Macros_Test_2.scala:2: error: macro implementation has incompatible shape:
 required: (c: scala.reflect.macros.blackbox.Context): c.Expr[Any]
 or      : (c: scala.reflect.macros.blackbox.Context): c.Tree
 found   : (c: scala.reflect.macros.blackbox.Context): Int
type mismatch for return type: Int does not conform to c.Expr[Any]
  def foo1 = macro Impls.foo1
                         ^
Macros_Test_2.scala:3: error: macro implementation has incompatible shape:
 required: (c: scala.reflect.macros.blackbox.Context): c.Expr[Any]
 or      : (c: scala.reflect.macros.blackbox.Context): c.Tree
 found   : (c: scala.reflect.macros.blackbox.Context): reflect.runtime.universe.Literal
type mismatch for return type: reflect.runtime.universe.Literal does not conform to c.Expr[Any]
  def foo2 = macro Impls.foo2
                         ^
Macros_Test_2.scala:6: error: macro defs must have explicitly specified return types
  def foo5 = macro Impls.foo5
      ^
Macros_Test_2.scala:7: warning: macro defs must have explicitly specified return types (inference of Int from macro impl's c.Expr[Int] is deprecated and is going to stop working in 2.12)
  def foo6 = macro Impls.foo6
      ^
Macros_Test_2.scala:14: error: exception during macro expansion:
java.lang.NullPointerException
	at Impls$.foo3(Impls_1.scala:7)

  foo3
  ^
Macros_Test_2.scala:15: error: macro implementation is missing
  foo4
  ^
Macros_Test_2.scala:17: warning: a pure expression does nothing in statement position; multiline expressions may require enclosing parentheses
  foo6
  ^
two warnings found
5 errors found