1  /* Error table.
       2     Copyright (C) 2019-2023 Free Software Foundation, Inc.
       3  
       4     This file is part of libctf.
       5  
       6     libctf is free software; you can redistribute it and/or modify it under
       7     the terms of the GNU General Public License as published by the Free
       8     Software Foundation; either version 3, or (at your option) any later
       9     version.
      10  
      11     This program is distributed in the hope that it will be useful, but
      12     WITHOUT ANY WARRANTY; without even the implied warranty of
      13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
      14     See the GNU General Public License for more details.
      15  
      16     You should have received a copy of the GNU General Public License
      17     along with this program; see the file COPYING.  If not see
      18     <http://www.gnu.org/licenses/>.  */
      19  
      20  #include <ctf-impl.h>
      21  #include <stddef.h>
      22  #include <string.h>
      23  
      24  /* This construct is due to Bruno Haible: much thanks.  */
      25  
      26  /* Give each structure member a unique name.  The name does not matter, so we
      27     use the enum constant to uniquify them.  */
      28  
      29  #define ERRSTRFIELD(N) ctf_errstr##N
      30  
      31  /* In this file, we want to treat the first item of the ctf error
      32     macro like subsequent items.  */
      33  #define _CTF_FIRST(NAME, VALUE) _CTF_ITEM(NAME, VALUE)
      34  
      35  /* The error message strings, each in a unique structure member precisely big
      36     enough for that error, plus a str member to access them all as a string
      37     table.  */
      38  
      39  static const union _ctf_errlist_t
      40  {
      41    __extension__ struct
      42    {
      43  #define _CTF_ITEM(n, s) char ERRSTRFIELD (n) [sizeof (s)];
      44  _CTF_ERRORS
      45  #undef _CTF_ITEM
      46    };
      47    char str[1];
      48  } _ctf_errlist =
      49    {
      50     {
      51  #define _CTF_ITEM(n, s) N_(s),
      52  _CTF_ERRORS
      53  #undef _CTF_ITEM
      54     }
      55    };
      56  
      57  /* Offsets to each member in the string table, computed using offsetof.  */
      58  
      59  static const unsigned int _ctf_erridx[] =
      60    {
      61  #define _CTF_ITEM(n, s) [n - ECTF_BASE] = offsetof (union _ctf_errlist_t, ERRSTRFIELD (n)),
      62  _CTF_ERRORS
      63  #undef _CTF_ITEM
      64    };
      65  
      66  const char *
      67  ctf_errmsg (int error)
      68  {
      69    const char *str;
      70  
      71    if (error >= ECTF_BASE && (error - ECTF_BASE) < ECTF_NERR)
      72      str = _ctf_errlist.str + _ctf_erridx[error - ECTF_BASE];
      73    else
      74      str = (const char *) strerror (error);
      75  
      76    return (str ? gettext (str) : _("Unknown error"));
      77  }
      78  
      79  int
      80  ctf_errno (ctf_dict_t * fp)
      81  {
      82    return fp->ctf_errno;
      83  }