diff options
| -rw-r--r-- | src/compiler/scala/tools/nsc/transform/Erasure.scala | 13 | ||||
| -rw-r--r-- | test/files/run/null-and-intersect.check | 9 | ||||
| -rw-r--r-- | test/files/run/null-and-intersect.scala | 34 |
3 files changed, 54 insertions, 2 deletions
diff --git a/src/compiler/scala/tools/nsc/transform/Erasure.scala b/src/compiler/scala/tools/nsc/transform/Erasure.scala index 915aba63db..2cf3d06866 100644 --- a/src/compiler/scala/tools/nsc/transform/Erasure.scala +++ b/src/compiler/scala/tools/nsc/transform/Erasure.scala @@ -1022,9 +1022,18 @@ abstract class Erasure extends AddInterfaces Apply(Select(qual, cmpOp), List(gen.mkAttributedQualifier(targ.tpe))) } case RefinedType(parents, decls) if (parents.length >= 2) => - gen.evalOnce(qual, currentOwner, unit) { q => + // Optimization: don't generate isInstanceOf tests if the static type + // conforms, because it always succeeds. (Or at least it had better.) + // At this writing the pattern matcher generates some instance tests + // involving intersections where at least one parent is statically known true. + // That needs fixing, but filtering the parents here adds an additional + // level of robustness (in addition to the short term fix.) + val parentTests = parents filterNot (qual.tpe <:< _) + + if (parentTests.isEmpty) Literal(Constant(true)) + else gen.evalOnce(qual, currentOwner, unit) { q => atPos(tree.pos) { - parents map mkIsInstanceOf(q) reduceRight gen.mkAnd + parentTests map mkIsInstanceOf(q) reduceRight gen.mkAnd } } case _ => diff --git a/test/files/run/null-and-intersect.check b/test/files/run/null-and-intersect.check new file mode 100644 index 0000000000..81890cfeff --- /dev/null +++ b/test/files/run/null-and-intersect.check @@ -0,0 +1,9 @@ +1 +2 +3 +4 +1 +2 +1 +2 +2 diff --git a/test/files/run/null-and-intersect.scala b/test/files/run/null-and-intersect.scala new file mode 100644 index 0000000000..7266dabe6d --- /dev/null +++ b/test/files/run/null-and-intersect.scala @@ -0,0 +1,34 @@ +object Test { + trait Immortal + class Bippy extends Immutable with Immortal + class Boppy extends Immutable + + def f[T](x: Traversable[T]) = x match { + case _: Map[_, _] => 3 + case _: Seq[_] => 2 + case _: Iterable[_] => 1 + case _ => 4 + } + def g(x: Bippy) = x match { + case _: Immutable with Immortal => 1 + case _ => 2 + } + def h(x: Immutable) = x match { + case _: Immortal => 1 + case _ => 2 + } + + def main(args: Array[String]): Unit = { + println(f(Set(1))) + println(f(Seq(1))) + println(f(Map(1 -> 2))) + println(f(null)) + + println(g(new Bippy)) + println(g(null)) + + println(h(new Bippy)) + println(h(new Boppy)) + println(h(null)) + } +} |