[Spice-devel] [PATHCH win-qxl 4/8] display/qxldd.h: add DEBUG_PRINT_ONCE

[Hans de Goede]

Hi,

nit pick, the usual way to do preprocessor macros with { } is:

#define foo(x) \
    do { \
        bar \
    } while (0)

This way you don't end up with a stray ; after the
} which sometimes can lead to issues / warnings.

IE:

if (x)
    foo(x);
else
    ...

Would not work with your way because it would expand to:

if (x)
{
    ...
};
else

And the ; makes the compiler not expect else, since there
are now 2 statements between the if and the else

Regards,

Hans



On 04/07/2011 06:10 PM, Alon Levy wrote:
> ---
>   display/qxldd.h |    9 +++++++++
>   1 files changed, 9 insertions(+), 0 deletions(-)
>
> diff --git a/display/qxldd.h b/display/qxldd.h
> index 0f90af1..7130b47 100644
> --- a/display/qxldd.h
> +++ b/display/qxldd.h
> @@ -44,6 +44,15 @@
>
>   #define DEBUG_PRINT(arg) DebugPrint arg
>
> +#define DEBUG_PRINT_ONCE(arg)       \
> +    {                               \
> +        static int run = 0;         \
> +        if (!run) {                 \
> +            run = 1;                \
> +            DebugPrint arg;         \
> +        }                           \
> +    }
> +
>   #ifdef DBG
>   #define ASSERT(pdev, x) if (!(x)) { \
>       DebugPrint(pdev, 0, "ASSERT(%s) failed @ %s\n", #x, __FUNCTION__); \