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29 lines
994 B
C
29 lines
994 B
C
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/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_ARGS_H
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#define _LINUX_ARGS_H
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/*
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* How do these macros work?
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*
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* In __COUNT_ARGS() _0 to _12 are just placeholders from the start
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* in order to make sure _n is positioned over the correct number
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* from 12 to 0 (depending on X, which is a variadic argument list).
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* They serve no purpose other than occupying a position. Since each
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* macro parameter must have a distinct identifier, those identifiers
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* are as good as any.
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*
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* In COUNT_ARGS() we use actual integers, so __COUNT_ARGS() returns
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* that as _n.
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*/
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/* This counts to 12. Any more, it will return 13th argument. */
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#define __COUNT_ARGS(_0, _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _n, X...) _n
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#define COUNT_ARGS(X...) __COUNT_ARGS(, ##X, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
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/* Concatenate two parameters, but allow them to be expanded beforehand. */
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#define __CONCAT(a, b) a ## b
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#define CONCATENATE(a, b) __CONCAT(a, b)
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#endif /* _LINUX_ARGS_H */
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