From 59981e6a3d6074bf5413c1875a95325a4b8c01ca Mon Sep 17 00:00:00 2001 From: =?utf8?q?Marek=20Beh=C3=BAn?= Date: Sun, 3 Sep 2017 17:00:25 +0200 Subject: [PATCH] include: Add a variadic macro to call a callback for all arguments Add a header variadic-macro.h which defines the CALL_MACRO_FOR_EACH marco. This macro can be used as follows: #define TEST(x) CALL_MACRO_FOR_EACH(TEST, a, b, c, d) This will expand to TEST(a) TEST(b) TEST(c) TEST(d) The nice thing is that CALL_MACRO_FOR_EACH is a variadic macro, thus the number of arguments can vary (although it has an upper limit - in this implementation 32 arguments). Signed-off-by: Marek Behun create mode 100644 include/u-boot/variadic-macro.h --- include/u-boot/variadic-macro.h | 59 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+) create mode 100644 include/u-boot/variadic-macro.h diff --git a/include/u-boot/variadic-macro.h b/include/u-boot/variadic-macro.h new file mode 100644 index 0000000..922beaf --- /dev/null +++ b/include/u-boot/variadic-macro.h @@ -0,0 +1,59 @@ +/* + * Helper for work with variadic macros + * + * 2017 Marek Behun, CZ.NIC, marek.behun@nic.cz + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#ifndef __VARIADIC_MACRO_H__ +#define __VARIADIC_MACRO_H__ + +#define _VM_GET_NTH_ARG(_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, N, ...) N + +#define _VM_HELP_0(_call, ...) +#define _VM_HELP_1(_call, x, ...) _call(x) +#define _VM_HELP_2(_call, x, ...) _call(x) _VM_HELP_1(_call, __VA_ARGS__) +#define _VM_HELP_3(_call, x, ...) _call(x) _VM_HELP_2(_call, __VA_ARGS__) +#define _VM_HELP_4(_call, x, ...) _call(x) _VM_HELP_3(_call, __VA_ARGS__) +#define _VM_HELP_5(_call, x, ...) _call(x) _VM_HELP_4(_call, __VA_ARGS__) +#define _VM_HELP_6(_call, x, ...) _call(x) _VM_HELP_5(_call, __VA_ARGS__) +#define _VM_HELP_7(_call, x, ...) _call(x) _VM_HELP_6(_call, __VA_ARGS__) +#define _VM_HELP_8(_call, x, ...) _call(x) _VM_HELP_7(_call, __VA_ARGS__) +#define _VM_HELP_9(_call, x, ...) _call(x) _VM_HELP_8(_call, __VA_ARGS__) +#define _VM_HELP_10(_call, x, ...) _call(x) _VM_HELP_9(_call, __VA_ARGS__) +#define _VM_HELP_11(_call, x, ...) _call(x) _VM_HELP_10(_call, __VA_ARGS__) +#define _VM_HELP_12(_call, x, ...) _call(x) _VM_HELP_11(_call, __VA_ARGS__) +#define _VM_HELP_13(_call, x, ...) _call(x) _VM_HELP_12(_call, __VA_ARGS__) +#define _VM_HELP_14(_call, x, ...) _call(x) _VM_HELP_13(_call, __VA_ARGS__) +#define _VM_HELP_15(_call, x, ...) _call(x) _VM_HELP_14(_call, __VA_ARGS__) +#define _VM_HELP_16(_call, x, ...) _call(x) _VM_HELP_15(_call, __VA_ARGS__) +#define _VM_HELP_17(_call, x, ...) _call(x) _VM_HELP_16(_call, __VA_ARGS__) +#define _VM_HELP_18(_call, x, ...) _call(x) _VM_HELP_17(_call, __VA_ARGS__) +#define _VM_HELP_19(_call, x, ...) _call(x) _VM_HELP_18(_call, __VA_ARGS__) +#define _VM_HELP_20(_call, x, ...) _call(x) _VM_HELP_19(_call, __VA_ARGS__) +#define _VM_HELP_21(_call, x, ...) _call(x) _VM_HELP_20(_call, __VA_ARGS__) +#define _VM_HELP_22(_call, x, ...) _call(x) _VM_HELP_21(_call, __VA_ARGS__) +#define _VM_HELP_23(_call, x, ...) _call(x) _VM_HELP_22(_call, __VA_ARGS__) +#define _VM_HELP_24(_call, x, ...) _call(x) _VM_HELP_23(_call, __VA_ARGS__) +#define _VM_HELP_25(_call, x, ...) _call(x) _VM_HELP_24(_call, __VA_ARGS__) +#define _VM_HELP_26(_call, x, ...) _call(x) _VM_HELP_25(_call, __VA_ARGS__) +#define _VM_HELP_27(_call, x, ...) _call(x) _VM_HELP_26(_call, __VA_ARGS__) +#define _VM_HELP_28(_call, x, ...) _call(x) _VM_HELP_27(_call, __VA_ARGS__) +#define _VM_HELP_29(_call, x, ...) _call(x) _VM_HELP_28(_call, __VA_ARGS__) +#define _VM_HELP_30(_call, x, ...) _call(x) _VM_HELP_29(_call, __VA_ARGS__) +#define _VM_HELP_31(_call, x, ...) _call(x) _VM_HELP_30(_call, __VA_ARGS__) + +#define CALL_MACRO_FOR_EACH(x, ...) \ + _VM_GET_NTH_ARG("", ##__VA_ARGS__, _VM_HELP_31, _VM_HELP_30, \ + _VM_HELP_29, _VM_HELP_28, _VM_HELP_27, _VM_HELP_26, _VM_HELP_25, \ + _VM_HELP_24, _VM_HELP_23, _VM_HELP_22, _VM_HELP_21, _VM_HELP_20, \ + _VM_HELP_19, _VM_HELP_18, _VM_HELP_17, _VM_HELP_16, _VM_HELP_15, \ + _VM_HELP_14, _VM_HELP_13, _VM_HELP_12, _VM_HELP_11, _VM_HELP_10, \ + _VM_HELP_9, _VM_HELP_8, _VM_HELP_7, _VM_HELP_6, _VM_HELP_5, \ + _VM_HELP_4, _VM_HELP_3, _VM_HELP_2, _VM_HELP_1, \ + _VM_HELP_0)(x, __VA_ARGS__) + +#endif /* __VARIADIC_MACRO_H__ */ -- 2.7.4