llvm-project/clang/test/Preprocessor/macro_expand.c

// RUN: clang-cc -E %s | grep '^A: Y$' &&
// RUN: clang-cc -E %s | grep '^B: f()$' &&
// RUN: clang-cc -E %s | grep '^C: for()$'

#define X() Y
#define Y() X

A: X()()()

// PR3927
#define f(x) h(x
#define for(x) h(x
#define h(x) x()
B: f(f))
C: for(for))

// rdar://6880648
#define f(x,y...) y
f()