usr/src/lib/libc/port/i18n/wcstol.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 _wcstol = wcstol
  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 _WLONG_T        long long
  46 #define _WLONG_MAX      LLONG_MAX
  47 #define _WLONG_MIN      LLONG_MIN
  48 #else  /* _WCS_LONGLONG */
  49 #define _WLONG_T        long
  50 #define _WLONG_MAX      LONG_MAX
  51 #define _WLONG_MIN      LONG_MIN
  52 #endif /* _WCS_LONGLONG */
  53
  54 #ifdef  _WCS_LONGLONG
  55 long long
  56 wcstoll(const wchar_t *_RESTRICT_KYWD str, wchar_t **_RESTRICT_KYWD ptr,
  57     int base)
  58 #else  /* _WCS_LONGLONG */
  59 long
  60 wcstol(const wchar_t *str, wchar_t **ptr, int base)
  61 #endif /* _WCS_LONGLONG */
  62 {
  63         _WLONG_T        val;
  64         wchar_t c;
  65         int     xx, neg = 0;
  66         _WLONG_T        multmin, limit;
  67
  68         if (ptr != NULL)
  69                 *ptr = (wchar_t *)str; /* in case no number is formed */
  70         if (base < 0 || base > MBASE) {
  71                 errno = EINVAL;
  72                 return (0); /* base is invalid -- should be a fatal error */
  73         }
  74
  75         if (!iswalnum(c = *str)) {
  76                 while (iswspace(c)) {
  77                         c = *++str;
  78                 }
  79                 switch (c) {
  80                 case L'-':
  81                         neg++;
  82                         /*FALLTHRU*/
  83                 case L'+':
  84                         c = *++str;
  85                 }
  86         }
  87         if (base == 0) {
  88                 if (c != L'0')
  89                         base = 10;
  90                 else if (str[1] == L'x' || str[1] == L'X')
  91                         base = 16;
  92                 else
  93                         base = 8;
  94         }
  95         /*
  96          * for any base > 10, the digits incrementally following
  97          *      9 are assumed to be "abc...z" or "ABC...Z"
  98          */
  99         if (!iswalnum(c) || (xx = DIGIT(c)) >= base) {
 100                 errno = EINVAL;
 101                 return (0); /* no number formed */
 102         }
 103
 104         if (base == 16 && c == L'0' && iswxdigit(str[2]) &&
 105             (str[1] == L'x' || str[1] == L'X')) {
 106                 c = *(str += 2); /* skip over leading "0x" or "0X" */
 107         }
 108
 109         if (neg) {
 110                 limit = _WLONG_MIN;
 111         } else {
 112                 limit = -_WLONG_MAX;
 113         }
 114         multmin = limit / base;
 115
 116         val = -DIGIT(c);
 117         for (; iswalnum(c = *++str) && (xx = DIGIT(c)) < base; ) {
 118                 /* accumulate neg avoids surprises near MAXLONG */
 119                 if (val < multmin)
 120                         goto overflow;
 121                 val *= base;
 122                 if (val < limit + xx)
 123                         goto overflow;
 124                 val -= xx;
 125         }
 126         if (ptr != NULL)
 127                 *ptr = (wchar_t *)str;
 128         return (neg ? val : -val);
 129
 130 overflow:
 131         while (iswalnum(c = *++str) && (xx = DIGIT(c)) < base)
 132                 ;
 133
 134         if (ptr != NULL)
 135                 *ptr = (wchar_t *)str;
 136         errno = ERANGE;
 137         return (neg ? _WLONG_MIN : _WLONG_MAX);
 138 }