[Qemu-devel] Re: [PATCH 1/5] HACKING: add preprocessor rules

[Blue Swirl]

On Sun, Aug 15, 2010 at 9:27 PM, Andreas Schwab <address@hidden> wrote:
> Blue Swirl <address@hidden> writes:
>
>> +For variadic macros, stick with C99 syntax:
>> +
>> +#define DPRINTF(fmt, ...)                                       \
>> +    do { printf("IRQ: " fmt, ## __VA_ARGS__); } while (0)
>
> That's not C99 syntax, the combination with ## is a gcc extension.  In
> C99 you cannot have an empty __VA_ARGS__.

That's too bad, I picked the example from one of our current macros.
Maybe just s/C99/this/ or perhaps we shouldn't specify any
non-standard syntax.