glibc/wcsmbs/btowc.c

103 lines
3.0 KiB
C

/* Copyright (C) 1996-2000,2002,2005 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@gnu.org>, 1996.
The GNU C Library 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.
The GNU C Library 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 the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <ctype.h>
#include <dlfcn.h>
#include <gconv.h>
#include <stdio.h>
#include <string.h>
#include <wchar.h>
#include <wcsmbsload.h>
#include <limits.h>
#include <sysdep.h>
wint_t
__btowc (c)
int c;
{
const struct gconv_fcts *fcts;
/* If the parameter does not fit into one byte or it is the EOF value
we can give the answer now. */
if (c < SCHAR_MIN || c > UCHAR_MAX || c == EOF)
return WEOF;
/* We know that only ASCII compatible encodings are used for the
locale and that the wide character encoding is ISO 10646. */
if (isascii (c))
return (wint_t) c;
/* Get the conversion functions. */
fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));
__gconv_btowc_fct btowc_fct = fcts->towc->__btowc_fct;
if (__builtin_expect (fcts->towc_nsteps == 1, 1)
&& __builtin_expect (btowc_fct != NULL, 1))
{
/* Use the shortcut function. */
#ifdef PTR_DEMANGLE
if (fcts->towc->__shlib_handle != NULL)
PTR_DEMANGLE (btowc_fct);
#endif
return DL_CALL_FCT (btowc_fct, (fcts->towc, (unsigned char) c));
}
else
{
/* Fall back to the slow but generic method. */
wchar_t result;
struct __gconv_step_data data;
unsigned char inbuf[1];
const unsigned char *inptr = inbuf;
size_t dummy;
int status;
/* Tell where we want the result. */
data.__outbuf = (unsigned char *) &result;
data.__outbufend = data.__outbuf + sizeof (wchar_t);
data.__invocation_counter = 0;
data.__internal_use = 1;
data.__flags = __GCONV_IS_LAST;
data.__statep = &data.__state;
data.__trans = NULL;
/* Make sure we start in the initial state. */
memset (&data.__state, '\0', sizeof (mbstate_t));
/* Create the input string. */
inbuf[0] = c;
__gconv_fct fct = fcts->towc->__fct;
#ifdef PTR_DEMANGLE
if (fcts->towc->__shlib_handle != NULL)
PTR_DEMANGLE (fct);
#endif
status = DL_CALL_FCT (fct, (fcts->towc, &data, &inptr, inptr + 1,
NULL, &dummy, 0, 1));
if (status != __GCONV_OK && status != __GCONV_FULL_OUTPUT
&& status != __GCONV_EMPTY_INPUT)
/* The conversion failed. */
result = WEOF;
return result;
}
}
weak_alias (__btowc, btowc)