1/* Copyright (C) 1991-2023 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18#include <stdlib.h>
19#include <string.h>
20#include <wchar.h>
21#include <gconv.h>
22#include <wcsmbs/wcsmbsload.h>
23
24
25/* Convert the multibyte character at S, which is no longer
26 than N characters, to its `wchar_t' representation, placing
27 this n *PWC and returning its length.
28
29 Attention: this function should NEVER be intentionally used.
30 The interface is completely stupid. The state is shared between
31 all conversion functions. You should use instead the restartable
32 version `mbrtowc'. */
33int
34mbtowc (wchar_t *pwc, const char *s, size_t n)
35{
36 int result;
37 static mbstate_t state;
38
39 /* If S is NULL the function has to return null or not null
40 depending on the encoding having a state depending encoding or
41 not. */
42 if (s == NULL)
43 {
44 const struct gconv_fcts *fcts;
45
46 /* Get the conversion functions. */
47 fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
48
49 /* This is an extension in the Unix standard which does not directly
50 violate ISO C. */
51 memset (&state, '\0', sizeof state);
52
53 result = fcts->towc->__stateful;
54 }
55 else if (*s == '\0')
56 {
57 if (pwc != NULL)
58 *pwc = L'\0';
59 result = 0;
60 }
61 else
62 {
63 result = __mbrtowc (pwc, s, n, &state);
64
65 /* The `mbrtowc' functions tell us more than we need. Fold the -1
66 and -2 result into -1. */
67 if (result < 0)
68 result = -1;
69 }
70
71 return result;
72}
73