rt/bits/mqueue2.h

   1 /* Checking macros for mq functions.
   2    Copyright (C) 2007, 2011, 2012 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    <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _FCNTL_H
  20 # error "Never include <bits/mqueue2.h> directly; use <mqueue.h> instead."
  21 #endif
  22
  23 /* Check that calls to mq_open with O_CREAT set have an appropriate third and fourth
  24    parameter.  */
  25 extern mqd_t mq_open (const char *__name, int __oflag, ...)
  26      __THROW __nonnull ((1));
  27 extern mqd_t __mq_open_2 (const char *__name, int __oflag)
  28      __THROW __nonnull ((1));
  29 extern mqd_t __REDIRECT_NTH (__mq_open_alias, (const char *__name,
  30                                                int __oflag, ...), mq_open)
  31      __nonnull ((1));
  32 __errordecl (__mq_open_wrong_number_of_args,
  33              "mq_open can be called either with 2 or 4 arguments");
  34 __errordecl (__mq_open_missing_mode_and_attr,
  35              "mq_open with O_CREAT in second argument needs 4 arguments");
  36
  37 __fortify_function mqd_t
  38 __NTH (mq_open (const char *__name, int __oflag, ...))
  39 {
  40   if (__va_arg_pack_len () != 0 && __va_arg_pack_len () != 2)
  41     __mq_open_wrong_number_of_args ();
  42
  43   if (__builtin_constant_p (__oflag))
  44     {
  45       if ((__oflag & O_CREAT) != 0 && __va_arg_pack_len () == 0)
  46         {
  47           __mq_open_missing_mode_and_attr ();
  48           return __mq_open_2 (__name, __oflag);
  49         }
  50       return __mq_open_alias (__name, __oflag, __va_arg_pack ());
  51     }
  52
  53   if (__va_arg_pack_len () == 0)
  54     return __mq_open_2 (__name, __oflag);
  55
  56   return __mq_open_alias (__name, __oflag, __va_arg_pack ());
  57 }