usr/src/lib/libc/port/i18n/wcstoul.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1986 AT&T */
  28 /*        All Rights Reserved   */
  29
  30 #pragma ident   "%Z%%M% %I%     %E% SMI"
  31
  32 #ifndef _WCS_LONGLONG
  33 #pragma weak _wcstoul = wcstoul
  34 #endif
  35
  36 #include "lint.h"
  37 #include <limits.h>
  38 #include <errno.h>
  39 #include <wchar.h>
  40 #define DIGIT(x)        (iswdigit(x) ? (x) - L'0' : \
  41                         iswlower(x) ? (x) + 10 - L'a' : (x) + 10 - L'A')
  42 #define MBASE   (L'z' - L'a' + 1 + 10)
  43
  44 #ifdef  _WCS_LONGLONG
  45 #define _WULONG_T       unsigned long long
  46 #define _WULONG_MAX     ULLONG_MAX
  47 #else  /* _WCS_LONGLONG */
  48 #define _WULONG_T       unsigned long
  49 #define _WULONG_MAX     ULONG_MAX
  50 #endif /* _WCS_LONGLONG */
  51
  52 #ifdef  _WCS_LONGLONG
  53 unsigned long long
  54 wcstoull(const wchar_t *_RESTRICT_KYWD str, wchar_t **_RESTRICT_KYWD ptr,
  55     int base)
  56 #else /* _WCS_LONGLONG */
  57 unsigned long
  58 wcstoul(const wchar_t *str, wchar_t **ptr, int base)
  59 #endif /* _WCS_LONGLONG */
  60 {
  61         _WULONG_T       val;
  62         wchar_t c;
  63         int     xx, neg = 0;
  64         _WULONG_T       multmax;
  65
  66         if (ptr != NULL)
  67                 *ptr = (wchar_t *)str; /* in case no number is formed */
  68         if (base < 0 || base > MBASE) {
  69                 errno = EINVAL;
  70                 return (0); /* base is invalid -- should be a fatal error */
  71         }
  72
  73         if (!iswalnum(c = *str)) {
  74                 while (iswspace(c)) {
  75                         c = *++str;
  76                 }
  77                 switch (c) {
  78                 case L'-':
  79                         neg++;
  80                         /*FALLTHRU*/
  81                 case L'+':
  82                         c = *++str;
  83                 }
  84         }
  85         if (base == 0) {
  86                 if (c != L'0')
  87                         base = 10;
  88                 else if (str[1] == L'x' || str[1] == L'X')
  89                         base = 16;
  90                 else
  91                         base = 8;
  92         }
  93         /*
  94          * for any base > 10, the digits incrementally following
  95          *      9 are assumed to be "abc...z" or "ABC...Z"
  96          */
  97         if (!iswalnum(c) || (xx = DIGIT(c)) >= base) {
  98                 errno = EINVAL;
  99                 return (0); /* no number formed */
 100         }
 101         if (base == 16 && c == L'0' && iswxdigit(str[2]) &&
 102             (str[1] == L'x' || str[1] == L'X')) {
 103                 c = *(str += 2); /* skip over leading "0x" or "0X" */
 104         }
 105
 106         multmax = _WULONG_MAX / (_WULONG_T)base;
 107         val = DIGIT(c);
 108         for (; iswalnum(c = *++str) && (xx = DIGIT(c)) < base; ) {
 109                 /* accumulate neg avoids surprises near MAXLONG */
 110                 if (val > multmax)
 111                         goto overflow;
 112                 val *= base;
 113                 if (_WULONG_MAX - val < xx)
 114                         goto overflow;
 115                 val += xx;
 116         }
 117         if (ptr != NULL)
 118                 *ptr = (wchar_t *)str;
 119         return (neg ? -val : val);
 120
 121 overflow:
 122         while (iswalnum(c = *++str) && (xx = DIGIT(c)) < base)
 123                 ;
 124
 125         if (ptr != NULL)
 126                 *ptr = (wchar_t *)str;
 127         errno = ERANGE;
 128         return (_WULONG_MAX);
 129 }