/*-
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * 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.
 */

/* modified for long long <mgd@swarm.org> 1999-08-12 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#if HAVE_CTYPE_H
#include <ctype.h>
#endif
#if HAVE_ERRNO_H
#include <errno.h>
#endif

/* Specification.  */
#include "strtoll.h"


#ifndef INT64_MIN
/* Native 64 bit system without strtoll() */
#if defined(LONG_MIN) && (SIZEOF_LONG == 8)
#define INT64_MIN LONG_MIN
#else
/* 32 bit system */
#define INT64_MIN       -9223372036854775807L-1L
#endif
#endif

#ifndef INT64_MAX
/* Native 64 bit system without strtoll() */
#if defined(LONG_MAX) && (SIZEOF_LONG == 8)
#define INT64_MAX LONG_MAX
#else
/* 32 bit system */
#define INT64_MAX       9223372036854775807L
#endif
#endif


/*
 * Convert a string to a int64 integer.
 *
 * Ignores `locale' stuff.  Assumes that the upper and lower case
 * alphabets and digits are each contiguous.
 */
int64_t
strtoll (const char *nptr, char **endptr, int base)
{
  register const char *s = nptr;
  register u_int64_t acc;
  register int c;
  register u_int64_t cutoff;
  register int neg = 0, any, cutlim;
  
  /*
   * Skip white space and pick up leading +/- sign if any.
   * If base is 0, allow 0x for hex and 0 for octal, else
   * assume decimal; if base is already 16, allow 0x.
   */
  do
    {
      c = *s++;
    } while (xisspace(c));
  if (c == '-')
    {
      neg = 1;
      c = *s++;
    }
  else if (c == '+')
    c = *s++;
  if ((base == 0 || base == 16) && c == '0' && (*s == 'x' || *s == 'X'))
    {
      c = s[1];
      s += 2;
      base = 16;
    }
  if (base == 0)
    base = c == '0' ? 8 : 10;
  
  /*
   * Compute the cutoff value between legal numbers and illegal
   * numbers.  That is the largest legal value, divided by the
   * base.  An input number that is greater than this value, if
   * followed by a legal input character, is too big.  One that
   * is equal to this value may be valid or not; the limit
   * between valid and invalid numbers is then based on the last
   * digit.  For instance, if the range for longs is
   * [-2147483648..2147483647] and the input base is 10,
   * cutoff will be set to 214748364 and cutlim to either
   * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
   * a value > 214748364, or equal but the next digit is > 7 (or 8),
   * the number is too big, and we will return a range error.
   *
   * Set any if any `digits' consumed; make it negative to indicate
   * overflow.
   */
  cutoff = neg ? -(u_int64_t) INT64_MIN : INT64_MAX;
  cutlim = cutoff % (u_int64_t) base;
  cutoff /= (u_int64_t) base;
  for (acc = 0, any = 0;; c = *s++)
    {
      if (xisdigit(c))
        c -= '0';
      else if (xisalpha(c))
        c -= xisupper(c) ? 'A' - 10 : 'a' - 10;
      else
        break;
      if (c >= base)
        break;
      if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
        any = -1;
      else
        {
          any = 1;
          acc *= base;
          acc += c;
        }
    }
  if (any < 0)
    {
      acc = neg ? INT64_MIN : INT64_MAX;
      errno = ERANGE;
    }
  else if (neg)
    acc = -acc;
  if (endptr != 0)
    *endptr = (char *) (any ? s - 1 : nptr);
  return acc;
}