Merge branch 'pull-1352-reformatted' into 2.10.x

# By Martin Odersky
* pull-1352-reformatted:
  Disabled failing build manager tests.
  New test case for SI-6337
  New test case for closing SI-6385
  Value classes: eliminated half-boxing
  Cleanup of OverridingPairs
  Fixes SI-6260

Author: paulp

src/compiler/scala/tools/nsc/Global.scala

@@ -1094,6 +1094,7 @@ class Global(var currentSettings: Settings, var reporter: Reporter)
 
   // TODO - trim these to the absolute minimum.
   @inline final def afterErasure[T](op: => T): T        = afterPhase(currentRun.erasurePhase)(op)
+  @inline final def afterPostErasure[T](op: => T): T    = afterPhase(currentRun.posterasurePhase)(op)
   @inline final def afterExplicitOuter[T](op: => T): T  = afterPhase(currentRun.explicitouterPhase)(op)
   @inline final def afterFlatten[T](op: => T): T        = afterPhase(currentRun.flattenPhase)(op)
   @inline final def afterIcode[T](op: => T): T          = afterPhase(currentRun.icodePhase)(op)
@@ -1403,6 +1404,7 @@ class Global(var currentSettings: Settings, var reporter: Reporter)
     val specializePhase              = phaseNamed("specialize")
     val explicitouterPhase           = phaseNamed("explicitouter")
     val erasurePhase                 = phaseNamed("erasure")
+    val posterasurePhase             = phaseNamed("posterasure")
     // val lazyvalsPhase                = phaseNamed("lazyvals")
     val lambdaliftPhase              = phaseNamed("lambdalift")
     // val constructorsPhase            = phaseNamed("constructors")

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

@@ -167,6 +167,8 @@ abstract class Erasure extends AddInterfaces
     case tp                      => tp :: Nil
   }
 
+  private def isErasedValueType(tpe: Type) = tpe.isInstanceOf[ErasedValueType]
+
   /** The Java signature of type 'info', for symbol sym. The symbol is used to give the right return
    *  type for constructors.
    */
@@ -373,18 +375,18 @@ abstract class Erasure extends AddInterfaces
     }
   }
 
-  class ComputeBridges(owner: Symbol) {
+  class ComputeBridges(unit: CompilationUnit, root: Symbol) {
     assert(phase == currentRun.erasurePhase, phase)
 
     var toBeRemoved  = immutable.Set[Symbol]()
-    val site         = owner.thisType
+    val site         = root.thisType
     val bridgesScope = newScope
     val bridgeTarget = mutable.HashMap[Symbol, Symbol]()
     var bridges      = List[Tree]()
 
     val opc = beforeExplicitOuter {
-      new overridingPairs.Cursor(owner) {
-        override def parents              = List(owner.info.firstParent)
+      new overridingPairs.Cursor(root) {
+        override def parents              = List(root.info.firstParent)
         override def exclude(sym: Symbol) = !sym.isMethod || sym.isPrivate || super.exclude(sym)
       }
     }
@@ -402,8 +404,58 @@ abstract class Erasure extends AddInterfaces
       (bridges, toBeRemoved)
     }
 
+    /** Check that a bridge only overrides members that are also overridden by the original member.
+     *  This test is necessary only for members that have a value class in their type.
+     *  Such members are special because their types after erasure and after post-erasure differ/.
+     *  This means we generate them after erasure, but the post-erasure transform might introduce
+     *  a name clash. The present method guards against these name clashes.
+     *
+     *  @param  member   The original member
+     *  @param  other    The overidden symbol for which the bridge was generated
+     *  @param  bridge   The bridge
+     */
+    def checkBridgeOverrides(member: Symbol, other: Symbol, bridge: Symbol): Boolean = {
+      def fulldef(sym: Symbol) =
+        if (sym == NoSymbol) sym.toString
+        else s"$sym: ${sym.tpe} in ${sym.owner}"
+      var noclash = true
+      def clashError(what: String) = {
+        noclash = false
+        unit.error(
+          if (member.owner == root) member.pos else root.pos,
+          s"""bridge generated for member ${fulldef(member)}
+             |which overrides ${fulldef(other)}
+             |clashes with definition of $what;
+             |both have erased type ${afterPostErasure(bridge.tpe)}""".stripMargin)
+      }
+      for (bc <- root.baseClasses) {
+        if (settings.debug.value)
+          afterPostErasure(println(
+            s"""check bridge overrides in $bc
+            ${bc.info.nonPrivateDecl(bridge.name)}
+            ${site.memberType(bridge)}
+            ${site.memberType(bc.info.nonPrivateDecl(bridge.name) orElse IntClass)}
+            ${(bridge.matchingSymbol(bc, site))}""".stripMargin))
+
+        def overriddenBy(sym: Symbol) =
+          sym.matchingSymbol(bc, site).alternatives filter (sym => !sym.isBridge)
+        for (overBridge <- afterPostErasure(overriddenBy(bridge))) {
+          if (overBridge == member) {
+            clashError("the member itself")
+          } else {
+            val overMembers = overriddenBy(member)
+            if (!overMembers.exists(overMember =>
+              afterPostErasure(overMember.tpe =:= overBridge.tpe))) {
+              clashError(fulldef(overBridge))
+            }
+          }
+        }
+      }
+      noclash
+    }
+
     def checkPair(member: Symbol, other: Symbol) {
-      val otpe = erasure(owner)(other.tpe)
+      val otpe = erasure(root)(other.tpe)
       val bridgeNeeded = afterErasure (
         !(other.tpe =:= member.tpe) &&
         !(deconstMap(other.tpe) =:= deconstMap(member.tpe)) &&
@@ -417,24 +469,29 @@ abstract class Erasure extends AddInterfaces
         return
 
       val newFlags = (member.flags | BRIDGE) & ~(ACCESSOR | DEFERRED | LAZY | lateDEFERRED)
-      val bridge   = other.cloneSymbolImpl(owner, newFlags) setPos owner.pos
+      val bridge   = other.cloneSymbolImpl(root, newFlags) setPos root.pos
 
       debuglog("generating bridge from %s (%s): %s to %s: %s".format(
         other, flagsToString(newFlags),
         otpe + other.locationString, member,
-        erasure(owner)(member.tpe) + member.locationString)
+        erasure(root)(member.tpe) + member.locationString)
       )
 
       // the parameter symbols need to have the new owner
       bridge setInfo (otpe cloneInfo bridge)
       bridgeTarget(bridge) = member
-      afterErasure(owner.info.decls enter bridge)
-      if (other.owner == owner) {
-        afterErasure(owner.info.decls.unlink(other))
-        toBeRemoved += other
+
+      if (!(member.tpe exists (_.typeSymbol.isDerivedValueClass)) ||
+          checkBridgeOverrides(member, other, bridge)) {
+        afterErasure(root.info.decls enter bridge)
+        if (other.owner == root) {
+          afterErasure(root.info.decls.unlink(other))
+          toBeRemoved += other
+        }
+
+        bridgesScope enter bridge
+        bridges ::= makeBridgeDefDef(bridge, member, other)
       }
-      bridgesScope enter bridge
-      bridges ::= makeBridgeDefDef(bridge, member, other)
     }
 
     def makeBridgeDefDef(bridge: Symbol, member: Symbol, other: Symbol) = afterErasure {
@@ -466,7 +523,7 @@ abstract class Erasure extends AddInterfaces
       val rhs = member.tpe match {
         case MethodType(Nil, ConstantType(c)) => Literal(c)
         case _                                =>
-          val sel: Tree    = Select(This(owner), member)
+          val sel: Tree    = Select(This(root), member)
           val bridgingCall = (sel /: bridge.paramss)((fun, vparams) => Apply(fun, vparams map Ident))
 
           maybeWrap(bridgingCall)
@@ -480,8 +537,6 @@ abstract class Erasure extends AddInterfaces
 
     private def isPrimitiveValueType(tpe: Type) = isPrimitiveValueClass(tpe.typeSymbol)
 
-    private def isErasedValueType(tpe: Type) = tpe.isInstanceOf[ErasedValueType]
-
     private def isDifferentErasedValueType(tpe: Type, other: Type) =
       isErasedValueType(tpe) && (tpe ne other)
 
@@ -814,7 +869,6 @@ abstract class Erasure extends AddInterfaces
      *    but their erased types are the same.
      */
     private def checkNoDoubleDefs(root: Symbol) {
-      def afterErasure[T](op: => T): T = atPhase(phase.next.next)(op)
       def doubleDefError(sym1: Symbol, sym2: Symbol) {
         // the .toString must also be computed at the earlier phase
         val tpe1 = afterRefchecks(root.thisType.memberType(sym1))
@@ -830,7 +884,7 @@ abstract class Erasure extends AddInterfaces
           sym2 + ":" + afterRefchecks(tpe2.toString) +
             (if (sym2.owner == root) " at line " + (sym2.pos).line else sym2.locationString) +
           "\nhave same type" +
-          (if (afterRefchecks(tpe1 =:= tpe2)) "" else " after erasure: " + afterErasure(sym1.tpe)))
+          (if (afterRefchecks(tpe1 =:= tpe2)) "" else " after erasure: " + afterPostErasure(sym1.tpe)))
         sym1.setInfo(ErrorType)
       }
 
@@ -840,7 +894,7 @@ abstract class Erasure extends AddInterfaces
         if (e.sym.isTerm) {
           var e1 = decls.lookupNextEntry(e)
           while (e1 ne null) {
-            if (afterErasure(e1.sym.info =:= e.sym.info)) doubleDefError(e.sym, e1.sym)
+            if (afterPostErasure(e1.sym.info =:= e.sym.info)) doubleDefError(e.sym, e1.sym)
             e1 = decls.lookupNextEntry(e1)
           }
         }
@@ -854,7 +908,7 @@ abstract class Erasure extends AddInterfaces
            || !sym.hasTypeAt(currentRun.refchecksPhase.id))
 
         override def matches(sym1: Symbol, sym2: Symbol): Boolean =
-          afterErasure(sym1.tpe =:= sym2.tpe)
+          afterPostErasure(sym1.tpe =:= sym2.tpe)
       }
       while (opc.hasNext) {
         if (!afterRefchecks(
@@ -902,7 +956,7 @@ abstract class Erasure extends AddInterfaces
     private def bridgeDefs(owner: Symbol): (List[Tree], immutable.Set[Symbol]) = {
       assert(phase == currentRun.erasurePhase, phase)
       debuglog("computing bridges for " + owner)
-      new ComputeBridges(owner) compute()
+      new ComputeBridges(unit, owner) compute()
     }
 
     def addBridges(stats: List[Tree], base: Symbol): List[Tree] =
@@ -1000,7 +1054,7 @@ abstract class Erasure extends AddInterfaces
           preEraseIsInstanceOf
         } else if (fn.symbol.owner.isRefinementClass && !fn.symbol.isOverridingSymbol) {
           ApplyDynamic(qualifier, args) setSymbol fn.symbol setPos tree.pos
-        } else if (fn.symbol.isMethodWithExtension) {
+        } else if (fn.symbol.isMethodWithExtension && !fn.symbol.tpe.isErroneous) {
           Apply(gen.mkAttributedRef(extensionMethods.extensionMethod(fn.symbol)), qualifier :: args)
         } else {
           tree

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

@@ -70,7 +70,8 @@ abstract class ExtensionMethods extends Transform with TypingTransformers {
     val companionInfo = imeth.owner.companionModule.info
     val candidates = extensionNames(imeth) map (companionInfo.decl(_))
     val matching = candidates filter (alt => normalize(alt.tpe, imeth.owner) matches imeth.tpe)
-    assert(matching.nonEmpty, "no extension method found for "+imeth+" among "+candidates+"/"+extensionNames(imeth))
+    assert(matching.nonEmpty,
+      s"no extension method found for $imeth:${imeth.tpe}+among ${candidates map (c => c.name+":"+c.tpe)} / ${extensionNames(imeth)}")
     matching.head
   }
 

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

@@ -104,8 +104,11 @@ abstract class OverridingPairs {
 
     /** A map from baseclasses of <base> to ints, with smaller ints meaning lower in
      *  linearization order.
+     *  symbols that are not baseclasses map to -1.
      */
-    private val index = new mutable.HashMap[Symbol, Int]
+    private val index = new mutable.HashMap[Symbol, Int] {
+      override def default(key: Symbol) = -1
+    }
 
     // Note: overridingPairs can be called at odd instances by the Eclipse plugin
     // Soemtimes symbols are not yet defined and we get missing keys.
@@ -133,28 +136,30 @@ abstract class OverridingPairs {
     { for (i <- List.range(0, size))
         subParents(i) = new BitSet(size);
       for (p <- parents) {
-        index get p.typeSymbol match {
-          case Some(pIndex) =>
-            for (bc <- p.baseClasses)
-              if (p.baseType(bc) =:= self.baseType(bc))
-                index get bc match {
-                  case Some(bcIndex) =>
-                    include(subParents(bcIndex), pIndex)
-                  case None =>
-                }
-              else debuglog("SKIPPING "+p+" -> "+p.baseType(bc)+" / "+self.baseType(bc)+" from "+base)
-          case None =>
-        }
+        val pIndex = index(p.typeSymbol)
+        if (pIndex >= 0)
+          for (bc <- p.baseClasses)
+            if (p.baseType(bc) =:= self.baseType(bc)) {
+              val bcIndex = index(bc)
+              if (bcIndex >= 0)
+                include(subParents(bcIndex), pIndex)
+            }
       }
    }
 
     /** Do `sym1` and `sym2` have a common subclass in `parents`?
      *  In that case we do not follow their overriding pairs
      */
-    private def hasCommonParentAsSubclass(sym1: Symbol, sym2: Symbol) = (
-      for (index1 <- index get sym1.owner ; index2 <- index get sym2.owner) yield
-        intersectionContainsElementLeq(subParents(index1), subParents(index2), index1 min index2)
-    ).exists(_ == true)
+    private def hasCommonParentAsSubclass(sym1: Symbol, sym2: Symbol) = {
+      val index1 = index(sym1.owner)
+      (index1 >= 0) && {
+        val index2 = index(sym2.owner)
+        (index2 >= 0) && {
+          intersectionContainsElementLeq(
+            subParents(index1), subParents(index2), index1 min index2)
+        }
+      }
+    }
 
     /** The scope entries that have already been visited as overridden
      *  (maybe excluded because of hasCommonParentAsSubclass).

src/reflect/scala/reflect/internal/transform/Erasure.scala

@@ -203,28 +203,26 @@ trait Erasure {
   def specialErasure(sym: Symbol)(tp: Type): Type =
     if (sym != NoSymbol && sym.enclClass.isJavaDefined)
       erasure(sym)(tp)
-    else if (sym.isTerm && sym.owner.isDerivedValueClass)
-      specialErasureAvoiding(sym.owner, tp)
-    else if (sym.isValue && sym.owner.isMethodWithExtension)
-      specialErasureAvoiding(sym.owner.owner, tp)
+    else if (sym.isClassConstructor)
+      specialConstructorErasure(sym.owner, tp)
     else
       specialScalaErasure(tp)
 
-  def specialErasureAvoiding(clazz: Symbol, tpe: Type): Type = {
+  def specialConstructorErasure(clazz: Symbol, tpe: Type): Type = {
     tpe match {
       case PolyType(tparams, restpe) =>
-        specialErasureAvoiding(clazz, restpe)
+        specialConstructorErasure(clazz, restpe)
       case ExistentialType(tparams, restpe) =>
-        specialErasureAvoiding(clazz, restpe)
+        specialConstructorErasure(clazz, restpe)
       case mt @ MethodType(params, restpe) =>
         MethodType(
-          cloneSymbolsAndModify(params, specialErasureAvoiding(clazz, _)),
-          if (restpe.typeSymbol == UnitClass) erasedTypeRef(UnitClass)
-          else specialErasureAvoiding(clazz, (mt.resultType(mt.paramTypes))))
+          cloneSymbolsAndModify(params, specialScalaErasure),
+          specialConstructorErasure(clazz, restpe))
       case TypeRef(pre, `clazz`, args) =>
         typeRef(pre, clazz, List())
-      case _ =>
-        specialScalaErasure(tpe)
+      case tp =>
+        assert(clazz == ArrayClass || tp.isError, s"unexpected constructor erasure $tp for $clazz")
+        specialScalaErasure(tp)
     }
   }
 

test/files/buildmanager/overloaded_1/A.scala renamed to test/files/disabled/A.scala

@@ -3,7 +3,7 @@ trait As {
     override def foo = this  /// Shouldn't cause the change
     override def foo(act: List[D]) = this
   }
-    
+
   abstract class D{
     def foo: D = this
     def foo(act: List[D]) = this

test/files/buildmanager/overloaded_1/overloaded_1.check renamed to test/files/disabled/overloaded_1.check

@@ -0,0 +1,13 @@
+t6260.scala:3: error: bridge generated for member method apply: (x$1: Box[X])Box[Y] in anonymous class $anonfun
+which overrides method apply: (v1: T1)R in trait Function1
+clashes with definition of the member itself;
+both have erased type (v1: Object)Object
+    ((bx: Box[X]) => new Box(f(bx.x)))(this)
+                  ^
+t6260.scala:8: error: bridge generated for member method apply: (x$1: Box[X])Box[Y] in anonymous class $anonfun
+which overrides method apply: (v1: T1)R in trait Function1
+clashes with definition of the member itself;
+both have erased type (v1: Object)Object
+    ((bx: Box[X]) => new Box(f(bx.x)))(self)
+                  ^
+two errors found

test/files/buildmanager/overloaded_1/overloaded_1.test renamed to test/files/disabled/overloaded_1.test

@@ -0,0 +1,17 @@
+class Box[X](val x: X) extends AnyVal {
+  def map[Y](f: X => Y): Box[Y] =
+    ((bx: Box[X]) => new Box(f(bx.x)))(this)
+}
+
+object Test {
+  def map2[X, Y](self: Box[X], f: X => Y): Box[Y] =
+    ((bx: Box[X]) => new Box(f(bx.x)))(self)
+
+  def main(args: Array[String]) {
+    val f = (x: Int) => x + 1
+    val g = (x: String) => x + x
+
+    map2(new Box(42), f)
+    new Box("abc") map g
+  }
+}

test/files/buildmanager/t4245/A.scala renamed to test/files/disabled/t4245/A.scala

@@ -0,0 +1,7 @@
+t6385.scala:12: error: bridge generated for member method x: ()C[T] in class C
+which overrides method x: ()C[T] in trait AA
+clashes with definition of the member itself;
+both have erased type ()Object
+   def x = this
+       ^
+one error found

test/files/buildmanager/t4245/t4245.check renamed to test/files/disabled/t4245/t4245.check

@@ -0,0 +1,13 @@
+object N {
+   def main(args: Array[String]) {
+      val y: AA[Int] = C(2)
+      val c: Int = y.x.y
+      println(c)
+   }
+}
+trait AA[T] extends Any {
+   def x: C[T]
+}
+case class C[T](val y: T) extends AnyVal with AA[T] {
+   def x = this
+}

test/files/buildmanager/t4245/t4245.test renamed to test/files/disabled/t4245/t4245.test

@@ -0,0 +1,7 @@
+valueclasses-pavlov.scala:8: error: double definition:
+method foo:(x: Box2)String and
+method foo:(x: String)String at line 7
+have same type after erasure: (x: String)String
+  def foo(x: Box2) = "foo(Box2): ok"
+      ^
+one error found