com.sksamuel.scapegoat.inspections.unsafe.FinalizerWithoutSuper.scala Maven / Gradle / Ivy

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package com.sksamuel.scapegoat.inspections.unsafe

import com.sksamuel.scapegoat.{Inspection, InspectionContext, Inspector, Levels}

/**
 * @author Stephen Samuel
 */
class FinalizerWithoutSuper
    extends Inspection(
      text = "Finalizer without super",
      defaultLevel = Levels.Warning,
      description = "Checks for overridden finalizers that do not call super.",
      explanation =
        "Finalizers should call `super.finalize()` to ensure superclasses are able to run their finalization logic."
    ) {

  def inspector(context: InspectionContext): Inspector =
    new Inspector(context) {
      override def postTyperTraverser =
        new context.Traverser {

          import context.global._

          private val Finalize = TermName("finalize")
          private def containsSuper(tree: Tree): Boolean =
            tree match {
              case Apply(Select(Super(_, _), Finalize), List()) => true
              case Block(stmts, expr)                           => (stmts :+ expr).exists(containsSuper)
              case _                                            => false
            }

          override def inspect(tree: Tree): Unit = {
            tree match {
              case DefDef(_, Finalize, _, _, tpt, rhs) if tpt.tpe <:< typeOf[Unit] =>
                if (!containsSuper(rhs))
                  context.warn(tree.pos, self)
              case _ => continue(tree)
            }
          }
        }
    }
}