1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ 2*4882a593Smuzhiyun #ifndef _UAPI_LINUX_STDDEF_H 3*4882a593Smuzhiyun #define _UAPI_LINUX_STDDEF_H 4*4882a593Smuzhiyun 5*4882a593Smuzhiyun #include <linux/compiler_types.h> 6*4882a593Smuzhiyun 7*4882a593Smuzhiyun #ifndef __always_inline 8*4882a593Smuzhiyun #define __always_inline inline 9*4882a593Smuzhiyun #endif 10*4882a593Smuzhiyun 11*4882a593Smuzhiyun /** 12*4882a593Smuzhiyun * __struct_group() - Create a mirrored named and anonyomous struct 13*4882a593Smuzhiyun * 14*4882a593Smuzhiyun * @TAG: The tag name for the named sub-struct (usually empty) 15*4882a593Smuzhiyun * @NAME: The identifier name of the mirrored sub-struct 16*4882a593Smuzhiyun * @ATTRS: Any struct attributes (usually empty) 17*4882a593Smuzhiyun * @MEMBERS: The member declarations for the mirrored structs 18*4882a593Smuzhiyun * 19*4882a593Smuzhiyun * Used to create an anonymous union of two structs with identical layout 20*4882a593Smuzhiyun * and size: one anonymous and one named. The former's members can be used 21*4882a593Smuzhiyun * normally without sub-struct naming, and the latter can be used to 22*4882a593Smuzhiyun * reason about the start, end, and size of the group of struct members. 23*4882a593Smuzhiyun * The named struct can also be explicitly tagged for layer reuse, as well 24*4882a593Smuzhiyun * as both having struct attributes appended. 25*4882a593Smuzhiyun */ 26*4882a593Smuzhiyun #define __struct_group(TAG, NAME, ATTRS, MEMBERS...) \ 27*4882a593Smuzhiyun union { \ 28*4882a593Smuzhiyun struct { MEMBERS } ATTRS; \ 29*4882a593Smuzhiyun struct TAG { MEMBERS } ATTRS NAME; \ 30*4882a593Smuzhiyun } 31*4882a593Smuzhiyun #endif 32