Macros_Test_2.scala:2: error: macro implementation reference has wrong shape. required:
macro [<static object>].<method name>[[<type args>]] or
macro [<macro bundle>].<method name>[[<type args>]]
  def foo1(x: Any) = macro 2
                           ^
Macros_Test_2.scala:3: error: macro implementation reference has wrong shape. required:
macro [<static object>].<method name>[[<type args>]] or
macro [<macro bundle>].<method name>[[<type args>]]
  def foo2(x: Any) = macro Impls.foo(null)(null)
                                 ^
Macros_Test_2.scala:4: error: missing argument list for method foo in object Impls
Unapplied methods are only converted to functions when a function type is expected.
You can make this conversion explicit by writing `foo _` or `foo(_)(_)` instead of `foo`.
  def foo3(x: Any) = macro {2; Impls.foo}
                                     ^
Macros_Test_2.scala:7: error: macro implementation reference has wrong shape. required:
macro [<static object>].<method name>[[<type args>]] or
macro [<macro bundle>].<method name>[[<type args>]]
    def foo = macro impl
                    ^
four errors found