2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1999 Marcel Moolenaar
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer
12 * in this position and unchanged.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. The name of the author may not be used to endorse or promote products
17 * derived from this software without specific prior written permission.
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36 #define ASSYM_BIAS 0x10000 /* avoid zero-length arrays */
37 #define ASSYM_ABS(value) ((value) < 0 ? -((value) + 1) + 1ULL : (value))
39 #define ASSYM(name, value) \
40 char name ## sign[((value) < 0 ? 1 : 0) + ASSYM_BIAS]; \
41 char name ## w0[(ASSYM_ABS(value) & 0xFFFFU) + ASSYM_BIAS]; \
42 char name ## w1[((ASSYM_ABS(value) & 0xFFFF0000UL) >> 16) + ASSYM_BIAS]; \
43 char name ## w2[((ASSYM_ABS(value) & 0xFFFF00000000ULL) >> 32) + ASSYM_BIAS]; \
44 char name ## w3[((ASSYM_ABS(value) & 0xFFFF000000000000ULL) >> 48) + ASSYM_BIAS]
46 /* char name ## _datatype_ ## STRINGIFY(typeof(((struct parenttype *)(0x0))-> name)) [1]; */
48 #define OFFSET_CTASSERT CTASSERT
50 #define OFFSET_CTASSERT(...)
53 #define OFFSYM(name, parenttype, datatype) \
54 ASSYM(name, offsetof(struct parenttype, name)); \
55 char name ## _datatype_ ## datatype [1]; \
56 char name ## _parenttype_ ## parenttype [1]; \
57 CTASSERT(__builtin_types_compatible_p(__typeof(((struct parenttype *)(0x0))-> name), datatype)); \
58 OFFSET_CTASSERT(offsetof(struct parenttype, name) == offsetof(struct parenttype ## _lite, name))
60 #endif /* !_SYS_ASSYM_H_ */