Having both LONG and SHORT versions of the SAFE macros with different names is not very convenient. Add helpers that facilitate overloading such macros using a single name.
In order to work around a known issue in MSVC [1], an indirection layer has to be introduced. [1] https://developercommunity.visualstudio.com/t/-va-args-seems-to-be-trated-as-a-single-parameter/460154 Acked-by: Dumitru Ceara <dce...@redhat.com> Signed-off-by: Adrian Moreno <amore...@redhat.com> --- include/openvswitch/util.h | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/include/openvswitch/util.h b/include/openvswitch/util.h index 157f8cecd..8184dd3d3 100644 --- a/include/openvswitch/util.h +++ b/include/openvswitch/util.h @@ -268,6 +268,27 @@ OVS_NO_RETURN void ovs_assert_failure(const char *, const char *, const char *); #define UPDATE_MULTIVAR_SAFE_LONG(VAR, NEXT_VAR) \ UPDATE_MULTIVAR(VAR, ITER_VAR(NEXT_VAR)) +/* Helpers to allow overloading the *_SAFE iterator macros and select either + * the LONG or the SHORT version depending on the number of arguments. + */ +#define GET_SAFE_MACRO2(_1, _2, NAME, ...) NAME +#define GET_SAFE_MACRO3(_1, _2, _3, NAME, ...) NAME +#define GET_SAFE_MACRO4(_1, _2, _3, _4, NAME, ...) NAME +#define GET_SAFE_MACRO5(_1, _2, _3, _4, _5, NAME, ...) NAME +#define GET_SAFE_MACRO6(_1, _2, _3, _4, _5, _6, NAME, ...) NAME +#define GET_SAFE_MACRO(MAX_ARGS) GET_SAFE_MACRO ## MAX_ARGS + +/* MSVC treats __VA_ARGS__ as a simple token in argument lists. Introduce + * a level of indirection to work around that. */ +#define EXPAND_MACRO(name, args) name args + +/* Overload the LONG and the SHORT version of the macros. MAX_ARGS is the + * maximum number of arguments (i.e: the number of arguments of the LONG + * version). */ +#define OVERLOAD_SAFE_MACRO(LONG, SHORT, MAX_ARGS, ...) \ + EXPAND_MACRO(GET_SAFE_MACRO(MAX_ARGS), \ + (__VA_ARGS__, LONG, SHORT))(__VA_ARGS__) + /* Returns the number of elements in ARRAY. */ #define ARRAY_SIZE(ARRAY) __ARRAY_SIZE(ARRAY) -- 2.34.1 _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev
