[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

1 files changed, 5 insertions, 0 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
index 5411ea1788..23fc30b9fb 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala
@@ -4250,6 +4250,11 @@ trait Typers extends Modes with Adaptations with PatMatVirtualiser {
             block1 = adapt(block1, mode, owntype)
             catches1 = catches1 map (adaptCase(_, owntype))
           }
+
+          if(!isPastTyper && opt.virtPatmat) {
+            catches1 = (MatchTranslator(this)).translateTry(catches1, owntype, tree.pos)
+          }
+
           treeCopy.Try(tree, block1, catches1, finalizer1) setType owntype
 
         case Throw(expr) =>