/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*      Copyright (c) 1986 AT&T */
/*        All Rights Reserved   */

#ifndef _WCS_LONGLONG
#pragma weak _wcstoul = wcstoul
#endif

#include "lint.h"
#include <limits.h>
#include <errno.h>
#include <wchar.h>
#define DIGIT(x)        (iswdigit(x) ? (x) - L'0' : \
                        iswlower(x) ? (x) + 10 - L'a' : (x) + 10 - L'A')
#define MBASE   (L'z' - L'a' + 1 + 10)

#ifdef  _WCS_LONGLONG
#define _WULONG_T       unsigned long long
#define _WULONG_MAX     ULLONG_MAX
#else  /* _WCS_LONGLONG */
#define _WULONG_T       unsigned long
#define _WULONG_MAX     ULONG_MAX
#endif /* _WCS_LONGLONG */

#ifdef  _WCS_LONGLONG
unsigned long long
wcstoull(const wchar_t *_RESTRICT_KYWD str, wchar_t **_RESTRICT_KYWD ptr,
    int base)
#else /* _WCS_LONGLONG */
unsigned long
wcstoul(const wchar_t *str, wchar_t **ptr, int base)
#endif /* _WCS_LONGLONG */
{
        _WULONG_T       val;
        wchar_t c;
        int     xx, neg = 0;
        _WULONG_T       multmax;

        if (ptr != NULL)
                *ptr = (wchar_t *)str; /* in case no number is formed */
        if (base < 0 || base > MBASE) {
                errno = EINVAL;
                return (0); /* base is invalid -- should be a fatal error */
        }

        if (!iswalnum(c = *str)) {
                while (iswspace(c)) {
                        c = *++str;
                }
                switch (c) {
                case L'-':
                        neg++;
                        /*FALLTHRU*/
                case L'+':
                        c = *++str;
                }
        }
        if (base == 0) {
                if (c != L'0')
                        base = 10;
                else if (str[1] == L'x' || str[1] == L'X')
                        base = 16;
                else
                        base = 8;
        }
        /*
         * for any base > 10, the digits incrementally following
         *      9 are assumed to be "abc...z" or "ABC...Z"
         */
        if (!iswalnum(c) || (xx = DIGIT(c)) >= base) {
                errno = EINVAL;
                return (0); /* no number formed */
        }
        if (base == 16 && c == L'0' && iswxdigit(str[2]) &&
            (str[1] == L'x' || str[1] == L'X')) {
                c = *(str += 2); /* skip over leading "0x" or "0X" */
        }

        multmax = _WULONG_MAX / (_WULONG_T)base;
        val = DIGIT(c);
        for (; iswalnum(c = *++str) && (xx = DIGIT(c)) < base; ) {
                /* accumulate neg avoids surprises near MAXLONG */
                if (val > multmax)
                        goto overflow;
                val *= base;
                if (_WULONG_MAX - val < xx)
                        goto overflow;
                val += xx;
        }
        if (ptr != NULL)
                *ptr = (wchar_t *)str;
        return (neg ? -val : val);

overflow:
        while (iswalnum(c = *++str) && (xx = DIGIT(c)) < base)
                ;

        if (ptr != NULL)
                *ptr = (wchar_t *)str;
        errno = ERANGE;
        return (_WULONG_MAX);
}