[Qemu-devel] block/stream.c -Werror build failure

[Qemu-devel] block/stream.c -Werror build failure

[Andreas Färber]

Hello,

As reported yesterday on IRC, since the last round of pulls I am getting
the following warning-treated-as-error:

  CC    block/stream.o
/home/andreas/QEMU/qemu/block/stream.c: In function ‘stream_run’:
/home/andreas/QEMU/qemu/block/stream.c:111:14: error: ‘copy’ may be used
uninitialized in this function [-Werror=maybe-uninitialized]
cc1: all warnings being treated as errors
make: *** [block/stream.o] Fehler 1

$ gcc --version
gcc (SUSE Linux) 4.7.2 20130108 [gcc-4_7-branch revision 195012]

However I only got this in 1 of 2 repositories I tried. It turns out
that --enable-debug avoids this build issue.

The stream.c code itself looks okay to me. In the case of ret >= 0, copy
is always assigned, including the goto code path.
Still, could we initialize the copy variable to false or revert whatever
change introduced this build regression? (-Wextra?)

Regards,
Andreas

-- 
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg

Re: [Qemu-devel] block/stream.c -Werror build failure

[Stefan Weil]

Am 19.09.2013 18:52, schrieb Andreas Färber:
> Hello,
>
> As reported yesterday on IRC, since the last round of pulls I am getting
> the following warning-treated-as-error:
>
>   CC    block/stream.o
> /home/andreas/QEMU/qemu/block/stream.c: In function ‘stream_run’:
> /home/andreas/QEMU/qemu/block/stream.c:111:14: error: ‘copy’ may be used
> uninitialized in this function [-Werror=maybe-uninitialized]
> cc1: all warnings being treated as errors
> make: *** [block/stream.o] Fehler 1
>
> $ gcc --version
> gcc (SUSE Linux) 4.7.2 20130108 [gcc-4_7-branch revision 195012]
>
> However I only got this in 1 of 2 repositories I tried. It turns out
> that --enable-debug avoids this build issue.
>
> The stream.c code itself looks okay to me. In the case of ret >= 0, copy
> is always assigned, including the goto code path.
> Still, could we initialize the copy variable to false or revert whatever
> change introduced this build regression? (-Wextra?)
>
> Regards,
> Andreas
>

This will be fixed by the next pull request for the block tree.
See also http://patchwork.ozlabs.org/patch/275503/

Regards,
Stefan

Re: [Qemu-devel] block/stream.c -Werror build failure

[Andreas Färber]

Am 19.09.2013 18:59, schrieb Stefan Weil:
> Am 19.09.2013 18:52, schrieb Andreas Färber:
>> Hello,
>>
>> As reported yesterday on IRC, since the last round of pulls I am getting
>> the following warning-treated-as-error:
>>
>>   CC    block/stream.o
>> /home/andreas/QEMU/qemu/block/stream.c: In function ‘stream_run’:
>> /home/andreas/QEMU/qemu/block/stream.c:111:14: error: ‘copy’ may be used
>> uninitialized in this function [-Werror=maybe-uninitialized]
>> cc1: all warnings being treated as errors
>> make: *** [block/stream.o] Fehler 1
>>
>> $ gcc --version
>> gcc (SUSE Linux) 4.7.2 20130108 [gcc-4_7-branch revision 195012]
>>
>> However I only got this in 1 of 2 repositories I tried. It turns out
>> that --enable-debug avoids this build issue.
>>
>> The stream.c code itself looks okay to me. In the case of ret >= 0, copy
>> is always assigned, including the goto code path.
>> Still, could we initialize the copy variable to false or revert whatever
>> change introduced this build regression? (-Wextra?)
>>
>> Regards,
>> Andreas
>>
> 
> This will be fixed by the next pull request for the block tree.
> See also http://patchwork.ozlabs.org/patch/275503/

Just spotted it myself and added a review comment.

Thanks,
Andreas

-- 
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg