From 1faf0a81e4ef7176f152165fe46ff65b598d09ce Mon Sep 17 00:00:00 2001 From: hathach Date: Mon, 2 Jul 2018 17:32:09 +0700 Subject: clean up --- src/common/tusb_common.h | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) (limited to 'src/common') diff --git a/src/common/tusb_common.h b/src/common/tusb_common.h index 2ac0e2e8b..2b45a50c9 100644 --- a/src/common/tusb_common.h +++ b/src/common/tusb_common.h @@ -102,6 +102,37 @@ #define __be2n_16(u16) __n2be_16(u16) #endif + +/*------------------------------------------------------------------*/ +/* Count number of arguments of __VA_ARGS__ + * - reference https://groups.google.com/forum/#!topic/comp.std.c/d-6Mj5Lko_s + * - _GET_NTH_ARG() takes args >= N (64) but only expand to Nth one (64th) + * - _RSEQ_N() is reverse sequential to N to add padding to have + * Nth position is the same as the number of arguments + * - ##__VA_ARGS__ is used to deal with 0 paramerter (swallows comma) + *------------------------------------------------------------------*/ +#ifndef VA_ARGS_NUM_ + +#define VA_ARGS_NUM_(...) NARG_(_0, ##__VA_ARGS__,_RSEQ_N()) +#define NARG_(...) _GET_NTH_ARG(__VA_ARGS__) +#define _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,_33,_34,_35,_36,_37,_38,_39,_40, \ + _41,_42,_43,_44,_45,_46,_47,_48,_49,_50, \ + _51,_52,_53,_54,_55,_56,_57,_58,_59,_60, \ + _61,_62,_63,N,...) N +#define _RSEQ_N() \ + 62,61,60, \ + 59,58,57,56,55,54,53,52,51,50, \ + 49,48,47,46,45,44,43,42,41,40, \ + 39,38,37,36,35,34,33,32,31,30, \ + 29,28,27,26,25,24,23,22,21,20, \ + 19,18,17,16,15,14,13,12,11,10, \ + 9,8,7,6,5,4,3,2,1,0 +#endif + //--------------------------------------------------------------------+ // INLINE FUNCTION //--------------------------------------------------------------------+ -- cgit v1.3.1