[Qemu-devel] Re: [PATCH] Suppress warning: zero-length gnu_printf format string

[Markus Armbruster]

Blue Swirl <address@hidden> writes:

> On Mon, Oct 11, 2010 at 12:52 PM, Markus Armbruster <address@hidden> wrote:
>> Warns about this line in check-qjson.c:
>>    QObject *obj = qobject_from_json("");
>>
>> The obvious fix (add -Wno-format-zero-length to gcc_flags) doesn't
>> work, because -Wall switches it on again.  Fix by putting configured
>> flags last.
>
> This would disable the flag globally. I'd rather disable the flag only
> for check-qjson.o

Is this warning worth the hassle?  What's the problem with empty format
strings?

>                   or more generically, remove -Werror for checks. For
> example, there could be a check for how we handle invalid formats and
> then the sources would contain format strings that annoy GCC, but we
> wouldn't want warnings from that to stop the build.

If you want to go that extra mile, feel free.  For me, --disable-werror
has been good enough.

Regardless, I think we need the second patch hunk, to prevent -Wall from
trampling over $gcc_flags.