/*-
 * 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. 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.
 *
 *	@(#)regerror.c	8.4 (Berkeley) 3/20/94
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)regerror.c	8.4 (Berkeley) 3/20/94";
#endif /* LIBC_SCCS and not lint */

/**
 * @file regerror.c
 *
 * @brief Error handling.
 *
 * @namespace regexp
 *
 */

#include "YapInterface.h"
#include "yapregex.h"
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>

#include "utils.h"

/* ========= begin header generated by ./mkh ========= */
#ifdef __cplusplus
extern "C" {
#endif

/* === regerror.c === */
static char *regatoi(const regex_t *preg, char *localbuf);

#ifdef __cplusplus
}
#endif
/* ========= end header generated by ./mkh ========= */
/*
 = #define	REG_NOMATCH	 1
 = #define	REG_BADPAT	 2
 = #define	REG_ECOLLATE	 3
 = #define	REG_ECTYPE	 4
 = #define	REG_EESCAPE	 5
 = #define	REG_ESUBREG	 6
 = #define	REG_EBRACK	 7
 = #define	REG_EPAREN	 8
 = #define	REG_EBRACE	 9
 = #define	REG_BADBR	10
 = #define	REG_ERANGE	11
 = #define	REG_ESPACE	12
 = #define	REG_BADRPT	13
 = #define	REG_EMPTY	14
 = #define	REG_ASSERT	15
 = #define	REG_INVARG	16
 = #define	REG_ATOI	255	// convert name to number (!)
 = #define	REG_ITOA	0400	// convert number to name (!)
 */
static struct rerr {
  int code;
  char *name;
  char *explain;
} rerrs[] = {{REG_NOMATCH, "REG_NOMATCH", "regexec() failed to match"},
             {REG_BADPAT, "REG_BADPAT", "invalid regular expression"},
             {REG_ECOLLATE, "REG_ECOLLATE", "invalid collating element"},
             {REG_ECTYPE, "REG_ECTYPE", "invalid character class"},
             {REG_EESCAPE, "REG_EESCAPE", "trailing backslash (\\)"},
             {REG_ESUBREG, "REG_ESUBREG", "invalid backreference number"},
             {REG_EBRACK, "REG_EBRACK", "brackets ([ ]) not balanced"},
             {REG_EPAREN, "REG_EPAREN", "parentheses not balanced"},
             {REG_EBRACE, "REG_EBRACE", "braces not balanced"},
             {REG_BADBR, "REG_BADBR", "invalid repetition count(s)"},
             {REG_ERANGE, "REG_ERANGE", "invalid character range"},
             {REG_ESPACE, "REG_ESPACE", "out of memory"},
             {REG_BADRPT, "REG_BADRPT", "repetition-operator operand invalid"},
             {REG_EMPTY, "REG_EMPTY", "empty (sub)expression"},
             {REG_ASSERT, "REG_ASSERT", "\"can't happen\" -- you found a bug"},
             {REG_INVARG, "REG_INVARG", "invalid argument to regex routine"},
             {0, "", "*** unknown regexp error code ***"}};

/*
 - regerror - the interface to error numbers
 = extern size_t regerror(int, const regex_t *, char *, size_t);
 */
/* ARGSUSED */
size_t yap_regerror(int errcode, const regex_t *preg, char *errbuf,
                    size_t errbuf_size) {
  register struct rerr *r;
  register size_t len;
  register int target = errcode & ~REG_ITOA;
  register char *s;
  char convbuf[50];

  if (errcode == REG_ATOI)
    s = regatoi(preg, convbuf);
  else {
    for (r = rerrs; r->code != 0; r++)
      if (r->code == target)
        break;

    if (errcode & REG_ITOA) {
      if (r->code != 0)
        (void)strcpy(convbuf, r->name);
      else
        sprintf(convbuf, "REG_0x%x", target);
      assert(strlen(convbuf) < sizeof(convbuf));
      s = convbuf;
    } else
      s = r->explain;
  }

  len = strlen(s) + 1;
  if (errbuf_size > 0) {
    if (errbuf_size > len)
      (void)strcpy(errbuf, s);
    else {
      (void)strncpy(errbuf, s, errbuf_size - 1);
      errbuf[errbuf_size - 1] = '\0';
    }
  }

  return (len);
}

/*
 - regatoi - internal routine to implement REG_ATOI
 == static char *regatoi(const regex_t *preg, char *localbuf);
 */
static char *regatoi(preg, localbuf) const regex_t *preg;
char *localbuf;
{
  register struct rerr *r;

  for (r = rerrs; r->code != 0; r++)
    if (strcmp(r->name, preg->re_endp) == 0)
      break;
  if (r->code == 0)
    return ("0");

  sprintf(localbuf, "%d", r->code);
  return (localbuf);
}