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The C and C++ Include Header Files

/usr/include/x86_64-linux-gnu/bits/mqueue2.h


$ cat -n /usr/include/x86_64-linux-gnu/bits/mqueue2.h

     1	/* Checking macros for mq functions.
     2	   Copyright (C) 2007-2024 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	#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	}