not var macro scala

NotVar.scala

def macro NotVar(c:Any) = {
  import reflect.api.Modifier.mutable
  (new Transformer{
    override def transform(tree:Tree):Tree = tree match{
      case ValDef(m,_,_,_) if m.hasModifier(mutable) => sys.error("can't use var !!!")
      case _ => super.transform(tree)
    }
  }).transform(c)
}

reploutput.scala

$ scala -Xmacros
Welcome to Scala version 2.10.0-M2 (Java HotSpot(TM) 64-Bit Server VM, Java 1.6.0_29).
Type in expressions to have them evaluated.
Type :help for more information.

scala> def macro NotVar(c:Any) = {
     |   import reflect.api.Modifier.mutable
     |   (new Transformer{
     |     override def transform(tree:Tree):Tree = tree match{
     |       case ValDef(m,_,_,_) if m.hasModifier(mutable) => sys.error("can't use var !!!")
     |       case _ => super.transform(tree)
     |     }
     |   }).transform(c)
     | }
NotVar: (c: Any)Any

scala> NotVar({val a = 1 ; a })
res0: Int = 1

scala> NotVar({var b = 2 ; b })
<console>:9: error: exception during macro expansion: can't use var !!!
              NotVar({var b = 2 ; b })
                    ^