Re: [Qemu-devel] [PATCH v2] xics_kvm: fix a build break

[Cédric Le Goater]

On 06/12/2018 01:41 PM, Greg Kurz wrote:
> On Tue, 12 Jun 2018 12:11:35 +0200
> Cédric Le Goater <address@hidden> wrote:
> 
>> On CentOS 7.5, gcc-4.8.5-28.el7_5.1.ppc64le fails to build QEMU due to :
>>
>>   hw/intc/xics_kvm.c: In function ‘ics_set_kvm_state’:
>>   hw/intc/xics_kvm.c:281:13: error: ‘ret’ may be used uninitialized in this
>>     function [-Werror=maybe-uninitialized]
>>              return ret;
>>
>> Fix the breakage and also remove the extra error reporting as
>> kvm_device_access() already provides a substantial error message.
>>
>> Signed-off-by: Cédric Le Goater <address@hidden>
>> ---
>>
>>  Greg, can you please test ? RHEL7.5 does not catch the issue with the
>>  same compiler level :/ I don't understand why.
>>
> 
> This fixes the build breakage for me. Now this should really be squashed
> into your original patch to preserve bisect on master.

After some analysis, you need to configure with '--enable-debug' to reproduce 
the breakage. '--enable-debug' removes -O2. 

With -O2, the compiler doesn't catch the error. It looks very much like a gcc 
issue to me.

Thanks,

C.