commit 7e364e56293bb98cae1b55fd835f5991c4e96e7d Signed-off-by: David 'Digit' Turner <digit@google.com> Message-Id: <20230405172109.3081788-4-digit@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
		
			
				
	
	
		
			48 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			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
 |