This gcc-centric macro in or/config.c doesn't work well in MSVC v16/18: #define COMPLAIN(args...) \ STMT_BEGIN log_warn(LD_CONFIG, args); STMT_END I suggest it should be patched like this: --- a/config.c 2015-05-06 22:22:09 +0000 +++ b/config.c 2015-05-06 23:15:57 +0000 @@ -2571,8 +2571,8 @@ #define REJECT(arg) \ STMT_BEGIN *msg = tor_strdup(arg); return -1; STMT_END -#define COMPLAIN(args...) \ - STMT_BEGIN log_warn(LD_CONFIG, args); STMT_END +#define COMPLAIN(args, ...) \ + STMT_BEGIN log_warn(LD_CONFIG, args, ## __VA_ARGS__); STMT_END /** Log a warning message iff <b>filepath</b> is not absolute. * Warning message must contain option name <b>option</b> and ------- All recent compilers supports '__VA_ARGS__'? -- --gv