Top-level private definitions are not reported as unused

[rochala]

Compiler version

3.5.1-RC1-bin-20240602-c6fbe6f-NIGHTLY

Minimized code

Top level private definitions are not reported as unused.

//> using scala 3.nightly
//> using option -Wunused:all

@main def run =
  val veryUnusedVariable: Int = ???

private def veryUnusedMethod(x: Int): Unit = ???
private val veryUnusedVariableToplevel: Unit = ???

Output

//> using scala 3.nightly
//> using option -Wunused:all

@main def run =
  val veryUnusedVariable: Int = ??? // unused local definition

private def veryUnusedMethod(x: Int): Unit = ??? // no unused definition reported
private val veryUnusedVariableToplevel: Unit = ??? // no unused definition reported

Expectation

//> using scala 3.nightly
//> using option -Wunused:all

@main def run =
  val veryUnusedVariable: Int = ??? // unused local definition

private def veryUnusedMethod(x: Int): Unit = ??? // unused local definition
private val veryUnusedVariableToplevel: Unit = ??? // unused local definition

[som-snytt]

This is as expected, because the example is

private[<empty>] def veryUnusedMethod(x: Int): Unit = println()

and if it's in a named package, then it is private to the package. The members can be accessed under separate compilation.

Possibly, the expectation was that private means private to the file or the package object, but that is not the case.

Also members that are unimplemented with ??? do not warn for unused, and their params also do not warn.

Closing here as not a bug, but there is a test for status quo.