port/i18n/wcstol.c

	wcstol.c revision 7257d1b4d25bfac0c802847390e98a464fd787ac
/*
 * 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   */

#pragma ident   "%Z%%M% %I% %E% SMI"

#ifndef _WCS_LONGLONG
#pragma weak _wcstol = wcstol
#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 _WLONG_T    long long
#define _WLONG_MAX  LLONG_MAX
#define _WLONG_MIN  LLONG_MIN
#else  /* _WCS_LONGLONG */
#define _WLONG_T    long
#define _WLONG_MAX  LONG_MAX
#define _WLONG_MIN  LONG_MIN
#endif /* _WCS_LONGLONG */

#ifdef  _WCS_LONGLONG
long long
wcstoll(const wchar_t *_RESTRICT_KYWD str, wchar_t **_RESTRICT_KYWD ptr,
    int base)
#else  /* _WCS_LONGLONG */
long
wcstol(const wchar_t *str, wchar_t **ptr, int base)
#endif /* _WCS_LONGLONG */
{
    _WLONG_T    val;
    wchar_t c;
    int xx, neg = 0;
    _WLONG_T    multmin, limit;

    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" */
    }

    if (neg) {
        limit = _WLONG_MIN;
    } else {
        limit = -_WLONG_MAX;
    }
    multmin = limit / base;

    val = -DIGIT(c);
    for (; iswalnum(c = *++str) && (xx = DIGIT(c)) < base; ) {
        /* accumulate neg avoids surprises near MAXLONG */
        if (val < multmin)
            goto overflow;
        val *= base;
        if (val < limit + 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 (neg ? _WLONG_MIN : _WLONG_MAX);
}