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Commit	Line	Data
	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 <stdlib.h>
	31	#include <wchar.h>
	32	#include <wctype.h>
	33
	34	/*
	35	* Convert a string to a double-precision number.
	36	*
	37	* This is the wide-character counterpart of strtod(). So that we do not
	38	* have to duplicate the code of strtod() here, we convert the supplied
	39	* wide character string to multibyte and call strtod() on the result.
	40	* This assumes that the multibyte encoding is compatible with ASCII
	41	* for at least the digits, radix character and letters.
	42	*/
	43	double
	44	wcstod(const wchar_t * __restrict nptr, wchar_t ** __restrict endptr)
	45	{
	46	static const mbstate_t initial;
	47	mbstate_t mbs;
	48	double val;
	49	char buf, end;
	50	const wchar_t *wcp;
	51	size_t len;
	52
	53	while (iswspace(*nptr))
	54	nptr++;
	55
	56	/*
	57	* Convert the supplied numeric wide char. string to multibyte.
	58	*
	59	* We could attempt to find the end of the numeric portion of the
	60	* wide char. string to avoid converting unneeded characters but
	61	* choose not to bother; optimising the uncommon case where
	62	* the input string contains a lot of text after the number
	63	* duplicates a lot of strtod()'s functionality and slows down the
	64	* most common cases.
	65	*/
	66	wcp = nptr;
	67	mbs = initial;
	68	if ((len = wcsrtombs(NULL, &wcp, 0, &mbs)) == (size_t)-1) {
	69	if (endptr != NULL)
	70	endptr = (wchar_t )nptr;
	71	return (0.0);
	72	}
	73	if ((buf = malloc(len + 1)) == NULL)
	74	return (0.0);
	75	mbs = initial;
	76	wcsrtombs(buf, &wcp, len + 1, &mbs);
	77
	78	/* Let strtod() do most of the work for us. */
	79	val = strtod(buf, &end);
	80
	81	/*
	82	* We only know where the number ended in the _multibyte_
	83	* representation of the string. If the caller wants to know
	84	* where it ended, count multibyte characters to find the
	85	* corresponding position in the wide char string.
	86	*/
	87	if (endptr != NULL)
	88	/* XXX Assume each wide char is one byte. */
	89	endptr = (wchar_t )nptr + (end - buf);
	90
	91	free(buf);
	92
	93	return (val);
	94	}