function f/0
  "a"
  if 1
    return
  end if
  0
end function
function g/0
  "a"
  if 1
    "b"
    return
  end if
  0
end function
macro m/0
  "\f()" : "\g()"
  if 1
    return
  end if
  "" : 0
end macro
m()