stdlib/errno.h

   1 /* Copyright (C) 1991-2016 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 /*
  19  *      ISO C99 Standard: 7.5 Errors    <errno.h>
  20  */
  21
  22 #ifndef _ERRNO_H
  23
  24 /* The includer defined __need_Emath if he wants only the definitions
  25    of EDOM and ERANGE, and not everything else.  */
  26 #ifndef __need_Emath
  27 # define _ERRNO_H       1
  28 # include <features.h>
  29 #endif
  30
  31 __BEGIN_DECLS
  32
  33 /* Get the error number constants from the system-specific file.
  34    This file will test __need_Emath and _ERRNO_H.  */
  35 #include <bits/errno.h>
  36 #undef  __need_Emath
  37
  38 #ifdef  _ERRNO_H
  39
  40 /* Declare the `errno' variable, unless it's defined as a macro by
  41    bits/errno.h.  This is the case in GNU, where it is a per-thread
  42    variable.  This redeclaration using the macro still works, but it
  43    will be a function declaration without a prototype and may trigger
  44    a -Wstrict-prototypes warning.  */
  45 #ifndef errno
  46 extern int errno;
  47 #endif
  48
  49 #ifdef __USE_GNU
  50
  51 /* The full and simple forms of the name with which the program was
  52    invoked.  These variables are set up automatically at startup based on
  53    the value of ARGV[0] (this works only if you use GNU ld).  */
  54 extern char *program_invocation_name, *program_invocation_short_name;
  55 #endif /* __USE_GNU */
  56 #endif /* _ERRNO_H */
  57
  58 __END_DECLS
  59
  60 #endif /* _ERRNO_H */
  61
  62 /* The Hurd <bits/errno.h> defines `error_t' as an enumerated type so
  63    that printing `error_t' values in the debugger shows the names.  We
  64    might need this definition sometimes even if this file was included
  65    before.  */
  66 #if defined __USE_GNU || defined __need_error_t
  67 # ifndef __error_t_defined
  68 typedef int error_t;
  69 #  define __error_t_defined     1
  70 # endif
  71 # undef __need_error_t
  72 #endif