SI-8040 Improve unused warnings

Add symbol names, don't warn for both getters and setters
or for synthetics (except default arg getters).

Tweak messages for readability.

1 files changed, 36 insertions, 0 deletions

diff --git a/test/files/neg/warn-unused-privates.scala b/test/files/neg/warn-unused-privates.scala
index 2eda280d40..2f67882632 100644
--- a/test/files/neg/warn-unused-privates.scala
+++ b/test/files/neg/warn-unused-privates.scala
@@ -52,6 +52,19 @@ trait Accessors {
   }
 }
 
+class StableAccessors {
+  private var s1: Int = 0 // warn
+  private var s2: Int = 0 // warn, never set
+  private var s3: Int = 0 // warn, never got
+  private var s4: Int = 0 // no warn
+
+  def bippy(): Int = {
+    s3 = 5
+    s4 = 6
+    s2 + s4
+  }
+}
+
 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
@@ -59,6 +72,11 @@ trait DefaultArgs {
   def boppy() = bippy(5, 100, 200)
 }
 
+/* SI-7707 Both usages warn default arg because using PrivateRyan.apply, not new.
+case class PrivateRyan private (ryan: Int = 42) { def f = PrivateRyan() }
+object PrivateRyan { def f = PrivateRyan() }
+*/
+
 class Outer {
   class Inner
 }
@@ -104,3 +122,21 @@ object Types {
     (new Bippy): Something
   }
 }
+
+trait Underwarn {
+  def f(): Seq[Int]
+
+  def g() = {
+    val Seq(_, _) = f()  // no warn
+    true
+  }
+}
+
+class OtherNames {
+  private def x_=(i: Int): Unit = ???
+  private def x: Int = 42
+  private def y_=(i: Int): Unit = ???
+  private def y: Int = 42
+
+  def f = y
+}