vswprintf.c revision 205021 
1/*	$OpenBSD: vasprintf.c,v 1.4 1998/06/21 22:13:47 millert Exp $	*/
2
3/*
4 * Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. The name of the author may not be used to endorse or promote products
16 *    derived from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
19 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
20 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
21 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
22 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
23 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
24 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
25 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
26 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
27 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30#include <sys/cdefs.h>
31#if 0
32__FBSDID("FreeBSD: src/lib/libc/stdio/vasprintf.c,v 1.16 2002/08/21 16:19:57 mike Exp ");
33#endif
34__FBSDID("$FreeBSD: head/lib/libc/stdio/vswprintf.c 205021 2010-03-11 17:03:32Z jhb $");
35
36#include <errno.h>
37#include <stdio.h>
38#include <stdlib.h>
39#include <wchar.h>
40#include "local.h"
41
42int
43vswprintf(wchar_t * __restrict s, size_t n, const wchar_t * __restrict fmt,
44    __va_list ap)
45{
46	static const mbstate_t initial;
47	mbstate_t mbs;
48	FILE f = FAKE_FILE;
49	char *mbp;
50	int ret, sverrno;
51	size_t nwc;
52
53	if (n == 0) {
54		errno = EINVAL;
55		return (-1);
56	}
57
58	f._flags = __SWR | __SSTR | __SALC;
59	f._bf._base = f._p = (unsigned char *)malloc(128);
60	if (f._bf._base == NULL) {
61		errno = ENOMEM;
62		return (-1);
63	}
64	f._bf._size = f._w = 127;		/* Leave room for the NUL */
65	ret = __vfwprintf(&f, fmt, ap);
66	if (ret < 0) {
67		sverrno = errno;
68		free(f._bf._base);
69		errno = sverrno;
70		return (-1);
71	}
72	*f._p = '\0';
73	mbp = f._bf._base;
74	/*
75	 * XXX Undo the conversion from wide characters to multibyte that
76	 * fputwc() did in __vfwprintf().
77	 */
78	mbs = initial;
79	nwc = mbsrtowcs(s, (const char **)&mbp, n, &mbs);
80	free(f._bf._base);
81	if (nwc == (size_t)-1) {
82		errno = EILSEQ;
83		return (-1);
84	}
85	if (nwc == n) {
86		s[n - 1] = L'\0';
87		errno = EOVERFLOW;
88		return (-1);
89	}
90
91	return (ret);
92}
93