/* 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 <assert.h>

#include <dlfcn.h>

#include <errno.h>

#include <gconv.h>

#include <string.h>

#include <wchar.h>

#include <wcsmbsload.h>

#include <sysdep.h>

#ifndef EILSEQ

# define EILSEQ EINVAL

#endif

/* This is the private state used if PS is NULL.  */

static mbstate_t state;

/* This is a non-standard function but it is very useful in the

   implementation of stdio because we have to deal with unterminated

   buffers.  At most NMC bytes will be converted.  */

size_t

__mbsnrtowcs (wchar_t *dst, const char **src, size_t nmc, size_t len,

	      mbstate_t *ps)

{

  const unsigned char *srcend;

  struct __gconv_step_data data;

  size_t result;

  int status;

  struct __gconv_step *towc;

  size_t dummy;

  const struct gconv_fcts *fcts;

  /* Tell where we want the result.  */

  data.__invocation_counter = 0;

  data.__internal_use = 1;

  data.__flags = __GCONV_IS_LAST;

  data.__statep = ps ?: &stat;;

  if (nmc == 0)

    return 0;

  srcend = (const unsigned char *) *src + __strnlen (*src, nmc - 1) + 1;

  /* Get the conversion functions.  */

  fcts = get_gconv_fcts (_NL_CURRENT_DATA (LC_CTYPE));

  /* Get the structure with the function pointers.  */

  towc = fcts->towc;

  __gconv_fct fct = towc->__fct;

#ifdef PTR_DEMANGLE

  if (towc->__shlib_handle != NULL)

    PTR_DEMANGLE (fct);

#endif

  /* We have to handle DST == NULL special.  */

  if (dst == NULL)

    {

      mbstate_t temp_state;

      wchar_t buf[64];		/* Just an arbitrary size.  */

      const unsigned char *inbuf = (const unsigned char *) *src;

      temp_state = *data.__statep;

      data.__statep = &temp_state;

      result = 0;

      data.__outbufend = (unsigned char *) buf + sizeof (buf);

      do

	{

	  data.__outbuf = (unsigned char *) buf;

	  status = DL_CALL_FCT (fct, (towc, &data, &inbuf, srcend, NULL,

				      &dummy, 0, 1));

	  result += (wchar_t *) data.__outbuf - buf;

	}

      while (status == __GCONV_FULL_OUTPUT);

      if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)

	  && ((wchar_t *) data.__outbuf)[-1] == L'\0')

	/* Don't count the NUL character in.  */

	--result;

    }

  else

    {

      /* This code is based on the safe assumption that all internal

	 multi-byte encodings use the NUL byte only to mark the end

	 of the string.  */

      data.__outbuf = (unsigned char *) dst;

      data.__outbufend = data.__outbuf + len * sizeof (wchar_t);

      status = DL_CALL_FCT (fct,

			    (towc, &data, (const unsigned char **) src, srcend,

			     NULL, &dummy, 0, 1));

      result = (wchar_t *) data.__outbuf - dst;

      /* We have to determine whether the last character converted

	 is the NUL character.  */

      if ((status == __GCONV_OK || status == __GCONV_EMPTY_INPUT)

	  && (assert (result > 0),

	      ((wchar_t *) dst)[result - 1] == L'\0'))

	{

	  assert (__mbsinit (data.__statep));

	  *src = NULL;

	  --result;

	}

    }

  /* There must not be any problems with the conversion but illegal input

     characters.  */

  assert (status == __GCONV_OK || status == __GCONV_EMPTY_INPUT

	  || status == __GCONV_ILLEGAL_INPUT

	  || status == __GCONV_INCOMPLETE_INPUT

	  || status == __GCONV_FULL_OUTPUT);

  if (status != __GCONV_OK && status != __GCONV_FULL_OUTPUT

      && status != __GCONV_EMPTY_INPUT && status != __GCONV_INCOMPLETE_INPUT)

    {

      result = (size_t) -1;

      __set_errno (EILSEQ);

    }

  return result;

}

weak_alias (__mbsnrtowcs, mbsnrtowcs)