tweak conditions for warning

Handle match types
No transparent inline exclusion

Author: som-snytt

compiler/src/dotty/tools/backend/jvm/BCodeSkelBuilder.scala

@@ -818,7 +818,7 @@ trait BCodeSkelBuilder extends BCodeHelpers {
 
       methSymbol  = dd.symbol
       jMethodName = methSymbol.javaSimpleName
-      returnType  = asmMethodType(dd.symbol).returnType
+      returnType  = asmMethodType(methSymbol).returnType
       isMethSymStaticCtor = methSymbol.isStaticConstructor
 
       resetMethodBookkeeping(dd)
@@ -915,7 +915,7 @@ trait BCodeSkelBuilder extends BCodeHelpers {
             for (p <- params) { emitLocalVarScope(p.symbol, veryFirstProgramPoint, onePastLastProgramPoint, force = true) }
           }
 
-          if (isMethSymStaticCtor) { appendToStaticCtor(dd) }
+          if (isMethSymStaticCtor) { appendToStaticCtor() }
         } // end of emitNormalMethodBody()
 
         lineNumber(rhs)
@@ -936,7 +936,7 @@ trait BCodeSkelBuilder extends BCodeHelpers {
      *
      *  TODO document, explain interplay with `fabricateStaticInitAndroid()`
      */
-    private def appendToStaticCtor(dd: DefDef): Unit = {
+    private def appendToStaticCtor(): Unit = {
 
       def insertBefore(
             location: asm.tree.AbstractInsnNode,

compiler/src/dotty/tools/dotc/Compiler.scala

@@ -33,7 +33,7 @@ class Compiler {
   protected def frontendPhases: List[List[Phase]] =
     List(new Parser) ::             // Compiler frontend: scanner, parser
     List(new TyperPhase) ::         // Compiler frontend: namer, typer
-    List(/*LintPreparation(),*/ CheckUnused.PostTyper()/*, CheckShadowing()*/) :: // Check for unused, shadowed elements
+    List(CheckUnused.PostTyper(), CheckShadowing()) :: // Check for unused, shadowed elements
     List(new YCheckPositions) ::    // YCheck positions
     List(new sbt.ExtractDependencies) :: // Sends information on classes' dependencies to sbt via callbacks
     List(new semanticdb.ExtractSemanticDB.ExtractSemanticInfo) :: // Extract info into .semanticdb files
@@ -51,7 +51,7 @@ class Compiler {
     List(new Staging) ::            // Check staging levels and heal staged types
     List(new Splicing) ::           // Replace level 1 splices with holes
     List(new PickleQuotes) ::       // Turn quoted trees into explicit run-time data structures
-    List(/*LintPreparation(),*/ CheckUnused.PostInlining()) ::  // Check for unused elements
+    List(CheckUnused.PostInlining()) ::  // Check for unused elements
     Nil
 
   /** Phases dealing with the transformation from pickled trees to backend trees */

compiler/src/dotty/tools/dotc/reporting/messages.scala

@@ -3287,16 +3287,17 @@ extends TypeMsg(ConstructorProxyNotValueID):
        |companion value with the (term-)name `A`. However, these context bound companions
        |are not values themselves, they can only be referred to in selections."""
 
-class UnusedSymbol(errorText: String)(using Context)
+class UnusedSymbol(errorText: String, val actions: List[CodeAction] = Nil)(using Context)
 extends Message(UnusedSymbolID) {
   def kind = MessageKind.UnusedSymbol
 
   override def msg(using Context) = errorText
   override def explain(using Context) = ""
+  override def actions(using Context) = this.actions
 }
 
 object UnusedSymbol:
-  def imports(using Context): UnusedSymbol = UnusedSymbol(i"unused import")
+  def imports(actions: List[CodeAction])(using Context): UnusedSymbol = UnusedSymbol(i"unused import", actions)
   def localDefs(using Context): UnusedSymbol = UnusedSymbol(i"unused local definition")
   def explicitParams(using Context): UnusedSymbol = UnusedSymbol(i"unused explicit parameter")
   def implicitParams(using Context): UnusedSymbol = UnusedSymbol(i"unused implicit parameter")