Incomplete function macro call should be an error

[jyn514]

Expected behavior

Function macros which do not have a terminating ) should give an error. Instead they are silently discarded.

$ clang -E replace.c 
replace.c:2:2: error: unterminated function-like macro invocation
 f (
 ^

Code

#define f(a) a
 f (

http://port70.net/~nsz/c/c11/n1570.html#6.10.3p4:

There shall exist a ) preprocessing token that terminates the invocation.