freebsd-dev/lib/libc/locale/wcstod.c

108 lines
3.4 KiB
C

/*-
* 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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <stdlib.h>
#include <wchar.h>
#include <wctype.h>
/*
* Convert a string to a double-precision number.
*
* This is the wide-character counterpart of strtod(). So that we do not
* have to duplicate the code of strtod() here, we convert the supplied
* wide character string to multibyte and call strtod() on the result.
* This assumes that the multibyte encoding is compatible with ASCII
* for at least the digits, radix character and letters.
*/
double
wcstod(const wchar_t * __restrict nptr, wchar_t ** __restrict endptr)
{
static const mbstate_t initial;
mbstate_t state;
double val;
char *buf, *end, *p;
const wchar_t *wcp;
size_t clen, len;
while (iswspace(*nptr))
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.
*/
state = initial;
wcp = nptr;
if ((len = wcsrtombs(NULL, &wcp, 0, &state)) == (size_t)-1) {
if (endptr != NULL)
*endptr = (wchar_t *)nptr;
return (0.0);
}
if ((buf = malloc(len + 1)) == NULL)
return (0.0);
state = initial;
wcsrtombs(buf, &wcp, len + 1, &state);
/* Let strtod() do most of the work for us. */
val = strtod(buf, &end);
/*
* 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) {
#if 1 /* Fast, assume 1:1 WC:MBS mapping. */
*endptr = (wchar_t *)nptr + (end - buf);
(void)clen;
(void)p;
#else /* Slow, conservative approach. */
state = initial;
*endptr = (wchar_t *)nptr;
p = buf;
while (p < end &&
(clen = mbrlen(p, end - p, &state)) > 0) {
p += clen;
(*endptr)++;
}
#endif
}
free(buf);
return (val);
}