Re: [RFC] Splitting out kernel<=>userspace ABI headers

[H. Peter Anvin]

Erik Andersen wrote:
> That is certainly not what I was proposing.  Why are you bringing
> sys/stat.h into this?  The contents of sys/stat.h are entirely up
> to SUSv3 and the C library to worry about.  Nobody has proposed
> mucking with that.  I dunno about your C library, but mine
> doesn't include linux/* header files (not even sys/stat.h).  And
> I'd really like to fix uClibc to not use any asm/* either, since
> much of it is entirely unsuitable for user space.

That's the whole problem here, isn't it, so let's fix it the sane way 
instead of putting Descartes before Dehorse.

Anyway, to answer your implied question is: since I explicitly don't 
have to worry about forward ABI compatibility, I expose the kernel ABI 
raw.  Thus I want to be able to use the kernel ABI directly, including 
for things like struct stat.  It poses a particularly interesting 
problem, actually, because the real stat system call is called stat64 on 
most platforms.

Thus, an ABIzed <linux/abi/stat.h> or whatever it's called might export 
 "struct __kabi_stat" and "struct __kabi_stat64" with the expectation 
that the caller would "#define __kabi_stat64 stat" if that is the 
version they want.  A typedef isn't good enough for C, since you can't 
typedef struct tags.

	-hpa
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