include/uapi/linux/stddef.h

/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
#ifndef _UAPI_LINUX_STDDEF_H
#define _UAPI_LINUX_STDDEF_H

#include <linux/compiler_types.h>

#ifndef __always_inline
#define __always_inline inline
#endif

/**
 * __struct_group() - Create a mirrored named and anonyomous struct
 *
 * @TAG: The tag name for the named sub-struct (usually empty)
 * @NAME: The identifier name of the mirrored sub-struct
 * @ATTRS: Any struct attributes (usually empty)
 * @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's members 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.
 * The named struct can also be explicitly tagged for layer reuse, as well
 * as both having struct attributes appended.
 */
#define __struct_group(TAG, NAME, ATTRS, MEMBERS...) \
	union { \
		struct { MEMBERS } ATTRS; \
		struct TAG { MEMBERS } ATTRS NAME; \
	}
#endif