You do need to omit whitespace between the name and the opening parenthesis when defining a functionlike macro, but it doesn't matter when you're calling it.
I furiously looked at the C standard (C99, anyway) and the documentation to the gcc preprocessor, and have to admit somewhat embarassedly, that you are right.
The gcc preprocessor documentation clearly states:
> "If you use the macro name followed by something other than an open-parenthesis (after ignoring any spaces, tabs and comments that follow), it is not a call to the macro, and the preprocessor does not change what you have written."
