Re: [PATCH v6 2/3] tools: copy include/linux/stddef.h to tools/include

[Charlie Jenkins <charlie@rivosinc.com>]

On Wed, Jan 15, 2025 at 07:13:28PM +0800, Celeste Liu wrote:
> Some macro defined in stddef.h are useful and have been used in many
> code in selftests. Copy them to tools/include so developers needn't
> create their copy in every files.
> 
> Remove some definitions like NULL and true/false to be suitable to
> non-kernel environment.
> 
> Signed-off-by: Celeste Liu <uwu@coelacanthus.name>

Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Tested-by: Charlie Jenkins <charlie@rivosinc.com>

> ---
>  tools/include/linux/stddef.h      | 85 +++++++++++++++++++++++++++++++++++++++
>  tools/include/uapi/linux/stddef.h |  6 +--
>  2 files changed, 87 insertions(+), 4 deletions(-)
> 
> diff --git a/tools/include/linux/stddef.h b/tools/include/linux/stddef.h
> new file mode 100644
> index 0000000000000000000000000000000000000000..55f3964d9a3d9f9f9345a75248eec027c56faef9
> --- /dev/null
> +++ b/tools/include/linux/stddef.h
> @@ -0,0 +1,85 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef _LINUX_STDDEF_H
> +#define _LINUX_STDDEF_H
> +
> +#include <uapi/linux/stddef.h>
> +
> +/**
> + * sizeof_field() - Report the size of a struct field in bytes
> + *
> + * @TYPE: The structure containing the field of interest
> + * @MEMBER: The field to return the size of
> + */
> +#define sizeof_field(TYPE, MEMBER) sizeof((((TYPE *)0)->MEMBER))
> +
> +/**
> + * offsetofend() - Report the offset of a struct field within the struct
> + *
> + * @TYPE: The type of the structure
> + * @MEMBER: The member within the structure to get the end offset of
> + */
> +#define offsetofend(TYPE, MEMBER) \
> +	(offsetof(TYPE, MEMBER)	+ sizeof_field(TYPE, MEMBER))
> +
> +/**
> + * struct_group() - Wrap a set of declarations in a mirrored struct
> + *
> + * @NAME: The identifier name of the mirrored sub-struct
> + * @MEMBERS: The member declarations for the mirrored structs
> + *
> + * Used to create an anonymous union of two structs with identical
> + * layout and size: one anonymous and one named. The former can be
> + * used normally without sub-struct naming, and the latter can be
> + * used to reason about the start, end, and size of the group of
> + * struct members.
> + */
> +#define struct_group(NAME, MEMBERS...)	\
> +	__struct_group(/* no tag */, NAME, /* no attrs */, MEMBERS)
> +
> +/**
> + * struct_group_attr() - Create a struct_group() with trailing attributes
> + *
> + * @NAME: The identifier name of the mirrored sub-struct
> + * @ATTRS: Any struct attributes to apply
> + * @MEMBERS: The member declarations for the mirrored structs
> + *
> + * Used to create an anonymous union of two structs with identical
> + * layout and size: one anonymous and one named. The former can be
> + * used normally without sub-struct naming, and the latter can be
> + * used to reason about the start, end, and size of the group of
> + * struct members. Includes structure attributes argument.
> + */
> +#define struct_group_attr(NAME, ATTRS, MEMBERS...) \
> +	__struct_group(/* no tag */, NAME, ATTRS, MEMBERS)
> +
> +/**
> + * struct_group_tagged() - Create a struct_group with a reusable tag
> + *
> + * @TAG: The tag name for the named sub-struct
> + * @NAME: The identifier name of the mirrored sub-struct
> + * @MEMBERS: The member declarations for the mirrored structs
> + *
> + * Used to create an anonymous union of two structs with identical
> + * layout and size: one anonymous and one named. The former can be
> + * used normally without sub-struct naming, and the latter can be
> + * used to reason about the start, end, and size of the group of
> + * struct members. Includes struct tag argument for the named copy,
> + * so the specified layout can be reused later.
> + */
> +#define struct_group_tagged(TAG, NAME, MEMBERS...) \
> +	__struct_group(TAG, NAME, /* no attrs */, MEMBERS)
> +
> +/**
> + * DECLARE_FLEX_ARRAY() - Declare a flexible array usable in a union
> + *
> + * @TYPE: The type of each flexible array element
> + * @NAME: The name of the flexible array member
> + *
> + * In order to have a flexible array member in a union or alone in a
> + * struct, it needs to be wrapped in an anonymous struct with at least 1
> + * named member, but that member can be empty.
> + */
> +#define DECLARE_FLEX_ARRAY(TYPE, NAME) \
> +	__DECLARE_FLEX_ARRAY(TYPE, NAME)
> +
> +#endif
> diff --git a/tools/include/uapi/linux/stddef.h b/tools/include/uapi/linux/stddef.h
> index bb6ea517efb51177a7983fadad9b590b12b786e5..f2548fd95f6e1d8cb218d52918bb81a3317d10b1 100644
> --- a/tools/include/uapi/linux/stddef.h
> +++ b/tools/include/uapi/linux/stddef.h
> @@ -1,8 +1,6 @@
>  /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
> -#ifndef _LINUX_STDDEF_H
> -#define _LINUX_STDDEF_H
> -
> -
> +#ifndef _UAPI_LINUX_STDDEF_H
> +#define _UAPI_LINUX_STDDEF_H
>  
>  #ifndef __always_inline
>  #define __always_inline __inline__
> 
> -- 
> 2.48.0
>