glibc/socket/sys/un.h
Florian Weimer 26e7005728 socket: Use may_alias on sockaddr structs (bug 19622)
This supports common coding patterns.  The GCC C front end before
version 7 rejects the may_alias attribute on a struct definition
if it was not present in a previous forward declaration, so this
attribute can only be conditionally applied.

This implements the spirit of the change in Austin Group issue 1641.

Suggested-by: Marek Polacek <polacek@redhat.com>
Suggested-by: Jakub Jelinek <jakub@redhat.com>
Reviewed-by: Sam James <sam@gentoo.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit 8d7b6b4cb2)
2024-05-27 17:25:13 +02:00

48 lines
1.5 KiB
C

/* Copyright (C) 1991-2024 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#ifndef _SYS_UN_H
#define _SYS_UN_H 1
#include <sys/cdefs.h>
/* Get the definition of the macro to define the common sockaddr members. */
#include <bits/sockaddr.h>
__BEGIN_DECLS
/* Structure describing the address of an AF_LOCAL (aka AF_UNIX) socket. */
struct __attribute_struct_may_alias__ sockaddr_un
{
__SOCKADDR_COMMON (sun_);
char sun_path[108]; /* Path name. */
};
#ifdef __USE_MISC
# include <stddef.h>
# include <string.h> /* For prototype of `strlen'. */
/* Evaluate to actual length of the `sockaddr_un' structure. */
# define SUN_LEN(ptr) (offsetof (struct sockaddr_un, sun_path) \
+ strlen ((ptr)->sun_path))
#endif
__END_DECLS
#endif /* sys/un.h */