org.wartremover.warts.Recursion.scala Maven / Gradle / Ivy
package org.wartremover
package warts
object Recursion extends WartTraverser {
def apply(u: WartUniverse): u.Traverser = {
import u.universe._
new u.Traverser {
val Tailrec = typeOf[scala.annotation.tailrec]
var open: Set[Symbol] = Set()
def inside[A](sym: Symbol)(expr: => A): A = {
open = open + sym
try expr
finally open = open - sym
}
def isTailrec(m: Symbol) = m.annotations exists (_.tree.tpe <:< Tailrec)
override def traverse(tree: Tree): Unit = {
tree match {
// Ignore trees marked by SuppressWarnings
case t if hasWartAnnotation(u)(t) =>
case t: DefDef if !isTailrec(t.symbol) => inside(tree.symbol)(super.traverse(tree))
case t: RefTree if open(tree.symbol) => error(u)(t.pos, "Unmarked recursion"); super.traverse(tree)
case _ => super.traverse(tree)
}
}
}
}
}