/* Get descriptor for character set conversion.

   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 <alloca.h>

#include <errno.h>

#include <iconv.h>

#include <stdbool.h>

#include <stdlib.h>

#include <string.h>

#include <gconv_int.h>

#include "gconv_charset.h"

iconv_t

iconv_open (const char *tocode, const char *fromcode)

{

  /* Normalize the name.  We remove all characters beside alpha-numeric,

     '_', '-', '/', '.', and ':'.  */

  size_t tocode_len = strlen (tocode) + 3;

  char *tocode_conv;

  bool tocode_usealloca = __libc_use_alloca (tocode_len);

  if (tocode_usealloca)

    tocode_conv = (char *) alloca (tocode_len);

  else

    {

      tocode_conv = (char *) malloc (tocode_len);

      if (tocode_conv == NULL)

	return (iconv_t) -1;

    }

  strip (tocode_conv, tocode);

  tocode = (tocode_conv[2] == '\0' && tocode[0] != '\0'

	    ? upstr (tocode_conv, tocode) : tocode_conv);

  size_t fromcode_len = strlen (fromcode) + 3;

  char *fromcode_conv;

  bool fromcode_usealloca = __libc_use_alloca (fromcode_len);

  if (fromcode_usealloca)

    fromcode_conv = (char *) alloca (fromcode_len);

  else

    {

      fromcode_conv = (char *) malloc (fromcode_len);

      if (fromcode_conv == NULL)

	{

	  if (! tocode_usealloca)

	    free (tocode_conv);

	  return (iconv_t) -1;

	}

    }

  strip (fromcode_conv, fromcode);

  fromcode = (fromcode_conv[2] == '\0' && fromcode[0] != '\0'

	      ? upstr (fromcode_conv, fromcode) : fromcode_conv);

  __gconv_t cd;

  int res = __gconv_open (tocode, fromcode, &cd, 0);

  if (! fromcode_usealloca)

    free (fromcode_conv);

  if (! tocode_usealloca)

    free (tocode_conv);

  if (__builtin_expect (res, __GCONV_OK) != __GCONV_OK)

    {

      /* We must set the error number according to the specs.  */

      if (res == __GCONV_NOCONV || res == __GCONV_NODB)

	__set_errno (EINVAL);

      cd = (iconv_t) -1;

    }

  return (iconv_t) cd;

}