Re: [PATCH 1/2] tools/kvm/9p: Always include system header before our headers

Pekka Enberg
2011-06-18T07:50:33Z

On Sat, 2011-06-18 at 12:37 +0530, Aneesh Kumar K.V wrote:
> On Fri, 17 Jun 2011 22:47:39 +0300, Pekka Enberg <penberg@kernel.org> wrote:
> > On Fri, 2011-06-17 at 15:45 -0400, Sasha Levin wrote:
> > > On Fri, 2011-06-17 at 23:41 +0530, Aneesh Kumar K.V wrote:
> > > > Otherwise many things can break, such as mapping of stat to stat64
> > >
> > > We always include our headers before system headers to make sure we
> > > don't have any hidden prerequisites or dependencies within the headers.
> > >
> > > Why did you need to move system headers before our headers in this case?
> >
> > The stat64() breakage seems rather odd since we do this in the Makefile:
> >
> > DEFINES += -D_FILE_OFFSET_BITS=64
> > DEFINES += -D_GNU_SOURCE
> >
> > Aneesh, what kind of build problems are you seeing?
>
> Ok the below change also fix the issue for me. So it could be some
> mapping in the kernel headers
>
> diff --git a/tools/kvm/virtio/9p.c b/tools/kvm/virtio/9p.c
> index 38a997d..730f4a1 100644
> --- a/tools/kvm/virtio/9p.c
> +++ b/tools/kvm/virtio/9p.c
> @@ -9,16 +9,16 @@
> #include "kvm/threadpool.h"
> #include "kvm/irq.h"
>
> -#include <linux/virtio_ring.h>
> -#include <linux/virtio_9p.h>
> -#include <net/9p/9p.h>
> -
> #include <fcntl.h>
> #include <sys/types.h>
> #include <sys/stat.h>
> #include <pthread.h>
> #include <dirent.h>
>
> +#include <linux/virtio_ring.h>
> +#include <linux/virtio_9p.h>
> +#include <net/9p/9p.h>
> +
> #define NUM_VIRT_QUEUES 1
> #define VIRTIO_P9_QUEUE_SIZE 128
> #define VIRTIO_P9_TAG "kvm_9p"

Yes, makes sense. Can you send that as a proper patch and I'll apply it?

The ordering of #includes is as follows:

1. Our own headers. This helps in ensuring there's no missing
#includes in the headers themselves.

2. Library headers and glibc headers

3. Linux kernel headers.

Code that doesn't follow that is a bug waiting to happen.

Pekka