Re: [PATCH 00/12] scsi/NCR5380: fix debugging macros and #include structure

From: Joe Perches
Date: Tue Mar 18 2014 - 21:54:55 EST


On Wed, 2014-03-19 at 12:46 +1100, Finn Thain wrote:
> On Tue, 18 Mar 2014, Joe Perches wrote:
>
> > But using "if (0)" prevents the no_printk from occurring at all so there
> > would be no side-effects and the format & args would still be verified
> > by the compiler.
>
> I'd prefer this (for symmetry and clarity):
>
> #if NDEBUG
> #define dprintk(flg, fmt, ...) \
> do { if ((NDEBUG) & (flg)) pr_debug(fmt, ## __VA_ARGS__); } while (0)
> #else
> #define dprintk(flg, fmt, ...) \
> do { if (0) pr_debug(fmt, ## __VA_ARGS__); } while (0)
> #endif
>
> But you seem to be asking for this instead:
>
> #if NDEBUG
> #define dprintk(flg, fmt, ...) \
> do { if ((NDEBUG) & (flg)) pr_debug(fmt, ## __VA_ARGS__); } while (0)
> #else
> #define dprintk(flg, fmt, ...) \
> do { if (0) no_printk(fmt, ## __VA_ARGS__); } while (0)
> #endif
>
> Why is that better?

It's not to me.

I suggested exactly your first block with if (0) pr_debug...
in the first thing I wrote.

https://lkml.org/lkml/2014/3/18/216

Geert suggested no_printk.

cheers, Joe


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