/* Copyright (C) 1996-2018 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 (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;

#ifdef PTR_DEMANGLE

  if (fcts->towc->__shlib_handle != NULL)

    PTR_DEMANGLE (btowc_fct);

#endif

  if (__builtin_expect (fcts->towc_nsteps == 1, 1)

      && __builtin_expect (btowc_fct != NULL, 1))

    {

      /* Use the shortcut function.  */

      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;

      /* 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)