/* Convert characters in input buffer using conversion descriptor to

   output buffer.

   Copyright (C) 1997-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.

   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 <stddef.h> /* for NULL */

#include <errno.h>

#include <iconv.h>

#include <gconv_int.h>

#include <assert.h>

size_t

iconv (iconv_t cd, char **inbuf, size_t *inbytesleft, char **outbuf,

       size_t *outbytesleft)

{

  __gconv_t gcd = (__gconv_t) cd;

  char *outstart = outbuf ? *outbuf : NULL;

  size_t irreversible;

  int result;

  if (__glibc_unlikely (inbuf == NULL || *inbuf == NULL))

    {

      if (outbuf == NULL || *outbuf == NULL)

	result = __gconv (gcd, NULL, NULL, NULL, NULL, &irreversible);

      else

	result = __gconv (gcd, NULL, NULL, (unsigned char **) outbuf,

			  (unsigned char *) (outstart + *outbytesleft),

			  &irreversible);

    }

  else

    {

      const char *instart = *inbuf;

      result = __gconv (gcd, (const unsigned char **) inbuf,

			(const unsigned char *)  (*inbuf + *inbytesleft),

			(unsigned char **) outbuf,

			(unsigned char *) (*outbuf + *outbytesleft),

			&irreversible);

      *inbytesleft -= *inbuf - instart;

    }

  if (outstart != NULL)

    *outbytesleft -= *outbuf - outstart;

  switch (__builtin_expect (result, __GCONV_OK))

    {

    case __GCONV_ILLEGAL_DESCRIPTOR:

      __set_errno (EBADF);

      irreversible = (size_t) -1L;

      break;

    case __GCONV_ILLEGAL_INPUT:

      __set_errno (EILSEQ);

      irreversible = (size_t) -1L;

      break;

    case __GCONV_FULL_OUTPUT:

      __set_errno (E2BIG);

      irreversible = (size_t) -1L;

      break;

    case __GCONV_INCOMPLETE_INPUT:

      __set_errno (EINVAL);

      irreversible = (size_t) -1L;

      break;

    case __GCONV_EMPTY_INPUT:

    case __GCONV_OK:

      /* Nothing.  */

      break;

    default:

      assert (!"Nothing like this should happen");

    }

  return irreversible;

}