Suppress unused value warning, avoid inferred Any (also unused)

Author: som-snytt

build.sbt

@@ -67,9 +67,7 @@ lazy val runtime = (projectMatrix in file("scalapb-runtime"))
       ProblemFilters.exclude[ReversedMissingMethodProblem]("scalapb.GeneratedEnum.asRecognized"),
       ProblemFilters.exclude[InheritedNewAbstractMethodProblem]("*Extension*"),
       ProblemFilters.exclude[Problem]("scalapb.options.*"),
-      ProblemFilters.exclude[FinalMethodProblem]("*.parseFrom"),
-      ProblemFilters.exclude[IncompatibleResultTypeProblem]("scalapb.UnknownFieldSet#Builder.parseField"),
-      ProblemFilters.exclude[IncompatibleResultTypeProblem]("scalapb.UnknownFieldSet#Field#Builder.parseField"),
+      ProblemFilters.exclude[FinalMethodProblem]("*.parseFrom")
     )
   )
   .jvmPlatform(

compiler-plugin/src/main/scala/scalapb/compiler/ParseFromGenerator.scala

@@ -213,15 +213,20 @@ private[compiler] class ParseFromGenerator(
             } else p
           }
           .when(!message.preservesUnknownFields)(
-            _.add("    case tag => _input__.skipField(tag): Unit")
+            _.add(
+              """|    case tag =>
+                 |      _input__.skipField(tag): @_root_.scala.annotation.nowarn
+                 |      ()""".stripMargin
+            )
           )
           .when(message.preservesUnknownFields)(
             _.add(
               """    case tag =>
                 |      if (_unknownFields__ == null) {
                 |        _unknownFields__ = new _root_.scalapb.UnknownFieldSet.Builder()
                 |      }
-                |      _unknownFields__.parseField(tag, _input__)""".stripMargin
+                |      _unknownFields__.parseField(tag, _input__): @_root_.scala.annotation.nowarn
+                |      ()""".stripMargin
             )
           )
           .add("  }")

scalapb-runtime/src/main/scala/scalapb/UnknownFieldSet.scala

@@ -89,7 +89,7 @@ object UnknownFieldSet {
           lengthDelimited = lengthDelimited.result()
         )
 
-      def parseField(tag: Int, input: CodedInputStream): this.type = {
+      def parseField(tag: Int, input: CodedInputStream) = {
         val wireType = WireType.getTagWireType(tag)
 
         wireType match {
@@ -106,7 +106,6 @@ object UnknownFieldSet {
               s"Protocol message tag had invalid wire type: ${wireType}"
             )
         }
-        this
       }
     }
 
@@ -136,10 +135,9 @@ object UnknownFieldSet {
       if (fieldBuilders.isEmpty) UnknownFieldSet.empty
       else new UnknownFieldSet(fieldBuilders.view.mapValues(_.result()).toMap)
 
-    def parseField(tag: Int, input: CodedInputStream): this.type = {
+    def parseField(tag: Int, input: CodedInputStream) = {
       val fieldNumber = WireType.getTagFieldNumber(tag)
       fieldBuilders.getOrElseUpdate(fieldNumber, new Field.Builder()).parseField(tag, input)
-      this
     }
   }
 }