ungetwc.c revision 330897 
1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2002-2004 Tim J. Robbins.
5 * All rights reserved.
6 *
7 * Copyright (c) 2011 The FreeBSD Foundation
8 * All rights reserved.
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 <sys/cdefs.h>
35__FBSDID("$FreeBSD: stable/11/lib/libc/stdio/ungetwc.c 330897 2018-03-14 03:19:51Z eadler $");
36
37#include "namespace.h"
38#include <errno.h>
39#include <limits.h>
40#include <stdio.h>
41#include <stdlib.h>
42#include <wchar.h>
43#include "un-namespace.h"
44#include "libc_private.h"
45#include "local.h"
46#include "mblocal.h"
47#include "xlocale_private.h"
48
49/*
50 * Non-MT-safe version.
51 */
52wint_t
53__ungetwc(wint_t wc, FILE *fp, locale_t locale)
54{
55	char buf[MB_LEN_MAX];
56	size_t len;
57	struct xlocale_ctype *l = XLOCALE_CTYPE(locale);
58
59	if (wc == WEOF)
60		return (WEOF);
61	if ((len = l->__wcrtomb(buf, wc, &fp->_mbstate)) == (size_t)-1) {
62		fp->_flags |= __SERR;
63		return (WEOF);
64	}
65	while (len-- != 0)
66		if (__ungetc((unsigned char)buf[len], fp) == EOF)
67			return (WEOF);
68
69	return (wc);
70}
71
72/*
73 * MT-safe version.
74 */
75wint_t
76ungetwc_l(wint_t wc, FILE *fp, locale_t locale)
77{
78	wint_t r;
79	FIX_LOCALE(locale);
80
81	FLOCKFILE_CANCELSAFE(fp);
82	ORIENT(fp, 1);
83	r = __ungetwc(wc, fp, locale);
84	FUNLOCKFILE_CANCELSAFE();
85
86	return (r);
87}
88wint_t
89ungetwc(wint_t wc, FILE *fp)
90{
91	return ungetwc_l(wc, fp, __get_locale());
92}
93