Fixed bug #1205 to optimize even more tail calls.

2 files changed, 9 insertions, 8 deletions

diff --git a/src/compiler/scala/tools/nsc/backend/icode/GenICode.scala b/src/compiler/scala/tools/nsc/backend/icode/GenICode.scala
index 33d8739333..d79310ec93 100644
--- a/src/compiler/scala/tools/nsc/backend/icode/GenICode.scala
+++ b/src/compiler/scala/tools/nsc/backend/icode/GenICode.scala
@@ -47,9 +47,6 @@ abstract class GenICode extends SubComponent  {
     val Comparator_equals = definitions.getMember(definitions.getModule("scala.runtime.Comparator"),
                                                  nme.equals_)
 
-    /** Tree transformer that makes fresh label defs. */
-    val duplicator = new DuplicateLabels
-
     ///////////////////////////////////////////////////////////
 
     override def run: Unit = {
@@ -558,7 +555,7 @@ abstract class GenICode extends SubComponent  {
               ctx1
             }) :: handlers;
 
-          val duppedFinalizer = duplicator(ctx, finalizer)
+          val duppedFinalizer = (new DuplicateLabels(ctx.labels.keySet))(ctx, finalizer)
           if (settings.debug.value)
             log("Duplicated finalizer: " + duppedFinalizer)
           ctx.Try(
@@ -1666,7 +1663,7 @@ abstract class GenICode extends SubComponent  {
      *  All LabelDefs are entered into the context label map, since it makes no sense
      *  to delay it any more: they will be used at some point.
      */
-    class DuplicateLabels extends Transformer {
+    class DuplicateLabels(boundLabels: collection.Set[Symbol]) extends Transformer {
       val labels: Map[Symbol, Symbol] = new HashMap
       var method: Symbol = _
       var ctx: Context = _
@@ -1679,7 +1676,7 @@ abstract class GenICode extends SubComponent  {
 
       override def transform(t: Tree): Tree = {
         t match {
-          case t @ Apply(fun, args) if t.symbol.isLabel =>
+          case t @ Apply(fun, args) if (t.symbol.isLabel && !boundLabels(t.symbol)) =>
             if (!labels.isDefinedAt(t.symbol)) {
               val oldLabel = t.symbol
               val sym = method.newLabel(oldLabel.pos, unit.fresh.newName(oldLabel.name.toString))
diff --git a/src/compiler/scala/tools/nsc/transform/TailCalls.scala b/src/compiler/scala/tools/nsc/transform/TailCalls.scala
index 605cf3f3fc..142ae140fd 100644
--- a/src/compiler/scala/tools/nsc/transform/TailCalls.scala
+++ b/src/compiler/scala/tools/nsc/transform/TailCalls.scala
@@ -227,8 +227,12 @@ abstract class TailCalls extends Transform
 
         case Return(expr) => super.transform(tree)
         case Try(block, catches, finalizer) =>
-          if (finalizer == EmptyTree) super.transform(tree)
-          else tree
+          if (finalizer == EmptyTree)
+            super.transform(tree)
+          else
+            copy.Try(tree, transform(block, mkContext(ctx, false)), // recursive calls are not in tail position if there is non-empty finally clause
+                           transformTrees(catches, ctx).asInstanceOf[List[CaseDef]],
+                           transform(finalizer, ctx))
 
         case Throw(expr) => super.transform(tree)
         case New(tpt) => super.transform(tree)