lib/libc/locale/_wcstod.h

   1 /* $NetBSD$ */
   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;
 125 }
 126 #endif /*__WCSTOD_H_*/