unifdef problem (xen)

unifdef problem (xen)

[Randy Dunlap]

Hi,

I'm using xen.git
<git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen.git>.

When I build allmodconfig on x86_64 (with O=xx64), I see this warning:


unifdef: /xen/xx64/usr/include/xen/privcmd.h.tmp: 79: Premature EOF (#if line 33 depth 1)
unifdef: output may be truncated


The original file contains:
#ifndef __user
#define __user
#endif

and the generated/unifdef output file contains:
#ifndef #define #endif

all on one line.

Is this expected/normal?  Is this a problem with unifdef or with something
in xen.git?

thanks,
---
~Randy

Re: unifdef problem (xen)

[Jeremy Fitzhardinge]

On 10/22/09 12:52, Randy Dunlap wrote:
> Hi,
>
> I'm using xen.git
> <git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen.git>.
>
> When I build allmodconfig on x86_64 (with O=xx64), I see this warning:
>
>
> unifdef: /xen/xx64/usr/include/xen/privcmd.h.tmp: 79: Premature EOF (#if line 33 depth 1)
> unifdef: output may be truncated
>
>
> The original file contains:
> #ifndef __user
> #define __user
> #endif
>
> and the generated/unifdef output file contains:
> #ifndef #define #endif
>
> all on one line.
>
> Is this expected/normal?  Is this a problem with unifdef or with something
> in xen.git?
>   

I'd say its a bug in unifdef, but I'm not precisely sure what its trying
to do.

That said, there's no reason for those lines to be in privcmd.h, I think.

    J

Re: unifdef problem (xen)

[Sam Ravnborg]

On Thu, Oct 22, 2009 at 12:52:23PM -0700, Randy Dunlap wrote:
> Hi,
> 
> I'm using xen.git
> <git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen.git>.
> 
> When I build allmodconfig on x86_64 (with O=xx64), I see this warning:
> 
> 
> unifdef: /xen/xx64/usr/include/xen/privcmd.h.tmp: 79: Premature EOF (#if line 33 depth 1)
> unifdef: output may be truncated
> 
> 
> The original file contains:
> #ifndef __user
> #define __user
> #endif

The problem is scripts/headers_install.pl
Here we do:

    $line =~ s/([\s(])__user\s/$1/g;

And this zaps the newline when we see __user.

It is not obvious why this zaps the newline - must be
some perl foo I have forgotten.

I checked this by removing the unlink in said perl script
and looking at the .tmp file.


	Sam