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[glibc/history.git] / wcsmbs / btowc.c
blob6517d4f635ec161c7bed7f69e519e2a96050dfcb
1 /* Copyright (C) 1996-2000,2002,2005 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@gnu.org>, 1996.
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.
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.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18 02111-1307 USA. */
20 #include <ctype.h>
21 #include <dlfcn.h>
22 #include <gconv.h>
23 #include <stdio.h>
24 #include <string.h>
25 #include <wchar.h>
26 #include <wcsmbsload.h>
27 #include <limits.h>
29 #include <sysdep.h>
32 wint_t
33 __btowc (c)
34 int c;
36 const struct gconv_fcts *fcts;
38 /* If the parameter does not fit into one byte or it is the EOF value
39 we can give the answer now. */
40 if (c < SCHAR_MIN || c > UCHAR_MAX || c == EOF)
41 return WEOF;
43 /* We know that only ASCII compatible encodings are used for the
44 locale and that the wide character encoding is ISO 10646. */
45 if (isascii (c))
46 return (wint_t) c;
48 /* Get the conversion functions. */
49 fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
50 __gconv_btowc_fct btowc_fct = fcts->towc->__btowc_fct;
52 if (__builtin_expect (fcts->towc_nsteps == 1, 1)
53 && __builtin_expect (btowc_fct != NULL, 1))
55 /* Use the shortcut function. */
56 #ifdef PTR_DEMANGLE
57 if (fcts->towc->__shlib_handle != NULL)
58 PTR_DEMANGLE (btowc_fct);
59 #endif
60 return DL_CALL_FCT (btowc_fct, (fcts->towc, (unsigned char) c));
62 else
64 /* Fall back to the slow but generic method. */
65 wchar_t result;
66 struct __gconv_step_data data;
67 unsigned char inbuf[1];
68 const unsigned char *inptr = inbuf;
69 size_t dummy;
70 int status;
72 /* Tell where we want the result. */
73 data.__outbuf = (unsigned char *) &result;
74 data.__outbufend = data.__outbuf + sizeof (wchar_t);
75 data.__invocation_counter = 0;
76 data.__internal_use = 1;
77 data.__flags = __GCONV_IS_LAST;
78 data.__statep = &data.__state;
79 data.__trans = NULL;
81 /* Make sure we start in the initial state. */
82 memset (&data.__state, '\0', sizeof (mbstate_t));
84 /* Create the input string. */
85 inbuf[0] = c;
87 __gconv_fct fct = fcts->towc->__fct;
88 #ifdef PTR_DEMANGLE
89 if (fcts->towc->__shlib_handle != NULL)
90 PTR_DEMANGLE (fct);
91 #endif
92 status = DL_CALL_FCT (fct, (fcts->towc, &data, &inptr, inptr + 1,
93 NULL, &dummy, 0, 1));
95 if (status != __GCONV_OK && status != __GCONV_FULL_OUTPUT
96 && status != __GCONV_EMPTY_INPUT)
97 /* The conversion failed. */
98 result = WEOF;
100 return result;
103 weak_alias (__btowc, btowc)