mirror_ubuntu-kernels/tools/include/uapi/linux/stddef.h

48 lines
1.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
#ifndef _LINUX_STDDEF_H
#define _LINUX_STDDEF_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; \
}
/**
* __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) \
struct { \
struct { } __empty_ ## NAME; \
TYPE NAME[]; \
}
#endif