[vpm] working type switch for try/catch

catch handlers are now also translated by the virtualizing pattern matcher
emit type-based switches when possible, fallback to catch-all with full pattern match
(the logic used to emit constant-based switches was generalized to type-based switches,
 abstracting out how to refer to the scrutinee and the shape of a default/catch-all case)

this was the last missing piece of essential functionality
now the virtualizing pattern matcher and the old one are mutually exclusive:
-Yvirtpatmat disables the old matcher logic completely

4 files changed, 57 insertions, 1 deletions

diff --git a/test/files/run/virtpatmat_switch.scala b/test/files/run/virtpatmat_switch.scala
index 2e2c31e8e5..1329c19d0f 100644
--- a/test/files/run/virtpatmat_switch.scala
+++ b/test/files/run/virtpatmat_switch.scala
@@ -14,9 +14,15 @@ object Test extends App {
     case 'b' => "got b"
     case _ => "got some letter"
   }
+
+  def byteSwitch(x: Byte) = x match {
+    case 'a' => "got a"
+    case 'b' => "got b"
+    case _ => "got some letter"
+  }
   
   println(charSwitch('a'))
-  println(charSwitch('b'))
+  println(byteSwitch('b'))
   println(charSwitch('z'))
   
   def implicitDefault(x: Int) = x match {
diff --git a/test/files/run/virtpatmat_try.check b/test/files/run/virtpatmat_try.check
new file mode 100644
index 0000000000..80ebbf494a
--- /dev/null
+++ b/test/files/run/virtpatmat_try.check
@@ -0,0 +1,2 @@
+meh
+B
diff --git a/test/files/run/virtpatmat_try.flags b/test/files/run/virtpatmat_try.flags
new file mode 100644
index 0000000000..9769db9257
--- /dev/null
+++ b/test/files/run/virtpatmat_try.flags
@@ -0,0 +1 @@
+ -Yvirtpatmat -Xexperimental
diff --git a/test/files/run/virtpatmat_try.scala b/test/files/run/virtpatmat_try.scala
new file mode 100644
index 0000000000..46e67cb72e
--- /dev/null
+++ b/test/files/run/virtpatmat_try.scala
@@ -0,0 +1,47 @@
+object Test extends App {
+  case class A(val x: String) extends Throwable
+  class B extends Exception { override def toString = "B" }
+  def bla = 0
+
+  try {
+    throw new A("meh")
+  } catch { // this should emit a "catch-switch"
+    case y: A => println(y.x)
+    case (_ : A | _ : B)  => println("B")
+    case _ => println("other")
+  }
+
+  try {
+    throw new B()
+  } catch { // case classes and alternative flattening aren't supported yet, but could be in principle
+    // case A(x) => println(x)
+    case y: A => println(y.x)
+    case x@((_ : A) | (_ : B))  => println(x)
+    case _ => println("other")
+  }
+
+ def simpleTry {
+    try {
+      bla
+    } catch {
+      case x: Exception if x.getMessage == "test" => println("first case " + x)
+      case x: Exception => println("second case " + x)
+    }
+  }
+
+  def typedWildcardTry {
+    try { bla } catch { case _: ClassCastException => bla }
+  }
+
+  def wildcardTry {
+    try { bla } catch { case _ => bla }
+  }
+
+  def tryPlusFinally {
+    try { bla } finally { println("finally") }
+  }
+
+  def catchAndPassToLambda {
+    try { bla } catch { case ex: Exception => val f = () => ex }
+  }
+}
\ No newline at end of file