Add missing cases in tail return transform

Disabled warnings that no longer apply because of tail returns.
Add several test cases.

4 files changed, 26 insertions, 8 deletions

diff --git a/src/continuations/plugin/scala/tools/selectivecps/CPSUtils.scala b/src/continuations/plugin/scala/tools/selectivecps/CPSUtils.scala
index 545172d407..a6d4cf45d7 100644
--- a/src/continuations/plugin/scala/tools/selectivecps/CPSUtils.scala
+++ b/src/continuations/plugin/scala/tools/selectivecps/CPSUtils.scala
@@ -169,13 +169,8 @@ trait CPSUtils {
 
   // anf transform
 
-  def getExternalAnswerTypeAnn(tp: Type) = {
-    cpsParamTypes(tp) orElse {
-      if (hasPlusMarker(tp))
-        global.warning("trying to instantiate type " + tp + " to unknown cps type")
-      None
-    }
-  }
+  def getExternalAnswerTypeAnn(tp: Type) =
+    cpsParamTypes(tp) orElse None
 
   def getAnswerTypeAnn(tp: Type): Option[(Type, Type)] =
     cpsParamTypes(tp) filterNot (_ => hasPlusMarker(tp))
diff --git a/src/continuations/plugin/scala/tools/selectivecps/SelectiveANFTransform.scala b/src/continuations/plugin/scala/tools/selectivecps/SelectiveANFTransform.scala
index 8ab9ba881f..b789bc7716 100644
--- a/src/continuations/plugin/scala/tools/selectivecps/SelectiveANFTransform.scala
+++ b/src/continuations/plugin/scala/tools/selectivecps/SelectiveANFTransform.scala
@@ -43,6 +43,12 @@ abstract class SelectiveANFTransform extends PluginComponent with Transform with
         case If(cond, r1 @ Return(thenExpr), r2 @ Return(elseExpr)) =>
           treeCopy.If(tree, cond, transform(thenExpr), transform(elseExpr))
 
+        case If(cond, r1 @ Return(thenExpr), elseExpr) =>
+          treeCopy.If(tree, cond, transform(thenExpr), transform(elseExpr))
+
+        case If(cond, thenExpr, r2 @ Return(elseExpr)) =>
+          treeCopy.If(tree, cond, transform(thenExpr), transform(elseExpr))
+
         case If(cond, thenExpr, elseExpr) =>
           treeCopy.If(tree, cond, transform(thenExpr), transform(elseExpr))
 
@@ -440,7 +446,9 @@ abstract class SelectiveANFTransform extends PluginComponent with Transform with
         // all is well
 
         if (hasPlusMarker(expr.tpe)) {
-          unit.warning(tree.pos, "expression " + expr + " of type " + expr.tpe + " is not expected to have a cps type")
+          // the following warning no longer applies, since expr may have originated from a tail return expr
+          // note that it would be illegal to remove the plus marker (thus disabling required transformations)
+          //unit.warning(tree.pos, "expression " + expr + " of type " + expr.tpe + " is not expected to have a cps type")
           expr modifyType removeAllCPSAnnotations
         }
 
diff --git a/test/files/continuations-run/t5314.check b/test/files/continuations-run/t5314.check
index 4951e7caae..4b35d8e6d0 100644
--- a/test/files/continuations-run/t5314.check
+++ b/test/files/continuations-run/t5314.check
@@ -1,3 +1,7 @@
+7
+7
+7
+8
 8
 hi
 8
diff --git a/test/files/continuations-run/t5314.scala b/test/files/continuations-run/t5314.scala
index 0bdea19824..d611016ce4 100644
--- a/test/files/continuations-run/t5314.scala
+++ b/test/files/continuations-run/t5314.scala
@@ -29,6 +29,17 @@ object Test extends App {
 
   def nocps(x: Int): Int = { return x; x }
 
+  def foo2(x:Int): Int @cps[Int] = 7
+  def bar2(x:Int): Int @cps[Int] = { foo2(x); return 7 }
+  def bar3(x:Int): Int @cps[Int] = { foo2(x); if (x == 7) return 7 else return foo2(x) }
+  def bar4(x:Int): Int @cps[Int] = { foo2(x); if (x == 7) return 7 else foo2(x) }
+  def bar5(x:Int): Int @cps[Int] = { foo2(x); if (x == 7) return 7 else 8 }
+  println(reset { bar2(10) })
+  println(reset { bar3(10) })
+  println(reset { bar4(10) })
+  println(reset { bar5(10) })
+  
+  /* original test case */
   val repro = new ReturnRepro
   repro.caller
   repro.caller2