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      1 /* $NetBSD: _wcstod.h,v 1.1 2006/04/15 12:17:23 tnozaki Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2002 Tim J. Robbins
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26  * SUCH DAMAGE.
     27  *
     28  * Original version ID:
     29  *   FreeBSD: /repoman/r/ncvs/src/lib/libc/locale/wcstod.c,v 1.4 2004/04/07 09:47:56 tjr Exp
     30  *   NetBSD: wcstod.c,v 1.8 2006/04/13 01:25:13 tnozaki Exp
     31  */
     32 
     33 /*
     34  * function template for wcstof, wcstod, wcstold.
     35  *
     36  * parameters:
     37  *  _FUNCNAME    : function name
     38  *  _RETURN_TYPE : return type
     39  *  _STRTOD_FUNC : real conversion function
     40  */
     41 #ifndef __WCSTOD_H_
     42 #define __WCSTOD_H_
     43 
     44 /*
     45  * Convert a string to a double-precision number.
     46  *
     47  * This is the wide-character counterpart of strto{f,d,ld}(). So that
     48  * we do not have to duplicate the code of strto{f,d,ld}() here,
     49  * we convert the supplied wide character string to multibyte and
     50  * call strto{f,d,ld}() on the result.
     51  * This assumes that the multibyte encoding is compatible with ASCII
     52  * for at least the digits, radix character and letters.
     53  */
     54 _RETURN_TYPE
     55 _FUNCNAME(const wchar_t * __restrict nptr, wchar_t ** __restrict endptr)
     56 {
     57   const wchar_t *src, *start;
     58   _RETURN_TYPE val;
     59   char *buf, *end;
     60   size_t bufsiz, len;
     61 
     62   _DIAGASSERT(nptr != NULL);
     63   /* endptr may be null */
     64 
     65   src = nptr;
     66   while (iswspace((wint_t)*src) != 0)
     67     ++src;
     68   if (*src == L'\0')
     69     goto no_convert;
     70 
     71   /*
     72    * Convert the supplied numeric wide char. string to multibyte.
     73    *
     74    * We could attempt to find the end of the numeric portion of the
     75    * wide char. string to avoid converting unneeded characters but
     76    * choose not to bother; optimising the uncommon case where
     77    * the input string contains a lot of text after the number
     78    * duplicates a lot of strto{f,d,ld}()'s functionality and
     79    * slows down the most common cases.
     80    */
     81   start = src;
     82   len = wcstombs(NULL, src, 0);
     83   if (len == (size_t)-1)
     84     /* errno = EILSEQ */
     85     goto no_convert;
     86 
     87   _DIAGASSERT(len > 0);
     88 
     89   bufsiz = len;
     90   buf = (void *)malloc(bufsiz + 1);
     91   if (buf == NULL)
     92     /* errno = ENOMEM */
     93     goto no_convert;
     94 
     95   len = wcstombs(buf, src, bufsiz + 1);
     96 
     97   _DIAGASSERT(len == bufsiz);
     98   _DIAGASSERT(buf[len] == '\0');
     99 
    100   /* Let strto{f,d,ld}() do most of the work for us. */
    101   val = _STRTOD_FUNC(buf, &end);
    102   if (buf == end) {
    103     free(buf);
    104     goto no_convert;
    105   }
    106 
    107   /*
    108    * We only know where the number ended in the _multibyte_
    109    * representation of the string. If the caller wants to know
    110    * where it ended, count multibyte characters to find the
    111    * corresponding position in the wide char string.
    112    */
    113   if (endptr != NULL)
    114     /* XXX Assume each wide char is one byte. */
    115     *endptr = __UNCONST(start + (size_t)(end - buf));
    116 
    117   free(buf);
    118 
    119   return val;
    120 
    121 no_convert:
    122   if (endptr != NULL)
    123     *endptr = __UNCONST(nptr);
    124   return 0.0;
    125 }
    126 #endif /*__WCSTOD_H_*/
    127