Re: [Qemu-devel] [PATCH for 2.5] QEMU does not care about left shifts of signed negative values

[Laszlo Ersek]

On 11/17/15 11:43, Paolo Bonzini wrote:
> 
> 
> On 17/11/2015 11:41, Laszlo Ersek wrote:
>>> If and when this happens we will add "-fno-strict-overflow" for clang,
>>> just like we are using "-fno-strict-aliasing" already.
>>
>> How about adding "-fwrapv -fno-strict-overflow" right now? (Spelling out
>> the latter of those explicitly for pointer arithmetic.)
> 
> If it makes the change to HACKING more palatable, I'm all for it.

In general I'm not overly happy about this change :), but, if the
consensus is that we simply don't want to worry about this kind of UB in
QEMU, then let's actually prevent the compiler from exploiting the
standard's lenience, rather than just suppress the warning.

Thanks!
Laszlo