source: trunk/libs/newlib/src/newlib/libc/stdlib/wcstod.c @ 471

/*
FUNCTION
        <<wcstod>>, <<wcstof>>, <<wcstold>>, <<wcstod_l>>, <<wcstof_l>>, <<wcstold_l>>---wide char string to double or float

INDEX
        wcstod

INDEX
        wcstof

INDEX
        wcstold

INDEX
        wcstod_l

INDEX
        wcstof_l

INDEX
        wcstold_l

INDEX
        _wcstod_r

INDEX
        _wcstof_r

SYNOPSIS
        #include <stdlib.h>
        double wcstod(const wchar_t *__restrict <[str]>,
                      wchar_t **__restrict <[tail]>);
        float wcstof(const wchar_t *__restrict <[str]>,
                     wchar_t **__restrict <[tail]>);
        long double wcstold(const wchar_t *__restrict <[str]>,
                            wchar_t **__restrict <[tail]>);

        #include <stdlib.h>
        double wcstod_l(const wchar_t *__restrict <[str]>,
                        wchar_t **__restrict <[tail]>, locale_t <[locale]>);
        float wcstof_l(const wchar_t *__restrict <[str]>,
                       wchar_t **__restrict <[tail]>, locale_t <[locale]>);
        long double wcstold_l(const wchar_t *__restrict <[str]>,
                              wchar_t **__restrict <[tail]>,
                              locale_t <[locale]>);

        double _wcstod_r(void *<[reent]>,
                         const wchar_t *<[str]>, wchar_t **<[tail]>);
        float _wcstof_r(void *<[reent]>,
                         const wchar_t *<[str]>, wchar_t **<[tail]>);

DESCRIPTION
        <<wcstod>>, <<wcstof>>, <<wcstold>> parse the wide-character string
        <[str]>, producing a substring which can be converted to a double,
        float, or long double value.  The substring converted is the longest
        initial subsequence of <[str]>, beginning with the first non-whitespace
        character, that has one of these formats:
        .[+|-]<[digits]>[.[<[digits]>]][(e|E)[+|-]<[digits]>]
        .[+|-].<[digits]>[(e|E)[+|-]<[digits]>]
        .[+|-](i|I)(n|N)(f|F)[(i|I)(n|N)(i|I)(t|T)(y|Y)]
        .[+|-](n|N)(a|A)(n|N)[<(>[<[hexdigits]>]<)>]
        .[+|-]0(x|X)<[hexdigits]>[.[<[hexdigits]>]][(p|P)[+|-]<[digits]>]
        .[+|-]0(x|X).<[hexdigits]>[(p|P)[+|-]<[digits]>]
        The substring contains no characters if <[str]> is empty, consists
        entirely of whitespace, or if the first non-whitespace
        character is something other than <<+>>, <<->>, <<.>>, or a
        digit, and cannot be parsed as infinity or NaN. If the platform
        does not support NaN, then NaN is treated as an empty substring.
        If the substring is empty, no conversion is done, and
        the value of <[str]> is stored in <<*<[tail]>>>.  Otherwise,
        the substring is converted, and a pointer to the final string
        (which will contain at least the terminating null character of
        <[str]>) is stored in <<*<[tail]>>>.  If you want no
        assignment to <<*<[tail]>>>, pass a null pointer as <[tail]>.

        This implementation returns the nearest machine number to the
        input decimal string.  Ties are broken by using the IEEE
        round-even rule.  However, <<wcstof>> is currently subject to
        double rounding errors.

        <<wcstod_l>>, <<wcstof_l>>, <<wcstold_l>> are like <<wcstod>>,
        <<wcstof>>, <<wcstold>> but perform the conversion based on the
        locale specified by the locale object locale.  If <[locale]> is
        LC_GLOBAL_LOCALE or not a valid locale object, the behaviour is
        undefined.

        The alternate functions <<_wcstod_r>> and <<_wcstof_r>> are 
        reentrant versions of <<wcstod>> and <<wcstof>>, respectively.
        The extra argument <[reent]> is a pointer to a reentrancy structure.

RETURNS
        Return the converted substring value, if any.  If
        no conversion could be performed, 0 is returned.  If the
        correct value is out of the range of representable values,
        plus or minus <<HUGE_VAL>> is returned, and <<ERANGE>> is
        stored in errno. If the correct value would cause underflow, 0
        is returned and <<ERANGE>> is stored in errno.

PORTABILITY
<<wcstod>> is ANSI.
<<wcstof>>, <<wcstold>> are C99.
<<wcstod_l>>, <<wcstof_l>>, <<wcstold_l>> are GNU extensions.

Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
<<lseek>>, <<read>>, <<sbrk>>, <<write>>.
*/

/*-
 * Copyright (c) 2002 Tim J. Robbins
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <_ansi.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <wchar.h>
#include <wctype.h>
#include <locale.h>
#include <math.h>
#include "mprec.h"

double
_wcstod_l (struct _reent *ptr, const wchar_t *nptr, wchar_t **endptr,
           locale_t loc)
{
        static const mbstate_t initial;
        mbstate_t mbs;
        double val;
        char *buf, *end;
        const wchar_t *wcp;
        size_t len;

        while (iswspace_l(*nptr, loc))
                nptr++;

        /*
         * Convert the supplied numeric wide char. string to multibyte.
         *
         * We could attempt to find the end of the numeric portion of the
         * wide char. string to avoid converting unneeded characters but
         * choose not to bother; optimising the uncommon case where
         * the input string contains a lot of text after the number
         * duplicates a lot of strtod()'s functionality and slows down the
         * most common cases.
         */
        wcp = nptr;
        mbs = initial;
        if ((len = _wcsnrtombs_l(ptr, NULL, &wcp, (size_t) -1, 0, &mbs, loc))
            == (size_t) -1) {
                if (endptr != NULL)
                        *endptr = (wchar_t *)nptr;
                return (0.0);
        }
        if ((buf = _malloc_r(ptr, len + 1)) == NULL)
                return (0.0);
        mbs = initial;
        _wcsnrtombs_l(ptr, buf, &wcp, (size_t) -1, len + 1, &mbs, loc);

        /* Let strtod() do most of the work for us. */
        val = _strtod_l(ptr, buf, &end, loc);

        /*
         * We only know where the number ended in the _multibyte_
         * representation of the string. If the caller wants to know
         * where it ended, count multibyte characters to find the
         * corresponding position in the wide char string.
         */
        if (endptr != NULL) {
                /* The only valid multibyte char in a float converted by
                   strtod/wcstod is the radix char.  What we do here is,
                   figure out if the radix char was in the valid leading
                   float sequence in the incoming string.  If so, the
                   multibyte float string is strlen(radix char) - 1 bytes
                   longer than the incoming wide char string has characters.
                   To fix endptr, reposition end as if the radix char was
                   just one byte long.  The resulting difference (end - buf)
                   is then equivalent to the number of valid wide characters
                   in the input string. */
                len = strlen (__localeconv_l (loc)->decimal_point);
                if (len > 1) {
                        char *d = strstr (buf,
                                          __localeconv_l (loc)->decimal_point);
                        if (d && d < end)
                                end -= len - 1;
                }
                *endptr = (wchar_t *)nptr + (end - buf);
        }

        _free_r(ptr, buf);

        return (val);
}

double
_wcstod_r (struct _reent *ptr,
        const wchar_t *nptr,
        wchar_t **endptr)
{
  return _wcstod_l (ptr, nptr, endptr, __get_current_locale ());
}

float
_wcstof_r (struct _reent *ptr,
        const wchar_t *nptr,
        wchar_t **endptr)
{
  double retval = _wcstod_l (ptr, nptr, endptr, __get_current_locale ());
  if (isnan (retval))
    return nanf (NULL);
  return (float)retval;
}

#ifndef _REENT_ONLY

double
wcstod_l (const wchar_t *__restrict nptr, wchar_t **__restrict endptr,
          locale_t loc)
{
  return _wcstod_l (_REENT, nptr, endptr, loc);
}

double
wcstod (const wchar_t *__restrict nptr, wchar_t **__restrict endptr)
{
  return _wcstod_l (_REENT, nptr, endptr, __get_current_locale ());
}

float
wcstof_l (const wchar_t *__restrict nptr, wchar_t **__restrict endptr,
          locale_t loc)
{
  double val = _wcstod_l (_REENT, nptr, endptr, loc);
  if (isnan (val))
    return nanf (NULL);
  float retval = (float) val;
#ifndef NO_ERRNO
  if (isinf (retval) && !isinf (val))
    _REENT->_errno = ERANGE;
#endif
  return retval;
}

float
wcstof (const wchar_t *__restrict nptr,
        wchar_t **__restrict endptr)
{
  double val = _wcstod_l (_REENT, nptr, endptr, __get_current_locale ());
  if (isnan (val))
    return nanf (NULL);
  float retval = (float) val;
#ifndef NO_ERRNO
  if (isinf (retval) && !isinf (val))
    _REENT->_errno = ERANGE;
#endif

  return retval;
}

#endif