xref: /freebsd/lib/libc/locale/wcstod.c (revision f4b37ed0f8b307b1f3f0f630ca725d68f1dff30d)
1 /*-
2  * Copyright (c) 2002 Tim J. Robbins
3  * All rights reserved.
4  *
5  * Copyright (c) 2011 The FreeBSD Foundation
6  * All rights reserved.
7  * Portions of this software were developed by David Chisnall
8  * under sponsorship from the FreeBSD Foundation.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include <stdlib.h>
36 #include <wchar.h>
37 #include <wctype.h>
38 #include "xlocale_private.h"
39 
40 /*
41  * Convert a string to a double-precision number.
42  *
43  * This is the wide-character counterpart of strtod(). So that we do not
44  * have to duplicate the code of strtod() here, we convert the supplied
45  * wide character string to multibyte and call strtod() on the result.
46  * This assumes that the multibyte encoding is compatible with ASCII
47  * for at least the digits, radix character and letters.
48  */
49 double
50 wcstod_l(const wchar_t * __restrict nptr, wchar_t ** __restrict endptr,
51 		locale_t locale)
52 {
53 	static const mbstate_t initial;
54 	mbstate_t mbs;
55 	double val;
56 	char *buf, *end;
57 	const wchar_t *wcp = nptr;
58 	size_t len;
59 	size_t spaces = 0;
60 	FIX_LOCALE(locale);
61 
62 	while (iswspace_l(*wcp, locale)) {
63 		wcp++;
64 		spaces++;
65 	}
66 
67 	/*
68 	 * Convert the supplied numeric wide char. string to multibyte.
69 	 *
70 	 * We could attempt to find the end of the numeric portion of the
71 	 * wide char. string to avoid converting unneeded characters but
72 	 * choose not to bother; optimising the uncommon case where
73 	 * the input string contains a lot of text after the number
74 	 * duplicates a lot of strtod()'s functionality and slows down the
75 	 * most common cases.
76 	 */
77 	mbs = initial;
78 	if ((len = wcsrtombs_l(NULL, &wcp, 0, &mbs, locale)) == (size_t)-1) {
79 		if (endptr != NULL)
80 			*endptr = (wchar_t *)nptr;
81 		return (0.0);
82 	}
83 	if ((buf = malloc(len + 1)) == NULL)
84 		return (0.0);
85 	mbs = initial;
86 	wcsrtombs_l(buf, &wcp, len + 1, &mbs, locale);
87 
88 	/* Let strtod() do most of the work for us. */
89 	val = strtod_l(buf, &end, locale);
90 
91 	/*
92 	 * We only know where the number ended in the _multibyte_
93 	 * representation of the string. If the caller wants to know
94 	 * where it ended, count multibyte characters to find the
95 	 * corresponding position in the wide char string.
96 	 */
97 	if (endptr != NULL) {
98 		/* XXX Assume each wide char is one byte. */
99 		*endptr = (wchar_t *)nptr + (end - buf);
100 		if (buf != end)
101 			*endptr += spaces;
102 	}
103 
104 
105 	free(buf);
106 
107 	return (val);
108 }
109 double
110 wcstod(const wchar_t * __restrict nptr, wchar_t ** __restrict endptr)
111 {
112 	return wcstod_l(nptr, endptr, __get_locale());
113 }
114