fgetwc.c revision 320942 
1/*-
2 * Copyright (c) 2002-2004 Tim J. Robbins.
3 * All rights reserved.
4 *
5 * Copyright (c) 2011 The FreeBSD Foundation
6 * All rights reserved.
7 * Portions of this software were developed by David Chisnall
8 * under sponsorship from the FreeBSD Foundation.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33__FBSDID("$FreeBSD: stable/11/lib/libc/stdio/fgetwc.c 320942 2017-07-13 09:27:11Z kib $");
34
35#include "namespace.h"
36#include <errno.h>
37#include <stdio.h>
38#include <stdlib.h>
39#include <wchar.h>
40#include "un-namespace.h"
41#include "libc_private.h"
42#include "local.h"
43#include "mblocal.h"
44#include "xlocale_private.h"
45
46/*
47 * MT-safe version.
48 */
49wint_t
50fgetwc_l(FILE *fp, locale_t locale)
51{
52	wint_t r;
53	FIX_LOCALE(locale);
54
55	FLOCKFILE_CANCELSAFE(fp);
56	ORIENT(fp, 1);
57	r = __fgetwc(fp, locale);
58	FUNLOCKFILE_CANCELSAFE();
59
60	return (r);
61}
62
63wint_t
64fgetwc(FILE *fp)
65{
66	return fgetwc_l(fp, __get_locale());
67}
68
69/*
70 * Internal (non-MPSAFE) version of fgetwc().  This version takes an
71 * mbstate_t argument specifying the initial conversion state.  For
72 * wide streams, this should always be fp->_mbstate.  On return, *nread
73 * is set to the number of bytes read.
74 */
75wint_t
76__fgetwc_mbs(FILE *fp, mbstate_t *mbs, int *nread, locale_t locale)
77{
78	wchar_t wc;
79	size_t nconv;
80	struct xlocale_ctype *l = XLOCALE_CTYPE(locale);
81
82	*nread = 0;
83	if (fp->_r <= 0 && __srefill(fp))
84		return (WEOF);
85	do {
86		nconv = l->__mbrtowc(&wc, fp->_p, fp->_r, mbs);
87		if (nconv == (size_t)-1) {
88			fp->_flags |= __SERR;
89			return (WEOF);
90		} else if (nconv == (size_t)-2)
91			continue;
92		else if (nconv == 0) {
93			fp->_p++;
94			fp->_r--;
95			(*nread)++;
96			return (L'\0');
97		} else {
98			fp->_p += nconv;
99			fp->_r -= nconv;
100			*nread += nconv;
101			return (wc);
102		}
103	} while (__srefill(fp) == 0);
104	if (__sfeof(fp)) {
105		fp->_flags |= __SERR;
106		errno = EILSEQ;
107	}
108	return (WEOF);
109}
110