1 /* Copyright (C) 1996-2022 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 <dlfcn.h>
19 #include <gconv.h>
20 #include <stdio.h>
21 #include <string.h>
22 #include <wchar.h>
23 #include <wcsmbsload.h>
24 
25 #include <sysdep.h>
26 
27 
28 int
wctob(wint_t c)29 wctob (wint_t c)
30 {
31   unsigned char buf[MB_LEN_MAX];
32   struct __gconv_step_data data;
33   wchar_t inbuf[1];
34   wchar_t *inptr = inbuf;
35   size_t dummy;
36   int status;
37   const struct gconv_fcts *fcts;
38 
39   if (c == WEOF)
40     return EOF;
41 
42   /* We know that only ASCII compatible encodings are used for the
43      locale and that the wide character encoding is ISO 10646.  */
44   if (c >= L'\0' && c <= L'\x7f')
45     return (int) c;
46 
47   /* Tell where we want the result.  */
48   data.__outbuf = buf;
49   data.__outbufend = buf + MB_LEN_MAX;
50   data.__invocation_counter = 0;
51   data.__internal_use = 1;
52   data.__flags = __GCONV_IS_LAST;
53   data.__statep = &data.__state;
54 
55   /* Make sure we start in the initial state.  */
56   memset (&data.__state, '\0', sizeof (mbstate_t));
57 
58   /* Get the conversion functions.  */
59   fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
60 
61   /* Create the input string.  */
62   inbuf[0] = c;
63 
64   const unsigned char *argptr = (const unsigned char *) inptr;
65   __gconv_fct fct = fcts->tomb->__fct;
66 #ifdef PTR_DEMANGLE
67   if (fcts->tomb->__shlib_handle != NULL)
68     PTR_DEMANGLE (fct);
69 #endif
70   status = DL_CALL_FCT (fct,
71 			(fcts->tomb, &data, &argptr,
72 			 argptr + sizeof (inbuf[0]), NULL, &dummy, 0, 1));
73 
74   /* The conversion failed or the output is too long.  */
75   if ((status != __GCONV_OK && status != __GCONV_FULL_OUTPUT
76        && status != __GCONV_EMPTY_INPUT)
77       || data.__outbuf != (unsigned char *) (buf + 1))
78     return EOF;
79 
80   return buf[0];
81 }
82