/* Copyright (C) 2002-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   Contributed by Ulrich Drepper <drepper@gnu.org>, 2002.

   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 <ctype.h>

#include <string.h>

#include "wcsmbsload.h"

#include <dlfcn.h>

#include <errno.h>

#include <gconv.h>

#include <stdlib.h>

#include <string.h>

#include <wchar.h>

#include <wcsmbsload.h>

#include <sysdep.h>

#ifndef EILSEQ

# define EILSEQ EINVAL

#endif

size_t

attribute_hidden

__mbsrtowcs_l (wchar_t *dst, const char **src, size_t len, mbstate_t *ps,

	       locale_t l)

{

  struct __gconv_step_data data;

  size_t result;

  int status;

  struct __gconv_step *towc;

  size_t non_reversible;

  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;

  /* Get the conversion functions.  */

  fcts = get_gconv_fcts (l->__locales[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;

      const unsigned char *srcend = inbuf + strlen (*src) + 1;

      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,

				      &non_reversible, 0, 1));

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

	}

      while (status == __GCONV_FULL_OUTPUT);

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

	{

	  /* There better should be a NUL wide char at the end.  */

	  assert (((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.  */

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

      const unsigned char *srcend;

      data.__outbuf = (unsigned char *) dst;

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

      status = __GCONV_FULL_OUTPUT;

      while (len > 0)

	{

	  /* Pessimistic guess as to how much input we can use.  In the

	     worst case we need one input byte for one output wchar_t.  */

	  srcend = srcp + __strnlen ((const char *) srcp, len) + 1;

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

				      &non_reversible, 0, 1));

	  if ((status != __GCONV_EMPTY_INPUT

	       && status != __GCONV_INCOMPLETE_INPUT)

	      /* Not all input read.  */

	      || srcp != srcend

	      /* Reached the end of the input.  */

	      || srcend[-1] == '\0')

	    break;

	  len = (wchar_t *) data.__outbufend - (wchar_t *) data.__outbuf;

	}

      /* Make the end if the input known to the caller.  */

      *src = (const char *) srcp;

      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)

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

	{

	  assert (result > 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;

}