xref: /freebsd/lib/libc/stdio/vswprintf.c (revision a3cf0ef5a295c885c895fabfd56470c0d1db322d)
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("$FreeBSD$");
35 
36 #include <errno.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <wchar.h>
40 #include "local.h"
41 
42 int
43 vswprintf(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