Fork channel

Create a new channel as a copy of main.

Rename channel

Rename main to:

Delete channel

Delete main? This cannot be undone.

macro_fn_lparen_scan2.c
// RUN: %clang_cc1 -E %s | grep 'FUNC (3 +1);'

#define F(a) a 
#define FUNC(a) (a+1) 

F(FUNC) FUNC (3); /* final token sequence is FUNC(3+1) */