1 /* Convert multibyte character to wide character.
2 Copyright (C) 1999-2002, 2005-2023 Free Software Foundation, Inc.
3 Written by Bruno Haible <bruno@clisp.org>, 2008.
4
5 This file is free software: you can redistribute it and/or modify
6 it under the terms of the GNU Lesser General Public License as
7 published by the Free Software Foundation; either version 2.1 of the
8 License, or (at your option) any later version.
9
10 This file is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public License
16 along with this program. If not, see <https://www.gnu.org/licenses/>. */
17
18 #include <config.h>
19
20 /* Specification. */
21 #include <wchar.h>
22
23 #if GNULIB_defined_mbstate_t
24 /* Implement mbrtowc() on top of mbtowc() for the non-UTF-8 locales
25 and directly for the UTF-8 locales. */
26
27 # include <errno.h>
28 # include <stdint.h>
29 # include <stdlib.h>
30
31 # if defined _WIN32 && !defined __CYGWIN__
32
33 # define WIN32_LEAN_AND_MEAN /* avoid including junk */
34 # include <windows.h>
35
36 # elif HAVE_PTHREAD_API
37
38 # include <pthread.h>
39 # if HAVE_THREADS_H && HAVE_WEAK_SYMBOLS
40 # include <threads.h>
41 # pragma weak thrd_exit
42 # define c11_threads_in_use() (thrd_exit != NULL)
43 # else
44 # define c11_threads_in_use() 0
45 # endif
46
47 # elif HAVE_THREADS_H
48
49 # include <threads.h>
50
51 # endif
52
53 # include "attribute.h"
54 # include "lc-charset-dispatch.h"
55 # include "mbtowc-lock.h"
56
57 static_assert (sizeof (mbstate_t) >= 4);
58 static char internal_state[4];
59
60 size_t
61 mbrtowc (wchar_t *pwc, const char *s, size_t n, mbstate_t *ps)
62 {
63 # define FITS_IN_CHAR_TYPE(wc) ((wc) <= WCHAR_MAX)
64 # include "mbrtowc-impl.h"
65 }
66
67 #else
68 /* Override the system's mbrtowc() function. */
69
70 # if MBRTOWC_IN_C_LOCALE_MAYBE_EILSEQ
71 # include "hard-locale.h"
72 # include <locale.h>
73 # endif
74
75 # undef mbrtowc
76
77 size_t
78 rpl_mbrtowc (wchar_t *pwc, const char *s, size_t n, mbstate_t *ps)
79 {
80 size_t ret;
81 wchar_t wc;
82
83 # if MBRTOWC_NULL_ARG2_BUG || MBRTOWC_RETVAL_BUG || MBRTOWC_EMPTY_INPUT_BUG
84 if (s == NULL)
85 {
86 pwc = NULL;
87 s = "";
88 n = 1;
89 }
90 # endif
91
92 # if MBRTOWC_EMPTY_INPUT_BUG
93 if (n == 0)
94 return (size_t) -2;
95 # endif
96
97 if (! pwc)
98 pwc = &wc;
99
100 # if MBRTOWC_RETVAL_BUG
101 {
102 static mbstate_t internal_state;
103
104 /* Override mbrtowc's internal state. We cannot call mbsinit() on the
105 hidden internal state, but we can call it on our variable. */
106 if (ps == NULL)
107 ps = &internal_state;
108
109 if (!mbsinit (ps))
110 {
111 /* Parse the rest of the multibyte character byte for byte. */
112 size_t count = 0;
113 for (; n > 0; s++, n--)
114 {
115 ret = mbrtowc (&wc, s, 1, ps);
116
117 if (ret == (size_t)(-1))
118 return (size_t)(-1);
119 count++;
120 if (ret != (size_t)(-2))
121 {
122 /* The multibyte character has been completed. */
123 *pwc = wc;
124 return (wc == 0 ? 0 : count);
125 }
126 }
127 return (size_t)(-2);
128 }
129 }
130 # endif
131
132 # if MBRTOWC_STORES_INCOMPLETE_BUG
133 ret = mbrtowc (&wc, s, n, ps);
134 if (ret < (size_t) -2 && pwc != NULL)
135 *pwc = wc;
136 # else
137 ret = mbrtowc (pwc, s, n, ps);
138 # endif
139
140 # if MBRTOWC_NUL_RETVAL_BUG
141 if (ret < (size_t) -2 && !*pwc)
142 return 0;
143 # endif
144
145 # if MBRTOWC_IN_C_LOCALE_MAYBE_EILSEQ
146 if ((size_t) -2 <= ret && n != 0 && ! hard_locale (LC_CTYPE))
147 {
148 unsigned char uc = *s;
149 *pwc = uc;
150 return 1;
151 }
152 # endif
153
154 return ret;
155 }
156
157 #endif