lib/libc/locale/wcstod.c

   1 /*-
   2  * Copyright (c) 2002 Tim J. Robbins
   3  * All rights reserved.
   4  *
   5  * Copyright (c) 2011 The FreeBSD Foundation
   6  * All rights reserved.
   7  * Portions of this software were developed by David Chisnall
   8  * under sponsorship from the FreeBSD Foundation.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  * $FreeBSD: head/lib/libc/locale/wcstod.c 227753 2011-11-20 14:45:42Z theraven $
  32  */
  33
  34
  35 #include <stdlib.h>
  36 #include <wchar.h>
  37 #include <wctype.h>
  38 #include "xlocale_private.h"
  39
  40 /*
  41  * Convert a string to a double-precision number.
  42  *
  43  * This is the wide-character counterpart of strtod(). So that we do not
  44  * have to duplicate the code of strtod() here, we convert the supplied
  45  * wide character string to multibyte and call strtod() on the result.
  46  * This assumes that the multibyte encoding is compatible with ASCII
  47  * for at least the digits, radix character and letters.
  48  */
  49 double
  50 wcstod_l(const wchar_t * __restrict nptr, wchar_t ** __restrict endptr,
  51                 locale_t locale)
  52 {
  53         static const mbstate_t initial;
  54         mbstate_t mbs;
  55         double val;
  56         char *buf, *end;
  57         const wchar_t *wcp = nptr;
  58         size_t len;
  59         size_t spaces = 0;
  60         FIX_LOCALE(locale);
  61
  62         while (iswspace_l(*wcp, locale)) {
  63                 wcp++;
  64                 spaces++;
  65         }
  66
  67         /*
  68          * Convert the supplied numeric wide char. string to multibyte.
  69          *
  70          * We could attempt to find the end of the numeric portion of the
  71          * wide char. string to avoid converting unneeded characters but
  72          * choose not to bother; optimising the uncommon case where
  73          * the input string contains a lot of text after the number
  74          * duplicates a lot of strtod()'s functionality and slows down the
  75          * most common cases.
  76          */
  77         mbs = initial;
  78         if ((len = wcsrtombs_l(NULL, &wcp, 0, &mbs, locale)) == (size_t)-1) {
  79                 if (endptr != NULL)
  80                         *endptr = (wchar_t *)nptr;
  81                 return (0.0);
  82         }
  83         if ((buf = malloc(len + 1)) == NULL)
  84                 return (0.0);
  85         mbs = initial;
  86         wcsrtombs_l(buf, &wcp, len + 1, &mbs, locale);
  87
  88         /* Let strtod() do most of the work for us. */
  89         val = strtod_l(buf, &end, locale);
  90
  91         /*
  92          * We only know where the number ended in the _multibyte_
  93          * representation of the string. If the caller wants to know
  94          * where it ended, count multibyte characters to find the
  95          * corresponding position in the wide char string.
  96          */
  97         if (endptr != NULL) {
  98                 /* XXX Assume each wide char is one byte. */
  99                 *endptr = (wchar_t *)nptr + (end - buf);
 100                 if (buf != end)
 101                         *endptr += spaces;
 102         }
 103
 104
 105         free(buf);
 106
 107         return (val);
 108 }
 109 double
 110 wcstod(const wchar_t * __restrict nptr, wchar_t ** __restrict endptr)
 111 {
 112         return wcstod_l(nptr, endptr, __get_locale());
 113 }