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/wcsftime.c,v 1.6 2009/01/15 20:45:59 rdivacky Exp $");
29
30#include "xlocale_private.h"
31
32#include <errno.h>
33#include <limits.h>
34#include <stdlib.h>
35#include <time.h>
36#include <wchar.h>
37
38/*
39 * Convert date and time to a wide-character string.
40 *
41 * This is the wide-character counterpart of strftime(). So that we do not
42 * have to duplicate the code of strftime(), we convert the format string to
43 * multibyte, call strftime(), then convert the result back into wide
44 * characters.
45 *
46 * This technique loses in the presence of stateful multibyte encoding if any
47 * of the conversions in the format string change conversion state. When
48 * stateful encoding is implemented, we will need to reset the state between
49 * format specifications in the format string.
50 */
51size_t
52wcsftime_l(wchar_t * __restrict wcs, size_t maxsize,
53    const wchar_t * __restrict format, const struct tm * __restrict timeptr,
54    locale_t loc)
55{
56	static const mbstate_t initial;
57	mbstate_t mbs;
58	char *dst, *sformat;
59	const char *dstp;
60	const wchar_t *formatp;
61	size_t n, sflen;
62	int sverrno;
63
64	NORMALIZE_LOCALE(loc);
65	sformat = dst = NULL;
66
67	/*
68	 * Convert the supplied format string to a multibyte representation
69	 * for strftime(), which only handles single-byte characters.
70	 */
71	mbs = initial;
72	formatp = format;
73	sflen = wcsrtombs_l(NULL, &formatp, 0, &mbs, loc);
74	if (sflen == (size_t)-1)
75		goto error;
76	if ((sformat = malloc(sflen + 1)) == NULL)
77		goto error;
78	mbs = initial;
79	wcsrtombs_l(sformat, &formatp, sflen + 1, &mbs, loc);
80
81	/*
82	 * Allocate memory for longest multibyte sequence that will fit
83	 * into the caller's buffer and call strftime() to fill it.
84	 * Then, copy and convert the result back into wide characters in
85	 * the caller's buffer.
86	 */
87	if (SIZE_T_MAX / MB_CUR_MAX_L(loc) <= maxsize) {
88		/* maxsize is prepostorously large - avoid int. overflow. */
89		errno = EINVAL;
90		goto error;
91	}
92	if ((dst = malloc(maxsize * MB_CUR_MAX_L(loc))) == NULL)
93		goto error;
94	if (strftime_l(dst, maxsize, sformat, timeptr, loc) == 0)
95		goto error;
96	dstp = dst;
97	mbs = initial;
98	n = mbsrtowcs_l(wcs, &dstp, maxsize, &mbs, loc);
99	if (n == (size_t)-2 || n == (size_t)-1 || dstp != NULL)
100		goto error;
101
102	free(sformat);
103	free(dst);
104	return (n);
105
106error:
107	sverrno = errno;
108	free(sformat);
109	free(dst);
110	errno = sverrno;
111	return (0);
112}
113
114size_t
115wcsftime(wchar_t * __restrict wcs, size_t maxsize,
116    const wchar_t * __restrict format, const struct tm * __restrict timeptr)
117{
118	return wcsftime_l(wcs, maxsize, format, timeptr, __current_locale());
119}
120