Fixes SI-4717.

A lazy val declared inside an anonymous class inside a specialized
context no longer crashes Duplicators.

Previously, a duplicated lazy val was assigned to the wrong owner
in Duplicators:

    def x[B >: A]: Unit = new Bounds[B] {
      lazy val it = ???  // def or val okay
    }

Above, the `it` in `$anon` in `x$mcZ$sp` had its owner set to `x$mcZ$sp`
instead of `$anon`. This crashed the typer when it had to retype its
lazy accessor, because there was no `lazy var it` in `$anon$`.
Furthermore, the duplicated symbol wasn't being added to the list of
declarations of `$anon`.

Changes:
1) `invalidate` in Duplicators takes an additional parameter which is
the new owner of the new symbol that has to be duplicated. If this parameter
is set to `NoSymbol`, then the new owner is `context.owner`, as before.
2) the newly created lazy val symbol is being added to the list of
declarations of its new owner.

Removes debugging output from the previous commit.

Review by dragos.
@mention dragos

Author: Aleksandar Prokopec

src/compiler/scala/tools/nsc/transform/SpecializeTypes.scala

@@ -1550,7 +1550,7 @@ abstract class SpecializeTypes extends InfoTransform with TypingTransformers {
       val meth   = addBody(tree, source)
 
       val d = new Duplicator
-      log("-->d DUPLICATING: " + meth)
+      debuglog("-->d DUPLICATING: " + meth)
       d.retyped(
         localTyper.context1.asInstanceOf[d.Context],
         meth,

src/compiler/scala/tools/nsc/typechecker/Duplicators.scala

@@ -143,8 +143,8 @@ abstract class Duplicators extends Analyzer {
       else
         sym
 
-    private def invalidate(tree: Tree) {
-      log("attempting to invalidate " + tree.symbol + ", owner - " + (if (tree.symbol ne null) tree.symbol.owner else "<NULL>"))
+    private def invalidate(tree: Tree, owner: Symbol = NoSymbol) {
+      debuglog("attempting to invalidate " + tree.symbol)
       if (tree.isDef && tree.symbol != NoSymbol) {
         debuglog("invalid " + tree.symbol)
         invalidSyms(tree.symbol) = tree
@@ -158,18 +158,20 @@ abstract class Duplicators extends Analyzer {
             newsym.setInfo(fixType(ldef.symbol.info))
             ldef.symbol = newsym
             debuglog("newsym: " + newsym + " info: " + newsym.info)
-
+          
           case vdef @ ValDef(mods, name, _, rhs) if mods.hasFlag(Flags.LAZY) =>
-            log("ValDef " + name + " sym.info: " + vdef.symbol.info + ", owner: " + vdef.symbol.owner + " vs. context owner: " + context.owner)
+            debuglog("ValDef " + name + " sym.info: " + vdef.symbol.info)
             invalidSyms(vdef.symbol) = vdef
-            val newsym = vdef.symbol.cloneSymbol(context.owner)
+            val newowner = if (owner != NoSymbol) owner else context.owner
+            val newsym = vdef.symbol.cloneSymbol(newowner)
             newsym.setInfo(fixType(vdef.symbol.info))
             vdef.symbol = newsym
-            log("newsym: " + newsym + " info: " + newsym.info + ", " + newsym.owner + ", whereas symbol.owner is: " + vdef.symbol.owner)
-
+            newsym.owner.info.decls enter newsym
+            debuglog("newsym: " + newsym + " info: " + newsym.info)
+          
           case DefDef(_, name, tparams, vparamss, _, rhs) =>
             // invalidate parameters
-            invalidate(tparams ::: vparamss.flatten)
+            invalidateAll(tparams ::: vparamss.flatten)
             tree.symbol = NoSymbol
 
           case _ =>
@@ -178,14 +180,14 @@ abstract class Duplicators extends Analyzer {
       }
     }
 
-    private def invalidate(stats: List[Tree]) {
-      stats foreach invalidate
+    private def invalidateAll(stats: List[Tree], owner: Symbol = NoSymbol) {
+      stats.foreach(invalidate(_, owner))
     }
 
     def retypedMethod(ddef: DefDef, oldThis: Symbol, newThis: Symbol): Tree = {
       oldClassOwner = oldThis
       newClassOwner = newThis
-      invalidate(ddef.tparams)
+      invalidateAll(ddef.tparams)
       mforeach(ddef.vparamss) { vdef =>
         invalidate(vdef)
         vdef.tpe = null
@@ -239,15 +241,15 @@ abstract class Duplicators extends Analyzer {
 
         case Block(stats, res) =>
           debuglog("invalidating block")
-          invalidate(stats)
+          invalidateAll(stats)
           invalidate(res)
           tree.tpe = null
           super.typed(tree, mode, pt)
 
         case ClassDef(_, _, _, tmpl @ Template(parents, _, stats)) =>
-          log("invalidating classdef " + tree.tpe)
+          // log("invalidating classdef " + tree)
           tmpl.symbol = tree.symbol.newLocalDummy(tree.pos)
-          invalidate(stats)
+          invalidateAll(stats, tree.symbol)
           tree.tpe = null
           super.typed(tree, mode, pt)
 
@@ -257,7 +259,6 @@ abstract class Duplicators extends Analyzer {
           super.typed(ddef, mode, pt)
 
         case vdef @ ValDef(mods, name, tpt, rhs) =>
-          log("vdef: " + vdef)
           // log("vdef fixing tpe: " + tree.tpe + " with sym: " + tree.tpe.typeSymbol + " and " + invalidSyms)
           //if (mods.hasFlag(Flags.LAZY)) vdef.symbol.resetFlag(Flags.MUTABLE) // Martin to Iulian: lazy vars can now appear because they are no longer boxed; Please check that deleting this statement is OK.
           vdef.tpt.tpe = fixType(vdef.tpt.tpe)
@@ -359,15 +360,11 @@ abstract class Duplicators extends Analyzer {
           tree
 
         case _ =>
-          log("Duplicators default case: " + tree.summaryString)
+          debuglog("Duplicators default case: " + tree.summaryString)
           if (tree.hasSymbol && tree.symbol != NoSymbol && (tree.symbol.owner == definitions.AnyClass)) {
             tree.symbol = NoSymbol // maybe we can find a more specific member in a subclass of Any (see AnyVal members, like ==)
           }
           tree.tpe = null
-          tree match {
-            case Select(q, n) => log("Select: " + q + ", " + n + " = " + q.tpe.member(n) + ", members: " + q.tpe.members)
-            case _ => log(tree.getClass)
-          }
           super.typed(tree, mode, pt)
       }
     }

src/compiler/scala/tools/nsc/typechecker/Typers.scala

@@ -3657,10 +3657,6 @@ trait Typers extends Modes with Adaptations with Taggings {
 
     def typed1(tree: Tree, mode: Int, pt: Type): Tree = {
       def isPatternMode = inPatternMode(mode)
-      tree match {
-        case This(_) => log("typed1: " + tree + ", " + tree.tpe)
-        case _ =>
-      }
 
       //Console.println("typed1("+tree.getClass()+","+Integer.toHexString(mode)+","+pt+")")
       //@M! get the type of the qualifier in a Select tree, otherwise: NoType
@@ -4239,7 +4235,6 @@ trait Typers extends Modes with Adaptations with Taggings {
       def typedThis(qual: Name) = tree.symbol orElse qualifyingClass(tree, qual, packageOK = false) match {
         case NoSymbol => tree
         case clazz    =>
-          log("typedThis: " + qual + ", " + clazz.thisType.underlying)
           tree setSymbol clazz setType clazz.thisType.underlying
           if (isStableContext(tree, mode, pt)) tree setType clazz.thisType else tree
       }
@@ -4252,7 +4247,6 @@ trait Typers extends Modes with Adaptations with Taggings {
        *  @return     ...
        */
       def typedSelect(qual: Tree, name: Name): Tree = {
-        log("typedSelect: " + qual + ", name: " + name + ", member: " + (qual.tpe.members))
         def asDynamicCall = dyna.mkInvoke(context.tree, tree, qual, name) map (typed1(_, mode, pt))
 
         val sym = tree.symbol orElse member(qual, name) orElse {
@@ -4876,12 +4870,9 @@ trait Typers extends Modes with Adaptations with Taggings {
 
         case Select(qual, name) =>
           incCounter(typedSelectCount)
-          val tpq = typedQualifier(qual, mode)
-          if (qual.tpe ne null) log("Select: " + qual + ", " + name + " = " + qual.tpe.member(name) + ", members: " + qual.tpe.members)
-          var qual1 = checkDead(tpq)
+          var qual1 = checkDead(typedQualifier(qual, mode))
           if (name.isTypeName) qual1 = checkStable(qual1)
-          log("members: " + qual.tpe.members)
-          
+
           val tree1 = // temporarily use `filter` and an alternative for `withFilter`
             if (name == nme.withFilter)
               silent(_ => typedSelect(qual1, name)) match {

test/files/pos/t4717.scala

@@ -4,7 +4,7 @@
 
 
 
-/*
+
 trait Bug1[@specialized(Boolean) A] extends TraversableOnce[A] {
 
   def ++[B >: A](that: TraversableOnce[B]): Iterator[B] = new Iterator[B] {
@@ -14,25 +14,21 @@ trait Bug1[@specialized(Boolean) A] extends TraversableOnce[A] {
   }
 
 }
-*/
 
 
-/*
+
 trait WorksFine[@specialized(Boolean) A] {
   class SubBounds[B >: A] extends Bounds[B] {
     lazy val it = ???
-    it
   }
   def x[B >: A]: Unit = new SubBounds[B]
 }
-*/
 
 
 trait Bounds[@specialized(Boolean) A] {
   // okay without `>: A`
   def x[B >: A]: Unit = new Bounds[B] {
     lazy val it = ???  // def or val okay
-    it
   }
 }