Re: [Qemu-devel] git master build failure in 9pfs

[G 3 <programmingkidx@gmail.com>]

On Mar 3, 2017, at 9:59 AM, qemu-devel-request@nongnu.org wrote:
> On 02/03/17 17:40, Daniel P. Berrange wrote:
>
>> On Thu, Mar 02, 2017 at 05:28:24PM +0000, Mark Cave-Ayland wrote:
>>> Does anyone else see the following error when trying to build git  
>>> master?
>>>
>>> cc -I/home/build/src/qemu/git/qemu/hw/9pfs -Ihw/9pfs
>>> -I/home/build/src/qemu/git/qemu/tcg
>>> -I/home/build/src/qemu/git/qemu/tcg/i386
>>> -I/home/build/src/qemu/git/qemu/linux-headers
>>> -I/home/build/src/qemu/git/qemu/linux-headers -I.
>>> -I/home/build/src/qemu/git/qemu -I/home/build/src/qemu/git/qemu/ 
>>> include
>>> -I/usr/include/pixman-1   -I/home/build/src/qemu/git/qemu/dtc/libfdt
>>> -Werror -pthread -I/usr/include/glib-2.0
>>> -I/usr/lib/x86_64-linux-gnu/glib-2.0/include   -m64 -mcx16 - 
>>> D_GNU_SOURCE
>>> -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -Wstrict-prototypes
>>> -Wredundant-decls -Wall -Wundef -Wwrite-strings -Wmissing-prototypes
>>> -fno-strict-aliasing -fno-common -fwrapv  -Wendif-labels
>>> -Wno-missing-include-dirs -Wempty-body -Wnested-externs
>>> -Wformat-security -Wformat-y2k -Winit-self -Wignored-qualifiers
>>> -Wold-style-declaration -Wold-style-definition -Wtype-limits
>>> -fstack-protector-all -I/usr/include/p11-kit-1
>>> -I/usr/include/libpng12   -I/home/build/src/qemu/git/qemu/tests - 
>>> MMD -MP
>>> -MT hw/9pfs/9p-util.o -MF hw/9pfs/9p-util.d -O2 -U_FORTIFY_SOURCE
>>> -D_FORTIFY_SOURCE=2 -g   -c -o hw/9pfs/9p-util.o hw/9pfs/9p-util.c
>>> In file included from hw/9pfs/9p-util.c:15:0:
>>> hw/9pfs/9p-util.h: In function ?openat_dir?:
>>> hw/9pfs/9p-util.h:25:57: error: ?O_PATH? undeclared (first use in  
>>> this
>>> function)
>>> hw/9pfs/9p-util.h:25:57: note: each undeclared identifier is  
>>> reported
>>> only once for each function it appears in
>>> hw/9pfs/9p-util.h:26:1: error: control reaches end of non-void  
>>> function
>>> [-Werror=return-type]
>>>
>>> Build platform is Debian Wheezy on an x86_64 host.
>>
>> IIUC, O_PATH was introduced in glibc 2.14 and Wheezy only has 2.13.
>>
>> So unless we want to make this 9pfs code a configurable option, this
>> means Debian Wheezy is no longer a supportable platform for QEMU.
>
> Oh sure, I appreciate that wheezy is getting towards then end of its
> lifetime - it's just a little bit inconvenient to break my development
> environment just as we enter 2.9 freeze ;)
>
> If everyone agrees that wheezy is no longer supported after 2.9 then I
> can look to upgrading, however my QEMU development is done on my  
> laptop
> which is also setup for my day job so it's not a simple case of just
> switching the repository and running dist-upgrade to get me going  
> again...

I remember years ago something like O_PATH was not defined on Mac OS X,
so the solution was to define the constant as zero. Something like this:

#ifndef O_PATH
	#define O_PATH 0
#endif

Maybe this might work in 9p-util.h.