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

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

[Jan Kiszka]

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[ 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.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---

 configure |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/configure b/configure
index 85bc598..aa586bd 100755
--- a/configure
+++ b/configure
@@ -223,6 +223,7 @@ audio_possible_drivers="sdl"
 ;;
 MINGW32*)
 mingw32="yes"
+OS_CFLAGS="-Wno-format"
 if [ "$cpu" = "i386" ] ; then
     kqemu="yes"
 fi


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

[Blue Swirl]

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?

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

[Jan Kiszka]

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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

Jan


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

[Filip Navara]

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On Sun, Jun 14, 2009 at 8:23 PM, Jan Kiszka <jan.kiszka@web.de> 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
>
> Jan
>
> JFYI, for years there was a mingw32 patch for the format strings that
wasn't merged into the mainline gcc. It was in the MinGW patches for at
least 4 years. Not sure if it was merged now or not..
Best regards,
Filip Navara

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

[Jan Kiszka]

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Filip Navara wrote:
> On Sun, Jun 14, 2009 at 8:23 PM, Jan Kiszka <jan.kiszka@web.de> 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
>>
>> Jan
>>
>> JFYI, for years there was a mingw32 patch for the format strings that
> wasn't merged into the mainline gcc. It was in the MinGW patches for at
> least 4 years. Not sure if it was merged now or not..
> Best regards,
> Filip Navara
> 

Yes, I've seen the patch while looking for the reason, but I didn't read
that it is part of mingw's gcc version. Obviously, this toolchain does
not contain it. Don't know where it was derived from (hmm, mingw is
still "testing" gcc4...). I just picked what was there (for OpenSUSE) to
include a simple win32 build run in future patch development.

Well, if everyone else out there has I64 support, then I can also add
this switch to my --extra-cflags.

Jan


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

[Johannes Schindelin]

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.

Ciao,
Dscho

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

[Jan Kiszka]

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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.

Thanks,
Jan


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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 <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

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

[Johannes Schindelin]

Hi,

On Mon, 15 Jun 2009, 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.

The de-facto standard is http://www.tdragon.net/recentgcc/

Hth,
Dscho

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

[Jan Kiszka]

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Johannes Schindelin wrote:
> Hi,
> 
> On Mon, 15 Jun 2009, 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.
> 
> The de-facto standard is http://www.tdragon.net/recentgcc/

This is pre-built, but for an uninteresting host platform (also known as
Windows). :)

Jan


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