Merge pull request #1668 from scalamacros/topic/pre-typemacros

refactors handling of parent types

51 files changed, 616 insertions, 353 deletions

diff --git a/src/compiler/scala/reflect/reify/codegen/GenTrees.scala b/src/compiler/scala/reflect/reify/codegen/GenTrees.scala
index bdcc7383b0..918aedce51 100644
--- a/src/compiler/scala/reflect/reify/codegen/GenTrees.scala
+++ b/src/compiler/scala/reflect/reify/codegen/GenTrees.scala
@@ -45,7 +45,9 @@ trait GenTrees {
       case global.EmptyTree =>
         reifyMirrorObject(EmptyTree)
       case global.emptyValDef =>
-        mirrorBuildSelect(nme.emptyValDef)
+        mirrorSelect(nme.emptyValDef)
+      case global.pendingSuperCall =>
+        mirrorSelect(nme.pendingSuperCall)
       case FreeDef(_, _, _, _, _) =>
         reifyNestedFreeDef(tree)
       case FreeRef(_, _) =>
@@ -101,7 +103,8 @@ trait GenTrees {
             case ReifiedTree(_, _, inlinedSymtab, rtree, _, _, _) =>
               if (reifyDebug) println("inlining the splicee")
               // all free vars local to the enclosing reifee should've already been inlined by ``Metalevels''
-              inlinedSymtab.syms foreach (sym => if (sym.isLocalToReifee) assert(false, inlinedSymtab.symDef(sym)))
+              for (sym <- inlinedSymtab.syms if sym.isLocalToReifee)
+                abort("local free var, should have already been inlined by Metalevels: " + inlinedSymtab.symDef(sym))
               state.symtab ++= inlinedSymtab
               rtree
             case tree =>
diff --git a/src/compiler/scala/reflect/reify/codegen/GenUtils.scala b/src/compiler/scala/reflect/reify/codegen/GenUtils.scala
index 49877b4286..21db93d8f5 100644
--- a/src/compiler/scala/reflect/reify/codegen/GenUtils.scala
+++ b/src/compiler/scala/reflect/reify/codegen/GenUtils.scala
@@ -34,9 +34,6 @@ trait GenUtils {
   def mirrorSelect(name: String): Tree =
     termPath(nme.UNIVERSE_PREFIX + name)
 
-  def mirrorBuildSelect(name: String): Tree =
-    termPath(nme.UNIVERSE_BUILD_PREFIX + name)
-
   def mirrorMirrorSelect(name: String): Tree =
     termPath(nme.MIRROR_PREFIX + name)
 
diff --git a/src/compiler/scala/tools/nsc/ast/Positions.scala b/src/compiler/scala/tools/nsc/ast/Positions.scala
index d8fb632f73..49569f5e05 100644
--- a/src/compiler/scala/tools/nsc/ast/Positions.scala
+++ b/src/compiler/scala/tools/nsc/ast/Positions.scala
@@ -20,7 +20,7 @@ trait Positions extends scala.reflect.internal.Positions {
         // When we prune due to encountering a position, traverse the
         // pruned children so we can warn about those lacking positions.
         t.children foreach { c =>
-          if ((c eq EmptyTree) || (c eq emptyValDef)) ()
+          if (!c.canHaveAttrs) ()
           else if (c.pos == NoPosition) {
             reporter.warning(t.pos, " Positioned tree has unpositioned child in phase " + globalPhase)
             inform("parent: " + treeSymStatus(t))
diff --git a/src/compiler/scala/tools/nsc/ast/TreeGen.scala b/src/compiler/scala/tools/nsc/ast/TreeGen.scala
index 53d35791b6..5cb43575b8 100644
--- a/src/compiler/scala/tools/nsc/ast/TreeGen.scala
+++ b/src/compiler/scala/tools/nsc/ast/TreeGen.scala
@@ -58,7 +58,7 @@ abstract class TreeGen extends scala.reflect.internal.TreeGen with TreeDSL {
   def mkUnchecked(expr: Tree): Tree = atPos(expr.pos) {
     // This can't be "Annotated(New(UncheckedClass), expr)" because annotations
     // are very picky about things and it crashes the compiler with "unexpected new".
-    Annotated(New(scalaDot(UncheckedClass.name), ListOfNil), expr)
+    Annotated(New(scalaDot(UncheckedClass.name), Nil), expr)
   }
   // if it's a Match, mark the selector unchecked; otherwise nothing.
   def mkUncheckedMatch(tree: Tree) = tree match {
diff --git a/src/compiler/scala/tools/nsc/ast/Trees.scala b/src/compiler/scala/tools/nsc/ast/Trees.scala
index 296d55fec5..54402f0903 100644
--- a/src/compiler/scala/tools/nsc/ast/Trees.scala
+++ b/src/compiler/scala/tools/nsc/ast/Trees.scala
@@ -65,6 +65,13 @@ trait Trees extends scala.reflect.internal.Trees { self: Global =>
 
   // --- factory methods ----------------------------------------------------------
 
+  /** Factory method for a primary constructor super call `super.<init>(args_1)...(args_n)`
+   */
+  def PrimarySuperCall(argss: List[List[Tree]]): Tree = argss match {
+    case Nil        => Apply(gen.mkSuperSelect, Nil)
+    case xs :: rest => rest.foldLeft(Apply(gen.mkSuperSelect, xs): Tree)(Apply.apply)
+  }
+
     /** Generates a template with constructor corresponding to
    *
    *  constrmods (vparams1_) ... (vparams_n) preSuper { presupers }
@@ -82,7 +89,7 @@ trait Trees extends scala.reflect.internal.Trees { self: Global =>
    *    body
    *  }
    */
-  def Template(parents: List[Tree], self: ValDef, constrMods: Modifiers, vparamss: List[List[ValDef]], argss: List[List[Tree]], body: List[Tree], superPos: Position): Template = {
+  def Template(parents: List[Tree], self: ValDef, constrMods: Modifiers, vparamss: List[List[ValDef]], body: List[Tree], superPos: Position): Template = {
     /* Add constructor to template */
 
     // create parameters for <init> as synthetic trees.
@@ -117,9 +124,16 @@ trait Trees extends scala.reflect.internal.Trees { self: Global =>
         if (vparamss1.isEmpty || !vparamss1.head.isEmpty && vparamss1.head.head.mods.isImplicit)
           vparamss1 = List() :: vparamss1;
         val superRef: Tree = atPos(superPos)(gen.mkSuperSelect)
-        val superCall = (superRef /: argss) (Apply.apply)
+        val superCall = pendingSuperCall // we can't know in advance which of the parents will end up as a superclass
+                                         // this requires knowing which of the parents is a type macro and which is not
+                                         // and that's something that cannot be found out before typer
+                                         // (the type macros aren't in the trunk yet, but there is a plan for them to land there soon)
+                                         // this means that we don't know what will be the arguments of the super call
+                                         // therefore here we emit a dummy which gets populated when the template is named and typechecked
         List(
-          atPos(wrappingPos(superPos, lvdefs ::: argss.flatten)) (
+          // TODO: previously this was `wrappingPos(superPos, lvdefs ::: argss.flatten)`
+          // is it going to be a problem that we can no longer include the `argss`?
+          atPos(wrappingPos(superPos, lvdefs)) (
             DefDef(constrMods, nme.CONSTRUCTOR, List(), vparamss1, TypeTree(), Block(lvdefs ::: List(superCall), Literal(Constant())))))
       }
     }
@@ -137,11 +151,10 @@ trait Trees extends scala.reflect.internal.Trees { self: Global =>
    *  @param constrMods the modifiers for the class constructor, i.e. as in `class C private (...)`
    *  @param vparamss   the value parameters -- if they have symbols they
    *                    should be owned by `sym`
-   *  @param argss      the supercall arguments
    *  @param body       the template statements without primary constructor
    *                    and value parameter fields.
    */
-  def ClassDef(sym: Symbol, constrMods: Modifiers, vparamss: List[List[ValDef]], argss: List[List[Tree]], body: List[Tree], superPos: Position): ClassDef = {
+  def ClassDef(sym: Symbol, constrMods: Modifiers, vparamss: List[List[ValDef]], body: List[Tree], superPos: Position): ClassDef = {
     // "if they have symbols they should be owned by `sym`"
     assert(
       mforall(vparamss)(p => (p.symbol eq NoSymbol) || (p.symbol.owner == sym)),
@@ -151,7 +164,7 @@ trait Trees extends scala.reflect.internal.Trees { self: Global =>
     ClassDef(sym,
       Template(sym.info.parents map TypeTree,
                if (sym.thisSym == sym || phase.erasedTypes) emptyValDef else ValDef(sym.thisSym),
-               constrMods, vparamss, argss, body, superPos))
+               constrMods, vparamss, body, superPos))
   }
 
  // --- subcomponents --------------------------------------------------
@@ -324,6 +337,8 @@ trait Trees extends scala.reflect.internal.Trees { self: Global =>
         else
           super.transform {
             tree match {
+              case tree if !tree.canHaveAttrs =>
+                tree
               case tpt: TypeTree =>
                 if (tpt.original != null)
                   transform(tpt.original)
@@ -337,8 +352,6 @@ trait Trees extends scala.reflect.internal.Trees { self: Global =>
                 transform(fn)
               case This(_) if tree.symbol != null && tree.symbol.isPackageClass =>
                 tree
-              case EmptyTree =>
-                tree
               case _ =>
                 val dupl = tree.duplicate
                 if (tree.hasSymbol && (!localOnly || (locals contains tree.symbol)) && !(keepLabels && tree.symbol.isLabel))
diff --git a/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala b/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala
index 074fcabec8..33db4ee2d5 100644
--- a/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala
+++ b/src/compiler/scala/tools/nsc/ast/parser/Parsers.scala
@@ -1562,9 +1562,9 @@ self =>
             val nstart = in.skipToken()
             val npos = r2p(nstart, nstart, in.lastOffset)
             val tstart = in.offset
-            val (parents, argss, self, stats) = template(isTrait = false)
+            val (parents, self, stats) = template()
             val cpos = r2p(tstart, tstart, in.lastOffset max tstart)
-            makeNew(parents, self, stats, argss, npos, cpos)
+            makeNew(parents, self, stats, npos, cpos)
           case _ =>
             syntaxErrorOrIncomplete("illegal start of simple expression", true)
             errorTermTree
@@ -2106,7 +2106,7 @@ self =>
     def annotationExpr(): Tree = atPos(in.offset) {
       val t = exprSimpleType()
       if (in.token == LPAREN) New(t, multipleArgumentExprs())
-      else New(t, ListOfNil)
+      else New(t, Nil)
     }
 
 /* -------- PARAMETERS ------------------------------------------- */
@@ -2742,20 +2742,17 @@ self =>
      *  TraitParents       ::= AnnotType {with AnnotType}
      *  }}}
      */
-    def templateParents(isTrait: Boolean): (List[Tree], List[List[Tree]]) = {
-      val parents = new ListBuffer[Tree] += startAnnotType()
-      val argss = (
-        // TODO: the insertion of ListOfNil here is where "new Foo" becomes
-        // indistinguishable from "new Foo()".
-        if (in.token == LPAREN && !isTrait) multipleArgumentExprs()
-        else ListOfNil
-      )
-
-      while (in.token == WITH) {
-        in.nextToken()
-        parents += startAnnotType()
+    def templateParents(): List[Tree] = {
+      val parents = new ListBuffer[Tree]
+      def readAppliedParent() = {
+        val start = in.offset
+        val parent = startAnnotType()
+        val argss = if (in.token == LPAREN) multipleArgumentExprs() else Nil
+        parents += atPos(start)((parent /: argss)(Apply.apply))
       }
-      (parents.toList, argss)
+      readAppliedParent()
+      while (in.token == WITH) { in.nextToken(); readAppliedParent() }
+      parents.toList
     }
 
     /** {{{
@@ -2765,12 +2762,12 @@ self =>
      *  EarlyDef      ::= Annotations Modifiers PatDef
      *  }}}
      */
-    def template(isTrait: Boolean): (List[Tree], List[List[Tree]], ValDef, List[Tree]) = {
+    def template(): (List[Tree], ValDef, List[Tree]) = {
       newLineOptWhenFollowedBy(LBRACE)
       if (in.token == LBRACE) {
         // @S: pre template body cannot stub like post body can!
         val (self, body) = templateBody(isPre = true)
-        if (in.token == WITH && self.isEmpty) {
+        if (in.token == WITH && (self eq emptyValDef)) {
           val earlyDefs: List[Tree] = body flatMap {
             case vdef @ ValDef(mods, _, _, _) if !mods.isDeferred =>
               List(copyValDef(vdef)(mods = mods | Flags.PRESUPER))
@@ -2782,16 +2779,16 @@ self =>
             case _ => List()
           }
           in.nextToken()
-          val (parents, argss) = templateParents(isTrait = isTrait)
-          val (self1, body1) = templateBodyOpt(traitParentSeen = isTrait)
-          (parents, argss, self1, earlyDefs ::: body1)
+          val parents = templateParents()
+          val (self1, body1) = templateBodyOpt(parenMeansSyntaxError = false)
+          (parents, self1, earlyDefs ::: body1)
         } else {
-          (List(), ListOfNil, self, body)
+          (List(), self, body)
         }
       } else {
-        val (parents, argss) = templateParents(isTrait = isTrait)
-        val (self, body) = templateBodyOpt(traitParentSeen = isTrait)
-        (parents, argss, self, body)
+        val parents = templateParents()
+        val (self, body) = templateBodyOpt(parenMeansSyntaxError = false)
+        (parents, self, body)
       }
     }
 
@@ -2805,15 +2802,15 @@ self =>
      *  }}}
      */
     def templateOpt(mods: Modifiers, name: Name, constrMods: Modifiers, vparamss: List[List[ValDef]], tstart: Int): Template = {
-      val (parents0, argss, self, body) = (
+      val (parents0, self, body) = (
         if (in.token == EXTENDS || in.token == SUBTYPE && mods.isTrait) {
           in.nextToken()
-          template(isTrait = mods.isTrait)
+          template()
         }
         else {
           newLineOptWhenFollowedBy(LBRACE)
-          val (self, body) = templateBodyOpt(traitParentSeen = false)
-          (List(), ListOfNil, self, body)
+          val (self, body) = templateBodyOpt(parenMeansSyntaxError = mods.isTrait || name.isTermName)
+          (List(), self, body)
         }
       )
       def anyrefParents() = {
@@ -2835,7 +2832,7 @@ self =>
         if (inScalaRootPackage && ScalaValueClassNames.contains(name))
           Template(parents0, self, anyvalConstructor :: body)
         else
-          Template(anyrefParents, self, constrMods, vparamss, argss, body, o2p(tstart))
+          Template(anyrefParents, self, constrMods, vparamss, body, o2p(tstart))
       }
     }
 
@@ -2850,14 +2847,15 @@ self =>
       case (self, Nil)  => (self, EmptyTree.asList)
       case result       => result
     }
-    def templateBodyOpt(traitParentSeen: Boolean): (ValDef, List[Tree]) = {
+    def templateBodyOpt(parenMeansSyntaxError: Boolean): (ValDef, List[Tree]) = {
       newLineOptWhenFollowedBy(LBRACE)
       if (in.token == LBRACE) {
         templateBody(isPre = false)
       } else {
-        if (in.token == LPAREN)
-          syntaxError((if (traitParentSeen) "parents of traits" else "traits or objects")+
-                      " may not have parameters", true)
+        if (in.token == LPAREN) {
+          if (parenMeansSyntaxError) syntaxError(s"traits or objects may not have parameters", true)
+          else abort("unexpected opening parenthesis")
+        }
         (emptyValDef, List())
       }
     }
diff --git a/src/compiler/scala/tools/nsc/ast/parser/TreeBuilder.scala b/src/compiler/scala/tools/nsc/ast/parser/TreeBuilder.scala
index 0ac46a18bc..f94055f666 100644
--- a/src/compiler/scala/tools/nsc/ast/parser/TreeBuilder.scala
+++ b/src/compiler/scala/tools/nsc/ast/parser/TreeBuilder.scala
@@ -205,20 +205,26 @@ abstract class TreeBuilder {
    */
   def makeAnonymousNew(stats: List[Tree]): Tree = {
     val stats1 = if (stats.isEmpty) List(Literal(Constant(()))) else stats
-    makeNew(Nil, emptyValDef, stats1, ListOfNil, NoPosition, NoPosition)
+    makeNew(Nil, emptyValDef, stats1, NoPosition, NoPosition)
   }
 
   /** Create positioned tree representing an object creation <new parents { stats }
    *  @param npos  the position of the new
    *  @param cpos  the position of the anonymous class starting with parents
    */
-  def makeNew(parents: List[Tree], self: ValDef, stats: List[Tree], argss: List[List[Tree]],
+  def makeNew(parents: List[Tree], self: ValDef, stats: List[Tree],
               npos: Position, cpos: Position): Tree =
     if (parents.isEmpty)
-      makeNew(List(scalaAnyRefConstr), self, stats, argss, npos, cpos)
-    else if (parents.tail.isEmpty && stats.isEmpty)
-      atPos(npos union cpos) { New(parents.head, argss) }
-    else {
+      makeNew(List(scalaAnyRefConstr), self, stats, npos, cpos)
+    else if (parents.tail.isEmpty && stats.isEmpty) {
+      // `Parsers.template` no longer differentiates tpts and their argss
+      // e.g. `C()` will be represented as a single tree Apply(Ident(C), Nil)
+      // instead of parents = Ident(C), argss = Nil as before
+      // this change works great for things that are actually templates
+      // but in this degenerate case we need to perform postprocessing
+      val app = treeInfo.dissectApplied(parents.head)
+      atPos(npos union cpos) { New(app.callee, app.argss) }
+    } else {
       val x = tpnme.ANON_CLASS_NAME
       atPos(npos union cpos) {
         Block(
@@ -226,12 +232,12 @@ abstract class TreeBuilder {
             atPos(cpos) {
               ClassDef(
                 Modifiers(FINAL), x, Nil,
-                Template(parents, self, NoMods, ListOfNil, argss, stats, cpos.focus))
+                Template(parents, self, NoMods, ListOfNil, stats, cpos.focus))
             }),
           atPos(npos) {
             New(
               Ident(x) setPos npos.focus,
-              ListOfNil)
+              Nil)
           }
         )
       }
diff --git a/src/compiler/scala/tools/nsc/backend/icode/GenICode.scala b/src/compiler/scala/tools/nsc/backend/icode/GenICode.scala
index ea4e8475f9..fd2b11898c 100644
--- a/src/compiler/scala/tools/nsc/backend/icode/GenICode.scala
+++ b/src/compiler/scala/tools/nsc/backend/icode/GenICode.scala
@@ -753,7 +753,8 @@ abstract class GenICode extends SubComponent  {
               } else
                 ctx1.bb.emit(CONSTANT(Constant(false)))
             } else if (r.isValueType && cast) {
-              assert(false, tree) /* Erasure should have added an unboxing operation to prevent that. */
+              /* Erasure should have added an unboxing operation to prevent that. */
+              abort("should have been unboxed by erasure: " + tree)
             } else if (r.isValueType) {
               ctx.bb.emit(IS_INSTANCE(REFERENCE(definitions.boxedClass(r.toType.typeSymbol))))
             } else {
@@ -1257,7 +1258,7 @@ abstract class GenICode extends SubComponent  {
       val sym = (
         if (!tree.symbol.isPackageClass) tree.symbol
         else tree.symbol.info.member(nme.PACKAGE) match {
-          case NoSymbol => assert(false, "Cannot use package as value: " + tree) ; NoSymbol
+          case NoSymbol => abort("Cannot use package as value: " + tree)
           case s        => debugwarn("Bug: found package class where package object expected.  Converting.") ; s.moduleClass
         }
       )
diff --git a/src/compiler/scala/tools/nsc/interactive/RangePositions.scala b/src/compiler/scala/tools/nsc/interactive/RangePositions.scala
index b95f1fa7ca..64117bd8ee 100644
--- a/src/compiler/scala/tools/nsc/interactive/RangePositions.scala
+++ b/src/compiler/scala/tools/nsc/interactive/RangePositions.scala
@@ -144,7 +144,7 @@ self: scala.tools.nsc.Global =>
    */
   private def setChildrenPos(pos: Position, trees: List[Tree]): Unit = try {
     for (tree <- trees) {
-      if (!tree.isEmpty && tree.pos == NoPosition) {
+      if (!tree.isEmpty && tree.canHaveAttrs && tree.pos == NoPosition) {
         val children = tree.children
         if (children.isEmpty) {
           tree setPos pos.focus
@@ -165,7 +165,7 @@ self: scala.tools.nsc.Global =>
    */
   override def atPos[T <: Tree](pos: Position)(tree: T): T = {
     if (pos.isOpaqueRange) {
-      if (!tree.isEmpty && tree.pos == NoPosition) {
+      if (!tree.isEmpty && tree.canHaveAttrs && tree.pos == NoPosition) {
         tree.setPos(pos)
         val children = tree.children
         if (children.nonEmpty) {
@@ -203,7 +203,7 @@ self: scala.tools.nsc.Global =>
 
     def validate(tree: Tree, encltree: Tree): Unit = {
 
-      if (!tree.isEmpty) {
+      if (!tree.isEmpty && tree.canHaveAttrs) {
         if (settings.Yposdebug.value && (settings.verbose.value || settings.Yrangepos.value))
           println("[%10s] %s".format("validate", treeStatus(tree, encltree)))
 
diff --git a/src/compiler/scala/tools/nsc/javac/JavaParsers.scala b/src/compiler/scala/tools/nsc/javac/JavaParsers.scala
index 43a8402fc7..050f7a8f95 100644
--- a/src/compiler/scala/tools/nsc/javac/JavaParsers.scala
+++ b/src/compiler/scala/tools/nsc/javac/JavaParsers.scala
@@ -551,7 +551,7 @@ trait JavaParsers extends ast.parser.ParsersCommon with JavaScanners {
               if (parentToken == AT && in.token == DEFAULT) {
                 val annot =
                   atPos(pos) {
-                    New(Select(scalaDot(nme.runtime), tpnme.AnnotationDefaultATTR), ListOfNil)
+                    New(Select(scalaDot(nme.runtime), tpnme.AnnotationDefaultATTR), Nil)
                   }
                 mods1 = mods1 withAnnotations List(annot)
                 skipTo(SEMI)
diff --git a/src/compiler/scala/tools/nsc/symtab/classfile/Pickler.scala b/src/compiler/scala/tools/nsc/symtab/classfile/Pickler.scala
index b9eb1ba0cd..25b7813646 100644
--- a/src/compiler/scala/tools/nsc/symtab/classfile/Pickler.scala
+++ b/src/compiler/scala/tools/nsc/symtab/classfile/Pickler.scala
@@ -198,7 +198,7 @@ abstract class Pickler extends SubComponent {
         case RefinedType(parents, decls) =>
           val rclazz = tp.typeSymbol
           for (m <- decls.iterator)
-            if (m.owner != rclazz) assert(false, "bad refinement member "+m+" of "+tp+", owner = "+m.owner)
+            if (m.owner != rclazz) abort("bad refinement member "+m+" of "+tp+", owner = "+m.owner)
           putSymbol(rclazz); putTypes(parents); putSymbols(decls.toList)
         case ClassInfoType(parents, decls, clazz) =>
           putSymbol(clazz); putTypes(parents); putSymbols(decls.toList)
diff --git a/src/compiler/scala/tools/nsc/transform/Constructors.scala b/src/compiler/scala/tools/nsc/transform/Constructors.scala
index 4092d1262a..ec0797acb5 100644
--- a/src/compiler/scala/tools/nsc/transform/Constructors.scala
+++ b/src/compiler/scala/tools/nsc/transform/Constructors.scala
@@ -68,7 +68,7 @@ abstract class Constructors extends Transform with ast.TreeDSL {
         def matchesName(param: Symbol) = param.name == name || param.name.startsWith(name + nme.NAME_JOIN_STRING)
 
         (constrParams filter matchesName) match {
-          case Nil    => assert(false, name + " not in " + constrParams) ; null
+          case Nil    => abort(name + " not in " + constrParams)
           case p :: _ => p
         }
       }
@@ -511,7 +511,6 @@ abstract class Constructors extends Transform with ast.TreeDSL {
               sym = closureClass,
               constrMods = Modifiers(0),
               vparamss = List(List(outerFieldDef)),
-              argss = ListOfNil,
               body = List(applyMethodDef),
               superPos = impl.pos)
           }
diff --git a/src/compiler/scala/tools/nsc/transform/Mixin.scala b/src/compiler/scala/tools/nsc/transform/Mixin.scala
index 64bb98e2c5..ebbb1d7798 100644
--- a/src/compiler/scala/tools/nsc/transform/Mixin.scala
+++ b/src/compiler/scala/tools/nsc/transform/Mixin.scala
@@ -871,8 +871,7 @@ abstract class Mixin extends InfoTransform with ast.TreeDSL {
             val cond                    = Apply(Select(moduleVarRef, nme.eq), List(NULL))
             mkFastPathBody(clazz, moduleSym, cond, List(assign), List(NULL), returnTree, attrThis, args)
           case _ =>
-            assert(false, "Invalid getter " + rhs + " for module in class " + clazz)
-            EmptyTree
+            abort("Invalid getter " + rhs + " for module in class " + clazz)
         }
 
       def mkCheckedAccessor(clazz: Symbol, retVal: Tree, offset: Int, pos: Position, fieldSym: Symbol): Tree = {
diff --git a/src/compiler/scala/tools/nsc/transform/UnCurry.scala b/src/compiler/scala/tools/nsc/transform/UnCurry.scala
index 529009a058..9829fd0e57 100644
--- a/src/compiler/scala/tools/nsc/transform/UnCurry.scala
+++ b/src/compiler/scala/tools/nsc/transform/UnCurry.scala
@@ -267,7 +267,7 @@ abstract class UnCurry extends InfoTransform
 
           localTyper.typedPos(fun.pos) {
             Block(
-              List(ClassDef(anonClass, NoMods, ListOfNil, ListOfNil, List(applyMethodDef), fun.pos)),
+              List(ClassDef(anonClass, NoMods, ListOfNil, List(applyMethodDef), fun.pos)),
               Typed(New(anonClass.tpe), TypeTree(fun.tpe)))
           }
 
@@ -392,7 +392,7 @@ abstract class UnCurry extends InfoTransform
 
       localTyper.typedPos(fun.pos) {
         Block(
-          List(ClassDef(anonClass, NoMods, ListOfNil, ListOfNil, List(applyOrElseMethodDef, isDefinedAtMethodDef), fun.pos)),
+          List(ClassDef(anonClass, NoMods, ListOfNil, List(applyOrElseMethodDef, isDefinedAtMethodDef), fun.pos)),
           Typed(New(anonClass.tpe), TypeTree(fun.tpe)))
       }
     }
diff --git a/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala b/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala
index faacb60d75..ae3b0bc0b7 100644
--- a/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala
@@ -184,14 +184,18 @@ trait ContextErrors {
       }
 
       def ParentTypesError(templ: Template, ex: TypeError) = {
-         templ.tpe = null
-         issueNormalTypeError(templ, ex.getMessage())
+        templ.tpe = null
+        issueNormalTypeError(templ, ex.getMessage())
+        setError(templ)
       }
 
       // additional parentTypes errors
-      def ConstrArgsInTraitParentTpeError(arg: Tree, parent: Symbol) =
+      def ConstrArgsInParentWhichIsTraitError(arg: Tree, parent: Symbol) =
         issueNormalTypeError(arg, parent + " is a trait; does not take constructor arguments")
 
+      def ConstrArgsInParentOfTraitError(arg: Tree, parent: Symbol) =
+        issueNormalTypeError(arg, "parents of traits may not have parameters")
+
       def MissingTypeArgumentsParentTpeError(supertpt: Tree) =
         issueNormalTypeError(supertpt, "missing type arguments")
 
@@ -1043,9 +1047,6 @@ trait ContextErrors {
       def MaxParametersCaseClassError(tree: Tree) =
         issueNormalTypeError(tree, "Implementation restriction: case classes cannot have more than " + definitions.MaxFunctionArity + " parameters.")
 
-      def InheritsItselfError(tree: Tree) =
-        issueNormalTypeError(tree, tree.tpe.typeSymbol+" inherits itself")
-
       def MissingParameterOrValTypeError(vparam: Tree) =
         issueNormalTypeError(vparam, "missing parameter type")
 
@@ -1279,7 +1280,10 @@ trait ContextErrors {
       fail()
     }
 
-    private def implRefError(message: String) = genericError(methPart(macroDdef.rhs), message)
+    private def implRefError(message: String) = {
+      val treeInfo.Applied(implRef, _, _) = macroDdef.rhs
+      genericError(implRef, message)
+    }
 
     private def compatibilityError(message: String) =
       implRefError(
diff --git a/src/compiler/scala/tools/nsc/typechecker/Contexts.scala b/src/compiler/scala/tools/nsc/typechecker/Contexts.scala
index 507825ff15..0907f1088a 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Contexts.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Contexts.scala
@@ -510,8 +510,8 @@ trait Contexts { self: Analyzer =>
 /*
         var c = this
         while (c != NoContext && c.owner != owner) {
-          if (c.outer eq null) assert(false, "accessWithin(" + owner + ") " + c);//debug
-          if (c.outer.enclClass eq null) assert(false, "accessWithin(" + owner + ") " + c);//debug
+          if (c.outer eq null) abort("accessWithin(" + owner + ") " + c);//debug
+          if (c.outer.enclClass eq null) abort("accessWithin(" + owner + ") " + c);//debug
           c = c.outer.enclClass
         }
         c != NoContext
diff --git a/src/compiler/scala/tools/nsc/typechecker/Infer.scala b/src/compiler/scala/tools/nsc/typechecker/Infer.scala
index 5deed4ffee..22daf13e33 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Infer.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Infer.scala
@@ -221,7 +221,7 @@ trait Infer extends Checkable {
         // such as T <: T gets completed. See #360
         tvar.constr.inst = ErrorType
       else
-        assert(false, tvar.origin+" at "+tvar.origin.typeSymbol.owner)
+        abort(tvar.origin+" at "+tvar.origin.typeSymbol.owner)
     }
     tvars map instantiate
   }
diff --git a/src/compiler/scala/tools/nsc/typechecker/Namers.scala b/src/compiler/scala/tools/nsc/typechecker/Namers.scala
index 36edd46f25..fa9a4ba9ea 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Namers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Namers.scala
@@ -847,13 +847,8 @@ trait Namers extends MethodSynthesis {
     private def templateSig(templ: Template): Type = {
       val clazz = context.owner
       def checkParent(tpt: Tree): Type = {
-        val tp = tpt.tpe
-        val inheritsSelf = tp.typeSymbol == owner
-        if (inheritsSelf)
-          InheritsItselfError(tpt)
-
-        if (inheritsSelf || tp.isError) AnyRefClass.tpe
-        else tp
+        if (tpt.tpe.isError) AnyRefClass.tpe
+        else tpt.tpe
       }
 
       val parents = typer.parentTypes(templ) map checkParent
diff --git a/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala b/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala
index 78ec6508ed..fbeb401c7d 100644
--- a/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala
@@ -1671,7 +1671,7 @@ abstract class RefChecks extends InfoTransform with scala.reflect.internal.trans
             checkAnyValSubclass(currentOwner)
             if (bridges.nonEmpty) deriveTemplate(tree)(_ ::: bridges) else tree
 
-          case dc@TypeTreeWithDeferredRefCheck() => assert(false, "adapt should have turned dc: TypeTreeWithDeferredRefCheck into tpt: TypeTree, with tpt.original == dc"); dc
+          case dc@TypeTreeWithDeferredRefCheck() => abort("adapt should have turned dc: TypeTreeWithDeferredRefCheck into tpt: TypeTree, with tpt.original == dc")
           case tpt@TypeTree() =>
             if(tpt.original != null) {
               tpt.original foreach {
diff --git a/src/compiler/scala/tools/nsc/typechecker/StdAttachments.scala b/src/compiler/scala/tools/nsc/typechecker/StdAttachments.scala
index 64c5b41638..0a1d3bfa7a 100644
--- a/src/compiler/scala/tools/nsc/typechecker/StdAttachments.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/StdAttachments.scala
@@ -4,7 +4,31 @@ package typechecker
 trait StdAttachments {
   self: Analyzer =>
 
+  import global._
+
+  /** Carries information necessary to expand the host tree.
+   *  At times we need to store this info, because macro expansion can be delayed until its targs are inferred.
+   *  After a macro application has been successfully expanded, this attachment is destroyed.
+   */
   type UnaffiliatedMacroContext = scala.reflect.macros.runtime.Context
   type MacroContext = UnaffiliatedMacroContext { val universe: self.global.type }
   case class MacroRuntimeAttachment(delayed: Boolean, typerContext: Context, macroContext: Option[MacroContext])
+
+  /** After being synthesized by the parser, primary constructors aren't fully baked yet.
+   *  A call to super in such constructors is just a fill-me-in-later dummy resolved later
+   *  by `parentTypes`. This attachment coordinates `parentTypes` and `typedTemplate` and
+   *  allows them to complete the synthesis.
+   */
+  case class SuperCallArgsAttachment(argss: List[List[Tree]])
+
+  /** Convenience method for `SuperCallArgsAttachment`.
+   *  Compared with `MacroRuntimeAttachment` this attachment has different a usage pattern,
+   *  so it really benefits from a dedicated extractor.
+   */
+  def superCallArgs(tree: Tree): Option[List[List[Tree]]] =
+    tree.attachments.get[SuperCallArgsAttachment] collect { case SuperCallArgsAttachment(argss) => argss }
+
+  /** Determines whether the given tree has an associated SuperCallArgsAttachment.
+   */
+  def hasSuperArgs(tree: Tree): Boolean = superCallArgs(tree).nonEmpty
 }
\ No newline at end of file
diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
index ae506cd6ab..9e07b51b77 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
@@ -52,8 +52,10 @@ trait Typers extends Modes with Adaptations with Tags {
 
   object UnTyper extends Traverser {
     override def traverse(tree: Tree) = {
-      if (tree != EmptyTree) tree.tpe = null
-      if (tree.hasSymbol) tree.symbol = NoSymbol
+      if (tree.canHaveAttrs) {
+        tree.tpe = null
+        if (tree.hasSymbol) tree.symbol = NoSymbol
+      }
       super.traverse(tree)
     }
   }
@@ -1378,13 +1380,6 @@ trait Typers extends Modes with Adaptations with Tags {
       if (member(qual, name) != NoSymbol) qual
       else adaptToMember(qual, HasMember(name))
 
-    private def typePrimaryConstrBody(clazz : Symbol, cbody: Tree, tparams: List[Symbol], enclTparams: List[Symbol], vparamss: List[List[ValDef]]): Tree = {
-      // XXX: see about using the class's symbol....
-      enclTparams foreach (sym => context.scope.enter(sym))
-      namer.enterValueParams(vparamss)
-      typed(cbody)
-    }
-
     private def validateNoCaseAncestor(clazz: Symbol) = {
       if (!phase.erasedTypes) {
         for (ancestor <- clazz.ancestors find (_.isCase)) {
@@ -1486,125 +1481,243 @@ trait Typers extends Modes with Adaptations with Tags {
           unit.error(tparam.pos, "type parameter of value class may not be specialized")
     }
 
-    def parentTypes(templ: Template): List[Tree] =
-      if (templ.parents.isEmpty) List(atPos(templ.pos)(TypeTree(AnyRefClass.tpe)))
-      else try {
-        val clazz = context.owner
-        // Normalize supertype and mixins so that supertype is always a class, not a trait.
-        var supertpt = typedTypeConstructor(templ.parents.head)
-        val firstParent = supertpt.tpe.typeSymbol
-        var mixins = templ.parents.tail map typedType
-        // If first parent is a trait, make it first mixin and add its superclass as first parent
-        while ((supertpt.tpe.typeSymbol ne null) && supertpt.tpe.typeSymbol.initialize.isTrait) {
-          val supertpt1 = typedType(supertpt)
-          if (!supertpt1.isErrorTyped) {
-            mixins = supertpt1 :: mixins
-            supertpt = TypeTree(supertpt1.tpe.firstParent) setPos supertpt.pos.focus
+    /** Typechecks a parent type reference.
+     *
+     *  This typecheck is harder than it might look, because it should honor early
+     *  definitions and also perform type argument inference with the help of super call
+     *  arguments provided in `encodedtpt`.
+     *
+     *  The method is called in batches (batch = 1 time per each parent type referenced),
+     *  two batches per definition: once from namer, when entering a ClassDef or a ModuleDef
+     *  and once from typer, when typechecking the definition.
+     *
+     *  ***Arguments***
+     *
+     *  `encodedtpt` represents the parent type reference wrapped in an `Apply` node
+     *  which indicates value arguments (i.e. type macro arguments or super constructor call arguments)
+     *  If no value arguments are provided by the user, the `Apply` node is still
+     *  there, but its `args` will be set to `Nil`.
+     *  This argument is synthesized by `tools.nsc.ast.Parsers.templateParents`.
+     *
+     *  `templ` is an enclosing template, which contains a primary constructor synthesized by the parser.
+     *  Such a constructor is a DefDef which contains early initializers and maybe a super constructor call
+     *  (I wrote "maybe" because trait constructors don't call super constructors).
+     *  This argument is synthesized by `tools.nsc.ast.Trees.Template`.
+     *
+     *  `inMixinPosition` indicates whether the reference is not the first in the
+     *  list of parents (and therefore cannot be a class) or the opposite.
+     *
+     *  ***Return value and side effects***
+     *
+     *  Returns a `TypeTree` representing a resolved parent type.
+     *  If the typechecked parent reference implies non-nullary and non-empty argument list,
+     *  this argument list is attached to the returned value in SuperCallArgsAttachment.
+     *  The attachment is necessary for the subsequent typecheck to fixup a super constructor call
+     *  in the body of the primary constructor (see `typedTemplate` for details).
+     *
+     *  This method might invoke `typedPrimaryConstrBody`, hence it might cause the side effects
+     *  described in the docs of that method. It might also attribute the Super(_, _) reference
+     *  (if present) inside the primary constructor of `templ`.
+     *
+     *  ***Example***
+     *
+     *  For the following definition:
+     *
+     *    class D extends {
+     *      val x = 2
+     *      val y = 4
+     *    } with B(x)(3) with C(y) with T
+     *
+     *  this method will be called six times:
+     *
+     *    (3 times from the namer)
+     *    typedParentType(Apply(Apply(Ident(B), List(Ident(x))), List(3)), templ, inMixinPosition = false)
+     *    typedParentType(Apply(Ident(C), List(Ident(y))), templ, inMixinPosition = true)
+     *    typedParentType(Apply(Ident(T), List()), templ, inMixinPosition = true)
+     *
+     *    (3 times from the typer)
+     *    <the same three calls>
+     */
+    private def typedParentType(encodedtpt: Tree, templ: Template, inMixinPosition: Boolean): Tree = {
+      val app = treeInfo.dissectApplied(encodedtpt)
+      val (treeInfo.Applied(core, targs, argss), decodedtpt) = (app, app.callee)
+      val argssAreTrivial = argss == Nil || argss == ListOfNil
+
+      // we cannot avoid cyclic references with `initialize` here, because when type macros arrive,
+      // we'll have to check the probe for isTypeMacro anyways.
+      // therefore I think it's reasonable to trade a more specific "inherits itself" error
+      // for a generic, yet understandable "cyclic reference" error
+      var probe = typedTypeConstructor(core.duplicate).tpe.typeSymbol
+      if (probe == null) probe = NoSymbol
+      probe.initialize
+
+      if (probe.isTrait || inMixinPosition) {
+        if (!argssAreTrivial) {
+          if (probe.isTrait) ConstrArgsInParentWhichIsTraitError(encodedtpt, probe)
+          else () // a class in a mixin position - this warrants an error in `validateParentClasses`
+                  // therefore here we do nothing, e.g. don't check that the # of ctor arguments
+                  // matches the # of ctor parameters or stuff like that
+        }
+        typedType(decodedtpt)
+      } else {
+        var supertpt = typedTypeConstructor(decodedtpt)
+        val supertparams = if (supertpt.hasSymbol) supertpt.symbol.typeParams else Nil
+        if (supertparams.nonEmpty) {
+          typedPrimaryConstrBody(templ) {
+            val supertpe = PolyType(supertparams, appliedType(supertpt.tpe, supertparams map (_.tpeHK)))
+            val supercall = New(supertpe, mmap(argss)(_.duplicate))
+            val treeInfo.Applied(Select(ctor, nme.CONSTRUCTOR), _, _) = supercall
+            ctor setType supertpe // this is an essential hack, otherwise it will occasionally fail to typecheck
+            atPos(supertpt.pos.focus)(supercall)
+          } match {
+            case EmptyTree => MissingTypeArgumentsParentTpeError(supertpt)
+            case tpt => supertpt = TypeTree(tpt.tpe) setPos supertpt.pos.focus
           }
         }
-        if (supertpt.tpe.typeSymbol == AnyClass && firstParent.isTrait)
-          supertpt.tpe = AnyRefClass.tpe
-
-        // Determine
-        //  - supertparams: Missing type parameters from supertype
-        //  - supertpe: Given supertype, polymorphic in supertparams
-        val supertparams = if (supertpt.hasSymbol) supertpt.symbol.typeParams else List()
-        var supertpe = supertpt.tpe
-        if (!supertparams.isEmpty)
-          supertpe = PolyType(supertparams, appliedType(supertpe, supertparams map (_.tpeHK)))
-
-        // A method to replace a super reference by a New in a supercall
-        def transformSuperCall(scall: Tree): Tree = (scall: @unchecked) match {
-          case Apply(fn, args) =>
-            treeCopy.Apply(scall, transformSuperCall(fn), args map (_.duplicate))
-          case Select(Super(_, _), nme.CONSTRUCTOR) =>
-            treeCopy.Select(
-              scall,
-              atPos(supertpt.pos.focus)(New(TypeTree(supertpe)) setType supertpe),
-              nme.CONSTRUCTOR)
-        }
-
-        treeInfo.firstConstructor(templ.body) match {
-          case constr @ DefDef(_, _, _, vparamss, _, cbody @ Block(cstats, cunit)) =>
-            // Convert constructor body to block in environment and typecheck it
-            val (preSuperStats, superCall) = {
-              val (stats, rest) = cstats span (x => !treeInfo.isSuperConstrCall(x))
-              (stats map (_.duplicate), if (rest.isEmpty) EmptyTree else rest.head.duplicate)
-            }
-            val cstats1 = if (superCall == EmptyTree) preSuperStats else preSuperStats :+ superCall
-            val cbody1 = treeCopy.Block(cbody, preSuperStats, superCall match {
-              case Apply(_, _) if supertparams.nonEmpty => transformSuperCall(superCall)
-              case _                                    => cunit.duplicate
-            })
-            val outercontext = context.outer
-
-            assert(clazz != NoSymbol, templ)
-            val cscope = outercontext.makeNewScope(constr, outercontext.owner)
-            val cbody2 = newTyper(cscope) // called both during completion AND typing.
-                .typePrimaryConstrBody(clazz,
-                  cbody1, supertparams, clazz.unsafeTypeParams, vparamss map (_.map(_.duplicate)))
-
-            superCall match {
-              case Apply(_, _) =>
-                val sarg = treeInfo.firstArgument(superCall)
-                if (sarg != EmptyTree && supertpe.typeSymbol != firstParent)
-                  ConstrArgsInTraitParentTpeError(sarg, firstParent)
-                if (!supertparams.isEmpty)
-                  supertpt = TypeTree(cbody2.tpe) setPos supertpt.pos.focus
-              case _ =>
-                if (!supertparams.isEmpty)
-                  MissingTypeArgumentsParentTpeError(supertpt)
-            }
+        // this is the place where we tell the typer what argss should be used for the super call
+        // if argss are nullary or empty, then (see the docs for `typedPrimaryConstrBody`)
+        // the super call dummy is already good enough, so we don't need to do anything
+        if (argssAreTrivial) supertpt else supertpt updateAttachment SuperCallArgsAttachment(argss)
+      }
+    }
 
-            val preSuperVals = treeInfo.preSuperFields(templ.body)
-            if (preSuperVals.isEmpty && preSuperStats.nonEmpty)
-              debugwarn("Wanted to zip empty presuper val list with " + preSuperStats)
-            else
-              map2(preSuperStats, preSuperVals)((ldef, gdef) => gdef.tpt.tpe = ldef.symbol.tpe)
+    /** Typechecks the mishmash of trees that happen to be stuffed into the primary constructor of a given template.
+     *  Before commencing the typecheck, replaces the `pendingSuperCall` dummy with the result of `actualSuperCall`.
+     *  `actualSuperCall` can return `EmptyTree`, in which case the dummy is replaced with a literal unit.
+     *
+     *  ***Return value and side effects***
+     *
+     *  If a super call is present in the primary constructor and is not erased by the transform, returns it typechecked.
+     *  Otherwise (e.g. if the primary constructor is missing or the super call isn't there) returns `EmptyTree`.
+     *
+     *  As a side effect, this method attributes the underlying fields of early vals.
+     *  Early vals aren't typechecked anywhere else, so it's essential to call `typedPrimaryConstrBody`
+     *  at least once per definition. It'd be great to disentangle this logic at some point.
+     *
+     *  ***Example***
+     *
+     *  For the following definition:
+     *
+     *    class D extends {
+     *      val x = 2
+     *      val y = 4
+     *    } with B(x)(3) with C(y) with T
+     *
+     *  the primary constructor of `templ` will be:
+     *
+     *    Block(List(
+     *      ValDef(NoMods, x, TypeTree(), 2)
+     *      ValDef(NoMods, y, TypeTree(), 4)
+     *      global.pendingSuperCall,
+     *      Literal(Constant(())))
+     *
+     *  Note the `pendingSuperCall` part. This is the representation of a fill-me-in-later supercall dummy,
+     *  which encodes the fact that supercall argss are unknown during parsing and need to be transplanted
+     *  from one of the parent types. Read more about why the argss are unknown in `tools.nsc.ast.Trees.Template`.
+     */
+    private def typedPrimaryConstrBody(templ: Template)(actualSuperCall: => Tree): Tree =
+      treeInfo.firstConstructor(templ.body) match {
+        case ctor @ DefDef(_, _, _, vparamss, _, cbody @ Block(cstats, cunit)) =>
+          val (preSuperStats, superCall) = {
+            val (stats, rest) = cstats span (x => !treeInfo.isSuperConstrCall(x))
+            (stats map (_.duplicate), if (rest.isEmpty) EmptyTree else rest.head.duplicate)
+          }
+          val superCall1 = (superCall match {
+            case global.pendingSuperCall => actualSuperCall
+            case EmptyTree => EmptyTree
+          }) orElse cunit
+          val cbody1 = treeCopy.Block(cbody, preSuperStats, superCall1)
+
+          val clazz = context.owner
+          assert(clazz != NoSymbol, templ)
+          val cscope = context.outer.makeNewScope(ctor, context.outer.owner)
+          val cbody2 = { // called both during completion AND typing.
+            val typer1 = newTyper(cscope)
+            // XXX: see about using the class's symbol....
+            clazz.unsafeTypeParams foreach (sym => typer1.context.scope.enter(sym))
+            typer1.namer.enterValueParams(vparamss map (_.map(_.duplicate)))
+            typer1.typed(cbody1)
+          }
 
-          case _ =>
-            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)
-        }
-*/
+          val preSuperVals = treeInfo.preSuperFields(templ.body)
+          if (preSuperVals.isEmpty && preSuperStats.nonEmpty)
+            debugwarn("Wanted to zip empty presuper val list with " + preSuperStats)
+          else
+            map2(preSuperStats, preSuperVals)((ldef, gdef) => gdef.tpt.tpe = ldef.symbol.tpe)
 
-        //Console.println("parents("+clazz") = "+supertpt :: mixins);//DEBUG
+          if (superCall1 == cunit) EmptyTree else cbody2
+        case _ =>
+          EmptyTree
+      }
 
-        // Certain parents are added in the parser before it is known whether
-        // that class also declared them as parents.  For instance, this is an
-        // error unless we take corrective action here:
-        //
-        //   case class Foo() extends Serializable
-        //
-        // So we strip the duplicates before typer.
-        def fixDuplicates(remaining: List[Tree]): List[Tree] = remaining match {
-          case Nil      => Nil
-          case x :: xs  =>
-            val sym = x.symbol
-            x :: fixDuplicates(
-              if (isPossibleSyntheticParent(sym)) xs filterNot (_.symbol == sym)
-              else xs
-            )
+    /** Makes sure that the first type tree in the list of parent types is always a class.
+     *  If the first parent is a trait, prepend its supertype to the list until it's a class.
+     */
+    private def normalizeFirstParent(parents: List[Tree]): List[Tree] = parents match {
+      case first :: rest if treeInfo.isTraitRef(first) =>
+        def explode(supertpt: Tree, acc: List[Tree]): List[Tree] = {
+          if (treeInfo.isTraitRef(supertpt)) {
+            val supertpt1 = typedType(supertpt)
+            if (!supertpt1.isErrorTyped) {
+              val supersupertpt = TypeTree(supertpt1.tpe.firstParent) setPos supertpt.pos.focus
+              return explode(supersupertpt, supertpt1 :: acc)
+            }
+          }
+          if (supertpt.tpe.typeSymbol == AnyClass) supertpt.tpe = AnyRefClass.tpe
+          supertpt :: acc
         }
+        explode(first, Nil) ++ rest
+      case _ => parents
+    }
 
-        fixDuplicates(supertpt :: mixins) mapConserve (tpt => checkNoEscaping.privates(clazz, tpt))
-      }
-      catch {
-        case ex: TypeError =>
-          // fallback in case of cyclic errors
-          // @H none of the tests enter here but I couldn't rule it out
-          log("Type error calculating parents in template " + templ)
-          log("Error: " + ex)
-          ParentTypesError(templ, ex)
-          List(TypeTree(AnyRefClass.tpe))
-      }
+    /** Certain parents are added in the parser before it is known whether
+     *  that class also declared them as parents. For instance, this is an
+     *  error unless we take corrective action here:
+     *
+     *    case class Foo() extends Serializable
+     *
+     *  So we strip the duplicates before typer.
+     */
+    private def fixDuplicateSyntheticParents(parents: List[Tree]): List[Tree] = parents match {
+      case Nil      => Nil
+      case x :: xs  =>
+        val sym = x.symbol
+        x :: fixDuplicateSyntheticParents(
+          if (isPossibleSyntheticParent(sym)) xs filterNot (_.symbol == sym)
+          else xs
+        )
+    }
+
+    def parentTypes(templ: Template): List[Tree] = templ.parents match {
+      case Nil => List(atPos(templ.pos)(TypeTree(AnyRefClass.tpe)))
+      case first :: rest =>
+        try {
+          val supertpts = fixDuplicateSyntheticParents(normalizeFirstParent(
+            typedParentType(first, templ, inMixinPosition = false) +:
+            (rest map (typedParentType(_, templ, inMixinPosition = true)))))
+
+          // if that is required to infer the targs of a super call
+          // typedParentType calls typedPrimaryConstrBody to do the inferring typecheck
+          // as a side effect, that typecheck also assigns types to the fields underlying early vals
+          // however if inference is not required, the typecheck doesn't happen
+          // and therefore early fields have their type trees not assigned
+          // here we detect this situation and take preventive measures
+          if (treeInfo.hasUntypedPreSuperFields(templ.body))
+            typedPrimaryConstrBody(templ)(EmptyTree)
+
+          supertpts mapConserve (tpt => checkNoEscaping.privates(context.owner, tpt))
+        } catch {
+          case ex: TypeError =>
+            // fallback in case of cyclic errors
+            // @H none of the tests enter here but I couldn't rule it out
+            // upd. @E when a definitions inherits itself, we end up here
+            // because `typedParentType` triggers `initialize` for parent types symbols
+            log("Type error calculating parents in template " + templ)
+            log("Error: " + ex)
+            ParentTypesError(templ, ex)
+            List(TypeTree(AnyRefClass.tpe))
+        }
+    }
 
     /** <p>Check that</p>
      *  <ul>
@@ -1844,9 +1957,12 @@ trait Typers extends Modes with Adaptations with Tags {
       // the following is necessary for templates generated later
       assert(clazz.info.decls != EmptyScope, clazz)
       enterSyms(context.outer.make(templ, clazz, clazz.info.decls), templ.body)
-      validateParentClasses(parents1, selfType)
+      if (!templ.isErrorTyped) // if `parentTypes` has invalidated the template, don't validate it anymore
+        validateParentClasses(parents1, selfType)
       if (clazz.isCase)
         validateNoCaseAncestor(clazz)
+      if (clazz.isTrait && hasSuperArgs(parents1.head))
+        ConstrArgsInParentOfTraitError(parents1.head, clazz)
 
       if ((clazz isSubClass ClassfileAnnotationClass) && !clazz.owner.isPackageClass)
         unit.error(clazz.pos, "inner classes cannot be classfile annotations")
@@ -1854,9 +1970,21 @@ trait Typers extends Modes with Adaptations with Tags {
       if (!phase.erasedTypes && !clazz.info.resultType.isError) // @S: prevent crash for duplicated type members
         checkFinitary(clazz.info.resultType.asInstanceOf[ClassInfoType])
 
-      val body =
-        if (isPastTyper || reporter.hasErrors) templ.body
-        else templ.body flatMap rewrappingWrapperTrees(namer.addDerivedTrees(Typer.this, _))
+      val body = {
+        val body =
+          if (isPastTyper || reporter.hasErrors) templ.body
+          else templ.body flatMap rewrappingWrapperTrees(namer.addDerivedTrees(Typer.this, _))
+        val primaryCtor = treeInfo.firstConstructor(body)
+        val primaryCtor1 = primaryCtor match {
+          case DefDef(_, _, _, _, _, Block(earlyVals :+ global.pendingSuperCall, unit)) =>
+            val argss = superCallArgs(parents1.head) getOrElse Nil
+            val pos = wrappingPos(parents1.head.pos, argss.flatten)
+            val superCall = atPos(pos)(PrimarySuperCall(argss))
+            deriveDefDef(primaryCtor)(block => Block(earlyVals :+ superCall, unit) setPos pos) setPos pos
+          case _ => primaryCtor
+        }
+        body mapConserve { case `primaryCtor` => primaryCtor1; case stat => stat }
+      }
 
       val body1 = typedStats(body, templ.symbol)
 
@@ -2603,7 +2731,7 @@ trait Typers extends Modes with Adaptations with Tags {
         if (members.head eq EmptyTree) setError(tree)
         else {
           val typedBlock = typedPos(tree.pos, mode, pt) {
-            Block(ClassDef(anonClass, NoMods, ListOfNil, ListOfNil, members, tree.pos.focus), atPos(tree.pos.focus)(New(anonClass.tpe)))
+            Block(ClassDef(anonClass, NoMods, ListOfNil, members, tree.pos.focus), atPos(tree.pos.focus)(New(anonClass.tpe)))
           }
           // Don't leak implementation details into the type, see SI-6575
           if (isPartial && !typedBlock.isErrorTyped)
@@ -3891,7 +4019,7 @@ trait Typers extends Modes with Adaptations with Tags {
         case DynamicApplicationNamed(qual, _) if acceptsApplyDynamic(qual.tpe.widen) => true
         case _ => false
           // look deeper?
-          // val methPart = treeInfo.methPart(fun)
+          // val treeInfo.Applied(methPart, _, _) = fun
           // println("methPart of "+ fun +" is "+ methPart)
           // if (methPart ne fun) isApplyDynamicNamed(methPart)
           // else false
@@ -3927,7 +4055,7 @@ trait Typers extends Modes with Adaptations with Tags {
        */
       def mkInvoke(cxTree: Tree, tree: Tree, qual: Tree, name: Name): Option[Tree] = {
         log(s"dyna.mkInvoke($cxTree, $tree, $qual, $name)")
-        val treeSelection = treeInfo.methPart(tree)
+        val treeInfo.Applied(treeSelection, _, _) = tree
         def isDesugaredApply = treeSelection match {
           case Select(`qual`, nme.apply) => true
           case _                         => false
@@ -3940,7 +4068,7 @@ trait Typers extends Modes with Adaptations with Tags {
           // not supported: foo.bar(a1,..., an: _*)
           def hasStar(args: List[Tree]) = treeInfo.isWildcardStarArgList(args)
           def applyOp(args: List[Tree]) = if (hasNamed(args)) nme.applyDynamicNamed else nme.applyDynamic
-          def matches(t: Tree)          = isDesugaredApply || treeInfo.methPart(t) == treeSelection
+          def matches(t: Tree)          = isDesugaredApply || treeInfo.dissectApplied(t).core == treeSelection
 
           /** Note that the trees which arrive here are potentially some distance from
            *  the trees of direct interest. `cxTree` is some enclosing expression which
@@ -3958,9 +4086,8 @@ trait Typers extends Modes with Adaptations with Tags {
             case _                                => t.children flatMap findSelection headOption
           }
           findSelection(cxTree) match {
-            case Some((opName, tapply)) =>
-              val targs = treeInfo.typeArguments(tapply)
-              val fun   = gen.mkTypeApply(Select(qual, opName), targs)
+            case Some((opName, treeInfo.Applied(_, targs, _))) =>
+              val fun = gen.mkTypeApply(Select(qual, opName), targs)
               atPos(qual.pos)(Apply(fun, Literal(Constant(name.decode)) :: Nil))
             case _ =>
               setError(tree)
@@ -4149,8 +4276,8 @@ trait Typers extends Modes with Adaptations with Tags {
           return fail()
 
         if (treeInfo.mayBeVarGetter(varsym)) {
-          treeInfo.methPart(lhs1) match {
-            case Select(qual, name) =>
+          lhs1 match {
+            case treeInfo.Applied(Select(qual, name), _, _) =>
               val sel = Select(qual, nme.getterToSetter(name.toTermName)) setPos lhs.pos
               val app = Apply(sel, List(rhs)) setPos tree.pos
               return typed(app, mode, pt)
@@ -4568,9 +4695,9 @@ trait Typers extends Modes with Adaptations with Tags {
             }
 
           case Apply(fn, indices) =>
-            treeInfo.methPart(fn) match {
-              case Select(table, nme.apply) => mkUpdate(table, indices)
-              case _                        => UnexpectedTreeAssignmentConversionError(qual)
+            fn match {
+              case treeInfo.Applied(Select(table, nme.apply), _, _) => mkUpdate(table, indices)
+              case _  => UnexpectedTreeAssignmentConversionError(qual)
             }
         }
         typed1(tree1, mode, pt)
@@ -5602,21 +5729,21 @@ trait Typers extends Modes with Adaptations with Tags {
         // enough to see those. See #3938
         ConstructorPrefixError(tree, restpe)
       } else {
-	      //@M fix for #2208
-	      // if there are no type arguments, normalization does not bypass any checks, so perform it to get rid of AnyRef
-	      if (result.tpe.typeArgs.isEmpty) {
-	        // minimal check: if(result.tpe.typeSymbolDirect eq AnyRefClass) {
-	        // must expand the fake AnyRef type alias, because bootstrapping (init in Definitions) is not
-	        // designed to deal with the cycles in the scala package (ScalaObject extends
-	        // AnyRef, but the AnyRef type alias is entered after the scala package is
-	        // loaded and completed, so that ScalaObject is unpickled while AnyRef is not
-	        // yet defined )
-	        // !!! TODO - revisit now that ScalaObject is gone.
-	        result setType(restpe)
-	      } else { // must not normalize: type application must be (bounds-)checked (during RefChecks), see #2208
-	        // during uncurry (after refchecks), all types are normalized
-	        result
-	      }
+        //@M fix for #2208
+        // if there are no type arguments, normalization does not bypass any checks, so perform it to get rid of AnyRef
+        if (result.tpe.typeArgs.isEmpty) {
+          // minimal check: if(result.tpe.typeSymbolDirect eq AnyRefClass) {
+          // must expand the fake AnyRef type alias, because bootstrapping (init in Definitions) is not
+          // designed to deal with the cycles in the scala package (ScalaObject extends
+          // AnyRef, but the AnyRef type alias is entered after the scala package is
+          // loaded and completed, so that ScalaObject is unpickled while AnyRef is not
+          // yet defined )
+          // !!! TODO - revisit now that ScalaObject is gone.
+          result setType(restpe)
+        } else { // must not normalize: type application must be (bounds-)checked (during RefChecks), see #2208
+          // during uncurry (after refchecks), all types are normalized
+          result
+        }
       }
     }
 
diff --git a/src/compiler/scala/tools/nsc/typechecker/Unapplies.scala b/src/compiler/scala/tools/nsc/typechecker/Unapplies.scala
index bf44b65406..a34d7389bf 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Unapplies.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Unapplies.scala
@@ -126,7 +126,7 @@ trait Unapplies extends ast.TreeDSL
     ModuleDef(
       Modifiers(cdef.mods.flags & AccessFlags | SYNTHETIC, cdef.mods.privateWithin),
       cdef.name.toTermName,
-      Template(parents, emptyValDef, NoMods, Nil, ListOfNil, body, cdef.impl.pos.focus))
+      Template(parents, emptyValDef, NoMods, Nil, body, cdef.impl.pos.focus))
   }
 
   private val caseMods = Modifiers(SYNTHETIC | CASE)
diff --git a/src/compiler/scala/tools/reflect/ToolBoxFactory.scala b/src/compiler/scala/tools/reflect/ToolBoxFactory.scala
index 95135b84e0..0125f1b189 100644
--- a/src/compiler/scala/tools/reflect/ToolBoxFactory.scala
+++ b/src/compiler/scala/tools/reflect/ToolBoxFactory.scala
@@ -230,7 +230,6 @@ abstract class ToolBoxFactory[U <: JavaUniverse](val u: U) { factorySelf =>
                   emptyValDef,
                   NoMods,
                   List(),
-                  List(List()),
                   List(methdef),
                   NoPosition))
           trace("wrapped: ")(showAttributed(moduledef, true, true, settings.Yshowsymkinds.value))
diff --git a/src/reflect/scala/reflect/api/BuildUtils.scala b/src/reflect/scala/reflect/api/BuildUtils.scala
index 0c8e81a220..8f256aa1f5 100644
--- a/src/reflect/scala/reflect/api/BuildUtils.scala
+++ b/src/reflect/scala/reflect/api/BuildUtils.scala
@@ -59,8 +59,6 @@ private[reflect] trait BuildUtils { self: Universe =>
 
     def flagsFromBits(bits: Long): FlagSet
 
-    def emptyValDef: ValDef
-
     def This(sym: Symbol): Tree
 
     def Select(qualifier: Tree, sym: Symbol): Select
diff --git a/src/reflect/scala/reflect/api/Trees.scala b/src/reflect/scala/reflect/api/Trees.scala
index 0937a93738..cfa6315797 100644
--- a/src/reflect/scala/reflect/api/Trees.scala
+++ b/src/reflect/scala/reflect/api/Trees.scala
@@ -75,11 +75,26 @@ trait Trees { self: Universe =>
     def isDef: Boolean
 
     /** Is this tree one of the empty trees?
+     *
      *  Empty trees are: the `EmptyTree` null object, `TypeTree` instances that don't carry a type
      *  and the special `emptyValDef` singleton.
+     *
+     *  In the compiler the `isEmpty` check and the derived `orElse` method are mostly used
+     *  as a check for a tree being a null object (`EmptyTree` for term trees and empty TypeTree for type trees).
+     *
+     *  Unfortunately `emptyValDef` is also considered to be `isEmpty`, but this is deemed to be
+     *  a conceptual mistake pending a fix in https://issues.scala-lang.org/browse/SI-6762.
+     *
+     *  @see `canHaveAttrs`
      */
     def isEmpty: Boolean
 
+    /** Can this tree carry attributes (i.e. symbols, types or positions)?
+     *  Typically the answer is yes, except for the `EmptyTree` null object and
+     *  two special singletons: `emptyValDef` and `pendingSuperCall`.
+     */
+    def canHaveAttrs: Boolean
+
     /** The canonical way to test if a Tree represents a term.
      */
     def isTerm: Boolean
@@ -2405,6 +2420,15 @@ trait Trees { self: Universe =>
    */
   val emptyValDef: ValDef
 
+  /** An empty superclass constructor call corresponding to:
+   *    super.<init>()
+   *  This is used as a placeholder in the primary constructor body in class templates
+   *  to denote the insertion point of a call to superclass constructor after the typechecker
+   *  figures out the superclass of a given template.
+   *  @group Trees
+   */
+  val pendingSuperCall: Apply
+
 // ---------------------- factories ----------------------------------------------
 
   /** A factory method for `ClassDef` nodes.
@@ -2907,7 +2931,8 @@ trait Trees { self: Universe =>
       trees mapConserve (tree => transform(tree).asInstanceOf[TypeDef])
     /** Transforms a `ValDef`. */
     def transformValDef(tree: ValDef): ValDef =
-      if (tree.isEmpty) tree else transform(tree).asInstanceOf[ValDef]
+      if (tree eq emptyValDef) tree
+      else transform(tree).asInstanceOf[ValDef]
     /** Transforms a list of `ValDef` nodes. */
     def transformValDefs(trees: List[ValDef]): List[ValDef] =
       trees mapConserve (transformValDef(_))
diff --git a/src/reflect/scala/reflect/internal/BaseTypeSeqs.scala b/src/reflect/scala/reflect/internal/BaseTypeSeqs.scala
index d72f08674e..3c2b128c52 100644
--- a/src/reflect/scala/reflect/internal/BaseTypeSeqs.scala
+++ b/src/reflect/scala/reflect/internal/BaseTypeSeqs.scala
@@ -60,7 +60,7 @@ trait BaseTypeSeqs {
         elems(i) match {
           case rtp @ RefinedType(variants, decls) =>
             // can't assert decls.isEmpty; see t0764
-            //if (!decls.isEmpty) assert(false, "computing closure of "+this+":"+this.isInstanceOf[RefinedType]+"/"+closureCache(j))
+            //if (!decls.isEmpty) abort("computing closure of "+this+":"+this.isInstanceOf[RefinedType]+"/"+closureCache(j))
             //Console.println("compute closure of "+this+" => glb("+variants+")")
             pending += i
             try {
diff --git a/src/reflect/scala/reflect/internal/BuildUtils.scala b/src/reflect/scala/reflect/internal/BuildUtils.scala
index 9f41f0336e..b1b0c5b60b 100644
--- a/src/reflect/scala/reflect/internal/BuildUtils.scala
+++ b/src/reflect/scala/reflect/internal/BuildUtils.scala
@@ -47,8 +47,6 @@ trait BuildUtils { self: SymbolTable =>
 
     def flagsFromBits(bits: Long): FlagSet = bits
 
-    def emptyValDef: ValDef = self.emptyValDef
-
     def This(sym: Symbol): Tree = self.This(sym)
 
     def Select(qualifier: Tree, sym: Symbol): Select = self.Select(qualifier, sym)
diff --git a/src/reflect/scala/reflect/internal/Importers.scala b/src/reflect/scala/reflect/internal/Importers.scala
index 43902c1930..2f2b02975c 100644
--- a/src/reflect/scala/reflect/internal/Importers.scala
+++ b/src/reflect/scala/reflect/internal/Importers.scala
@@ -334,6 +334,8 @@ trait Importers extends api.Importers { self: SymbolTable =>
           new ModuleDef(importModifiers(mods), importName(name).toTermName, importTemplate(impl))
         case from.emptyValDef =>
           emptyValDef
+        case from.pendingSuperCall =>
+          pendingSuperCall
         case from.ValDef(mods, name, tpt, rhs) =>
           new ValDef(importModifiers(mods), importName(name).toTermName, importTree(tpt), importTree(rhs))
         case from.DefDef(mods, name, tparams, vparamss, tpt, rhs) =>
diff --git a/src/reflect/scala/reflect/internal/Positions.scala b/src/reflect/scala/reflect/internal/Positions.scala
index faa161d6b1..f8c670827a 100644
--- a/src/reflect/scala/reflect/internal/Positions.scala
+++ b/src/reflect/scala/reflect/internal/Positions.scala
@@ -38,7 +38,7 @@ trait Positions extends api.Positions { self: SymbolTable =>
   protected class DefaultPosAssigner extends PosAssigner {
     var pos: Position = _
     override def traverse(t: Tree) {
-      if (t eq EmptyTree) ()
+      if (!t.canHaveAttrs) ()
       else if (t.pos == NoPosition) {
         t.setPos(pos)
         super.traverse(t)   // TODO: bug? shouldn't the traverse be outside of the if?
diff --git a/src/reflect/scala/reflect/internal/Printers.scala b/src/reflect/scala/reflect/internal/Printers.scala
index 80d247c0ea..a8085a4c58 100644
--- a/src/reflect/scala/reflect/internal/Printers.scala
+++ b/src/reflect/scala/reflect/internal/Printers.scala
@@ -435,7 +435,7 @@ trait Printers extends api.Printers { self: SymbolTable =>
         case tree =>
           xprintTree(this, tree)
       }
-      if (printTypes && tree.isTerm && !tree.isEmpty) {
+      if (printTypes && tree.isTerm && tree.canHaveAttrs) {
         print("{", if (tree.tpe eq null) "<null>" else tree.tpe.toString, "}")
       }
     }
@@ -542,8 +542,10 @@ trait Printers extends api.Printers { self: SymbolTable =>
           print(")")
         case EmptyTree =>
           print("EmptyTree")
-        case emptyValDef: AnyRef if emptyValDef eq self.emptyValDef =>
+        case self.emptyValDef =>
           print("emptyValDef")
+        case self.pendingSuperCall =>
+          print("pendingSuperCall")
         case tree: Tree =>
           val hasSymbol = tree.hasSymbol && tree.symbol != NoSymbol
           val isError = hasSymbol && tree.symbol.name.toString == nme.ERROR.toString
diff --git a/src/reflect/scala/reflect/internal/StdNames.scala b/src/reflect/scala/reflect/internal/StdNames.scala
index 5e7f5777b2..c870d8972d 100644
--- a/src/reflect/scala/reflect/internal/StdNames.scala
+++ b/src/reflect/scala/reflect/internal/StdNames.scala
@@ -730,6 +730,7 @@ trait StdNames {
     val null_ : NameType               = "null"
     val ofDim: NameType                = "ofDim"
     val origin: NameType               = "origin"
+    val pendingSuperCall: NameType     = "pendingSuperCall"
     val prefix : NameType              = "prefix"
     val productArity: NameType         = "productArity"
     val productElement: NameType       = "productElement"
diff --git a/src/reflect/scala/reflect/internal/Symbols.scala b/src/reflect/scala/reflect/internal/Symbols.scala
index a27afe9dfd..a4287fb181 100644
--- a/src/reflect/scala/reflect/internal/Symbols.scala
+++ b/src/reflect/scala/reflect/internal/Symbols.scala
@@ -3090,7 +3090,7 @@ trait Symbols extends api.Symbols { self: SymbolTable =>
   class RefinementClassSymbol protected[Symbols] (owner0: Symbol, pos0: Position)
   extends ClassSymbol(owner0, pos0, tpnme.REFINE_CLASS_NAME) {
     override def name_=(name: Name) {
-      assert(false, "Cannot set name of RefinementClassSymbol to " + name)
+      abort("Cannot set name of RefinementClassSymbol to " + name)
       super.name_=(name)
     }
     override def isRefinementClass       = true
diff --git a/src/reflect/scala/reflect/internal/TreeInfo.scala b/src/reflect/scala/reflect/internal/TreeInfo.scala
index 8ad15f37e4..8908036442 100644
--- a/src/reflect/scala/reflect/internal/TreeInfo.scala
+++ b/src/reflect/scala/reflect/internal/TreeInfo.scala
@@ -159,7 +159,7 @@ abstract class TreeInfo {
    * Also accounts for varargs.
    */
   private def applyMethodParameters(fn: Tree): List[Symbol] = {
-    val depth  = applyDepth(fn)
+    val depth  = dissectApplied(fn).applyDepth
     // There could be applies which go beyond the parameter list(s),
     // being applied to the result of the method call.
     // !!! Note that this still doesn't seem correct, although it should
@@ -195,29 +195,26 @@ abstract class TreeInfo {
     def isGetter  = mayBeVarGetter(sym) && sym.owner.info.member(nme.getterToSetter(sym.name.toTermName)) != NoSymbol
 
     tree match {
-      case Ident(_)         => isVar
-      case Select(_, _)     => isVar || isGetter
-      case _                =>
-        methPart(tree) match {
-          case Select(qual, nme.apply)  => qual.tpe.member(nme.update) != NoSymbol
-          case _                        => false
-        }
+      case Ident(_)                               => isVar
+      case Select(_, _)                           => isVar || isGetter
+      case Applied(Select(qual, nme.apply), _, _) => qual.tpe.member(nme.update) != NoSymbol
+      case _                                      => false
     }
   }
 
   /** Is tree a self constructor call this(...)? I.e. a call to a constructor of the
    *  same object?
    */
-  def isSelfConstrCall(tree: Tree): Boolean = methPart(tree) match {
-    case Ident(nme.CONSTRUCTOR)
-       | Select(This(_), nme.CONSTRUCTOR) => true
+  def isSelfConstrCall(tree: Tree): Boolean = tree match {
+    case Applied(Ident(nme.CONSTRUCTOR), _, _) => true
+    case Applied(Select(This(_), nme.CONSTRUCTOR), _, _) => true
     case _ => false
   }
 
   /** Is tree a super constructor call?
    */
-  def isSuperConstrCall(tree: Tree): Boolean = methPart(tree) match {
-    case Select(Super(_, _), nme.CONSTRUCTOR) => true
+  def isSuperConstrCall(tree: Tree): Boolean = tree match {
+    case Applied(Select(Super(_, _), nme.CONSTRUCTOR), _, _) => true
     case _ => false
   }
 
@@ -333,6 +330,9 @@ abstract class TreeInfo {
   def preSuperFields(stats: List[Tree]): List[ValDef] =
     stats collect { case vd: ValDef if isEarlyValDef(vd) => vd }
 
+  def hasUntypedPreSuperFields(stats: List[Tree]): Boolean =
+    preSuperFields(stats) exists (_.tpt.isEmpty)
+
   def isEarlyDef(tree: Tree) = tree match {
     case TypeDef(mods, _, _, _) => mods hasFlag PRESUPER
     case ValDef(mods, _, _, _) => mods hasFlag PRESUPER
@@ -399,22 +399,6 @@ abstract class TreeInfo {
     case _                                  => false
   }
 
-  /** If this tree represents a type application (after unwrapping
-   *  any applies) the first type argument.  Otherwise, EmptyTree.
-   */
-  def firstTypeArg(tree: Tree): Tree = tree match {
-    case Apply(fn, _)            => firstTypeArg(fn)
-    case TypeApply(_, targ :: _) => targ
-    case _                       => EmptyTree
-  }
-
-  /** If this tree represents a type application the type arguments. Otherwise Nil.
-   */
-  def typeArguments(tree: Tree): List[Tree] = tree match {
-    case TypeApply(_, targs) => targs
-    case _                   => Nil
-  }
-
   /** If this tree has type parameters, those.  Otherwise Nil.
    */
   def typeParameters(tree: Tree): List[TypeDef] = tree match {
@@ -513,31 +497,126 @@ abstract class TreeInfo {
   def isSynthCaseSymbol(sym: Symbol) = sym hasAllFlags SYNTH_CASE_FLAGS
   def hasSynthCaseSymbol(t: Tree)    = t.symbol != null && isSynthCaseSymbol(t.symbol)
 
+  def isTraitRef(tree: Tree): Boolean = {
+    val sym = if (tree.tpe != null) tree.tpe.typeSymbol else null
+    ((sym ne null) && sym.initialize.isTrait)
+  }
 
-  /** The method part of an application node
+  /** Applications in Scala can have one of the following shapes:
+   *
+   *    1) naked core: Ident(_) or Select(_, _) or basically anything else
+   *    2) naked core with targs: TypeApply(core, targs) or AppliedTypeTree(core, targs)
+   *    3) apply or several applies wrapping a core: Apply(core, _), or Apply(Apply(core, _), _), etc
+   *
+   *  This class provides different ways to decompose applications and simplifies their analysis.
+   *
+   *  ***Examples***
+   *  (TypeApply in the examples can be replaced with AppliedTypeTree)
+   *
+   *    Ident(foo):
+   *      * callee = Ident(foo)
+   *      * core = Ident(foo)
+   *      * targs = Nil
+   *      * argss = Nil
+   *
+   *    TypeApply(foo, List(targ1, targ2...))
+   *      * callee = TypeApply(foo, List(targ1, targ2...))
+   *      * core = foo
+   *      * targs = List(targ1, targ2...)
+   *      * argss = Nil
+   *
+   *    Apply(foo, List(arg1, arg2...))
+   *      * callee = foo
+   *      * core = foo
+   *      * targs = Nil
+   *      * argss = List(List(arg1, arg2...))
+   *
+   *    Apply(Apply(foo, List(arg21, arg22, ...)), List(arg11, arg12...))
+   *      * callee = foo
+   *      * core = foo
+   *      * targs = Nil
+   *      * argss = List(List(arg11, arg12...), List(arg21, arg22, ...))
+   *
+   *    Apply(Apply(TypeApply(foo, List(targs1, targs2, ...)), List(arg21, arg22, ...)), List(arg11, arg12...))
+   *      * callee = TypeApply(foo, List(targs1, targs2, ...))
+   *      * core = foo
+   *      * targs = Nil
+   *      * argss = List(List(arg11, arg12...), List(arg21, arg22, ...))
    */
-  def methPart(tree: Tree): Tree = tree match {
-    case Apply(fn, _)           => methPart(fn)
-    case TypeApply(fn, _)       => methPart(fn)
-    case AppliedTypeTree(fn, _) => methPart(fn)
-    case _                      => tree
+  class Applied(val tree: Tree) {
+    /** The tree stripped of the possibly nested applications.
+     *  The original tree if it's not an application.
+     */
+    def callee: Tree = {
+      def loop(tree: Tree): Tree = tree match {
+        case Apply(fn, _) => loop(fn)
+        case tree         => tree
+      }
+      loop(tree)
+    }
+
+    /** The `callee` unwrapped from type applications.
+     *  The original `callee` if it's not a type application.
+     */
+    def core: Tree = callee match {
+      case TypeApply(fn, _)       => fn
+      case AppliedTypeTree(fn, _) => fn
+      case tree                   => tree
+    }
+
+    /** The type arguments of the `callee`.
+     *  `Nil` if the `callee` is not a type application.
+     */
+    def targs: List[Tree] = callee match {
+      case TypeApply(_, args)       => args
+      case AppliedTypeTree(_, args) => args
+      case _                        => Nil
+    }
+
+    /** (Possibly multiple lists of) value arguments of an application.
+     *  `Nil` if the `callee` is not an application.
+     */
+    def argss: List[List[Tree]] = {
+      def loop(tree: Tree): List[List[Tree]] = tree match {
+        case Apply(fn, args) => loop(fn) :+ args
+        case _               => Nil
+      }
+      loop(tree)
+    }
+
+    /** The depth of the nested applies: e.g. Apply(Apply(Apply(_, _), _), _)
+     *  has depth 3.  Continues through type applications (without counting them.)
+     */
+    def applyDepth: Int = {
+      def loop(tree: Tree): Int = tree match {
+        case Apply(fn, _)           => 1 + loop(fn)
+        case TypeApply(fn, _)       => loop(fn)
+        case AppliedTypeTree(fn, _) => loop(fn)
+        case _                      => 0
+      }
+      loop(tree)
+    }
   }
 
-  /** The depth of the nested applies: e.g. Apply(Apply(Apply(_, _), _), _)
-   *  has depth 3.  Continues through type applications (without counting them.)
+  /** Returns a wrapper that knows how to destructure and analyze applications.
    */
-  def applyDepth(tree: Tree): Int = tree match {
-    case Apply(fn, _)           => 1 + applyDepth(fn)
-    case TypeApply(fn, _)       => applyDepth(fn)
-    case AppliedTypeTree(fn, _) => applyDepth(fn)
-    case _                      => 0
-  }
-  def firstArgument(tree: Tree): Tree = tree match {
-    case Apply(fn, args) =>
-      val f = firstArgument(fn)
-      if (f == EmptyTree && !args.isEmpty) args.head else f
-    case _ =>
-      EmptyTree
+  def dissectApplied(tree: Tree) = new Applied(tree)
+
+  /** Destructures applications into important subparts described in `Applied` class,
+   *  namely into: core, targs and argss (in the specified order).
+   *
+   *  Trees which are not applications are also accepted. Their callee and core will
+   *  be equal to the input, while targs and argss will be Nil.
+   *
+   *  The provided extractors don't expose all the API of the `Applied` class.
+   *  For advanced use, call `dissectApplied` explicitly and use its methods instead of pattern matching.
+   */
+  object Applied {
+    def unapply(applied: Applied): Option[(Tree, List[Tree], List[List[Tree]])] =
+      Some((applied.core, applied.targs, applied.argss))
+
+    def unapply(tree: Tree): Option[(Tree, List[Tree], List[List[Tree]])] =
+      unapply(dissectApplied(tree))
   }
 
   /** Does list of trees start with a definition of
@@ -634,7 +713,7 @@ abstract class TreeInfo {
     }
 
     def unapply(tree: Tree) = refPart(tree) match {
-      case ref: RefTree => Some((ref.qualifier.symbol, ref.symbol, typeArguments(tree)))
+      case ref: RefTree => Some((ref.qualifier.symbol, ref.symbol, dissectApplied(tree).targs))
       case _            => None
     }
   }
diff --git a/src/reflect/scala/reflect/internal/Trees.scala b/src/reflect/scala/reflect/internal/Trees.scala
index 6df4b75a88..dceec18e57 100644
--- a/src/reflect/scala/reflect/internal/Trees.scala
+++ b/src/reflect/scala/reflect/internal/Trees.scala
@@ -36,6 +36,7 @@ trait Trees extends api.Trees { self: SymbolTable =>
     def isDef = false
 
     def isEmpty = false
+    def canHaveAttrs = true
 
     /** The canonical way to test if a Tree represents a term.
      */
@@ -228,14 +229,6 @@ trait Trees extends api.Trees { self: SymbolTable =>
     override def isDef = true
   }
 
-  case object EmptyTree extends TermTree {
-    val asList = List(this)
-    super.tpe_=(NoType)
-    override def tpe_=(t: Type) =
-      if (t != NoType) throw new UnsupportedOperationException("tpe_=("+t+") inapplicable for <empty>")
-    override def isEmpty = true
-  }
-
   abstract class MemberDef extends DefTree with MemberDefApi {
     def mods: Modifiers
     def keyword: String = this match {
@@ -599,6 +592,7 @@ trait Trees extends api.Trees { self: SymbolTable =>
         case _: ApplyToImplicitArgs => new ApplyToImplicitArgs(fun, args)
         case _: ApplyImplicitView => new ApplyImplicitView(fun, args)
         // TODO: ApplyConstructor ???
+        case self.pendingSuperCall => self.pendingSuperCall
         case _ => new Apply(fun, args)
       }).copyAttrs(tree)
     def ApplyDynamic(tree: Tree, qual: Tree, args: List[Tree]) =
@@ -961,12 +955,23 @@ trait Trees extends api.Trees { self: SymbolTable =>
 
   def ValDef(sym: Symbol): ValDef = ValDef(sym, EmptyTree)
 
-  object emptyValDef extends ValDef(Modifiers(PRIVATE), nme.WILDCARD, TypeTree(NoType), EmptyTree) {
-    override def isEmpty = true
+  trait CannotHaveAttrs extends Tree {
+    override def canHaveAttrs = false
+
+    private def unsupported(what: String, args: Any*) =
+      throw new UnsupportedOperationException(s"$what($args) inapplicable for "+self.toString)
+
     super.setPos(NoPosition)
-    override def setPos(pos: Position) = { assert(false); this }
+    override def setPos(pos: Position) = unsupported("setPos", pos)
+
+    super.setType(NoType)
+    override def tpe_=(t: Type) = if (t != NoType) unsupported("tpe_=", t)
   }
 
+  case object EmptyTree extends TermTree with CannotHaveAttrs { override def isEmpty = true; val asList = List(this) }
+  object emptyValDef extends ValDef(Modifiers(PRIVATE), nme.WILDCARD, TypeTree(NoType), EmptyTree) with CannotHaveAttrs
+  object pendingSuperCall extends Apply(Select(Super(This(tpnme.EMPTY), tpnme.EMPTY), nme.CONSTRUCTOR), List()) with CannotHaveAttrs
+
   def DefDef(sym: Symbol, mods: Modifiers, vparamss: List[List[ValDef]], rhs: Tree): DefDef =
     atPos(sym.pos) {
       assert(sym != NoSymbol)
@@ -1034,6 +1039,9 @@ trait Trees extends api.Trees { self: SymbolTable =>
   def New(tpe: Type, args: Tree*): Tree =
     ApplyConstructor(TypeTree(tpe), args.toList)
 
+  def New(tpe: Type, argss: List[List[Tree]]): Tree =
+    New(TypeTree(tpe), argss)
+
   def New(sym: Symbol, args: Tree*): Tree =
     New(sym.tpe, args: _*)
 
@@ -1114,7 +1122,7 @@ trait Trees extends api.Trees { self: SymbolTable =>
         traverse(annot); traverse(arg)
       case Template(parents, self, body) =>
         traverseTrees(parents)
-        if (!self.isEmpty) traverse(self)
+        if (self ne emptyValDef) traverse(self)
         traverseStats(body, tree.symbol)
       case Block(stats, expr) =>
         traverseTrees(stats); traverse(expr)
diff --git a/src/reflect/scala/reflect/internal/Types.scala b/src/reflect/scala/reflect/internal/Types.scala
index 0c4cda8313..d82692000d 100644
--- a/src/reflect/scala/reflect/internal/Types.scala
+++ b/src/reflect/scala/reflect/internal/Types.scala
@@ -1401,7 +1401,7 @@ trait Types extends api.Types { self: SymbolTable =>
     if (!sym.isClass) {
       // SI-6640 allow StubSymbols to reveal what's missing from the classpath before we trip the assertion.
       sym.failIfStub()
-      assert(false, sym)
+      abort(s"ThisType($sym) for sym which is not a class")
     }
 
     //assert(sym.isClass && !sym.isModuleClass || sym.isRoot, sym)
@@ -7067,7 +7067,7 @@ trait Types extends api.Types { self: SymbolTable =>
     case ExistentialType(tparams, quantified) :: rest =>
       mergePrefixAndArgs(quantified :: rest, variance, depth) map (existentialAbstraction(tparams, _))
     case _ =>
-      assert(false, tps); None
+      abort(s"mergePrefixAndArgs($tps, $variance, $depth): unsupported tps")
   }
 
   def addMember(thistp: Type, tp: Type, sym: Symbol): Unit = addMember(thistp, tp, sym, AnyDepth)
diff --git a/src/reflect/scala/reflect/internal/pickling/UnPickler.scala b/src/reflect/scala/reflect/internal/pickling/UnPickler.scala
index f3a5053a91..603fff4f1c 100644
--- a/src/reflect/scala/reflect/internal/pickling/UnPickler.scala
+++ b/src/reflect/scala/reflect/internal/pickling/UnPickler.scala
@@ -309,7 +309,7 @@ abstract class UnPickler {
           if (isModuleRoot) moduleRoot setFlag pflags
           else owner.newLinkedModule(clazz, pflags)
         case VALsym =>
-          if (isModuleRoot) { assert(false); NoSymbol }
+          if (isModuleRoot) { abort(s"VALsym at module root: owner = $owner, name = $name") }
           else owner.newTermSymbol(name.toTermName, NoPosition, pflags)
 
         case _ =>
diff --git a/src/reflect/scala/reflect/internal/transform/UnCurry.scala b/src/reflect/scala/reflect/internal/transform/UnCurry.scala
index 0c1640ceb9..6dc6a0f7b8 100644
--- a/src/reflect/scala/reflect/internal/transform/UnCurry.scala
+++ b/src/reflect/scala/reflect/internal/transform/UnCurry.scala
@@ -19,8 +19,7 @@ trait UnCurry {
         case MethodType(params, MethodType(params1, restpe)) =>
           apply(MethodType(params ::: params1, restpe))
         case MethodType(params, ExistentialType(tparams, restpe @ MethodType(_, _))) =>
-          assert(false, "unexpected curried method types with intervening existential")
-          tp0
+          abort("unexpected curried method types with intervening existential")
         case MethodType(h :: t, restpe) if h.isImplicit =>
           apply(MethodType(h.cloneSymbol.resetFlag(IMPLICIT) :: t, restpe))
         case NullaryMethodType(restpe) =>
diff --git a/src/reflect/scala/reflect/internal/util/Position.scala b/src/reflect/scala/reflect/internal/util/Position.scala
index 0725e9775b..3d10d4c9ce 100644
--- a/src/reflect/scala/reflect/internal/util/Position.scala
+++ b/src/reflect/scala/reflect/internal/util/Position.scala
@@ -7,6 +7,7 @@
 package scala.reflect.internal.util
 
 import scala.reflect.ClassTag
+import scala.reflect.internal.FatalError
 import scala.reflect.macros.Attachments
 
 object Position {
@@ -269,7 +270,7 @@ class OffsetPosition(override val source: SourceFile, override val point: Int) e
 /** new for position ranges */
 class RangePosition(source: SourceFile, override val start: Int, point: Int, override val end: Int)
 extends OffsetPosition(source, point) {
-  if (start > end) assert(false, "bad position: "+show)
+  if (start > end) sys.error("bad position: "+show)
   override def isRange: Boolean = true
   override def isOpaqueRange: Boolean = true
   override def startOrPoint: Int = start
diff --git a/src/reflect/scala/reflect/runtime/JavaMirrors.scala b/src/reflect/scala/reflect/runtime/JavaMirrors.scala
index ab93d7033a..d110bd4273 100644
--- a/src/reflect/scala/reflect/runtime/JavaMirrors.scala
+++ b/src/reflect/scala/reflect/runtime/JavaMirrors.scala
@@ -416,7 +416,7 @@ private[reflect] trait JavaMirrors extends internal.SymbolTable with api.JavaUni
           case sym if sym.owner.isPrimitiveValueClass => invokePrimitiveMethod
           case sym if sym == Predef_classOf           => fail("Predef.classOf is a compile-time function")
           case sym if sym.isTermMacro                 => fail(s"${symbol.fullName} is a macro, i.e. a compile-time function")
-          case _                                      => assert(false, this)
+          case _                                      => abort(s"unsupported symbol $symbol when invoking $this")
         }
       }
     }
diff --git a/test/files/neg/anyval-anyref-parent.check b/test/files/neg/anyval-anyref-parent.check
index fe20e5de81..8c2aa36583 100644
--- a/test/files/neg/anyval-anyref-parent.check
+++ b/test/files/neg/anyval-anyref-parent.check
@@ -3,7 +3,7 @@ trait Foo2 extends AnyVal // fail
       ^
 anyval-anyref-parent.scala:5: error: Any does not have a constructor
 class Bar1 extends Any      // fail
-           ^
+                   ^
 anyval-anyref-parent.scala:6: error: value class needs to have exactly one public val parameter
 class Bar2(x: Int) extends AnyVal // fail
       ^
diff --git a/test/files/neg/cyclics-import.check b/test/files/neg/cyclics-import.check
index ef355fab0a..be09fca374 100644
--- a/test/files/neg/cyclics-import.check
+++ b/test/files/neg/cyclics-import.check
@@ -3,13 +3,4 @@ Note: this is often due in part to a class depending on a definition nested with
 If applicable, you may wish to try moving some members into another object.
 import User.UserStatus._
             ^
-cyclics-import.scala:12: error: not found: type Value
-    type UserStatus = Value
-                      ^
-cyclics-import.scala:14: error: not found: value Value
-    val Active = Value("1")
-                 ^
-cyclics-import.scala:15: error: not found: value Value
-    val Disabled = Value("2")
-                   ^
-four errors found
+one error found
diff --git a/test/files/neg/names-defaults-neg.check b/test/files/neg/names-defaults-neg.check
index f3c45a6aa0..6f9dc7d127 100644
--- a/test/files/neg/names-defaults-neg.check
+++ b/test/files/neg/names-defaults-neg.check
@@ -100,7 +100,7 @@ Error occurred in an application involving default arguments.
   ^
 names-defaults-neg.scala:86: error: module extending its companion class cannot use default constructor arguments
     object C extends C()
-             ^
+                     ^
 names-defaults-neg.scala:90: error: deprecated parameter name x has to be distinct from any other parameter name (deprecated or not).
   def deprNam1(x: Int, @deprecatedName('x) y: String) = 0
                                            ^
diff --git a/test/files/neg/protected-constructors.check b/test/files/neg/protected-constructors.check
index f137158ed6..e295917050 100644
--- a/test/files/neg/protected-constructors.check
+++ b/test/files/neg/protected-constructors.check
@@ -19,7 +19,4 @@ protected-constructors.scala:15: error: class Foo3 in object Ding cannot be acce
  object Ding in package dingus where target is defined
     class Bar3 extends Ding.Foo3("abc")
                             ^
-protected-constructors.scala:15: error: too many arguments for constructor Object: ()Object
-    class Bar3 extends Ding.Foo3("abc")
-               ^
-5 errors found
+four errors found
diff --git a/test/files/neg/t2148.check b/test/files/neg/t2148.check
index 5113b48e51..27b5dce507 100644
--- a/test/files/neg/t2148.check
+++ b/test/files/neg/t2148.check
@@ -1,4 +1,4 @@
-t2148.scala:9: error: type A is not a stable prefix
+t2148.scala:9: error: A is not a legal prefix for a constructor
   val b = new A with A#A1
                        ^
 one error found
diff --git a/test/files/neg/t409.check b/test/files/neg/t409.check
index 433d64d25d..0edc0d03cd 100644
--- a/test/files/neg/t409.check
+++ b/test/files/neg/t409.check
@@ -1,4 +1,4 @@
-t409.scala:6: error: traits or objects may not have parameters
+t409.scala:6: error: class Case1 needs to be a trait to be mixed in
 class Toto extends Expr with Case1(12);
-                                  ^
+                             ^
 one error found
diff --git a/test/files/neg/t5529.check b/test/files/neg/t5529.check
index 5d2175fa79..da3f84e1ec 100644
--- a/test/files/neg/t5529.check
+++ b/test/files/neg/t5529.check
@@ -4,7 +4,4 @@ t5529.scala:12: error: File is already defined as class File
 t5529.scala:10: error: class type required but test.Test.File found
   sealed class Dir extends File { }
                            ^
-t5529.scala:10: error: test.Test.File does not have a constructor
-  sealed class Dir extends File { }
-                   ^
-three errors found
+two errors found
diff --git a/test/files/neg/t5696.check b/test/files/neg/t5696.check
index 72b7781fc4..e0fb61b839 100644
--- a/test/files/neg/t5696.check
+++ b/test/files/neg/t5696.check
@@ -15,5 +15,5 @@ t5696.scala:38: error: too many argument lists for constructor invocation
       ^
 t5696.scala:46: error: too many argument lists for constructor invocation
   object x extends G(1)(2) {}
-           ^
+                   ^
 6 errors found
diff --git a/test/files/neg/t667.check b/test/files/neg/t667.check
index d4367bc87b..e68c6dea00 100644
--- a/test/files/neg/t667.check
+++ b/test/files/neg/t667.check
@@ -1,4 +1,4 @@
-t667.scala:8: error: class Ni inherits itself
+t667.scala:8: error: illegal cyclic reference involving class Ni
     class Ni extends super.Ni with Ni;
-                                   ^
+             ^
 one error found
diff --git a/test/files/neg/t877.check b/test/files/neg/t877.check
index 5f25bd439c..c3d4ab6584 100644
--- a/test/files/neg/t877.check
+++ b/test/files/neg/t877.check
@@ -1,7 +1,7 @@
 t877.scala:3: error: Invalid literal number
 trait Foo extends A(22A, Bug!) {}
                     ^
-t877.scala:3: error: parents of traits may not have parameters
+t877.scala:3: error: ')' expected but eof found.
 trait Foo extends A(22A, Bug!) {}
-                   ^
+                                 ^
 two errors found
diff --git a/test/files/run/t5064.check b/test/files/run/t5064.check
index 077006abd9..61ccfd16e7 100644
--- a/test/files/run/t5064.check
+++ b/test/files/run/t5064.check
@@ -1,6 +1,6 @@
-[12]            T5064.super.<init>()
-[12]            T5064.super.<init>
-[12]            this
+[53]            T5064.super.<init>()
+[53]            T5064.super.<init>
+[53]            this
 [16:23]         immutable.this.List.apply(scala.this.Predef.wrapIntArray(Array[Int]{1}))
 [16:20]         immutable.this.List.apply
 <16:20>         immutable.this.List
diff --git a/test/files/run/t5603.check b/test/files/run/t5603.check
index 5127d3c1c7..3b2eb55313 100644
--- a/test/files/run/t5603.check
+++ b/test/files/run/t5603.check
@@ -12,7 +12,7 @@
     [95:101]<paramaccessor> private[this] val i: [98:101]Int = _;
     <119:139>def <init>([95]i: [98]Int) = <119:139>{
       <119:139>val nameElse = <134:139>"Bob";
-      [94][94][94]super.<init>();
+      [NoPosition][NoPosition][NoPosition]super.<init>();
       [94]()
     };
     [168:184]val name = [179:184]"avc";
@@ -20,7 +20,7 @@
   };
   [215:241]object Test extends [227:241][235:238]App {
     [227]def <init>() = [227]{
-      [227][227][227]super.<init>();
+      [NoPosition][NoPosition][NoPosition]super.<init>();
       [227]()
     };
     [NoPosition]<empty>