Re: [PATCH] tools/virtio: fix build caused by virtio_ring changes

["Michael S. Tsirkin" <mst@redhat.com>]

On Mon, Apr 10, 2023 at 06:24:19PM +0900, Shunsuke Mie wrote:
> Fix the build dependency for virtio_test. virtio_ring requires
> container_of_const() and struce device.
> 
> Signed-off-by: Shunsuke Mie <mie@igel.co.jp>
> ---
>  tools/include/linux/container_of.h | 36 ++++++++++++++++++++++++++++++
>  tools/virtio/linux/compiler.h      |  3 +++
>  tools/virtio/linux/kernel.h        |  5 +----
>  tools/virtio/linux/module.h        |  1 +
>  4 files changed, 41 insertions(+), 4 deletions(-)
>  create mode 100644 tools/include/linux/container_of.h
> 
> diff --git a/tools/include/linux/container_of.h b/tools/include/linux/container_of.h
> new file mode 100644
> index 000000000000..06e293b7cfda
> --- /dev/null
> +++ b/tools/include/linux/container_of.h
> @@ -0,0 +1,36 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef _LINUX_CONTAINER_OF_H
> +#define _LINUX_CONTAINER_OF_H
> +
> +#include <linux/build_bug.h>
> +#include <linux/stddef.h>
> +
> +/**
> + * container_of - cast a member of a structure out to the containing structure
> + * @ptr:	the pointer to the member.
> + * @type:	the type of the container struct this is embedded in.
> + * @member:	the name of the member within the struct.
> + *
> + * WARNING: any const qualifier of @ptr is lost.
> + */
> +#define container_of(ptr, type, member) ({				\
> +	void *__mptr = (void *)(ptr);					\
> +	static_assert(__same_type(*(ptr), ((type *)0)->member) ||	\
> +		      __same_type(*(ptr), void),			\
> +		      "pointer type mismatch in container_of()");	\
> +	((type *)(__mptr - offsetof(type, member))); })
> +
> +/**
> + * container_of_const - cast a member of a structure out to the containing
> + *			structure and preserve the const-ness of the pointer
> + * @ptr:		the pointer to the member
> + * @type:		the type of the container struct this is embedded in.
> + * @member:		the name of the member within the struct.
> + */
> +#define container_of_const(ptr, type, member)				\
> +	_Generic(ptr,							\
> +		const typeof(*(ptr)) *: ((const type *)container_of(ptr, type, member)),\
> +		default: ((type *)container_of(ptr, type, member))	\
> +	)
> +
> +#endif	/* _LINUX_CONTAINER_OF_H */


Please just do
#include "../../../include/linux/container_of.h"
instead.


> diff --git a/tools/virtio/linux/compiler.h b/tools/virtio/linux/compiler.h
> index 2c51bccb97bb..ac27b3ea6e67 100644
> --- a/tools/virtio/linux/compiler.h
> +++ b/tools/virtio/linux/compiler.h
> @@ -8,4 +8,7 @@
>  #define READ_ONCE(var) (*((volatile typeof(var) *)(&(var))))
>  
>  #define __aligned(x) __attribute((__aligned__(x)))
> +
> +#define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
> +
>  #endif

#include "../../../include/linux/compiler_types.h" instead?

> diff --git a/tools/virtio/linux/kernel.h b/tools/virtio/linux/kernel.h
> index 8b877167933d..3cd20cb92649 100644
> --- a/tools/virtio/linux/kernel.h
> +++ b/tools/virtio/linux/kernel.h
> @@ -10,6 +10,7 @@
>  #include <stdarg.h>
>  
>  #include <linux/compiler.h>
> +#include <linux/container_of.h>
>  #include <linux/log2.h>
>  #include <linux/types.h>
>  #include <linux/overflow.h>
> @@ -107,10 +108,6 @@ static inline void free_page(unsigned long addr)
>  	free((void *)addr);
>  }
>  
> -#define container_of(ptr, type, member) ({			\
> -	const typeof( ((type *)0)->member ) *__mptr = (ptr);	\
> -	(type *)( (char *)__mptr - offsetof(type,member) );})
> -
>  # ifndef likely
>  #  define likely(x)	(__builtin_expect(!!(x), 1))
>  # endif
> diff --git a/tools/virtio/linux/module.h b/tools/virtio/linux/module.h
> index 9dfa96fea2b2..e2e791dbd104 100644
> --- a/tools/virtio/linux/module.h
> +++ b/tools/virtio/linux/module.h
> @@ -5,3 +5,4 @@
>  	static __attribute__((unused)) const char *__MODULE_LICENSE_name = \
>  		__MODULE_LICENSE_value
>  
> +struct device;


It's not there in include/linux/module - pls put it in the
same here where it is for linux.

> -- 
> 2.25.1

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