Re: C++ pushback

From: Linus Torvalds
Date: Wed Apr 26 2006 - 16:10:03 EST




On Wed, 26 Apr 2006, Jan-Benedict Glaw wrote:
>
> There's one _practical_ thing you need to keep in mind: you'll either
> need 'C++'-clean kernel headers (to interface low-level kernel
> functions) or a separate set of headers.

I suspect it would be easier to just do

extern "C" {
#include <linux/xyz.h>
...
}

instead of having anything really C++'aware in the headers.

If by "clean" you meant that the above works, then yeah, there might be
_some_ cases where we use C++ keywords etc in the headers, but they should
be pretty unusual and easy to fix.

The real problem with C++ for kernel modules is:

- the language just sucks. Sorry, but it does.
- some of the C features we use may or may not be usable from C++
(statement expressions?)
- the compilers are slower, and less reliable. This is _less_ of an issue
these days than it used to be (at least the reliability part), but it's
still true.
- a lot of the C++ features just won't be supported sanely (ie the kernel
infrastructure just doesn't do exceptions for C++, nor will it run any
static constructors etc).

Anyway, it should all be doable. Not necessarily even very hard. But I
doubt it's worth it.

Linus
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