Re: [Qemu-devel] [PATCH] mingw: Do not perform string format checks

[Anthony Liguori <anthony@codemonkey.ws>]

Jan Kiszka wrote:
> Johannes Schindelin wrote:
>   
>> Hi,
>>
>> On Sun, 14 Jun 2009, Jan Kiszka wrote:
>>
>>     
>>> Blue Swirl wrote:
>>>       
>>>> On 6/14/09, Jan Kiszka <jan.kiszka@web.de> wrote:
>>>>         
>>>>> [ I can't check the situation with cygwin, so this is mingw-only. ]
>>>>>
>>>>>  gcc still does not support the Windows-specific format string modifier
>>>>>  "I64". Therefore, it makes no sense to check for format string
>>>>>  correctness and generate tons of false positives.
>>>>>           
>>>> I don't have this problem, currently mingw builds with zero warnings
>>>> for me. But I didn't enable automatic -Werror flag for mingw just
>>>> because I guessed this would happen. What's the gcc version you're
>>>> using?
>>>>         
>>> i686-pc-mingw32-gcc (GCC) 4.3.3
>>>       
>> 4.3.3 is known to show this bad behavior.  AFAICT it is fixed in 4.4.0.  
>> (At least it fixed things for msysGit.)
>>
>> FWIW by "bad behavior" I mean that a compiler warning is emitted when 
>> using %I64, but not when using %ll.  But when executing the program, it 
>> actually _requires_ a %I64, _not_ a %ll.
>>
>> In light of this, I _strongly_ recommend updating to 4.4.0.
>>     
>
> I will, once I come across a pre-built one that fits. For now I'll carry
> the -Wno-format as extra flags. The toolchain performs nicely otherwise.
>   

If we're on mingw, and you run a test case with -Werror that fails 
because of broken I64, we could automatically add -Wno-format.

It'll help us get closer to -Werror on mingw.

Regards,

Anthony Liguori