summaryrefslogtreecommitdiff
path: root/lib/mbrtowc.c
blob: 8a1646d2f7b91f7bf13c72308a135292309184e6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
/* Convert multibyte character to wide character.
   Copyright (C) 1999-2002, 2005-2024 Free Software Foundation, Inc.
   Written by Bruno Haible <bruno@clisp.org>, 2008.

   This file is free software: you can redistribute it and/or modify
   it under the terms of the GNU Lesser General Public License as
   published by the Free Software Foundation; either version 2.1 of the
   License, or (at your option) any later version.

   This file is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public License
   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */

#include <config.h>

/* Specification.  */
#include <wchar.h>

#if GNULIB_defined_mbstate_t
/* Implement mbrtowc() on top of mbtowc() for the non-UTF-8 locales
   and directly for the UTF-8 locales.  */

# include <errno.h>
# include <stdint.h>
# include <stdlib.h>

# if AVOID_ANY_THREADS

/* The option '--disable-threads' explicitly requests no locking.  */

# elif defined _WIN32 && !defined __CYGWIN__

#  define WIN32_LEAN_AND_MEAN  /* avoid including junk */
#  include <windows.h>

# elif HAVE_PTHREAD_API

#  include <pthread.h>
#  if HAVE_THREADS_H && HAVE_WEAK_SYMBOLS
#   include <threads.h>
#   pragma weak thrd_exit
#   define c11_threads_in_use() (thrd_exit != NULL)
#  else
#   define c11_threads_in_use() 0
#  endif

# elif HAVE_THREADS_H

#  include <threads.h>

# endif

# include "attribute.h"
# include "lc-charset-dispatch.h"
# include "mbtowc-lock.h"

static_assert (sizeof (mbstate_t) >= 4);
static char internal_state[4];

size_t
mbrtowc (wchar_t *pwc, const char *s, size_t n, mbstate_t *ps)
{
# define FITS_IN_CHAR_TYPE(wc)  ((wc) <= WCHAR_MAX)
# include "mbrtowc-impl.h"
}

#else
/* Override the system's mbrtowc() function.  */

# if MBRTOWC_IN_C_LOCALE_MAYBE_EILSEQ
#  include "hard-locale.h"
#  include <locale.h>
# endif

# undef mbrtowc

size_t
rpl_mbrtowc (wchar_t *pwc, const char *s, size_t n, mbstate_t *ps)
{
  size_t ret;
  wchar_t wc;

# if MBRTOWC_NULL_ARG2_BUG || MBRTOWC_RETVAL_BUG || MBRTOWC_EMPTY_INPUT_BUG
  if (s == NULL)
    {
      pwc = NULL;
      s = "";
      n = 1;
    }
# endif

# if MBRTOWC_EMPTY_INPUT_BUG
  if (n == 0)
    return (size_t) -2;
# endif

  if (! pwc)
    pwc = &wc;

# if MBRTOWC_RETVAL_BUG
  {
    static mbstate_t internal_state;

    /* Override mbrtowc's internal state.  We cannot call mbsinit() on the
       hidden internal state, but we can call it on our variable.  */
    if (ps == NULL)
      ps = &internal_state;

    if (!mbsinit (ps))
      {
        /* Parse the rest of the multibyte character byte for byte.  */
        size_t count = 0;
        for (; n > 0; s++, n--)
          {
            ret = mbrtowc (&wc, s, 1, ps);

            if (ret == (size_t)(-1))
              return (size_t)(-1);
            count++;
            if (ret != (size_t)(-2))
              {
                /* The multibyte character has been completed.  */
                *pwc = wc;
                return (wc == 0 ? 0 : count);
              }
          }
        return (size_t)(-2);
      }
  }
# endif

# if MBRTOWC_STORES_INCOMPLETE_BUG
  ret = mbrtowc (&wc, s, n, ps);
  if (ret < (size_t) -2 && pwc != NULL)
    *pwc = wc;
# else
  ret = mbrtowc (pwc, s, n, ps);
# endif

# if MBRTOWC_NUL_RETVAL_BUG
  if (ret < (size_t) -2 && !*pwc)
    return 0;
# endif

# if MBRTOWC_IN_C_LOCALE_MAYBE_EILSEQ
  if ((size_t) -2 <= ret && n != 0 && ! hard_locale (LC_CTYPE))
    {
      unsigned char uc = *s;
      *pwc = uc;
      return 1;
    }
# endif

  return ret;
}

#endif