xref: /xnu-11417.121.6/libkern/os/ptrtools.h (revision a1e26a70f38d1d7daa7b49b258e2f8538ad81650)
1*a1e26a70SApple OSS Distributions /* * Copyright (c) 2018 Apple Inc. All rights reserved.
2*a1e26a70SApple OSS Distributions  *
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4*a1e26a70SApple OSS Distributions  *
5*a1e26a70SApple OSS Distributions  * This file contains Original Code and/or Modifications of Original Code
6*a1e26a70SApple OSS Distributions  * as defined in and that are subject to the Apple Public Source License
7*a1e26a70SApple OSS Distributions  * Version 2.0 (the 'License'). You may not use this file except in
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27*a1e26a70SApple OSS Distributions 
28*a1e26a70SApple OSS Distributions #ifndef _OS_PTRTOOLS_H
29*a1e26a70SApple OSS Distributions #define _OS_PTRTOOLS_H
30*a1e26a70SApple OSS Distributions 
31*a1e26a70SApple OSS Distributions /* dereference unaligned pointer 'p' */
32*a1e26a70SApple OSS Distributions #define os_unaligned_deref(p) ((__os_unaligned_type(p))(p))->val
33*a1e26a70SApple OSS Distributions 
34*a1e26a70SApple OSS Distributions /* ensure the compiler emits at most one access to 'val' */
35*a1e26a70SApple OSS Distributions #define os_access_once(val) (*((volatile __typeof__((val)) *)&(val)))
36*a1e26a70SApple OSS Distributions 
37*a1e26a70SApple OSS Distributions #define __os_unaligned_type(p) struct { __typeof__(*(p)) val; } __attribute__((packed)) *
38*a1e26a70SApple OSS Distributions 
39*a1e26a70SApple OSS Distributions #endif /* _OS_PTRTOOLS_H */
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