[libvirt] main: fix some compilation issues on non-linux platforms

[Eric Blake]

On 08/16/2011 01:01 PM, Stefan Berger wrote:
>> Following the latter couldn't it just be handled during runtime
>> altogether?

That actually sounds better.

>>
>> Stefan
>>
> Along those lines I propose this patch below:
>
> Signed-off-by: Stefan Berger <stefanb at linux.vnet.ibm.com>
>
> +int virFileIsLink(const char *linkpath)
> +{
> + struct stat st;
> +
> + if (lstat(linkpath, &st) < 0)
> + return -errno;
> +
> + return S_ISLNK(st.st_mode);

S_ISLNK is only guaranteed to return non-zero for links, not 1.  You 
need to sanitize it:

return S_ISLNK(st.st_mode) != 0;

or

return !!S_ISLNK(st.st_mode);

> +++ libvirt-acl/src/util/util.h
> @@ -78,6 +78,8 @@ int virFileLinkPointsTo(const char *chec
> int virFileResolveLink(const char *linkpath,
> char **resultpath) ATTRIBUTE_RETURN_CHECK;
>
> +int virFileIsLink(const char *linkpath) ATTRIBUTE_RETURN_CHECK;

Also add ATTRIBUTE_NONNULL(1), since lstat(NULL) is invalid.

ACK with those two fixes.

-- 
Eric Blake   eblake at redhat.com    +1-801-349-2682
Libvirt virtualization library http://libvirt.org