Sperate matchingDecl and mathingMember.

RefChecks needs both methods.

Author: odersky

src/dotty/tools/dotc/core/SymDenotations.scala

@@ -714,20 +714,29 @@ object SymDenotations {
 
     /** The non-private symbol whose name and type matches the type of this symbol
      *  in the given class.
-     *  @param inClass   The class containing the symbol's definition
+     *  @param inClass   The class containing the result symbol's definition
      *  @param site      The base type from which member types are computed
      *
      *  inClass <-- find denot.symbol      class C { <-- symbol is here
      *
      *                   site: Subtype of both inClass and C
      */
-    final def matchingSymbol(inClass: Symbol, site: Type)(implicit ctx: Context): Symbol = {
+    final def matchingDecl(inClass: Symbol, site: Type)(implicit ctx: Context): Symbol = {
       var denot = inClass.info.nonPrivateDecl(name)
       if (denot.isTerm) // types of the same name always match
         denot = denot.matchingDenotation(site, site.memberInfo(symbol))
       denot.symbol
     }
 
+    /** The non-private member of `site` whose name and type matches the type of this symbol
+     */
+    final def matchingMember(site: Type)(implicit ctx: Context): Symbol = {
+      var denot = site.nonPrivateMember(name)
+      if (denot.isTerm) // types of the same name always match
+        denot = denot.matchingDenotation(site, site.memberInfo(symbol))
+      denot.symbol
+    }
+
     /** If false, this symbol cannot possibly participate in an override,
      *  either as overrider or overridee.
      */
@@ -737,7 +746,7 @@ object SymDenotations {
     /** The symbol, in class `inClass`, that is overridden by this denotation. */
     final def overriddenSymbol(inClass: ClassSymbol)(implicit ctx: Context): Symbol =
       if (!canMatchInheritedSymbols && (owner ne inClass)) NoSymbol
-      else matchingSymbol(inClass, owner.thisType)
+      else matchingDecl(inClass, owner.thisType)
 
     /** All symbols overriden by this denotation. */
     final def allOverriddenSymbols(implicit ctx: Context): Iterator[Symbol] =
@@ -757,7 +766,7 @@ object SymDenotations {
      *  @param ofclazz is a subclass of this symbol's owner
      */
     final def overridingSymbol(inClass: ClassSymbol)(implicit ctx: Context): Symbol =
-      if (canMatchInheritedSymbols) matchingSymbol(inClass, inClass.thisType)
+      if (canMatchInheritedSymbols) matchingDecl(inClass, inClass.thisType)
       else NoSymbol
 
     /** The symbol accessed by a super in the definition of this symbol when
@@ -767,7 +776,7 @@ object SymDenotations {
     final def superSymbolIn(base: Symbol)(implicit ctx: Context): Symbol = {
       def loop(bcs: List[ClassSymbol]): Symbol = bcs match {
         case bc :: bcs1 =>
-          val sym = matchingSymbol(bcs.head, base.thisType)
+          val sym = matchingDecl(bcs.head, base.thisType)
             .suchThat(alt => !(alt is Deferred)).symbol
           if (sym.exists) sym else loop(bcs.tail)
         case _ =>

src/dotty/tools/dotc/typer/RefChecks.scala

@@ -17,6 +17,7 @@ import scala.util.{Try, Success, Failure}
 import config.{ScalaVersion, NoScalaVersion}
 import typer.ErrorReporting._
 import DenotTransformers._
+import ValueClasses.isDerivedValueClass
 
 object RefChecks {
   import tpd._
@@ -296,7 +297,7 @@ object RefChecks {
     printMixinOverrideErrors()
 
     // Verifying a concrete class has nothing unimplemented.
-    if (!clazz.is(Abstract)) {
+    if (!clazz.is(AbstractOrTrait)) {
       val abstractErrors = new mutable.ListBuffer[String]
       def abstractErrorMessage =
         // a little formatting polish
@@ -348,8 +349,8 @@ object RefChecks {
 
         val missingMethods = grouped.toList flatMap {
           case (name, syms) =>
-            if (syms exists (_.symbol.isSetter)) syms filterNot (_.symbol.isGetter)
-            else syms
+            val withoutSetters = syms filterNot (_.symbol.isSetter)
+            if (withoutSetters.nonEmpty) withoutSetters else syms
         }
 
         def stubImplementations: List[String] = {
@@ -461,7 +462,7 @@ object RefChecks {
       def checkNoAbstractDecls(bc: Symbol): Unit = {
         for (decl <- bc.info.decls) {
           if (decl.is(Deferred) && !ignoreDeferred(decl)) {
-            val impl = decl.matchingSymbol(bc, clazz.thisType)
+            val impl = decl.matchingMember(clazz.thisType)
             if (impl == NoSymbol || (decl.owner isSubClass impl.owner)) {
               abstractClassError(false, "there is a deferred declaration of " + infoString(decl) +
                 " which is not implemented in a subclass" + err.abstractVarMessage(decl))
@@ -485,7 +486,7 @@ object RefChecks {
         // Have to use matchingSymbol, not a method involving overridden symbols,
         // because the scala type system understands that an abstract method here does not
         // override a concrete method in Object. The jvm, however, does not.
-        val overridden = decl.matchingSymbol(defn.ObjectClass, defn.ObjectType)
+        val overridden = decl.matchingDecl(defn.ObjectClass, defn.ObjectType)
         if (overridden.is(Final))
           ctx.error("trait cannot redefine final method from class AnyRef", decl.pos)
       }
@@ -605,7 +606,7 @@ object RefChecks {
 
   /** Verify classes extending AnyVal meet the requirements */
   private def checkAnyValSubclass(clazz: Symbol)(implicit ctx: Context) =
-    if (clazz.isDerivedValueClass) {
+    if (isDerivedValueClass(clazz)) {
       if (clazz.is(Trait))
         ctx.error("Only classes (not traits) are allowed to extend AnyVal", clazz.pos)
       else if (clazz.is(Abstract))
@@ -632,7 +633,7 @@ object RefChecks {
     var refSym: Symbol = _
 
     override def enterReference(sym: Symbol, pos: Position): Unit =
-      if (sym.owner.isTerm)
+      if (sym.exists && sym.owner.isTerm)
         levelAndIndex.get(sym) match {
           case Some((level, idx)) if (level.maxIndex < idx) =>
             level.maxIndex = idx
@@ -676,7 +677,7 @@ class RefChecks extends MiniPhase with IdentityDenotTransformer { thisTransforme
   class Transform(currentLevel: RefChecks.OptLevelInfo = RefChecks.NoLevelInfo) extends TreeTransform {
     def phase = thisTransformer
     override def prepareForStats(trees: List[Tree])(implicit ctx: Context) = {
-      println(i"preparing for $trees%; %, owner = ${ctx.owner}")
+      // println(i"preparing for $trees%; %, owner = ${ctx.owner}")
       if (ctx.owner.isTerm) new Transform(new LevelInfo(currentLevel.levelAndIndex, trees))
       else this
     }
@@ -706,7 +707,7 @@ class RefChecks extends MiniPhase with IdentityDenotTransformer { thisTransforme
       checkOverloadedRestrictions(cls)
       checkAllOverrides(cls)
       checkAnyValSubclass(cls)
-      if (cls.isDerivedValueClass)
+      if (isDerivedValueClass(cls))
         cls.primaryConstructor.makeNotPrivateAfter(NoSymbol, thisTransformer) // SI-6601, must be done *after* pickler!
       tree
     }
@@ -721,7 +722,6 @@ class RefChecks extends MiniPhase with IdentityDenotTransformer { thisTransforme
     }
 
     override def transformIdent(tree: Ident)(implicit ctx: Context, info: TransformerInfo) = {
-      assert(ctx.phase.exists)
       checkUndesiredProperties(tree.symbol, tree.pos)
       currentLevel.enterReference(tree.symbol, tree.pos)
       tree