Re: kdbus: add header file

From: Arnd Bergmann
Date: Thu Oct 30 2014 - 07:27:17 EST


On Thursday 30 October 2014 12:02:39 Tom Gundersen wrote:
> On Thu, Oct 30, 2014 at 9:20 AM, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> > I think in general, using enum is great, but for ioctl command numbers,
> > we probably want to have defines so the user space implementation can
> > use #ifdef to see if the kernel version that it is being built for
> > knows a particular command.
>
> Does that make sense for the first version? I agree that we should use
> #define to allow #ifdef for when we add more ioctls in the future,
> but these ioctls will always exist...

It's mainly for consistency really.

> The nice thing about enums is of course that it helps with debugging
> as gdb can show the string representation rather than the number,
> because in contrast to #defines, an enum is something the compliler
> knows about.

This doesn't get passed as an enum in user space though, and when debugging
the kernel it only helps within one function.

Arnd
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