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

[Anthony Liguori]

Jan Kiszka wrote:
> Johannes Schindelin wrote:
>   
> > Hi,
> >
> > On Sun, 14 Jun 2009, Jan Kiszka wrote:
> >
> >     
> > > Blue Swirl wrote:
> > >       
> > > > On 6/14/09, Jan Kiszka <address@hidden> 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