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| author | Quentin Young <qlyoung@nvidia.com> | 2020-11-29 07:49:06 +0100 |
|---|---|---|
| committer | Quentin Young <qlyoung@nvidia.com> | 2020-12-02 00:37:14 +0100 |
| commit | 9f79b3758dc305264623c779a677415572bc4d68 (patch) | |
| tree | 08a4f2ae9bed984b88897f69e675d9e3e78a3025 /lib/compiler.h | |
| parent | lib: make encoder type a typedef (diff) | |
| download | frr-9f79b3758dc305264623c779a677415572bc4d68.tar.xz frr-9f79b3758dc305264623c779a677415572bc4d68.zip | |
lib: add macros to count variadic args
Magical macro used to compute the number of arguments passed to a
variadic macro.
Signed-off-by: Quentin Young <qlyoung@nvidia.com>
Diffstat (limited to 'lib/compiler.h')
| -rw-r--r-- | lib/compiler.h | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/lib/compiler.h b/lib/compiler.h index 217a60d88..70ef8e9bc 100644 --- a/lib/compiler.h +++ b/lib/compiler.h @@ -279,6 +279,29 @@ extern "C" { #define array_size(ar) (sizeof(ar) / sizeof(ar[0])) +/* Some insane macros to count number of varargs to a functionlike macro */ +#define PP_ARG_N( \ + _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 PP_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 + +#define PP_NARG_(...) PP_ARG_N(__VA_ARGS__) +#define PP_NARG(...) PP_NARG_(_, ##__VA_ARGS__, PP_RSEQ_N()) + + /* sigh. this is so ugly, it overflows and wraps to being nice again. * * printfrr() supports "%Ld" for <int64_t>, whatever that is typedef'd to. |