Merge pull request #10154 from som-snytt/issue/12646-unused-local

Avoid warning on setter in trait
scala · Sep 26, 2022 · 8f57a00 · 8f57a00
2 parents fed3c2b + 8b7eedf
commit 8f57a00
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diff --git a/src/compiler/scala/tools/nsc/typechecker/TypeDiagnostics.scala b/src/compiler/scala/tools/nsc/typechecker/TypeDiagnostics.scala
@@ -547,7 +547,7 @@ trait TypeDiagnostics extends splain.SplainDiagnostics {
               if (sym.isPrimaryConstructor)
                 for (cpa <- sym.owner.constrParamAccessors if cpa.isPrivateLocal) params += cpa
               else if (sym.isSynthetic && sym.isImplicit) return
-              else if (!sym.isConstructor && !isTrivial(rhs))
+              else if (!sym.isConstructor && !sym.isVar && !isTrivial(rhs))
                 for (vs <- vparamss) params ++= vs.map(_.symbol)
               defnTrees += m
             case _ =>

diff --git a/test/files/pos/t12646.scala b/test/files/pos/t12646.scala
@@ -0,0 +1,11 @@
+
+// scalac: -Werror -Wunused:params
+
+trait T {
+  private var x: String = _
+
+  def y: String = {
+    if (x eq null) x = "hello, world"
+    x
+  }
+}