xref: /freebsd/lib/libc/locale/wcstod.c (revision 1e8742e9cdc054df3a792bfa338a320574faadd1)
103b716c4STim J. Robbins /*-
203b716c4STim J. Robbins  * Copyright (c) 2002 Tim J. Robbins
303b716c4STim J. Robbins  * All rights reserved.
403b716c4STim J. Robbins  *
503b716c4STim J. Robbins  * Redistribution and use in source and binary forms, with or without
603b716c4STim J. Robbins  * modification, are permitted provided that the following conditions
703b716c4STim J. Robbins  * are met:
803b716c4STim J. Robbins  * 1. Redistributions of source code must retain the above copyright
903b716c4STim J. Robbins  *    notice, this list of conditions and the following disclaimer.
1003b716c4STim J. Robbins  * 2. Redistributions in binary form must reproduce the above copyright
1103b716c4STim J. Robbins  *    notice, this list of conditions and the following disclaimer in the
1203b716c4STim J. Robbins  *    documentation and/or other materials provided with the distribution.
1303b716c4STim J. Robbins  *
1403b716c4STim J. Robbins  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
1503b716c4STim J. Robbins  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
1603b716c4STim J. Robbins  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
1703b716c4STim J. Robbins  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
1803b716c4STim J. Robbins  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
1903b716c4STim J. Robbins  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
2003b716c4STim J. Robbins  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
2103b716c4STim J. Robbins  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
2203b716c4STim J. Robbins  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
2303b716c4STim J. Robbins  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
2403b716c4STim J. Robbins  * SUCH DAMAGE.
2503b716c4STim J. Robbins  */
2603b716c4STim J. Robbins 
2703b716c4STim J. Robbins #include <sys/cdefs.h>
2803b716c4STim J. Robbins __FBSDID("$FreeBSD$");
2903b716c4STim J. Robbins 
3003b716c4STim J. Robbins #include <stdlib.h>
3103b716c4STim J. Robbins #include <wchar.h>
3203b716c4STim J. Robbins #include <wctype.h>
3303b716c4STim J. Robbins 
3403b716c4STim J. Robbins /*
3503b716c4STim J. Robbins  * Convert a string to a double-precision number.
3603b716c4STim J. Robbins  *
3703b716c4STim J. Robbins  * This is the wide-character counterpart of strtod(). So that we do not
3803b716c4STim J. Robbins  * have to duplicate the code of strtod() here, we convert the supplied
3903b716c4STim J. Robbins  * wide character string to multibyte and call strtod() on the result.
4003b716c4STim J. Robbins  * This assumes that the multibyte encoding is compatible with ASCII
4103b716c4STim J. Robbins  * for at least the digits, radix character and letters.
4203b716c4STim J. Robbins  */
4303b716c4STim J. Robbins double
4403b716c4STim J. Robbins wcstod(const wchar_t * __restrict nptr, wchar_t ** __restrict endptr)
4503b716c4STim J. Robbins {
4603b716c4STim J. Robbins 	double val;
471e8742e9STim J. Robbins 	char *buf, *end;
4803b716c4STim J. Robbins 	const wchar_t *wcp;
491e8742e9STim J. Robbins 	size_t len;
5003b716c4STim J. Robbins 
5103b716c4STim J. Robbins 	while (iswspace(*nptr))
5203b716c4STim J. Robbins 		nptr++;
5303b716c4STim J. Robbins 
5403b716c4STim J. Robbins 	/*
5503b716c4STim J. Robbins 	 * Convert the supplied numeric wide char. string to multibyte.
5603b716c4STim J. Robbins 	 *
5703b716c4STim J. Robbins 	 * We could attempt to find the end of the numeric portion of the
5803b716c4STim J. Robbins 	 * wide char. string to avoid converting unneeded characters but
5903b716c4STim J. Robbins 	 * choose not to bother; optimising the uncommon case where
6003b716c4STim J. Robbins 	 * the input string contains a lot of text after the number
6103b716c4STim J. Robbins 	 * duplicates a lot of strtod()'s functionality and slows down the
6203b716c4STim J. Robbins 	 * most common cases.
631e8742e9STim J. Robbins 	 *
641e8742e9STim J. Robbins 	 * We pass NULL as the state pointer to wcrtomb() because we don't
651e8742e9STim J. Robbins 	 * support state-dependent encodings and don't want to waste time
661e8742e9STim J. Robbins 	 * creating a zeroed mbstate_t that will not be used.
6703b716c4STim J. Robbins 	 */
6803b716c4STim J. Robbins 	wcp = nptr;
691e8742e9STim J. Robbins 	if ((len = wcsrtombs(NULL, &wcp, 0, NULL)) == (size_t)-1) {
7003b716c4STim J. Robbins 		if (endptr != NULL)
7103b716c4STim J. Robbins 			*endptr = (wchar_t *)nptr;
7203b716c4STim J. Robbins 		return (0.0);
7303b716c4STim J. Robbins 	}
7403b716c4STim J. Robbins 	if ((buf = malloc(len + 1)) == NULL)
7503b716c4STim J. Robbins 		return (0.0);
761e8742e9STim J. Robbins 	wcsrtombs(buf, &wcp, len + 1, NULL);
7703b716c4STim J. Robbins 
7803b716c4STim J. Robbins 	/* Let strtod() do most of the work for us. */
7903b716c4STim J. Robbins 	val = strtod(buf, &end);
8003b716c4STim J. Robbins 
8103b716c4STim J. Robbins 	/*
8203b716c4STim J. Robbins 	 * We only know where the number ended in the _multibyte_
8303b716c4STim J. Robbins 	 * representation of the string. If the caller wants to know
8403b716c4STim J. Robbins 	 * where it ended, count multibyte characters to find the
8503b716c4STim J. Robbins 	 * corresponding position in the wide char string.
8603b716c4STim J. Robbins 	 */
871e8742e9STim J. Robbins 	if (endptr != NULL)
881e8742e9STim J. Robbins 		/* XXX Assume each wide char is one byte. */
8903b716c4STim J. Robbins 		*endptr = (wchar_t *)nptr + (end - buf);
9003b716c4STim J. Robbins 
9103b716c4STim J. Robbins 	free(buf);
9203b716c4STim J. Robbins 
9303b716c4STim J. Robbins 	return (val);
9403b716c4STim J. Robbins }
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