TIOBE - C Coding Standard

SR: 12.3#10

Synopsis:	A function-like macro must be supplied with its expected arguments.
Language:	C
Severity Level:	2
Category:	PREPROCESSING

Description:

Not specifying them leads to undefined behaviour.

Example:

#define ORDINAL(num) num
...
void func(void)
{
    int empty = ORDINAL(); /* undefined */
    ...
}

is undefined because the use of ORDINAL() is missing the expected argument.