locale/FreeBSD/wcstod.c

   1 /*-
   2  * Copyright (c) 2002 Tim J. Robbins
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  */
  26
  27 #include <sys/cdefs.h>
  28 __FBSDID("$FreeBSD: src/lib/libc/locale/wcstod.c,v 1.4 2004/04/07 09:47:56 tjr Exp $");
  29
  30 #include "xlocale_private.h"
  31
  32 #include <stdlib.h>
  33 #include <wchar.h>
  34 #include <wctype.h>
  35 #include <_simple.h>
  36
  37 /*
  38  * __wcs_end_offset calculates the offset to the end within the wide character
  39  * string, assuming numbers and letters are single bytes in multibyte
  40  * representation, get the actual decimal string for localeconv_l.  If the
  41  * decimal point was within the string, compensate for the fact that the
  42  * (possible more than one byte) decimal point one takes one wide character.
  43  */
  44 __private_extern__ size_t
  45 __wcs_end_offset(const char * __restrict buf, const char * __restrict end, locale_t loc)
  46 {
  47         const char *decimalpoint = localeconv_l(loc)->decimal_point;
  48         size_t n = end - buf;
  49         char *p;
  50
  51         if ((p = strnstr(buf, decimalpoint, n)) != NULL)
  52                 n -= strlen(decimalpoint) - 1;
  53         return n;
  54 }
  55
  56 /*
  57  * Convert a string to a double-precision number.
  58  *
  59  * This is the wide-character counterpart of strtod(). So that we do not
  60  * have to duplicate the code of strtod() here, we convert the supplied
  61  * wide character string to multibyte and call strtod() on the result.
  62  * This assumes that the multibyte encoding is compatible with ASCII
  63  * for at least the digits and letters.  The radix character can be more
  64  * than one byte.
  65  */
  66
  67 double
  68 wcstod_l(const wchar_t * __restrict nptr, wchar_t ** __restrict endptr,
  69     locale_t loc)
  70 {
  71         static const mbstate_t initial;
  72         mbstate_t mbs;
  73         double val;
  74         char *buf, *end;
  75         size_t len;
  76         locale_t ctype;
  77         _SIMPLE_STRING b;
  78         char mb[MB_CUR_MAX + 1];
  79         const wchar_t *nptr0 = nptr;
  80         const wchar_t *first;
  81
  82         NORMALIZE_LOCALE(loc);
  83         ctype = __numeric_ctype(loc);
  84
  85         while (iswspace_l(*nptr, ctype))
  86                 nptr++;
  87
  88         if ((b = _simple_salloc()) == NULL)
  89                 return (0.0);
  90
  91         first = nptr;
  92         mbs = initial;
  93         while (*nptr && (len = wcrtomb_l(mb, *nptr, &mbs, ctype)) != (size_t)-1) {
  94                 mb[len] = 0;
  95                 if (_simple_sappend(b, mb) < 0) { /* no memory */
  96                         _simple_sfree(b);
  97                         return (0.0);
  98                 }
  99                 nptr++;
 100         }
 101
 102         /* Let strtod() do most of the work for us. */
 103         buf = _simple_string(b);
 104         val = strtod_l(buf, &end, loc);
 105
 106         /*
 107          * We only know where the number ended in the _multibyte_
 108          * representation of the string. If the caller wants to know
 109          * where it ended, count multibyte characters to find the
 110          * corresponding position in the wide char string.
 111          */
 112         if (endptr != NULL)
 113                 /* XXX Assume each wide char is one byte. */
 114                 *endptr = (end == buf) ? (wchar_t *)nptr0 : ((wchar_t *)first + __wcs_end_offset(buf, end, loc));
 115
 116         _simple_sfree(b);
 117
 118         return (val);
 119 }
 120
 121 double
 122 wcstod(const wchar_t * __restrict nptr, wchar_t ** __restrict endptr)
 123 {
 124         return wcstod_l(nptr, endptr, __current_locale());
 125 }