/* Convert multibyte character to wide character.

   Copyright (C) 1999-2002, 2005-2022 Free Software Foundation, Inc.

   Written by Bruno Haible <bruno@clisp.org>, 2008.

   This file 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.

   This file 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 this program.  If not, see <https://www.gnu.org/licenses/>.  */

#include <config.h>

/* Specification.  */

#include <wchar.h>

#if GNULIB_defined_mbstate_t

/* Implement mbrtowc() on top of mbtowc() for the non-UTF-8 locales

   and directly for the UTF-8 locales.  */

# include <errno.h>

# include <stdint.h>

# include <stdlib.h>

# if defined _WIN32 && !defined __CYGWIN__

#  define WIN32_LEAN_AND_MEAN  /* avoid including junk */

#  include <windows.h>

# elif HAVE_PTHREAD_API

#  include <pthread.h>

#  if HAVE_THREADS_H && HAVE_WEAK_SYMBOLS

#   include <threads.h>

#   pragma weak thrd_exit

#   define c11_threads_in_use() (thrd_exit != NULL)

#  else

#   define c11_threads_in_use() 0

#  endif

# elif HAVE_THREADS_H

#  include <threads.h>

# endif

# include "attribute.h"

# include "lc-charset-dispatch.h"

# include "mbtowc-lock.h"

static_assert (sizeof (mbstate_t) >= 4);

static char internal_state[4];

size_t

mbrtowc (wchar_t *pwc, const char *s, size_t n, mbstate_t *ps)

{

# define FITS_IN_CHAR_TYPE(wc)  ((wc) <= WCHAR_MAX)

# include "mbrtowc-impl.h"

}

#else

/* Override the system's mbrtowc() function.  */

# if MBRTOWC_IN_C_LOCALE_MAYBE_EILSEQ

#  include "hard-locale.h"

#  include <locale.h>

# endif

# undef mbrtowc

size_t

rpl_mbrtowc (wchar_t *pwc, const char *s, size_t n, mbstate_t *ps)

{

  size_t ret;

  wchar_t wc;

# if MBRTOWC_NULL_ARG2_BUG || MBRTOWC_RETVAL_BUG || MBRTOWC_EMPTY_INPUT_BUG

  if (s == NULL)

    {

      pwc = NULL;

      s = "";

      n = 1;

    }

# endif

# if MBRTOWC_EMPTY_INPUT_BUG

  if (n == 0)

    return (size_t) -2;

# endif

  if (! pwc)

    pwc = &wc;

# if MBRTOWC_RETVAL_BUG

  {

    static mbstate_t internal_state;

    /* Override mbrtowc's internal state.  We cannot call mbsinit() on the

       hidden internal state, but we can call it on our variable.  */

    if (ps == NULL)

      ps = &internal_state;

    if (!mbsinit (ps))

      {

        /* Parse the rest of the multibyte character byte for byte.  */

        size_t count = 0;

        for (; n > 0; s++, n--)

          {

            ret = mbrtowc (&wc, s, 1, ps);

            if (ret == (size_t)(-1))

              return (size_t)(-1);

            count++;

            if (ret != (size_t)(-2))

              {

                /* The multibyte character has been completed.  */

                *pwc = wc;

                return (wc == 0 ? 0 : count);

              }

          }

        return (size_t)(-2);

      }

  }

# endif

# if MBRTOWC_STORES_INCOMPLETE_BUG

  ret = mbrtowc (&wc, s, n, ps);

  if (ret < (size_t) -2 && pwc != NULL)

    *pwc = wc;

# else

  ret = mbrtowc (pwc, s, n, ps);

# endif

# if MBRTOWC_NUL_RETVAL_BUG

  if (ret < (size_t) -2 && !*pwc)

    return 0;

# endif

# if MBRTOWC_IN_C_LOCALE_MAYBE_EILSEQ

  if ((size_t) -2 <= ret && n != 0 && ! hard_locale (LC_CTYPE))

    {

      unsigned char uc = *s;

      *pwc = uc;

      return 1;

    }

# endif

  return ret;

}

#endif