| 1 | /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ |
| 2 | #ifndef _LINUX_STDDEF_H |
| 3 | #define _LINUX_STDDEF_H |
| 4 | |
| 5 | |
| 6 | |
| 7 | #ifndef __always_inline |
| 8 | #define __always_inline __inline__ |
| 9 | #endif |
| 10 | |
| 11 | /** |
| 12 | * __struct_group() - Create a mirrored named and anonyomous struct |
| 13 | * |
| 14 | * @TAG: The tag name for the named sub-struct (usually empty) |
| 15 | * @NAME: The identifier name of the mirrored sub-struct |
| 16 | * @ATTRS: Any struct attributes (usually empty) |
| 17 | * @MEMBERS: The member declarations for the mirrored structs |
| 18 | * |
| 19 | * Used to create an anonymous union of two structs with identical layout |
| 20 | * and size: one anonymous and one named. The former's members can be used |
| 21 | * normally without sub-struct naming, and the latter can be used to |
| 22 | * reason about the start, end, and size of the group of struct members. |
| 23 | * The named struct can also be explicitly tagged for layer reuse, as well |
| 24 | * as both having struct attributes appended. |
| 25 | */ |
| 26 | #define __struct_group(TAG, NAME, ATTRS, MEMBERS...) \ |
| 27 | union { \ |
| 28 | struct { MEMBERS } ATTRS; \ |
| 29 | struct TAG { MEMBERS } ATTRS NAME; \ |
| 30 | } |
| 31 | #endif |
| 32 | |