Warn about unused private members.

Warnings enabled via -Xlint. It's one of the most requested
features. And it is hard to argue we don't need it: see the
99 methods removed in the next commit.

This should close SI-440.

1 files changed, 58 insertions, 0 deletions

diff --git a/test/files/neg/warn-unused-privates.scala b/test/files/neg/warn-unused-privates.scala
new file mode 100644
index 0000000000..1ac272357f
--- /dev/null
+++ b/test/files/neg/warn-unused-privates.scala
@@ -0,0 +1,58 @@
+class Bippy(a: Int, b: Int) {
+  private def this(c: Int) = this(c, c)           // warn
+  private def bippy(x: Int): Int      = bippy(x)  // TODO: could warn
+  private def boop(x: Int)            = x+a+b     // warn
+  final private val MILLIS1           = 2000      // no warn, might have been inlined
+  final private val MILLIS2: Int      = 1000      // warn
+  final private val HI_COMPANION: Int = 500       // no warn, accessed from companion
+  def hi() = Bippy.HI_INSTANCE
+}
+object Bippy {
+  def hi(x: Bippy) = x.HI_COMPANION
+  private val HI_INSTANCE: Int = 500      // no warn, accessed from instance
+  private val HEY_INSTANCE: Int = 1000    // warn
+}
+
+class A(val msg: String)
+class B1(msg: String) extends A(msg)
+class B2(msg0: String) extends A(msg0)
+class B3(msg0: String) extends A("msg")
+
+/*** Early defs full of noise due to SI-6595. ***/
+/***
+class Boppy extends {
+  private val hmm: String = "abc"       // no warn, used in early defs
+  private val hom: String = "def"       // no warn, used in body
+  private final val him   = "ghi"       // no warn, might have been (was) inlined
+  final val him2          = "ghi"       // no warn, same
+  final val himinline     = him
+  private val hum: String = "jkl"       // warn
+  final val ding = hmm.length
+} with Mutable {
+  val dinger = hom
+  private val hummer = "def" // warn
+
+  private final val bum   = "ghi"       // no warn, might have been (was) inlined
+  final val bum2          = "ghi"       // no warn, same
+}
+***/
+
+trait Accessors {
+  private var v1: Int = 0 // warn
+  private var v2: Int = 0 // warn, never set
+  private var v3: Int = 0 // warn, never got
+  private var v4: Int = 0 // no warn
+
+  def bippy(): Int = {
+    v3 = 5
+    v4 = 6
+    v2 + v4
+  }
+}
+
+trait DefaultArgs {
+  // warn about default getters for x2 and x3
+  private def bippy(x1: Int, x2: Int = 10, x3: Int = 15): Int = x1 + x2 + x3
+
+  def boppy() = bippy(5, 100, 200)
+}