/usr/include/xorg/xfixes.h is in xserver-xorg-dev 2:1.15.1-0ubuntu2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 | /*
 * Copyright © 2002 Keith Packard
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that
 * copyright notice and this permission notice appear in supporting
 * documentation, and that the name of Keith Packard not be used in
 * advertising or publicity pertaining to distribution of the software without
 * specific, written prior permission.  Keith Packard makes no
 * representations about the suitability of this software for any purpose.  It
 * is provided "as is" without express or implied warranty.
 *
 * KEITH PACKARD DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL KEITH PACKARD BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */
#ifdef HAVE_DIX_CONFIG_H
#include <dix-config.h>
#endif
#ifndef _XFIXES_H_
#define _XFIXES_H_
#include "resource.h"
extern _X_EXPORT RESTYPE RegionResType;
extern _X_EXPORT int XFixesErrorBase;
#define VERIFY_REGION(pRegion, rid, client, mode)			\
    do {								\
	int err;							\
	err = dixLookupResourceByType((pointer *) &pRegion, rid,	\
				      RegionResType, client, mode);	\
	if (err != Success) {						\
	    client->errorValue = rid;					\
	    return err;							\
	}								\
    } while (0)
#define VERIFY_REGION_OR_NONE(pRegion, rid, client, mode) { \
    pRegion = 0; \
    if (rid) VERIFY_REGION(pRegion, rid, client, mode); \
}
extern _X_EXPORT RegionPtr
 XFixesRegionCopy(RegionPtr pRegion);
#include "xibarriers.h"
#endif                          /* _XFIXES_H_ */
 |