org.wartremover.warts.Recursion.scala Maven / Gradle / Ivy
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package org.wartremover
package warts
object Recursion extends WartTraverser {
def apply(u: WartUniverse): u.Traverser = {
new u.Traverser(this) {
import q.reflect.*
private val Tailrec = TypeRepr.of[scala.annotation.tailrec]
private var open: Set[Symbol] = Set.empty[Symbol]
private def inside[A](sym: Symbol)(expr: => A): A = {
open = open + sym
try expr
finally open = open - sym
}
private def isTailrec(m: Symbol): Boolean = m.annotations.exists(_.tpe <:< Tailrec)
override def traverseTree(tree: Tree)(owner: Symbol): Unit = {
tree match {
case _ if hasWartAnnotation(tree) =>
case t: DefDef if !isTailrec(t.symbol) =>
inside(tree.symbol)(super.traverseTree(tree)(owner))
case t: Ref if open(tree.symbol) =>
error(t.pos, "Unmarked recursion")
super.traverseTree(tree)(owner)
case _ =>
super.traverseTree(tree)(owner)
}
}
}
}
}