/*-

 * Copyright (c) 1992, 1993

 *  The Regents of the University of California.  All rights reserved.

 *

 * Copyright (c) 2011 The FreeBSD Foundation

 * All rights reserved.

 * Portions of this software were developed by David Chisnall

 * under sponsorship from the FreeBSD Foundation.

 *

 * 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.

 */

/*

 * Convert a string to an unsigned long long integer.

 *

 * Assumes that the upper and lower case

 * alphabets and digits are each contiguous.

 */

unsigned long long

qt_strtoull(const char * nptr, char **endptr, int base)

{

  const char *s;

  unsigned long long acc;

  char c;

  unsigned long long cutoff;

  int neg, any, cutlim;

  /*

   * See strtoq for comments as to the logic used.

   */

  s = nptr;

  do {

    c = *s++;

  } while (ascii_isspace(c));

  if (c == '-') {

    neg = 1;

    c = *s++;

  } else {

    neg = 0;

    if (c == '+')

      c = *s++;

  }

  if ((base == 0 || base == 16) &&

      c == '0' && (*s == 'x' || *s == 'X') &&

      ((s[1] >= '0' && s[1] <= '9') ||

      (s[1] >= 'A' && s[1] <= 'F') ||

      (s[1] >= 'a' && s[1] <= 'f'))) {

    c = s[1];

    s += 2;

    base = 16;

  }

  if (base == 0)

    base = c == '0' ? 8 : 10;

  acc = any = 0;

  if (base < 2 || base > 36)

    goto noconv;

  cutoff = ULLONG_MAX / base;

  cutlim = ULLONG_MAX % base;

  for ( ; ; c = *s++) {

    if (c >= '0' && c <= '9')

      c -= '0';

    else if (c >= 'A' && c <= 'Z')

      c -= 'A' - 10;

    else if (c >= 'a' && c <= 'z')

      c -= '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 = ULLONG_MAX;

    errno = ERANGE;

  } else if (!any) {

noconv:

    errno = EINVAL;

  } else if (neg)

    acc = -acc;

  if (endptr != NULL)

                *endptr = const_cast<char *>(any ? s - 1 : nptr);

  return (acc);

}