Re: [PATCH] Add compat_ioctl to st

[Matthew Wilcox <matthew@wil.cx>]

On Tue, Jan 18, 2005 at 01:30:24PM +0100, Andi Kleen wrote:
> > How about having a macro ...
> > 
> > 	.ioctl =	st_ioctl,
> > 	COMPAT_IOCTL_ENTRY(st_compat_ioctl)
> > 	.open =		st_open,
> > 
> > which could be defined something like:
> > 
> > #ifdef CONFIG_COMPAT
> > #define COMPAT_IOCTL_ENTRY(x)	.compat_ioctl = x,
> > #else
> > #define COMPAT_IOCTL_ENTRY(x)	/* */
> > #endif
> 
> To be honest I prefer the ifdef. It makes it clear 
> what is going on, without any unneeded abstraction.
> The macro in comparison looks unnatural in the definition
> block.

It would have prevented the mistake you made in sg (which message I only
read after writing this).  Another way of managing without ifdefs would
be:

	.compat_ioctl = COMPAT_IOCTL_ENTRY(st),

with

#ifdef CONFIG_COMPAT
#define COMPAT_IOCTL_ENTRY(x)	x##_compat_ioctl
#else
#define COMPAT_IOCTL_ENTRY(x)	NULL
#endif

-- 
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