Cleanups after code review

  - Remove unused references to "addTargetMethods"
  - Require that `targetMethodMap` is provided

3 files changed, 8 insertions, 21 deletions

diff --git a/src/compiler/scala/tools/nsc/backend/jvm/BTypes.scala b/src/compiler/scala/tools/nsc/backend/jvm/BTypes.scala
index 0845e440d7..bff58b426e 100644
--- a/src/compiler/scala/tools/nsc/backend/jvm/BTypes.scala
+++ b/src/compiler/scala/tools/nsc/backend/jvm/BTypes.scala
@@ -124,12 +124,13 @@ abstract class BTypes {
    */
   val indyLambdaImplMethods: mutable.AnyRefMap[InternalName, mutable.LinkedHashSet[asm.Handle]] = recordPerRunCache(mutable.AnyRefMap())
   def addIndyLambdaImplMethod(hostClass: InternalName, handle: Seq[asm.Handle]): Unit = {
-    indyLambdaImplMethods.getOrElseUpdate(hostClass, mutable.LinkedHashSet()) ++= handle
+    if (handle.nonEmpty)
+      indyLambdaImplMethods.getOrElseUpdate(hostClass, mutable.LinkedHashSet()) ++= handle
   }
-  def getIndyLambdaImplMethods(hostClass: InternalName): List[asm.Handle] = {
+  def getIndyLambdaImplMethods(hostClass: InternalName): Iterable[asm.Handle] = {
     indyLambdaImplMethods.getOrNull(hostClass) match {
       case null => Nil
-      case xs => xs.toList.distinct
+      case xs => xs
     }
   }
 
diff --git a/src/compiler/scala/tools/nsc/backend/jvm/CoreBTypes.scala b/src/compiler/scala/tools/nsc/backend/jvm/CoreBTypes.scala
index 1dbb18722f..acb950929f 100644
--- a/src/compiler/scala/tools/nsc/backend/jvm/CoreBTypes.scala
+++ b/src/compiler/scala/tools/nsc/backend/jvm/CoreBTypes.scala
@@ -289,19 +289,6 @@ class CoreBTypes[BTFS <: BTypesFromSymbols[_ <: Global]](val bTypes: BTFS) {
         coreBTypes.jliCallSiteRef
       ).descriptor,
       /* itf = */ coreBTypes.srLambdaDeserialize.isInterface.get)
-  lazy val lambdaDeserializeAddTargets =
-    new scala.tools.asm.Handle(scala.tools.asm.Opcodes.H_INVOKESTATIC,
-      coreBTypes.srLambdaDeserialize.internalName, "bootstrapAddTargets",
-      MethodBType(
-        List(
-          coreBTypes.jliMethodHandlesLookupRef,
-          coreBTypes.StringRef,
-          coreBTypes.jliMethodTypeRef,
-          ArrayBType(coreBTypes.jliMethodHandleRef)
-        ),
-        coreBTypes.jliCallSiteRef
-      ).descriptor,
-      /* itf = */ coreBTypes.srLambdaDeserialize.isInterface.get)
 }
 
 /**
diff --git a/src/compiler/scala/tools/nsc/backend/jvm/analysis/BackendUtils.scala b/src/compiler/scala/tools/nsc/backend/jvm/analysis/BackendUtils.scala
index d85d85003d..e25b55e7ab 100644
--- a/src/compiler/scala/tools/nsc/backend/jvm/analysis/BackendUtils.scala
+++ b/src/compiler/scala/tools/nsc/backend/jvm/analysis/BackendUtils.scala
@@ -76,7 +76,7 @@ class BackendUtils[BT <: BTypes](val btypes: BT) {
    * host a static field in the enclosing class. This allows us to add this method to interfaces
    * that define lambdas in default methods.
    */
-  def addLambdaDeserialize(classNode: ClassNode, implMethods: List[Handle]): Unit = {
+  def addLambdaDeserialize(classNode: ClassNode, implMethods: Iterable[Handle]): Unit = {
     val cw = classNode
 
     // Make sure to reference the ClassBTypes of all types that are used in the code generated
@@ -87,13 +87,12 @@ class BackendUtils[BT <: BTypes](val btypes: BT) {
 
     val nilLookupDesc = MethodBType(Nil, jliMethodHandlesLookupRef).descriptor
     val serlamObjDesc = MethodBType(jliSerializedLambdaRef :: Nil, ObjectRef).descriptor
-    val addTargetMethodsObjDesc = MethodBType(ObjectRef :: Nil, UNIT).descriptor
 
     {
       val mv = cw.visitMethod(ACC_PRIVATE + ACC_STATIC + ACC_SYNTHETIC, "$deserializeLambda$", serlamObjDesc, null, null)
       mv.visitCode()
       mv.visitVarInsn(ALOAD, 0)
-      mv.visitInvokeDynamicInsn("lambdaDeserialize", serlamObjDesc, lambdaDeserializeBootstrapHandle, implMethods: _*)
+      mv.visitInvokeDynamicInsn("lambdaDeserialize", serlamObjDesc, lambdaDeserializeBootstrapHandle, implMethods.toArray: _*)
       mv.visitInsn(ARETURN)
       mv.visitEnd()
     }
@@ -102,8 +101,8 @@ class BackendUtils[BT <: BTypes](val btypes: BT) {
   /**
    * Clone the instructions in `methodNode` into a new [[InsnList]], mapping labels according to
    * the `labelMap`. Returns the new instruction list and a map from old to new instructions, and
-   * a boolean indicating if the instruction list contains an instantiation of a serializable SAM
-   * type.
+   * a list of lambda implementation methods references by invokedynamic[LambdaMetafactory] for a
+   * serializable SAM types.
    */
   def cloneInstructions(methodNode: MethodNode, labelMap: Map[LabelNode, LabelNode], keepLineNumbers: Boolean): (InsnList, Map[AbstractInsnNode, AbstractInsnNode], List[Handle]) = {
     val javaLabelMap = labelMap.asJava