Wshadow option recognizes Wall (#24469)

Fixes #24466

Author: tgodzik

compiler/src/dotty/tools/dotc/config/ScalaSettings.scala

@@ -290,12 +290,16 @@ private sealed trait WarningSettings:
   )
 
   object WshadowHas:
-    def allOr(s: String)(using Context) =
-      Wshadow.value.pipe(us => us.contains("all") || us.contains(s))
+    // Is any choice set for -Wshadow?
+    def any(using Context): Boolean = Wall.value || Wshadow.value.nonEmpty
+
+    def allOr(s: String)(using Context): Boolean =
+      Wall.value || Wshadow.value.pipe(us => us.contains("all") || us.contains(s))
     def privateShadow(using Context) =
       allOr("private-shadow")
     def typeParameterShadow(using Context) =
       allOr("type-parameter-shadow")
+  end WshadowHas
 
   val WsafeInit: Setting[Boolean] = BooleanSetting(WarningSetting, "Wsafe-init", "Ensure safe initialization of objects.")
 

compiler/src/dotty/tools/dotc/transform/CheckShadowing.scala

@@ -48,10 +48,10 @@ class CheckShadowing extends MiniPhase:
 
   override def description: String = CheckShadowing.description
 
-  override def isEnabled(using Context): Boolean = ctx.settings.Wshadow.value.nonEmpty
+  override def isEnabled(using Context): Boolean = ctx.settings.WshadowHas.any
 
   override def isRunnable(using Context): Boolean =
-    super.isRunnable && ctx.settings.Wshadow.value.nonEmpty && !ctx.isJava
+    super.isRunnable && ctx.settings.WshadowHas.any && !ctx.isJava
 
   override def prepareForUnit(tree: tpd.Tree)(using Context): Context =
     val data = ShadowingData()

tests/warn/i24466.scala

@@ -0,0 +1,7 @@
+//> using options -Wall
+
+class A:
+  protected val x: String = ""
+
+class B extends A:
+  private val x: Int = 0 // warn // warn unused and shadowing