Re: [PATCH] linux/fs.h - Convert debug functions declared inline__attribute__((format (printf,x,y) to statement expression macros

From: David Rientjes
Date: Wed Feb 27 2008 - 00:45:51 EST


On Tue, 26 Feb 2008, Matthew Wilcox wrote:

> On Tue, Feb 26, 2008 at 08:02:27PM -0800, Joe Perches wrote:
> > Converting inline __attribute__((format (printf,x,y) functions
> > to macros or statement expressions produces smaller objects
> >
> > before:
> > $ size vmlinux
> > text data bss dec hex filename
> > 4716770 474560 618496 5809826 58a6a2 vmlinux
> > after:
> > $ size vmlinux
> > text data bss dec hex filename
> > 4716706 474560 618496 5809762 58a662 vmlinux
>
> > -static inline void __attribute__((format(printf, 1, 2)))
> > -__simple_attr_check_format(const char *fmt, ...)
> > -{
> > - /* don't do anything, just let the compiler check the arguments; */
> > -}
> > +/* don't do anything, just let the compiler check the arguments; */
> > +
> > +#define __simple_attr_check_format(fmt, args...) \
> > + do { if (0) printk(fmt, ##args); } while (0)
>
> That's very interesting. It's only 64 bytes, but still, it's not
> supposed to have any different effect. Could you distill a test case
> for the GCC folks and file it in their bugzilla?
>

I'm not seeing any change in text size with allyesconfig after applying
this patch with latest git:

text data bss dec hex filename
32696210 5021759 6735572 44453541 2a64ea5 vmlinux.before
32696210 5021759 6735572 44453541 2a64ea5 vmlinux.after

Joe, what version of gcc are you using?

David
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/