[alsa-devel] usr/include/linux/soundcard.h warnings for 'make headers_check'

Jaswinder Singh Rajput jaswinder at kernel.org
Wed Feb 4 09:34:54 CET 2009


On Wed, 2009-02-04 at 07:39 +0100, Takashi Iwai wrote:
> At Wed, 04 Feb 2009 09:34:12 +0530,
> Jaswinder Singh Rajput wrote:
> > 
> > On Tue, 2009-02-03 at 21:27 +0100, Arnd Bergmann wrote:
> > > On Wednesday 21 January 2009, Sam Ravnborg wrote:
> > > > 
> > > > > No, these are declarations for OSS-lib.
> > > > > It doesn't belong to kernel, but it's better to keep it for
> > > > > compatibility in some way.
> > > > 
> > > > But not in the kernel for sure.
> > > > I just checked and for example: OSS_init is not used anywhere in the kernel.
> > > > The kernel headers are not a "dump all your stuff" ground anymore.
> > > > 
> > > > So I encourage you to find a better home for the user space library definitons.
> > > > We can let the definiton stay for a while - but eventually they have to
> > > > be dropped from the kernel.
> > > 
> > > The last free version of OSSlib that matches this header is from ~1997, and
> > > no current distro appears to be shipping it. All new OSSlib versions (the
> > > oldest I found was from ~2003) contain in their documentation:
> > > 
> > > "Older versions of some OSS include files are distributed
> > >  with various operating systems. There is no danger in
> > >  using them but applications written for more recent OSS
> > >  versions will not compile with older header files.
> > > 
> > >  The latest versions of these include files (such as
> > >  soundcard.h) are distributed in ../include/sys. Use
> > >  the -I/usr/lib/oss/include switch when compiling
> > >  programs. Alternatively copy these files to /usr/include/sys
> > >  so that they replace the original ones."
> > > 
> > > I think it's safe enough to assume that everyone that builds against
> > > OSSlib by now also has the correct version of the header installed.
> > > Consequently, we should just drop the #ifndef __KERNEL__ section
> > > of soundcard.h (all the macros in there depend on the extern
> > > declarations), and maybe add an
> > > 
> > > #ifdef OSSLIB
> > > #error need to use <sys/soundcard.h> from libOSSlib
> > > #endif
> > > 
> > 
> > sys/soundcard.h is also pointing to linux/soundcard.h, we need to move
> > all this stuff to sys/soundcard.h.
> 
> All which stuff?
> If you are referring to OSS-lib stuff in soundcard.h, then I'm for
> it.
> 

We need to fix things in such a way that we can replace:
#if (!defined(__KERNEL__) && !defined(KERNEL) && !defined(INKERNEL) && !defined(_KERNEL)) || defined(USE_SEQ_MACROS)
with
#ifdef __KERNEL__
and only keep those things in this file which we need in kernel and move
userspace declarations which are not required for kernel to
sys/soundcard.h


> Also giving an error with an ifdef OSSLIB like Arnd suggested would be
> nice, too.  But maybe we need one more ifdef such as
> 
> #ifdef OSSLIB
> #ifndef _SYS_SOUNDCARD_H
> #error ...
> #endif
> #endif
> 

hmm, so you want to confirm that we only come through sys/soundcard.h
for OSSLIB

Thanks,
--
JSR



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