llvm_regexec() decision */
#define states  states1
#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) = (unsigned long)(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.inc looks after details */

#include "regengine.inc"

/* 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)  memmove(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 == 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 "regengine.inc"

/*
 - llvm_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 */
llvm_regexec(const llvm_regex_t *preg, const char *string, size_t nmatch,
             llvm_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 (g->nstates <= (long)(CHAR_BIT*sizeof(states1)) && !(eflags&REG_LARGE))
    return(smatcher(g, string, nmatch, pmatch, eflags));
  else
    return(lmatcher(g, string, nmatch, pmatch, eflags));
}