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From: Xiao Guangrong <guangrong.xiao@linux.intel.com>
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Date: Wed, 26 Aug 2015 18:42:01 +0800
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Subject: Re: [Qemu-devel] [PATCH v2 13/18] nvdimm: build namespace config
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To: Stefan Hajnoczi <stefanha@gmail.com>
Cc: ehabkost@redhat.com, kvm@vger.kernel.org, mst@redhat.com, gleb@kernel.org, mtosatti@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com, imammedo@redhat.com, pbonzini@redhat.com, rth@twiddle.net



On 08/26/2015 12:16 AM, Stefan Hajnoczi wrote:
> On Fri, Aug 14, 2015 at 10:52:06PM +0800, Xiao Guangrong wrote:
>> +#ifdef NVDIMM_DEBUG
>> +#define nvdebug(fmt, ...) fprintf(stderr, "nvdimm: " fmt, ## __VA_ARGS__)
>> +#else
>> +#define nvdebug(...)
>> +#endif
>
> The following allows the compiler to check format strings and syntax
> check the argument expressions:
>
> #define NVDIMM_DEBUG 0  /* set to 1 for debug output */
> #define nvdebug(fmt, ...) \
>      if (NVDIMM_DEBUG) { \
>          fprintf(stderr, "nvdimm: " fmt, ## __VA_ARGS__); \
>      }
>
> This approach avoids bitrot (e.g. debug format string arguments have
> become outdated).
>

Really good tips, thanks for your sharing.