1  /* Get descriptor for character set conversion.
       2     Copyright (C) 1997-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; if not, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #include <alloca.h>
      20  #include <errno.h>
      21  #include <iconv.h>
      22  #include <stdbool.h>
      23  #include <stdlib.h>
      24  #include <string.h>
      25  
      26  #include <gconv_int.h>
      27  #include "gconv_charset.h"
      28  
      29  
      30  iconv_t
      31  iconv_open (const char *tocode, const char *fromcode)
      32  {
      33    __gconv_t cd;
      34    struct gconv_spec conv_spec;
      35  
      36    if (__gconv_create_spec (&conv_spec, fromcode, tocode) == NULL)
      37      return (iconv_t) -1;
      38  
      39    int res = __gconv_open (&conv_spec, &cd, 0);
      40  
      41    __gconv_destroy_spec (&conv_spec);
      42  
      43    if (__builtin_expect (res, __GCONV_OK) != __GCONV_OK)
      44      {
      45        /* We must set the error number according to the specs.  */
      46        if (res == __GCONV_NOCONV || res == __GCONV_NODB)
      47  	__set_errno (EINVAL);
      48  
      49        cd = (iconv_t) -1;
      50      }
      51  
      52    return (iconv_t) cd;
      53  }