This is xnu-8019. See this file in:
/*
 * Copyright (c) 2016 Apple Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 *
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 *
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
#ifndef _KXLD_SPLITINFOLC_H_
#define _KXLD_SPLITINFOLC_H_

#include <sys/types.h>
#if KERNEL
#include <libkern/kxld_types.h>
#else
#include "kxld_types.h"
#endif

struct linkedit_data_command;
typedef struct kxld_splitinfolc KXLDsplitinfolc;

struct kxld_splitinfolc {
	uint32_t    cmdsize;
	uint32_t    dataoff;
	uint32_t    datasize;
	boolean_t   has_splitinfolc;
};

/*******************************************************************************
* Constructors and destructors
*******************************************************************************/

void kxld_splitinfolc_init_from_macho(KXLDsplitinfolc *splitinfolc, struct linkedit_data_command *src)
__attribute__((nonnull, visibility("hidden")));

void kxld_splitinfolc_clear(KXLDsplitinfolc *splitinfolc)
__attribute__((nonnull, visibility("hidden")));

/*******************************************************************************
* Accessors
*******************************************************************************/

u_long kxld_splitinfolc_get_macho_header_size(void)
__attribute__((pure, visibility("hidden")));

kern_return_t
kxld_splitinfolc_export_macho(const KXLDsplitinfolc *splitinfolc,
    splitKextLinkInfo *linked_object,
    u_long *header_offset,
    u_long header_size,
    u_long *data_offset,
    u_long size)
__attribute__((pure, nonnull, visibility("hidden")));

#endif /* _KXLD_SPLITINFOLC_H_ */