newlib/libc/stdlib/wcstold.c

   1 /*
   2 (C) Copyright IBM Corp. 2009
   3
   4 All rights reserved.
   5
   6 Redistribution and use in source and binary forms, with or without
   7 modification, are permitted provided that the following conditions are met:
   8
   9 * Redistributions of source code must retain the above copyright notice,
  10 this list of conditions and the following disclaimer.
  11 * Redistributions in binary form must reproduce the above copyright
  12 notice, this list of conditions and the following disclaimer in the
  13 documentation and/or other materials provided with the distribution.
  14 * Neither the name of IBM nor the names of its contributors may be
  15 used to endorse or promote products derived from this software without
  16 specific prior written permission.
  17
  18 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  19 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  22 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  23 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  24 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  25 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  26 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  27 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  28 POSSIBILITY OF SUCH DAMAGE.
  29 */
  30
  31 #define _GNU_SOURCE
  32 #include <stdlib.h>
  33 #include <string.h>
  34 #include <wchar.h>
  35 #include <wctype.h>
  36 #include <locale.h>
  37 #include "local.h"
  38 #include "../locale/setlocale.h"
  39
  40 long double
  41 wcstold_l (const wchar_t *__restrict nptr, wchar_t **__restrict endptr,
  42            locale_t loc)
  43 {
  44 #ifdef _LDBL_EQ_DBL
  45 /* On platforms where long double is as wide as double.  */
  46   return wcstod_l(nptr, endptr, loc);
  47
  48 #else /* This is a duplicate of the code in wcstod.c, but converted to long double.  */
  49
  50   static const mbstate_t initial;
  51   mbstate_t mbs;
  52   long double val;
  53   char *buf, *end;
  54   const wchar_t *wcp;
  55   size_t len;
  56
  57   while (iswspace (*nptr))
  58     nptr++;
  59
  60   /* Convert the supplied numeric wide char string to multibyte.  */
  61   wcp = nptr;
  62   mbs = initial;
  63   if ((len = _wcsnrtombs_l (_REENT, NULL, &wcp, (size_t) -1, 0, &mbs, loc))
  64       == (size_t) -1)
  65     {
  66       if (endptr != NULL)
  67         *endptr = (wchar_t *) nptr;
  68       return 0.0L;
  69     }
  70
  71   if ((buf = malloc (len + 1)) == NULL)
  72     return 0.0L;
  73
  74   mbs = initial;
  75   _wcsnrtombs_l (_REENT, buf, &wcp, (size_t) -1, len + 1, &mbs, loc);
  76
  77   val = strtold_l (buf, &end, loc);
  78
  79   /* We only know where the number ended in the _multibyte_
  80      representation of the string. If the caller wants to know
  81      where it ended, count multibyte characters to find the
  82      corresponding position in the wide char string.  */
  83
  84   if (endptr != NULL)
  85     {
  86       const char *decimal_point = __get_numeric_locale(loc)->decimal_point;
  87       /* The only valid multibyte char in a float converted by
  88          strtold/wcstold is the radix char.  What we do here is,
  89          figure out if the radix char was in the valid leading
  90          float sequence in the incoming string.  If so, the
  91          multibyte float string is strlen (radix char) - 1 bytes
  92          longer than the incoming wide char string has characters.
  93          To fix endptr, reposition end as if the radix char was
  94          just one byte long.  The resulting difference (end - buf)
  95          is then equivalent to the number of valid wide characters
  96          in the input string.  */
  97       len = strlen (decimal_point);
  98       if (len > 1)
  99         {
 100           char *d = strstr (buf, decimal_point);
 101
 102           if (d && d < end)
 103             end -= len - 1;
 104         }
 105
 106       *endptr = (wchar_t *) nptr + (end - buf);
 107     }
 108
 109   free (buf);
 110
 111   return val;
 112 #endif /* _LDBL_EQ_DBL */
 113 }
 114
 115 long double
 116 wcstold (const wchar_t *__restrict nptr, wchar_t **__restrict endptr)
 117 {
 118 #ifdef _LDBL_EQ_DBL
 119 /* On platforms where long double is as wide as double.  */
 120   return wcstod_l(nptr, endptr, __get_current_locale ());
 121 #else
 122   return wcstold_l(nptr, endptr, __get_current_locale ());
 123 #endif
 124 }