freebsd-nq/lib/libc/sys/POSIX2x_Fork.c
Jessica Clarke 877175a17a libc: Fix build on case-insensitive file systems
On case-insensitive file systems (most likely to be seen on macOS, where
it is the default), _Fork.o for the new POSIX _Fork function conflicts
with _fork.o for the PSEUDO file. This results in non-determinsitic
behaviour in terms of which ends up being present; if _Fork.o wins then
the build fails to link libc.so due to missing __sys_fork, and if
_fork.o wins then libc silently fails to include the implementation of
_Fork. A similar issue occurred in the past for C99's _Exit conflicting
with exit(2) and was fixed in cb1cb6a2a8, so this adds a fix based on
that.

As a longer-term solution it might be better to instead make the
generated files use a different prefix that's less likely to conflict
with other things (such as __sys_foo.o given they always contain that)
but that's a rather more invasive change.

Fixes:	49ad342cc1 ("Add _Fork()")
Reviewed by:	kib
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D31895
2021-09-10 01:19:38 +01:00

46 lines
1.8 KiB
C

/*
* Copyright (c) 2021 The FreeBSD Foundation.
* All rights reserved.
*
* Portions of this software were developed by Konstantin Belousov
* under sponsorship from the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice(s), this list of conditions and the following disclaimer as
* the first lines of this file unmodified other than the possible
* addition of one or more copyright notices.
* 2. Redistributions in binary form must reproduce the above copyright
* notice(s), this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <unistd.h>
#include "libc_private.h"
#pragma weak _Fork
pid_t
_Fork(void)
{
return (__sys_fork());
}