1/* Copyright (C) 1996-2021 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@gnu.org>, 1996.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library 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 GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <ctype.h>
20#include <dlfcn.h>
21#include <gconv.h>
22#include <stdio.h>
23#include <string.h>
24#include <wchar.h>
25#include <wcsmbsload.h>
26#include <limits.h>
27
28#include <sysdep.h>
29
30
31wint_t
32__btowc (int c)
33{
34 const struct gconv_fcts *fcts;
35
36 /* If the parameter does not fit into one byte or it is the EOF value
37 we can give the answer now. */
38 if (c < SCHAR_MIN || c > UCHAR_MAX || c == EOF)
39 return WEOF;
40
41 /* We know that only ASCII compatible encodings are used for the
42 locale and that the wide character encoding is ISO 10646. */
43 if (isascii (c))
44 return (wint_t) c;
45
46 /* Get the conversion functions. */
47 fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
48 __gconv_btowc_fct btowc_fct = fcts->towc->__btowc_fct;
49#ifdef PTR_DEMANGLE
50 if (fcts->towc->__shlib_handle != NULL)
51 PTR_DEMANGLE (btowc_fct);
52#endif
53
54 if (__builtin_expect (fcts->towc_nsteps == 1, 1)
55 && __builtin_expect (btowc_fct != NULL, 1))
56 {
57 /* Use the shortcut function. */
58 return DL_CALL_FCT (btowc_fct, (fcts->towc, (unsigned char) c));
59 }
60 else
61 {
62 /* Fall back to the slow but generic method. */
63 wchar_t result;
64 struct __gconv_step_data data;
65 unsigned char inbuf[1];
66 const unsigned char *inptr = inbuf;
67 size_t dummy;
68 int status;
69
70 /* Tell where we want the result. */
71 data.__outbuf = (unsigned char *) &result;
72 data.__outbufend = data.__outbuf + sizeof (wchar_t);
73 data.__invocation_counter = 0;
74 data.__internal_use = 1;
75 data.__flags = __GCONV_IS_LAST;
76 data.__statep = &data.__state;
77
78 /* Make sure we start in the initial state. */
79 memset (&data.__state, '\0', sizeof (mbstate_t));
80
81 /* Create the input string. */
82 inbuf[0] = c;
83
84 __gconv_fct fct = fcts->towc->__fct;
85#ifdef PTR_DEMANGLE
86 if (fcts->towc->__shlib_handle != NULL)
87 PTR_DEMANGLE (fct);
88#endif
89 status = DL_CALL_FCT (fct, (fcts->towc, &data, &inptr, inptr + 1,
90 NULL, &dummy, 0, 1));
91
92 if (status != __GCONV_OK && status != __GCONV_FULL_OUTPUT
93 && status != __GCONV_EMPTY_INPUT)
94 /* The conversion failed. */
95 result = WEOF;
96
97 return result;
98 }
99}
100weak_alias (__btowc, btowc)
101