sd-bus-vtable: add dummy macro to support compile without GNU extension

If SD_BUS_METHOD_WITH_ARGS() is set with SD_BUS_NO_ARGS and/or SD_BUS_NO_RESULT,
then it introduces
_SD_VARARGS_FOREACH_EVEN(_SD_ECHO, NULL)
    -> _SD_VARARGS_FOREACH_SEQ(_01, …, _50, NULL)
Hence, the variadic argument `...` in _SD_VARARGS_FOREACH_SEQ() has no
argument, but it is not allowed if built without GNU extension, e.g. -std=c11.

Let's introduce one more unused dummy argument to support such situation.

diff --git a/src/systemd/sd-bus-vtable.h b/src/systemd/sd-bus-vtable.h
index 5e80ea895d4eba6941e80f256cf480f17a9918e5..d06c5c30155465ed301554fb7a78b3c35005325a 100644 (file)
--- a/src/systemd/sd-bus-vtable.h
+++ b/src/systemd/sd-bus-vtable.h
@@ -208,6 +208,7 @@ struct sd_bus_vtable {
                                 _41, _42, _43, _44, _45, _46, _47, _48, _49, _50, \
                                 NAME, ...) NAME
 
+#define _SD_VARARGS_FOREACH_EVEN_00(FN)
 #define _SD_VARARGS_FOREACH_EVEN_01(FN, X)         FN(X)
 #define _SD_VARARGS_FOREACH_EVEN_02(FN, X, Y)      FN(X)
 #define _SD_VARARGS_FOREACH_EVEN_04(FN, X, Y, ...) FN(X) _SD_VARARGS_FOREACH_EVEN_02(FN, __VA_ARGS__)
@@ -261,9 +262,11 @@ struct sd_bus_vtable {
                                 _SD_VARARGS_FOREACH_EVEN_08, _SD_VARARGS_FOREACH_EVEN_07, \
                                 _SD_VARARGS_FOREACH_EVEN_06, _SD_VARARGS_FOREACH_EVEN_05, \
                                 _SD_VARARGS_FOREACH_EVEN_04, _SD_VARARGS_FOREACH_EVEN_03, \
-                                _SD_VARARGS_FOREACH_EVEN_02, _SD_VARARGS_FOREACH_EVEN_01) \
+                                _SD_VARARGS_FOREACH_EVEN_02, _SD_VARARGS_FOREACH_EVEN_01, \
+                                _SD_VARARGS_FOREACH_EVEN_00)                              \
                                 (FN, __VA_ARGS__)
 
+#define _SD_VARARGS_FOREACH_ODD_00(FN)
 #define _SD_VARARGS_FOREACH_ODD_01(FN, X)
 #define _SD_VARARGS_FOREACH_ODD_02(FN, X, Y)      FN(Y)
 #define _SD_VARARGS_FOREACH_ODD_04(FN, X, Y, ...) FN(Y) _SD_VARARGS_FOREACH_ODD_02(FN, __VA_ARGS__)
@@ -317,7 +320,8 @@ struct sd_bus_vtable {
                                 _SD_VARARGS_FOREACH_ODD_08, _SD_VARARGS_FOREACH_ODD_07, \
                                 _SD_VARARGS_FOREACH_ODD_06, _SD_VARARGS_FOREACH_ODD_05, \
                                 _SD_VARARGS_FOREACH_ODD_04, _SD_VARARGS_FOREACH_ODD_03, \
-                                _SD_VARARGS_FOREACH_ODD_02, _SD_VARARGS_FOREACH_ODD_01) \
+                                _SD_VARARGS_FOREACH_ODD_02, _SD_VARARGS_FOREACH_ODD_01, \
+                                _SD_VARARGS_FOREACH_ODD_00)                             \
                                 (FN, __VA_ARGS__)
 
 #define SD_BUS_ARGS(...) __VA_ARGS__