Merge pull request #1648 from paulp/unused-bonanza-2

Removing unused code, take 2.

17 files changed, 92 insertions, 442 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/ConstantFolder.scala b/src/compiler/scala/tools/nsc/typechecker/ConstantFolder.scala
index a9f6e2517b..65bfd8e34e 100644
--- a/src/compiler/scala/tools/nsc/typechecker/ConstantFolder.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/ConstantFolder.scala
@@ -27,9 +27,6 @@ abstract class ConstantFolder {
 
   /** If tree is a constant value that can be converted to type `pt`, perform
    *  the conversion.
-   *
-   *  @param tree ...
-   *  @param pt ...
    */
   def apply(tree: Tree, pt: Type): Tree = fold(apply(tree), tree.tpe match {
     case ConstantType(x) => x convertTo pt
diff --git a/src/compiler/scala/tools/nsc/typechecker/Contexts.scala b/src/compiler/scala/tools/nsc/typechecker/Contexts.scala
index e51f4bc28f..1af61d31ec 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Contexts.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Contexts.scala
@@ -219,8 +219,6 @@ trait Contexts { self: Analyzer =>
       current
     }
 
-    def logError(err: AbsTypeError) = buffer += err
-
     def withImplicitsEnabled[T](op: => T): T = {
       val saved = implicitsEnabled
       implicitsEnabled = true
@@ -312,15 +310,6 @@ trait Contexts { self: Analyzer =>
       c
     }
 
-    // TODO: remove? Doesn't seem to be used
-    def make(unit: CompilationUnit): Context = {
-      val c = make(unit, EmptyTree, owner, scope, imports)
-      c.setReportErrors()
-      c.implicitsEnabled = true
-      c.macrosEnabled = true
-      c
-    }
-
     def makeNewImport(sym: Symbol): Context =
       makeNewImport(gen.mkWildcardImport(sym))
 
@@ -491,17 +480,6 @@ trait Contexts { self: Analyzer =>
       sub.isNonBottomSubClass(base) ||
       sub.isModuleClass && sub.linkedClassOfClass.isNonBottomSubClass(base)
 
-    /** Return closest enclosing context that defines a superclass of `clazz`, or a
-     *  companion module of a superclass of `clazz`, or NoContext if none exists */
-    def enclosingSuperClassContext(clazz: Symbol): Context = {
-      var c = this.enclClass
-      while (c != NoContext &&
-             !clazz.isNonBottomSubClass(c.owner) &&
-             !(c.owner.isModuleClass && clazz.isNonBottomSubClass(c.owner.companionClass)))
-        c = c.outer.enclClass
-      c
-    }
-
     /** Return the closest enclosing context that defines a subclass of `clazz`
      *  or a companion object thereof, or `NoContext` if no such context exists.
      */
diff --git a/src/compiler/scala/tools/nsc/typechecker/DestructureTypes.scala b/src/compiler/scala/tools/nsc/typechecker/DestructureTypes.scala
index 79cd46e018..73572bcae9 100644
--- a/src/compiler/scala/tools/nsc/typechecker/DestructureTypes.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/DestructureTypes.scala
@@ -64,15 +64,6 @@ trait DestructureTypes {
       },
       tree.productPrefix
     )
-    def wrapSymbol(label: String, sym: Symbol): Node = {
-      if (sym eq NoSymbol) wrapEmpty
-      else atom(label, sym)
-    }
-    def wrapInfo(sym: Symbol) = sym.info match {
-      case TypeBounds(lo, hi)        => typeBounds(lo, hi)
-      case PolyType(tparams, restpe) => polyFunction(tparams, restpe)
-      case _                         => wrapEmpty
-    }
     def wrapSymbolInfo(sym: Symbol): Node = {
       if ((sym eq NoSymbol) || openSymbols(sym)) wrapEmpty
       else {
@@ -95,7 +86,6 @@ trait DestructureTypes {
     def constant(label: String, const: Constant): Node = atom(label, const)
 
     def scope(decls: Scope): Node          = node("decls", scopeMemberList(decls.toList))
-    def const[T](named: (String, T)): Node = constant(named._1, Constant(named._2))
 
     def resultType(restpe: Type): Node          = this("resultType", restpe)
     def typeParams(tps: List[Symbol]): Node     = node("typeParams", symbolList(tps))
diff --git a/src/compiler/scala/tools/nsc/typechecker/Duplicators.scala b/src/compiler/scala/tools/nsc/typechecker/Duplicators.scala
index 7d58155eb2..9c23b8663c 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Duplicators.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Duplicators.scala
@@ -19,11 +19,6 @@ abstract class Duplicators extends Analyzer {
   import global._
   import definitions.{ AnyRefClass, AnyValClass }
 
-  def retyped(context: Context, tree: Tree): Tree = {
-    resetClassOwners
-    (newBodyDuplicator(context)).typed(tree)
-  }
-
   /** Retype the given tree in the given context. Use this method when retyping
    *  a method in a different class. The typer will replace references to the this of
    *  the old class with the new class, and map symbols through the given 'env'. The
@@ -42,9 +37,6 @@ abstract class Duplicators extends Analyzer {
 
   protected def newBodyDuplicator(context: Context) = new BodyDuplicator(context)
 
-  def retypedMethod(context: Context, tree: Tree, oldThis: Symbol, newThis: Symbol): Tree =
-    (newBodyDuplicator(context)).retypedMethod(tree.asInstanceOf[DefDef], oldThis, newThis)
-
   /** Return the special typer for duplicate method bodies. */
   override def newTyper(context: Context): Typer =
     newBodyDuplicator(context)
@@ -186,20 +178,6 @@ abstract class Duplicators extends Analyzer {
       stats.foreach(invalidate(_, owner))
     }
 
-    def retypedMethod(ddef: DefDef, oldThis: Symbol, newThis: Symbol): Tree = {
-      oldClassOwner = oldThis
-      newClassOwner = newThis
-      invalidateAll(ddef.tparams)
-      mforeach(ddef.vparamss) { vdef =>
-        invalidate(vdef)
-        vdef.tpe = null
-      }
-      ddef.symbol = NoSymbol
-      enterSym(context, ddef)
-      debuglog("remapping this of " + oldClassOwner + " to " + newClassOwner)
-      typed(ddef)
-    }
-
     /** Optionally cast this tree into some other type, if required.
      *  Unless overridden, just returns the tree.
      */
diff --git a/src/compiler/scala/tools/nsc/typechecker/EtaExpansion.scala b/src/compiler/scala/tools/nsc/typechecker/EtaExpansion.scala
index 9e21a2b82d..2806d7b2d9 100644
--- a/src/compiler/scala/tools/nsc/typechecker/EtaExpansion.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/EtaExpansion.scala
@@ -33,7 +33,7 @@ trait EtaExpansion { self: Analyzer =>
   }
 
   /** <p>
-   *    Expand partial function applications of type <code>type</code>.
+   *    Expand partial function applications of type `type`.
    *  </p><pre>
    *  p.f(es_1)...(es_n)
    *     ==>  {
@@ -56,11 +56,8 @@ trait EtaExpansion { self: Analyzer =>
     }
     val defs = new ListBuffer[Tree]
 
-    /** Append to <code>defs</code> value definitions for all non-stable
-     *  subexpressions of the function application <code>tree</code>.
-     *
-     *  @param tree ...
-     *  @return     ...
+    /** Append to `defs` value definitions for all non-stable
+     *  subexpressions of the function application `tree`.
      */
     def liftoutPrefix(tree: Tree): Tree = {
       def liftout(tree: Tree, byName: Boolean): Tree =
diff --git a/src/compiler/scala/tools/nsc/typechecker/Implicits.scala b/src/compiler/scala/tools/nsc/typechecker/Implicits.scala
index 710b7e9051..eb45f9b847 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Implicits.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Implicits.scala
@@ -233,10 +233,6 @@ trait Implicits {
   object HasMember {
     private val hasMemberCache = perRunCaches.newMap[Name, Type]()
     def apply(name: Name): Type = hasMemberCache.getOrElseUpdate(name, memberWildcardType(name, WildcardType))
-    def unapply(pt: Type): Option[Name] = pt match {
-      case RefinedType(List(WildcardType), Scope(sym)) if sym.tpe == WildcardType => Some(sym.name)
-      case _ => None
-    }
   }
 
   /** An extractor for types of the form ? { name: (? >: argtpe <: Any*)restp }
@@ -1493,9 +1489,7 @@ object ImplicitsStats {
   val subtypeImpl         = Statistics.newSubCounter("  of which in implicit", subtypeCount)
   val findMemberImpl      = Statistics.newSubCounter("  of which in implicit", findMemberCount)
   val subtypeAppInfos     = Statistics.newSubCounter("  of which in app impl", subtypeCount)
-  val subtypeImprovCount  = Statistics.newSubCounter("  of which in improves", subtypeCount)
   val implicitSearchCount = Statistics.newCounter   ("#implicit searches", "typer")
-  val triedImplicits      = Statistics.newSubCounter("  #tried", implicitSearchCount)
   val plausiblyCompatibleImplicits
                                   = Statistics.newSubCounter("  #plausibly compatible", implicitSearchCount)
   val matchingImplicits   = Statistics.newSubCounter("  #matching", implicitSearchCount)
diff --git a/src/compiler/scala/tools/nsc/typechecker/Infer.scala b/src/compiler/scala/tools/nsc/typechecker/Infer.scala
index ac367dfde6..be3c027259 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Infer.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Infer.scala
@@ -130,9 +130,6 @@ trait Infer extends Checkable {
   }
 
   /** A fresh type variable with given type parameter as origin.
-   *
-   *  @param tparam ...
-   *  @return       ...
    */
   def freshVar(tparam: Symbol): TypeVar = TypeVar(tparam)
 
@@ -169,9 +166,6 @@ trait Infer extends Checkable {
   }
 
   /** Is type fully defined, i.e. no embedded anytypes or wildcards in it?
-   *
-   *  @param tp ...
-   *  @return   ...
    */
   private[typechecker] def isFullyDefined(tp: Type): Boolean = tp match {
     case WildcardType | BoundedWildcardType(_) | NoType =>
@@ -457,11 +451,6 @@ trait Infer extends Checkable {
      *  its type parameters and result type and a prototype `pt`.
      *  If no minimal type variables exist that make the
      *  instantiated type a subtype of `pt`, return null.
-     *
-     *  @param tparams ...
-     *  @param restpe  ...
-     *  @param pt      ...
-     *  @return        ...
      */
     private def exprTypeArgs(tparams: List[Symbol], restpe: Type, pt: Type, useWeaklyCompatible: Boolean = false): (List[Type], List[TypeVar]) = {
       val tvars = tparams map freshVar
@@ -494,12 +483,6 @@ trait Infer extends Checkable {
     *  in the value parameter list.
     *  If instantiation of a type parameter fails,
     *  take WildcardType for the proto-type argument.
-    *
-    *  @param tparams ...
-    *  @param formals ...
-    *  @param restype ...
-    *  @param pt      ...
-    *  @return        ...
     */
     def protoTypeArgs(tparams: List[Symbol], formals: List[Type], restpe: Type,
                       pt: Type): List[Type] = {
@@ -927,10 +910,6 @@ trait Infer extends Checkable {
     /** Is type `ftpe1` strictly more specific than type `ftpe2`
      *  when both are alternatives in an overloaded function?
      *  @see SLS (sec:overloading-resolution)
-     *
-     *  @param ftpe1 ...
-     *  @param ftpe2 ...
-     *  @return      ...
      */
     def isAsSpecific(ftpe1: Type, ftpe2: Type): Boolean = ftpe1 match {
       case OverloadedType(pre, alts) =>
@@ -1173,11 +1152,6 @@ trait Infer extends Checkable {
 
     /** Substitute free type variables `undetparams` of polymorphic argument
      *  expression `tree` to `targs`, Error if `targs` is null.
-     *
-     *  @param tree ...
-     *  @param undetparams ...
-     *  @param targs ...
-     *  @param pt ...
      */
     private def substExpr(tree: Tree, undetparams: List[Symbol], targs: List[Type], pt: Type) {
       if (targs eq null) {
@@ -1641,8 +1615,6 @@ trait Infer extends Checkable {
 
     /** Try inference twice, once without views and once with views,
      *  unless views are already disabled.
-     *
-     *  @param infer ...
      */
     def tryTwice(infer: Boolean => Unit): Unit = {
       if (context.implicitsEnabled) {
@@ -1680,9 +1652,6 @@ trait Infer extends Checkable {
     /** Assign `tree` the type of all polymorphic alternatives
      *  with `nparams` as the number of type parameters, if it exists.
      *  If no such polymorphic alternative exist, error.
-     *
-     *  @param tree ...
-     *  @param nparams ...
      */
     def inferPolyAlternatives(tree: Tree, argtypes: List[Type]): Unit = {
       val OverloadedType(pre, alts) = tree.tpe
diff --git a/src/compiler/scala/tools/nsc/typechecker/Macros.scala b/src/compiler/scala/tools/nsc/typechecker/Macros.scala
index 09f3fefeba..4b534b0d2e 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Macros.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Macros.scala
@@ -720,16 +720,15 @@ trait Macros extends scala.tools.reflect.FastTrack with Traces {
   /** Does the same as `macroExpand`, but without typechecking the expansion
    *  Meant for internal use within the macro infrastructure, don't use it elsewhere.
    */
-  private def macroExpand1(typer: Typer, expandee: Tree): MacroExpansionResult =
+  private def macroExpand1(typer: Typer, expandee: Tree): MacroExpansionResult = {
     // verbose printing might cause recursive macro expansions, so I'm shutting it down here
     withInfoLevel(nodePrinters.InfoLevel.Quiet) {
       if (expandee.symbol.isErroneous || (expandee exists (_.isErroneous))) {
         val reason = if (expandee.symbol.isErroneous) "not found or incompatible macro implementation" else "erroneous arguments"
         macroTraceVerbose("cancelled macro expansion because of %s: ".format(reason))(expandee)
-        return Cancel(typer.infer.setError(expandee))
+        Cancel(typer.infer.setError(expandee))
       }
-
-      try {
+      else try {
         val runtime = macroRuntime(expandee.symbol)
         if (runtime != null) macroExpandWithRuntime(typer, expandee, runtime)
         else macroExpandWithoutRuntime(typer, expandee)
@@ -737,6 +736,7 @@ trait Macros extends scala.tools.reflect.FastTrack with Traces {
         case typer.TyperErrorGen.MacroExpansionException => Failure(expandee)
       }
     }
+  }
 
   /** Expands a macro when a runtime (i.e. the macro implementation) can be successfully loaded
    *  Meant for internal use within the macro infrastructure, don't use it elsewhere.
diff --git a/src/compiler/scala/tools/nsc/typechecker/MethodSynthesis.scala b/src/compiler/scala/tools/nsc/typechecker/MethodSynthesis.scala
index 6aafd32237..e67d6814f1 100644
--- a/src/compiler/scala/tools/nsc/typechecker/MethodSynthesis.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/MethodSynthesis.scala
@@ -29,61 +29,23 @@ trait MethodSynthesis {
       if (sym.isLazy) ValDef(sym, body)
       else DefDef(sym, body)
 
-    def applyTypeInternal(tags: List[TT[_]]): Type = {
-      val symbols = tags map compilerSymbolFromTag
-      val container :: args = symbols
-      val tparams = container.typeConstructor.typeParams
-
-      // Conservative at present - if manifests were more usable this could do a lot more.
-      // [Eugene to Paul] all right, they are now. what do you have in mind?
-      require(symbols forall (_ ne NoSymbol), "Must find all tags: " + symbols)
-      require(container.owner.isPackageClass, "Container must be a top-level class in a package: " + container)
-      require(tparams.size == args.size, "Arguments must match type constructor arity: " + tparams + ", " + args)
-
-      appliedType(container, args map (_.tpe): _*)
-    }
-
-    def companionType[T](implicit ct: CT[T]) =
-      rootMirror.getRequiredModule(ct.runtimeClass.getName).tpe
-
-    // Use these like `applyType[List, Int]` or `applyType[Map, Int, String]`
-    def applyType[CC](implicit t1: TT[CC]): Type =
-      applyTypeInternal(List(t1))
-
-    def applyType[CC[X1], X1](implicit t1: TT[CC[_]], t2: TT[X1]): Type =
-      applyTypeInternal(List(t1, t2))
-
-    def applyType[CC[X1, X2], X1, X2](implicit t1: TT[CC[_,_]], t2: TT[X1], t3: TT[X2]): Type =
-      applyTypeInternal(List(t1, t2, t3))
-
-    def applyType[CC[X1, X2, X3], X1, X2, X3](implicit t1: TT[CC[_,_,_]], t2: TT[X1], t3: TT[X2], t4: TT[X3]): Type =
-      applyTypeInternal(List(t1, t2, t3, t4))
-
-    def newMethodType[F](owner: Symbol)(implicit t: TT[F]): Type = {
-      val fnSymbol = compilerSymbolFromTag(t)
-      val formals = compilerTypeFromTag(t).typeArguments
-      assert(fnSymbol isSubClass FunctionClass(formals.size - 1), (owner, t))
-      val params  = owner newSyntheticValueParams formals
-      MethodType(params, formals.last)
-    }
-
-      /** The annotations amongst those found on the original symbol which
-       *  should be propagated to this kind of accessor.
-       */
-      def deriveAnnotations(initial: List[AnnotationInfo], category: Symbol, keepClean: Boolean): List[AnnotationInfo] = {
-        initial filter { ann =>
-          // There are no meta-annotation arguments attached to `ann`
-          if (ann.metaAnnotations.isEmpty) {
-            // A meta-annotation matching `annotKind` exists on `ann`'s definition.
-            (ann.defaultTargets contains category) ||
-            // `ann`'s definition has no meta-annotations, and `keepClean` is true.
-            (ann.defaultTargets.isEmpty && keepClean)
-          }
-          // There are meta-annotation arguments, and one of them matches `annotKind`
-          else ann.metaAnnotations exists (_ matches category)
+    /** The annotations amongst those found on the original symbol which
+     *  should be propagated to this kind of accessor.
+     */
+    def deriveAnnotations(initial: List[AnnotationInfo], category: Symbol, keepClean: Boolean): List[AnnotationInfo] = {
+      initial filter { ann =>
+        // There are no meta-annotation arguments attached to `ann`
+        if (ann.metaAnnotations.isEmpty) {
+          // A meta-annotation matching `annotKind` exists on `ann`'s definition.
+          (ann.defaultTargets contains category) ||
+          // `ann`'s definition has no meta-annotations, and `keepClean` is true.
+          (ann.defaultTargets.isEmpty && keepClean)
         }
+        // There are meta-annotation arguments, and one of them matches `annotKind`
+        else ann.metaAnnotations exists (_ matches category)
       }
-   }
+    }
+  }
   import synthesisUtil._
 
   class ClassMethodSynthesis(val clazz: Symbol, localTyper: Typer) {
@@ -118,22 +80,9 @@ trait MethodSynthesis {
       finishMethod(clazz.info.decls enter m, f)
     }
 
-    private def cloneInternal(original: Symbol, f: Symbol => Tree): Tree =
-      cloneInternal(original, f, original.name)
-
     def clazzMember(name: Name)  = clazz.info nonPrivateMember name
     def typeInClazz(sym: Symbol) = clazz.thisType memberType sym
 
-    /** Function argument takes the newly created method symbol of
-     *  the same type as `name` in clazz, and returns the tree to be
-     *  added to the template.
-     */
-    def overrideMethod(name: Name)(f: Symbol => Tree): Tree =
-      overrideMethod(clazzMember(name))(f)
-
-    def overrideMethod(original: Symbol)(f: Symbol => Tree): Tree =
-      cloneInternal(original, sym => f(sym setFlag OVERRIDE))
-
     def deriveMethod(original: Symbol, nameFn: Name => Name)(f: Symbol => Tree): Tree =
       cloneInternal(original, f, nameFn(original.name))
 
@@ -311,7 +260,6 @@ trait MethodSynthesis {
       // Final methods to make the rest easier to reason about.
       final def mods               = tree.mods
       final def basisSym           = tree.symbol
-      final def derivedFlags: Long = basisSym.flags & flagsMask | flagsExtra
     }
 
     trait DerivedFromClassDef extends DerivedFromMemberDef {
diff --git a/src/compiler/scala/tools/nsc/typechecker/Namers.scala b/src/compiler/scala/tools/nsc/typechecker/Namers.scala
index 51e3f95163..79fc0e0081 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Namers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Namers.scala
@@ -1388,12 +1388,6 @@ trait Namers extends MethodSynthesis {
         tpe
     }
 
-    def ensureParent(clazz: Symbol, parent: Symbol) = {
-      val info0 = clazz.info
-      val info1 = includeParent(info0, parent)
-      if (info0 ne info1) clazz setInfo info1
-    }
-
     class LogTransitions[S](onEnter: S => String, onExit: S => String) {
       val enabled = settings.debug.value
       @inline final def apply[T](entity: S)(body: => T): T = {
diff --git a/src/compiler/scala/tools/nsc/typechecker/NamesDefaults.scala b/src/compiler/scala/tools/nsc/typechecker/NamesDefaults.scala
index 252a738755..14c8d85836 100644
--- a/src/compiler/scala/tools/nsc/typechecker/NamesDefaults.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/NamesDefaults.scala
@@ -41,8 +41,6 @@ trait NamesDefaults { self: Analyzer =>
     blockTyper: Typer
   ) { }
 
-  val noApplyInfo = NamedApplyInfo(None, Nil, Nil, null)
-
   def nameOf(arg: Tree) = arg match {
     case AssignOrNamedArg(Ident(name), rhs) => Some(name)
     case _ => None
diff --git a/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala b/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala
index 6c916649f0..76ff341d3f 100644
--- a/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala
@@ -293,8 +293,6 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL
       // pt is the skolemized version
       val pt = repeatedToSeq(ptUnCPS)
 
-      // val packedPt = repeatedToSeq(typer.packedType(match_, context.owner))
-
       // the alternative to attaching the default case override would be to simply
       // append the default to the list of cases and suppress the unreachable case error that may arise (once we detect that...)
       val matchFailGenOverride = match_.attachments.get[DefaultOverrideMatchAttachment].map{case DefaultOverrideMatchAttachment(default) => ((scrut: Tree) => default)}
@@ -549,54 +547,55 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL
       def fromCaseClass(fun: Tree, args: List[Tree]): Option[ExtractorCall] =  Some(new ExtractorCallProd(fun, args))
 
       // THE PRINCIPLED SLOW PATH -- NOT USED
+      // !!! Use it, test it, or delete it, else it is unlikely to be an asset.
       // generate a call to the (synthetically generated) extractor of a case class
       // NOTE: it's an apply, not a select, since in general an extractor call may have multiple argument lists (including an implicit one)
       // that we need to preserve, so we supply the scrutinee as Ident(nme.SELECTOR_DUMMY),
       // and replace that dummy by a reference to the actual binder in translateExtractorPattern
-      def fromCaseClassUnapply(fun: Tree, args: List[Tree]): Option[ExtractorCall] = {
-        // TODO: can we rework the typer so we don't have to do all this twice?
-        // undo rewrite performed in (5) of adapt
-        val orig      = fun match {case tpt: TypeTree => tpt.original case _ => fun}
-        val origSym   = orig.symbol
-        val extractor = unapplyMember(origSym.filter(sym => reallyExists(unapplyMember(sym.tpe))).tpe)
-
-        if((fun.tpe eq null) || fun.tpe.isError || (extractor eq NoSymbol)) {
-          None
-        } else {
-          // this is a tricky balance: pos/t602.scala, pos/sudoku.scala, run/virtpatmat_alts.scala must all be happy
-          // bypass typing at own risk: val extractorCall = Select(orig, extractor) setType caseClassApplyToUnapplyTp(fun.tpe)
-          // can't always infer type arguments (pos/t602):
-          /*  case class Span[K <: Ordered[K]](low: Option[K]) {
-                override def equals(x: Any): Boolean = x match {
-                  case Span((low0 @ _)) if low0 equals low => true
-                }
-              }*/
-          // so... leave undetermined type params floating around if we have to
-          // (if we don't infer types, uninstantiated type params show up later: pos/sudoku.scala)
-          // (see also run/virtpatmat_alts.scala)
-          val savedUndets = context.undetparams
-          val extractorCall = try {
-            context.undetparams = Nil
-            silent(_.typed(Apply(Select(orig, extractor), List(Ident(nme.SELECTOR_DUMMY) setType fun.tpe.finalResultType)), EXPRmode, WildcardType), reportAmbiguousErrors = false) match {
-              case SilentResultValue(extractorCall) => extractorCall // if !extractorCall.containsError()
-              case _ =>
-                // this fails to resolve overloading properly...
-                // Apply(typedOperator(Select(orig, extractor)), List(Ident(nme.SELECTOR_DUMMY))) // no need to set the type of the dummy arg, it will be replaced anyway
-
-                // patmatDebug("funtpe after = "+ fun.tpe.finalResultType)
-                // patmatDebug("orig: "+(orig, orig.tpe))
-                val tgt = typed(orig, EXPRmode | QUALmode | POLYmode, HasMember(extractor.name)) // can't specify fun.tpe.finalResultType as the type for the extractor's arg,
-                // as it may have been inferred incorrectly (see t602, where it's  com.mosol.sl.Span[Any], instead of  com.mosol.sl.Span[?K])
-                // patmatDebug("tgt = "+ (tgt, tgt.tpe))
-                val oper = typed(Select(tgt, extractor.name), EXPRmode | FUNmode | POLYmode | TAPPmode, WildcardType)
-                // patmatDebug("oper: "+ (oper, oper.tpe))
-                Apply(oper, List(Ident(nme.SELECTOR_DUMMY))) // no need to set the type of the dummy arg, it will be replaced anyway
-            }
-          } finally context.undetparams = savedUndets
-
-          Some(this(extractorCall, args)) // TODO: simplify spliceApply?
-        }
-      }
+      // def fromCaseClassUnapply(fun: Tree, args: List[Tree]): Option[ExtractorCall] = {
+      //   // TODO: can we rework the typer so we don't have to do all this twice?
+      //   // undo rewrite performed in (5) of adapt
+      //   val orig      = fun match {case tpt: TypeTree => tpt.original case _ => fun}
+      //   val origSym   = orig.symbol
+      //   val extractor = unapplyMember(origSym.filter(sym => reallyExists(unapplyMember(sym.tpe))).tpe)
+
+      //   if((fun.tpe eq null) || fun.tpe.isError || (extractor eq NoSymbol)) {
+      //     None
+      //   } else {
+      //     // this is a tricky balance: pos/t602.scala, pos/sudoku.scala, run/virtpatmat_alts.scala must all be happy
+      //     // bypass typing at own risk: val extractorCall = Select(orig, extractor) setType caseClassApplyToUnapplyTp(fun.tpe)
+      //     // can't always infer type arguments (pos/t602):
+      //     /*  case class Span[K <: Ordered[K]](low: Option[K]) {
+      //           override def equals(x: Any): Boolean = x match {
+      //             case Span((low0 @ _)) if low0 equals low => true
+      //           }
+      //         }*/
+      //     // so... leave undetermined type params floating around if we have to
+      //     // (if we don't infer types, uninstantiated type params show up later: pos/sudoku.scala)
+      //     // (see also run/virtpatmat_alts.scala)
+      //     val savedUndets = context.undetparams
+      //     val extractorCall = try {
+      //       context.undetparams = Nil
+      //       silent(_.typed(Apply(Select(orig, extractor), List(Ident(nme.SELECTOR_DUMMY) setType fun.tpe.finalResultType)), EXPRmode, WildcardType), reportAmbiguousErrors = false) match {
+      //         case SilentResultValue(extractorCall) => extractorCall // if !extractorCall.containsError()
+      //         case _ =>
+      //           // this fails to resolve overloading properly...
+      //           // Apply(typedOperator(Select(orig, extractor)), List(Ident(nme.SELECTOR_DUMMY))) // no need to set the type of the dummy arg, it will be replaced anyway
+
+      //           // patmatDebug("funtpe after = "+ fun.tpe.finalResultType)
+      //           // patmatDebug("orig: "+(orig, orig.tpe))
+      //           val tgt = typed(orig, EXPRmode | QUALmode | POLYmode, HasMember(extractor.name)) // can't specify fun.tpe.finalResultType as the type for the extractor's arg,
+      //           // as it may have been inferred incorrectly (see t602, where it's  com.mosol.sl.Span[Any], instead of  com.mosol.sl.Span[?K])
+      //           // patmatDebug("tgt = "+ (tgt, tgt.tpe))
+      //           val oper = typed(Select(tgt, extractor.name), EXPRmode | FUNmode | POLYmode | TAPPmode, WildcardType)
+      //           // patmatDebug("oper: "+ (oper, oper.tpe))
+      //           Apply(oper, List(Ident(nme.SELECTOR_DUMMY))) // no need to set the type of the dummy arg, it will be replaced anyway
+      //       }
+      //     } finally context.undetparams = savedUndets
+
+      //     Some(this(extractorCall, args)) // TODO: simplify spliceApply?
+      //   }
+      // }
     }
 
     abstract class ExtractorCall(val args: List[Tree]) {
@@ -1415,10 +1414,8 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL
 
       // local / context-free
       def _asInstanceOf(b: Symbol, tp: Type): Tree
-      def _asInstanceOf(t: Tree, tp: Type): Tree
       def _equals(checker: Tree, binder: Symbol): Tree
       def _isInstanceOf(b: Symbol, tp: Type): Tree
-      def and(a: Tree, b: Tree): Tree
       def drop(tgt: Tree)(n: Int): Tree
       def index(tgt: Tree)(i: Int): Tree
       def mkZero(tp: Type): Tree
@@ -1460,12 +1457,10 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL
 
     abstract class CommonCodegen extends AbsCodegen { import CODE._
       def fun(arg: Symbol, body: Tree): Tree           = Function(List(ValDef(arg)), body)
-      def genTypeApply(tfun: Tree, args: Type*): Tree  = if(args contains NoType) tfun else TypeApply(tfun, args.toList map TypeTree)
       def tupleSel(binder: Symbol)(i: Int): Tree       = (REF(binder) DOT nme.productAccessorName(i)) // make tree that accesses the i'th component of the tuple referenced by binder
       def index(tgt: Tree)(i: Int): Tree               = tgt APPLY (LIT(i))
       def drop(tgt: Tree)(n: Int): Tree                = (tgt DOT vpmName.drop) (LIT(n))
       def _equals(checker: Tree, binder: Symbol): Tree = checker MEMBER_== REF(binder)          // NOTE: checker must be the target of the ==, that's the patmat semantics for ya
-      def and(a: Tree, b: Tree): Tree                  = a AND b
 
       // drop annotations generated by CPS plugin etc, since its annotationchecker rejects T @cps[U] <: Any
       // let's assume for now annotations don't affect casts, drop them there, and bring them back using the outer Typed tree
@@ -1473,10 +1468,8 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL
         Typed(gen.mkAsInstanceOf(t, tp.withoutAnnotations, true, false), TypeTree() setType tp)
 
       // the force is needed mainly to deal with the GADT typing hack (we can't detect it otherwise as tp nor pt need contain an abstract type, we're just casting wildly)
-      def _asInstanceOf(t: Tree, tp: Type): Tree = if (t.tpe != NoType && t.isTyped && typesConform(t.tpe, tp)) t else mkCast(t, tp)
       def _asInstanceOf(b: Symbol, tp: Type): Tree = if (typesConform(b.info, tp)) REF(b) else mkCast(REF(b), tp)
       def _isInstanceOf(b: Symbol, tp: Type): Tree = gen.mkIsInstanceOf(REF(b), tp.withoutAnnotations, true, false)
-      //   if (typesConform(b.info, tpX)) { patmatDebug("warning: emitted spurious isInstanceOf: "+(b, tp)); TRUE }
 
       // duplicated out of frustration with cast generation
       def mkZero(tp: Type): Tree = {
@@ -2881,8 +2874,6 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL
          v +"(="+ v.path +": "+ v.staticTpCheckable +") "+ assignment
        }.mkString("\n")
 
-    def modelString(model: Model) = varAssignmentString(modelToVarAssignment(model))
-
     // return constructor call when the model is a true counter example
     // (the variables don't take into account type information derived from other variables,
     //  so, naively, you might try to construct a counter example like _ :: Nil(_ :: _, _ :: _),
@@ -3540,7 +3531,6 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL
     // for the catch-cases in a try/catch
     private object typeSwitchMaker extends SwitchMaker {
       val unchecked = false
-      def switchableTpe(tp: Type) = true
       val alternativesSupported = false // TODO: needs either back-end support of flattening of alternatives during typers
       val canJump = false
 
@@ -3586,11 +3576,6 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL
   trait OptimizedCodegen extends CodegenCore with TypedSubstitution with OptimizedMatchMonadInterface {
     override def codegen: AbsCodegen = optimizedCodegen
 
-    // trait AbsOptimizedCodegen extends AbsCodegen {
-    //   def flatMapCondStored(cond: Tree, condSym: Symbol, res: Tree, nextBinder: Symbol, next: Tree): Tree
-    // }
-    // def optimizedCodegen: AbsOptimizedCodegen
-
     // when we know we're targetting Option, do some inlining the optimizer won't do
     // for example, `o.flatMap(f)` becomes `if(o == None) None else f(o.get)`, similarly for orElse and guard
     //   this is a special instance of the advanced inlining optimization that takes a method call on
diff --git a/src/compiler/scala/tools/nsc/typechecker/TreeCheckers.scala b/src/compiler/scala/tools/nsc/typechecker/TreeCheckers.scala
index 710adf5a9c..be7554abe2 100644
--- a/src/compiler/scala/tools/nsc/typechecker/TreeCheckers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/TreeCheckers.scala
@@ -142,13 +142,6 @@ abstract class TreeCheckers extends Analyzer {
     currentRun.units foreach (x => wrap(x)(check(x)))
   }
 
-  def printingTypings[T](body: => T): T = {
-    val saved = global.printTypings
-    global.printTypings = true
-    val result = body
-    global.printTypings = saved
-    result
-  }
   def runWithUnit[T](unit: CompilationUnit)(body: => Unit): Unit = {
     val unit0 = currentUnit
     currentRun.currentUnit = unit
diff --git a/src/compiler/scala/tools/nsc/typechecker/TypeDiagnostics.scala b/src/compiler/scala/tools/nsc/typechecker/TypeDiagnostics.scala
index 4f5291507e..19f0b56e94 100644
--- a/src/compiler/scala/tools/nsc/typechecker/TypeDiagnostics.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/TypeDiagnostics.scala
@@ -37,14 +37,6 @@ trait TypeDiagnostics {
   import global._
   import definitions._
 
-  /** The common situation of making sure nothing is erroneous could be
-   *  nicer if Symbols, Types, and Trees all implemented some common interface
-   *  in which isErroneous and similar would be placed.
-   */
-  def noErroneousTypes(tps: Type*)    = tps forall (x => !x.isErroneous)
-  def noErroneousSyms(syms: Symbol*)  = syms forall (x => !x.isErroneous)
-  def noErroneousTrees(trees: Tree*)  = trees forall (x => !x.isErroneous)
-
   /** For errors which are artifacts of the implementation: such messages
    *  indicate that the restriction may be lifted in the future.
    */
@@ -294,7 +286,6 @@ trait TypeDiagnostics {
     // distinguished from the other types in the same error message
     private val savedName = sym.name
     def restoreName()     = sym.name = savedName
-    def isAltered         = sym.name != savedName
     def modifyName(f: String => String) = sym setName newTypeName(f(sym.name.toString))
 
     /** Prepend java.lang, scala., or Predef. if this type originated
@@ -478,10 +469,6 @@ trait TypeDiagnostics {
           }
           super.traverse(t)
         }
-        def isUnused(t: Tree): Boolean = (
-          if (t.symbol.isTerm) isUnusedTerm(t.symbol)
-          else isUnusedType(t.symbol)
-        )
         def isUnusedType(m: Symbol): Boolean = (
               m.isType
           && !m.isTypeParameterOrSkolem // would be nice to improve this
diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
index fe5e6586ea..1cfc8c909b 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
@@ -57,16 +57,6 @@ trait Typers extends Modes with Adaptations with Tags {
       super.traverse(tree)
     }
   }
-/* needed for experimental version where early types can be type arguments
-  class EarlyMap(clazz: Symbol) extends TypeMap {
-    def apply(tp: Type): Type = tp match {
-      case TypeRef(NoPrefix, sym, List()) if (sym hasFlag PRESUPER) =>
-        TypeRef(ThisType(clazz), sym, List())
-      case _ =>
-        mapOver(tp)
-    }
-  }
-*/
 
   sealed abstract class SilentResult[+T] {
     @inline final def map[U](f: T => U): SilentResult[U] = this match {
@@ -240,10 +230,7 @@ trait Typers extends Modes with Adaptations with Tags {
       case _ => tp
     }
 
-    /** Check that <code>tree</code> is a stable expression.
-     *
-     *  @param tree ...
-     *  @return     ...
+    /** Check that `tree` is a stable expression.
      */
     def checkStable(tree: Tree): Tree = (
       if (treeInfo.isExprSafeToInline(tree)) tree
@@ -297,11 +284,7 @@ trait Typers extends Modes with Adaptations with Tags {
       )
     }
 
-    /** Check that type <code>tp</code> is not a subtype of itself.
-     *
-     *  @param pos ...
-     *  @param tp  ...
-     *  @return    <code>true</code> if <code>tp</code> is not a subtype of itself.
+    /** Check that type `tp` is not a subtype of itself.
      */
     def checkNonCyclic(pos: Position, tp: Type): Boolean = {
       def checkNotLocked(sym: Symbol) = {
@@ -316,12 +299,6 @@ trait Typers extends Modes with Adaptations with Tags {
 
         case SingleType(pre, sym) =>
           checkNotLocked(sym)
-/*
-        case TypeBounds(lo, hi) =>
-          var ok = true
-          for (t <- lo) ok = ok & checkNonCyclic(pos, t)
-          ok
-*/
         case st: SubType =>
           checkNonCyclic(pos, st.supertype)
         case ct: CompoundType =>
@@ -375,28 +352,13 @@ trait Typers extends Modes with Adaptations with Tags {
       private var scope: Scope = _
       private var hiddenSymbols: List[Symbol] = _
 
-      /** Check that type <code>tree</code> does not refer to private
+      /** Check that type `tree` does not refer to private
        *  components unless itself is wrapped in something private
-       *  (<code>owner</code> tells where the type occurs).
-       *
-       *  @param owner ...
-       *  @param tree  ...
-       *  @return      ...
+       *  (`owner` tells where the type occurs).
        */
       def privates[T <: Tree](owner: Symbol, tree: T): T =
         check(owner, EmptyScope, WildcardType, tree)
 
-      /** Check that type <code>tree</code> does not refer to entities
-       *  defined in scope <code>scope</code>.
-       *
-       *  @param scope ...
-       *  @param pt    ...
-       *  @param tree  ...
-       *  @return      ...
-       */
-      def locals[T <: Tree](scope: Scope, pt: Type, tree: T): T =
-        check(NoSymbol, scope, pt, tree)
-
       private def check[T <: Tree](owner: Symbol, scope: Scope, pt: Type, tree: T): T = {
         this.owner = owner
         this.scope = scope
@@ -472,7 +434,7 @@ trait Typers extends Modes with Adaptations with Tags {
       }
 
     /** The qualifying class
-     *  of a this or super with prefix <code>qual</code>.
+     *  of a this or super with prefix `qual`.
      *  packageOk is equal false when qualifying class symbol
      */
     def qualifyingClass(tree: Tree, qual: Name, packageOK: Boolean) =
@@ -558,7 +520,7 @@ trait Typers extends Modes with Adaptations with Tags {
       }
     }
 
-    /** Does the context of tree <code>tree</code> require a stable type?
+    /** Does the context of tree `tree` require a stable type?
      */
     private def isStableContext(tree: Tree, mode: Int, pt: Type) =
       isNarrowable(tree.tpe) && ((mode & (EXPRmode | LHSmode)) == EXPRmode) &&
@@ -660,12 +622,6 @@ trait Typers extends Modes with Adaptations with Tags {
       case _                                    => !phase.erasedTypes
     }
 
-    /**
-     *  @param tree ...
-     *  @param mode ...
-     *  @param pt   ...
-     *  @return     ...
-     */
     def stabilizeFun(tree: Tree, mode: Int, pt: Type): Tree = {
       val sym = tree.symbol
       val pre = tree match {
@@ -874,7 +830,6 @@ trait Typers extends Modes with Adaptations with Tags {
           debuglog("eta-expanding " + tree + ":" + tree.tpe + " to " + pt)
           checkParamsConvertible(tree, tree.tpe)
           val tree0 = etaExpand(context.unit, tree, this)
-          // println("eta "+tree+" ---> "+tree0+":"+tree0.tpe+" undet: "+context.undetparams+ " mode: "+Integer.toHexString(mode))
 
           if (context.undetparams.nonEmpty) {
             // #2624: need to infer type arguments for eta expansion of a polymorphic method
@@ -960,9 +915,11 @@ trait Typers extends Modes with Adaptations with Tags {
       def adaptConstrPattern(): Tree = { // (5)
         def hasUnapplyMember(tp: Type) = reallyExists(unapplyMember(tp))
         val overloadedExtractorOfObject = tree.symbol filter (sym => hasUnapplyMember(sym.tpe))
-        // if the tree's symbol's type does not define an extractor, maybe the tree's type does
-        // this is the case when we encounter an arbitrary tree as the target of an unapply call (rather than something that looks like a constructor call)
-        // (for now, this only happens due to wrapClassTagUnapply, but when we support parameterized extractors, it will become more common place)
+        // if the tree's symbol's type does not define an extractor, maybe the tree's type does.
+        // this is the case when we encounter an arbitrary tree as the target of an unapply call
+        // (rather than something that looks like a constructor call.) (for now, this only happens
+        // due to wrapClassTagUnapply, but when we support parameterized extractors, it will become
+        // more common place)
         val extractor = overloadedExtractorOfObject orElse unapplyMember(tree.tpe)
         if (extractor != NoSymbol) {
           // if we did some ad-hoc overloading resolution, update the tree's symbol
@@ -1555,16 +1512,6 @@ trait Typers extends Modes with Adaptations with Tags {
             if (!supertparams.isEmpty)
               MissingTypeArgumentsParentTpeError(supertpt)
         }
-/* experimental: early types as type arguments
-        val hasEarlyTypes = templ.body exists (treeInfo.isEarlyTypeDef)
-        val earlyMap = new EarlyMap(clazz)
-        List.mapConserve(supertpt :: mixins){ tpt =>
-          val tpt1 = checkNoEscaping.privates(clazz, tpt)
-          if (hasEarlyTypes) tpt1 else tpt1 setType earlyMap(tpt1.tpe)
-        }
-*/
-
-        //Console.println("parents("+clazz") = "+supertpt :: mixins);//DEBUG
 
         // Certain parents are added in the parser before it is known whether
         // that class also declared them as parents.  For instance, this is an
@@ -1652,9 +1599,6 @@ trait Typers extends Modes with Adaptations with Tags {
               !selfType.isErroneous &&
               !parent.tpe.isErroneous)
           {
-            //Console.println(context.owner);//DEBUG
-            //Console.println(context.owner.unsafeTypeParams);//DEBUG
-            //Console.println(List.fromArray(context.owner.info.closure));//DEBUG
             pending += ParentSelfTypeConformanceError(parent, selfType)
             if (settings.explaintypes.value) explainTypes(selfType, parent.tpe.typeOfThis)
           }
@@ -1670,13 +1614,6 @@ trait Typers extends Modes with Adaptations with Tags {
         for (p <- parents) validateParentClass(p, superclazz)
       }
 
-/*
-      if (settings.Xshowcls.value != "" &&
-          settings.Xshowcls.value == context.owner.fullName)
-        println("INFO "+context.owner+
-                ", baseclasses = "+(context.owner.info.baseClasses map (_.fullName))+
-                ", lin = "+(context.owner.info.baseClasses map (context.owner.thisType.baseType)))
-*/
       pending.foreach(ErrorUtils.issueTypeError)
     }
 
@@ -1700,12 +1637,7 @@ trait Typers extends Modes with Adaptations with Tags {
       }
     }
 
-    /**
-     *  @param cdef ...
-     *  @return     ...
-     */
     def typedClassDef(cdef: ClassDef): Tree = {
-//      attributes(cdef)
       val clazz = cdef.symbol
       val typedMods = typedModifiers(cdef.mods)
       assert(clazz != NoSymbol, cdef)
@@ -1734,10 +1666,6 @@ trait Typers extends Modes with Adaptations with Tags {
         .setType(NoType)
     }
 
-    /**
-     *  @param mdef ...
-     *  @return     ...
-     */
     def typedModuleDef(mdef: ModuleDef): Tree = {
       // initialize all constructors of the linked class: the type completer (Namer.methodSig)
       // might add default getters to this object. example: "object T; class T(x: Int = 1)"
@@ -1795,13 +1723,7 @@ trait Typers extends Modes with Adaptations with Tags {
       if (txt eq context) namer.enterSym(tree)
       else newNamer(txt).enterSym(tree)
 
-    /**
-     *  @param templ    ...
-     *  @param parents1 ...
-     *    <li> <!-- 2 -->
-     *      Check that inner classes do not inherit from Annotation
-     *    </li>
-     *  @return         ...
+    /** <!-- 2 --> Check that inner classes do not inherit from Annotation
      */
     def typedTemplate(templ: Template, parents1: List[Tree]): Template = {
       val clazz = context.owner
@@ -1876,12 +1798,7 @@ trait Typers extends Modes with Adaptations with Tags {
     def typedModifiers(mods: Modifiers): Modifiers =
       mods.copy(annotations = Nil) setPositions mods.positions
 
-    /**
-     *  @param vdef ...
-     *  @return     ...
-     */
     def typedValDef(vdef: ValDef): ValDef = {
-//      attributes(vdef)
       val sym = vdef.symbol.initialize
       val typer1 = constrTyperIf(sym.isParameter && sym.owner.isConstructor)
       val typedMods = typedModifiers(vdef.mods)
@@ -1922,10 +1839,6 @@ trait Typers extends Modes with Adaptations with Tags {
     }
 
     /** Enter all aliases of local parameter accessors.
-     *
-     *  @param clazz    ...
-     *  @param vparamss ...
-     *  @param rhs      ...
      */
     def computeParamAliases(clazz: Symbol, vparamss: List[List[ValDef]], rhs: Tree) {
       debuglog(s"computing param aliases for $clazz:${clazz.primaryConstructor.tpe}:$rhs")
@@ -2020,7 +1933,7 @@ trait Typers extends Modes with Adaptations with Tags {
           f(subTree)
       }
 
-      /** Check if a structurally defined method violates implementation restrictions.
+    /** Check if a structurally defined method violates implementation restrictions.
      *  A method cannot be called if it is a non-private member of a refinement type
      *  and if its parameter's types are any of:
      *    - the self-type of the refinement
@@ -2101,10 +2014,6 @@ trait Typers extends Modes with Adaptations with Tags {
         useCase.defined foreach (sym => println("defined use cases: %s:%s".format(sym, sym.tpe)))
     }
 
-    /**
-     *  @param ddef ...
-     *  @return     ...
-     */
     def typedDefDef(ddef: DefDef): DefDef = {
       val meth = ddef.symbol.initialize
 
@@ -2257,12 +2166,6 @@ trait Typers extends Modes with Adaptations with Tags {
       }
     }
 
-    /**
-     *  @param block ...
-     *  @param mode  ...
-     *  @param pt    ...
-     *  @return      ...
-     */
     def typedBlock(block: Block, mode: Int, pt: Type): Block = {
       val syntheticPrivates = new ListBuffer[Symbol]
       try {
@@ -2335,12 +2238,6 @@ trait Typers extends Modes with Adaptations with Tags {
       }
     }
 
-    /**
-     *  @param cdef   ...
-     *  @param pattpe ...
-     *  @param pt     ...
-     *  @return       ...
-     */
     def typedCase(cdef: CaseDef, pattpe: Type, pt: Type): CaseDef = {
       // verify no _* except in last position
       for (Apply(_, xs) <- cdef.pat ; x <- xs dropRight 1 ; if treeInfo isStar x)
@@ -2606,12 +2503,6 @@ trait Typers extends Modes with Adaptations with Tags {
       override def mkSel(params: List[Symbol]) = sel.duplicate
     }
 
-    /**
-     *  @param fun  ...
-     *  @param mode ...
-     *  @param pt   ...
-     *  @return     ...
-     */
     private def typedFunction(fun: Function, mode: Int, pt: Type): Tree = {
       val numVparams = fun.vparams.length
       if (numVparams > definitions.MaxFunctionArity)
@@ -3294,10 +3185,7 @@ trait Typers extends Modes with Adaptations with Tags {
         if (formals == null) duplErrorTree(WrongNumberOfArgsError(tree, fun))
         else {
           val args1 = typedArgs(args, mode, formals, formalsExpanded)
-          // This used to be the following (failing) assert:
-          //   assert(isFullyDefined(pt), tree+" ==> "+UnApply(fun1, args1)+", pt = "+pt)
-          // I modified as follows.  See SI-1048.
-          val pt1 = if (isFullyDefined(pt)) pt else makeFullyDefined(pt)
+          val pt1 = if (isFullyDefined(pt)) pt else makeFullyDefined(pt) // SI-1048
 
           val itype = glb(List(pt1, arg.tpe))
           arg.tpe = pt1    // restore type (arg is a dummy tree, just needs to pass typechecking)
@@ -4300,10 +4188,6 @@ trait Typers extends Modes with Adaptations with Tags {
           UnderscoreEtaError(expr1)
       }
 
-      /**
-       *  @param args ...
-       *  @return     ...
-       */
       def tryTypedArgs(args: List[Tree], mode: Int): Option[List[Tree]] = {
         val c = context.makeSilent(false)
         c.retyping = true
@@ -4563,12 +4447,8 @@ trait Typers extends Modes with Adaptations with Tags {
             if (isStableContext(tree, mode, pt)) tree setType clazz.thisType else tree
         }
 
-      /** Attribute a selection where <code>tree</code> is <code>qual.name</code>.
-       *  <code>qual</code> is already attributed.
-       *
-       *  @param qual ...
-       *  @param name ...
-       *  @return     ...
+      /** Attribute a selection where `tree` is `qual.name`.
+       *  `qual` is already attributed.
        */
       def typedSelect(tree: Tree, qual: Tree, name: Name): Tree = {
         val t = typedSelectInternal(tree, qual, name)
@@ -5186,12 +5066,6 @@ trait Typers extends Modes with Adaptations with Tags {
       }
     }
 
-    /**
-     *  @param tree ...
-     *  @param mode ...
-     *  @param pt   ...
-     *  @return     ...
-     */
     def typed(tree: Tree, mode: Int, pt: Type): Tree = {
       lastTreeToTyper = tree
       indentTyping()
@@ -5262,10 +5136,7 @@ trait Typers extends Modes with Adaptations with Tags {
     def atOwner(tree: Tree, owner: Symbol): Typer =
       newTyper(context.make(tree, owner))
 
-    /** Types expression or definition <code>tree</code>.
-     *
-     *  @param tree ...
-     *  @return     ...
+    /** Types expression or definition `tree`.
      */
     def typed(tree: Tree): Tree = {
       val ret = typed(tree, EXPRmode, WildcardType)
@@ -5278,23 +5149,19 @@ trait Typers extends Modes with Adaptations with Tags {
     // it makes for a lot less casting.
     // def typedPos[T <: Tree](pos: Position)(tree: T): T = typed(atPos(pos)(tree)).asInstanceOf[T]
 
-    /** Types expression <code>tree</code> with given prototype <code>pt</code>.
-     *
-     *  @param tree ...
-     *  @param pt   ...
-     *  @return     ...
+    /** Types expression `tree` with given prototype `pt`.
      */
     def typed(tree: Tree, pt: Type): Tree =
       typed(tree, EXPRmode, pt)
 
-    /** Types qualifier <code>tree</code> of a select node.
-     *  E.g. is tree occurs in a context like <code>tree.m</code>.
+    /** Types qualifier `tree` of a select node.
+     *  E.g. is tree occurs in a context like `tree.m`.
      */
     def typedQualifier(tree: Tree, mode: Int, pt: Type): Tree =
       typed(tree, EXPRmode | QUALmode | POLYmode | mode & TYPEPATmode, pt) // TR: don't set BYVALmode, since qualifier might end up as by-name param to an implicit
 
-    /** Types qualifier <code>tree</code> of a select node.
-     *  E.g. is tree occurs in a context like <code>tree.m</code>.
+    /** Types qualifier `tree` of a select node.
+     *  E.g. is tree occurs in a context like `tree.m`.
      */
     def typedQualifier(tree: Tree, mode: Int): Tree =
       typedQualifier(tree, mode, WildcardType)
@@ -5305,7 +5172,7 @@ trait Typers extends Modes with Adaptations with Tags {
     def typedOperator(tree: Tree): Tree =
       typed(tree, EXPRmode | FUNmode | POLYmode | TAPPmode, WildcardType)
 
-    /** Types a pattern with prototype <code>pt</code> */
+    /** Types a pattern with prototype `pt` */
     def typedPattern(tree: Tree, pt: Type): Tree = {
       // We disable implicits because otherwise some constructs will
       // type check which should not.  The pattern matcher does not
@@ -5343,8 +5210,6 @@ trait Typers extends Modes with Adaptations with Tags {
     def typedHigherKindedType(tree: Tree, mode: Int): Tree =
       typed(tree, HKmode, WildcardType)
 
-    def typedHigherKindedType(tree: Tree): Tree = typedHigherKindedType(tree, NOmode)
-
     /** Types a type constructor tree used in a new or supertype */
     def typedTypeConstructor(tree: Tree, mode: Int): Tree = {
       val result = typed(tree, forTypeMode(mode) | FUNmode, WildcardType)
@@ -5419,28 +5284,17 @@ trait Typers extends Modes with Adaptations with Tags {
       case Some(tree1) => transformed -= tree; tree1
       case None => typed(tree, mode, pt)
     }
-
-/*
-    def convertToTypeTree(tree: Tree): Tree = tree match {
-      case TypeTree() => tree
-      case _ => TypeTree(tree.tpe)
-    }
-*/
   }
 }
 
 object TypersStats {
   import scala.reflect.internal.TypesStats._
-  import scala.reflect.internal.BaseTypeSeqsStats._
   val typedIdentCount     = Statistics.newCounter("#typechecked identifiers")
   val typedSelectCount    = Statistics.newCounter("#typechecked selections")
   val typedApplyCount     = Statistics.newCounter("#typechecked applications")
   val rawTypeFailed       = Statistics.newSubCounter ("  of which in failed", rawTypeCount)
   val subtypeFailed       = Statistics.newSubCounter("  of which in failed", subtypeCount)
   val findMemberFailed    = Statistics.newSubCounter("  of which in failed", findMemberCount)
-  val compoundBaseTypeSeqCount = Statistics.newSubCounter("  of which for compound types", baseTypeSeqCount)
-  val typerefBaseTypeSeqCount = Statistics.newSubCounter("  of which for typerefs", baseTypeSeqCount)
-  val singletonBaseTypeSeqCount = Statistics.newSubCounter("  of which for singletons", baseTypeSeqCount)
   val failedSilentNanos   = Statistics.newSubTimer("time spent in failed", typerNanos)
   val failedApplyNanos    = Statistics.newSubTimer("  failed apply", typerNanos)
   val failedOpEqNanos     = Statistics.newSubTimer("  failed op=", typerNanos)
diff --git a/src/compiler/scala/tools/nsc/typechecker/Unapplies.scala b/src/compiler/scala/tools/nsc/typechecker/Unapplies.scala
index bf44b65406..061c6679da 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Unapplies.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Unapplies.scala
@@ -23,7 +23,6 @@ trait Unapplies extends ast.TreeDSL
 
   private val unapplyParamName = nme.x_0
 
-
   // In the typeCompleter (templateSig) of a case class (resp it's module),
   // synthetic `copy` (reps `apply`, `unapply`) methods are added. To compute
   // their signatures, the corresponding ClassDef is needed. During naming (in
@@ -46,17 +45,6 @@ trait Unapplies extends ast.TreeDSL
     }
   }
 
-  /** returns type of the unapply method returning T_0...T_n
-   *  for n == 0, boolean
-   *  for n == 1, Some[T0]
-   *  else Some[Product[Ti]]
-   */
-  def unapplyReturnTypeExpected(argsLength: Int) = argsLength match {
-    case 0 => BooleanClass.tpe
-    case 1 => optionType(WildcardType)
-    case n => optionType(productType((List fill n)(WildcardType)))
-  }
-
   /** returns unapply or unapplySeq if available */
   def unapplyMember(tp: Type): Symbol = (tp member nme.unapply) match {
     case NoSymbol => tp member nme.unapplySeq
diff --git a/src/compiler/scala/tools/nsc/typechecker/Variances.scala b/src/compiler/scala/tools/nsc/typechecker/Variances.scala
index ea436a71fb..aa66a8d00a 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Variances.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Variances.scala
@@ -40,7 +40,7 @@ trait Variances {
     (VARIANCES /: tps) ((v, tp) => v & varianceInType(tp)(tparam))
 
   /** Compute variance of type parameter `tparam` in all type arguments
-   *  <code>tps</code> which correspond to formal type parameters `tparams1`.
+   *  `tps` which correspond to formal type parameters `tparams1`.
    */
   def varianceInArgs(tps: List[Type], tparams1: List[Symbol])(tparam: Symbol): Int = {
     var v: Int = VARIANCES;
@@ -63,7 +63,7 @@ trait Variances {
     varianceInType(annot.atp)(tparam)
   }
 
-  /** Compute variance of type parameter <code>tparam</code> in type <code>tp</code>. */
+  /** Compute variance of type parameter `tparam` in type `tp`. */
   def varianceInType(tp: Type)(tparam: Symbol): Int = tp match {
     case ErrorType | WildcardType | NoType | NoPrefix | ThisType(_) | ConstantType(_) =>
       VARIANCES