1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2002 Tim J. Robbins
5 * All rights reserved.
6 *
7 * Copyright (c) 2011 The FreeBSD Foundation
8 *
9 * Portions of this software were developed by David Chisnall
10 * under sponsorship from the FreeBSD Foundation.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #include <errno.h>
35 #include <limits.h>
36 #include <stdlib.h>
37 #include <time.h>
38 #include <wchar.h>
39 #include "xlocale_private.h"
40
41 /*
42 * Convert date and time to a wide-character string.
43 *
44 * This is the wide-character counterpart of strftime(). So that we do not
45 * have to duplicate the code of strftime(), we convert the format string to
46 * multibyte, call strftime(), then convert the result back into wide
47 * characters.
48 *
49 * This technique loses in the presence of stateful multibyte encoding if any
50 * of the conversions in the format string change conversion state. When
51 * stateful encoding is implemented, we will need to reset the state between
52 * format specifications in the format string.
53 */
54 size_t
wcsftime_l(wchar_t * __restrict wcs,size_t maxsize,const wchar_t * __restrict format,const struct tm * __restrict timeptr,locale_t locale)55 wcsftime_l(wchar_t * __restrict wcs, size_t maxsize,
56 const wchar_t * __restrict format, const struct tm * __restrict timeptr,
57 locale_t locale)
58 {
59 static const mbstate_t initial;
60 mbstate_t mbs;
61 char *dst, *sformat;
62 const char *dstp;
63 const wchar_t *formatp;
64 size_t n, sflen;
65 int sverrno;
66 FIX_LOCALE(locale);
67
68 sformat = dst = NULL;
69
70 /*
71 * Convert the supplied format string to a multibyte representation
72 * for strftime(), which only handles single-byte characters.
73 */
74 mbs = initial;
75 formatp = format;
76 sflen = wcsrtombs_l(NULL, &formatp, 0, &mbs, locale);
77 if (sflen == (size_t)-1)
78 goto error;
79 if ((sformat = malloc(sflen + 1)) == NULL)
80 goto error;
81 mbs = initial;
82 wcsrtombs_l(sformat, &formatp, sflen + 1, &mbs, locale);
83
84 /*
85 * Allocate memory for longest multibyte sequence that will fit
86 * into the caller's buffer and call strftime() to fill it.
87 * Then, copy and convert the result back into wide characters in
88 * the caller's buffer.
89 */
90 if (SIZE_T_MAX / MB_CUR_MAX <= maxsize) {
91 /* maxsize is prepostorously large - avoid int. overflow. */
92 errno = EINVAL;
93 goto error;
94 }
95 if ((dst = malloc(maxsize * MB_CUR_MAX)) == NULL)
96 goto error;
97 if (strftime_l(dst, maxsize, sformat, timeptr, locale) == 0)
98 goto error;
99 dstp = dst;
100 mbs = initial;
101 n = mbsrtowcs_l(wcs, &dstp, maxsize, &mbs, locale);
102 if (n == (size_t)-2 || n == (size_t)-1 || dstp != NULL)
103 goto error;
104
105 free(sformat);
106 free(dst);
107 return (n);
108
109 error:
110 sverrno = errno;
111 free(sformat);
112 free(dst);
113 errno = sverrno;
114 return (0);
115 }
116 size_t
wcsftime(wchar_t * __restrict wcs,size_t maxsize,const wchar_t * __restrict format,const struct tm * __restrict timeptr)117 wcsftime(wchar_t * __restrict wcs, size_t maxsize,
118 const wchar_t * __restrict format, const struct tm * __restrict timeptr)
119 {
120 return wcsftime_l(wcs, maxsize, format, timeptr, __get_locale());
121 }
122