[Qemu-devel] Re: [PATCH 10/11] ppc: avoid write only variables

[Alexander Graf]

Am 07.10.2010 um 20:59 schrieb Blue Swirl <address@hidden>:

> On Wed, Oct 6, 2010 at 9:39 PM, Alexander Graf <address@hidden> wrote:
>> 
>> On 06.10.2010, at 23:34, Blue Swirl wrote:
>> 
>>> Compiling with GCC 4.6.0 20100925 produced warnings:
>>> /src/qemu/target-ppc/op_helper.c: In function 'helper_icbi':
>>> /src/qemu/target-ppc/op_helper.c:351:14: error: variable 'tmp' set but
>>> not used [-Werror=unused-but-set-variable]
>>> /src/qemu/target-ppc/op_helper.c: In function 'do_6xx_tlb':
>>> /src/qemu/target-ppc/op_helper.c:3805:28: error: variable 'EPN' set
>>> but not used [-Werror=unused-but-set-variable]
>>> /src/qemu/target-ppc/op_helper.c: In function 'do_74xx_tlb':
>>> /src/qemu/target-ppc/op_helper.c:3838:28: error: variable 'EPN' set
>>> but not used [-Werror=unused-but-set-variable]
>>> 
>>> Fix by making the variable declarations and their uses also conditional
>>> to debug definition. Delete tmp.
>> 
>> Maybe it would make more sense to get those LOG_* macros into static inline 
>> functions. But for the issue at hand, the solution looks good to me.
> 
> Perhaps all conditionally enabled debug printf stuff should be
> transformed into tracepoints? That would be more flexible than
> uncommenting DEBUG_foobar. Would it help with bitrot too?

I haven't looked at the qemu tracepoints framework yet, but some of this debug 
stuff is in hot paths and only very rarely used. So unless it is overhead free, 
I'd prefer debug function stubs.

Alex

> 
>> Signed-off-by: Alexander Graf <address@hidden>
> 
> Thanks.