xref: /titanic_41/usr/src/lib/libc/port/locale/fgetwc.c (revision c037192b037119c9fd354732fc29b38ce097d356)
1 /*
2  * Copyright 2010 Nexenta Systems, Inc.  All rights reserved.
3  * Copyright (c) 2002-2004 Tim J. Robbins.
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include "lint.h"
29 #include "mse_int.h"
30 #include "file64.h"
31 #include "mtlib.h"
32 #include <errno.h>
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <wchar.h>
36 #include "mblocal.h"
37 #include "stdiom.h"
38 
39 /*
40  * Non-MT-safe version.
41  */
42 wint_t
43 _fgetwc_unlocked(FILE *fp)
44 {
45 	wchar_t wc;
46 	size_t nconv;
47 	int	c;
48 	mbstate_t	*statep;
49 
50 	if ((c = GETC(fp)) == EOF)
51 		return (WEOF);
52 
53 	if (MB_CUR_MAX == 1) {
54 		/* Fast path for single-byte encodings. */
55 		return ((wint_t)c);
56 	}
57 	if ((statep = _getmbstate(fp)) == NULL) {
58 		fp->_flag = _IOERR;
59 		errno = EBADF;
60 		return (WEOF);
61 	}
62 	do {
63 		char	x = (char)c;
64 		nconv = __mbrtowc(&wc, &x, 1, statep);
65 		if (nconv == (size_t)-1) {
66 			break;
67 		} else if (nconv == (size_t)-2) {
68 			/* Incompletely decoded, consume another char */
69 			continue;
70 		} else if (nconv == 0) {
71 			/*
72 			 * Assume that the only valid representation of
73 			 * the null wide character is a single null byte.
74 			 */
75 			return (L'\0');
76 		} else {
77 			return (wc);
78 		}
79 	} while ((c = GETC(fp)) != EOF);
80 
81 	/*
82 	 * If we got here it means we got truncated in a character, or
83 	 * the character did not decode properly.  Note that in the case
84 	 * of a botched decoding, we don't UNGETC the bad bytes.  Should
85 	 * we?
86 	 */
87 	fp->_flag |= _IOERR;
88 	errno = EILSEQ;
89 	return (WEOF);
90 }
91 
92 
93 /*
94  * MT safe version
95  */
96 wint_t
97 fgetwc(FILE *fp)
98 {
99 	wint_t		r;
100 	rmutex_t	*l;
101 
102 	FLOCKFILE(l, fp);
103 	r = _fgetwc_unlocked(fp);
104 	FUNLOCKFILE(l);
105 
106 	return (r);
107 }
108 
109 #undef	getwc
110 wint_t
111 getwc(FILE *fp)
112 {
113 	return (getwc(fp));
114 }
115 
116 /*
117  * XPG5 version.
118  */
119 wint_t
120 __fgetwc_xpg5(FILE *fp)
121 {
122 	wint_t		r;
123 	rmutex_t	*l;
124 
125 	FLOCKFILE(l, fp);
126 	if (GET_NO_MODE(fp))
127 		_setorientation(fp, _WC_MODE);
128 	r = _fgetwc_unlocked(fp);
129 	FUNLOCKFILE(l);
130 
131 	return (r);
132 }
133 
134 #undef	__getwc_xpg5
135 wint_t
136 __getwc_xpg5(FILE *fp)
137 {
138 	return (__fgetwc_xpg5(fp));
139 }
140