Messages in this thread Patch in this message | | | From | Arnd Bergmann <> | Subject | Re: [PATCH v2] printk: help pr_debug and pr_devel to optimize out arguments | Date | Wed, 09 Dec 2015 12:52:38 +0100 |
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On Friday 04 December 2015 16:51:42 Aaron Conole wrote: > --- a/include/linux/printk.h > +++ b/include/linux/printk.h > @@ -106,13 +106,14 @@ struct va_format { > > /* > * Dummy printk for disabled debugging statements to use whilst maintaining > - * gcc's format and side-effect checking. > + * gcc's format checking. > */ > -static inline __printf(1, 2) > -int no_printk(const char *fmt, ...) > -{ > - return 0; > -} > +#define no_printk(fmt, ...) \ > +do { \ > + if (0) { \ > + printk(fmt, ##__VA_ARGS__); \ > + } \ > +} while (0) >
This change breaks compiling lib/842/, at least in some configurations:
lib/842/842_decompress.c: In function '__do_index': lib/842/842_decompress.c:205:12422: error: implicit declaration of function 'no_printk'
Using a gcc style vararg macro instead of the C99 style makes it work, but I don't know why the original version didn't work.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/include/linux/printk.h b/include/linux/printk.h index cc3803a8f73e..4d1851a82254 100644 --- a/include/linux/printk.h +++ b/include/linux/printk.h @@ -108,10 +108,10 @@ struct va_format { * Dummy printk for disabled debugging statements to use whilst maintaining * gcc's format checking. */ -#define no_printk(fmt, ...) \ +#define no_printk(arg ...) \ do { \ if (0) { \ - printk(fmt, ##__VA_ARGS__); \ + printk(arg); \ } \ } while (0)
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