diff options
| -rw-r--r-- | src/compiler/scala/tools/nsc/transform/Erasure.scala | 12 | ||||
| -rw-r--r-- | test/files/pos/bug4731.scala | 14 |
2 files changed, 23 insertions, 3 deletions
diff --git a/src/compiler/scala/tools/nsc/transform/Erasure.scala b/src/compiler/scala/tools/nsc/transform/Erasure.scala index c86a7b5867..5f1d5808b4 100644 --- a/src/compiler/scala/tools/nsc/transform/Erasure.scala +++ b/src/compiler/scala/tools/nsc/transform/Erasure.scala @@ -627,8 +627,14 @@ abstract class Erasure extends AddInterfaces /** Generate a synthetic cast operation from tree.tpe to pt. * @pre pt eq pt.normalize */ - private def cast(tree: Tree, pt: Type): Tree = - tree AS_ATTR pt + private def cast(tree: Tree, pt: Type): Tree = { + if (pt.typeSymbol == UnitClass) { + // See SI-4731 for one example of how this occurs. + log("Attempted to cast to Unit: " + tree) + tree.duplicate setType pt + } + else tree AS_ATTR pt + } private def isUnboxedValueMember(sym: Symbol) = sym != NoSymbol && isValueClass(sym.owner) @@ -647,7 +653,7 @@ abstract class Erasure extends AddInterfaces else if (isValueClass(tree.tpe.typeSymbol) && !isValueClass(pt.typeSymbol)) adaptToType(box(tree), pt) else if (tree.tpe.isInstanceOf[MethodType] && tree.tpe.params.isEmpty) { - if (!tree.symbol.isStable) assert(false, "adapt "+tree+":"+tree.tpe+" to "+pt) + assert(tree.symbol.isStable, "adapt "+tree+":"+tree.tpe+" to "+pt) adaptToType(Apply(tree, List()) setPos tree.pos setType tree.tpe.resultType, pt) } else if (pt <:< tree.tpe) cast(tree, pt) diff --git a/test/files/pos/bug4731.scala b/test/files/pos/bug4731.scala new file mode 100644 index 0000000000..d457543c1f --- /dev/null +++ b/test/files/pos/bug4731.scala @@ -0,0 +1,14 @@ +import java.util.Comparator + +trait Trait1[T] { def foo(arg: Comparator[T]): Unit } + +trait Trait2[T] extends Trait1[T] { def foo(arg: Comparator[String]): Int = 0 } + +class Class1 extends Trait2[String] { } + +object Test { + def main(args: Array[String]): Unit = { + val c = new Class1 + c.foo(Ordering[String]) + } +} |