Re: <linux/socket.h>, <linux/stat.h> breakage: AF_* constants are part of ABI definition

[David Miller <davem@davemloft.net>]

From: "H. Peter Anvin" <hpa@zytor.com>
Date: Mon, 19 Feb 2007 13:06:28 -0800

> In the current git tree, commit 57a87bb0720a5cf7a9ece49a8c8ed288398fd1bb 
> removes any way to automatically extracting a whole lot of ABI constants 
> from the kernel headers, especially AF_* and the various S_* constants.
> 
> Furthermore, the patch breaks <linux/in.h> which uses sa_family_t, which 
> is now defined under __KERNEL__.
 ...
> This patch breaks klibc in ways that are painfully hard to fix, and 
> *definitely* cannot be fixed by anything less than replication of all 
> these definitions, which is exactly the Wrong Thing[TM].
> 
> A much better solution (or complement) would be something like:
> 
> #if defined(__KERNEL__) || defined(__KHDR_CONSTANTS)
> 
> We could have __KHDR_CONSTANTS for the AF_* constants and __KHDR_MACROS 
> for the various macros (cmsg et al).  That way the userspace library can 
> ask for what it wants.

I'll think about what to do about this, thanks for pointing out
the problem.