1 files changed, 86 insertions, 0 deletions
diff --git a/test/junit/scala/tools/nsc/backend/jvm/opt/ClosureOptimizerTest.scala b/test/junit/scala/tools/nsc/backend/jvm/opt/ClosureOptimizerTest.scala
new file mode 100644
index 0000000000..f672237f10
--- /dev/null
+++ b/test/junit/scala/tools/nsc/backend/jvm/opt/ClosureOptimizerTest.scala
@@ -0,0 +1,86 @@
+package scala.tools.nsc
+package backend.jvm
+package opt
+
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.junit.runners.JUnit4
+
+import scala.tools.asm.Opcodes._
+import scala.tools.partest.ASMConverters._
+import scala.tools.testing.BytecodeTesting
+import scala.tools.testing.BytecodeTesting._
+
+@RunWith(classOf[JUnit4])
+class ClosureOptimizerTest extends BytecodeTesting {
+  override def compilerArgs = "-opt:l:classpath -opt-warnings:_"
+  import compiler._
+
+  @Test
+  def nothingTypedClosureBody(): Unit = {
+    val code =
+      """abstract class C {
+        |  def isEmpty: Boolean
+        |  @inline final def getOrElse[T >: C](f: => T) = if (isEmpty) f else this
+        |  def t = getOrElse(throw new Error(""))
+        |}
+      """.stripMargin
+
+    val c = compileClass(code)
+    val t = getAsmMethod(c, "t")
+    val bodyCall = findInstr(t, "INVOKESTATIC C.$anonfun$t$1 ()Lscala/runtime/Nothing$")
+    assert(bodyCall.getNext.getOpcode == ATHROW)
+  }
+
+  @Test
+  def nullTypedClosureBody(): Unit = {
+    val code =
+      """abstract class C {
+        |  def isEmpty: Boolean
+        |  @inline final def getOrElse[T >: C](f: => T) = if (isEmpty) f else this
+        |  def t = getOrElse(null)
+        |}
+      """.stripMargin
+
+    val c = compileClass(code)
+    val t = getAsmMethod(c, "t")
+    val bodyCall = findInstr(t, "INVOKESTATIC C.$anonfun$t$1 ()Lscala/runtime/Null$")
+    assert(bodyCall.getNext.getOpcode == POP)
+    assert(bodyCall.getNext.getNext.getOpcode == ACONST_NULL)
+  }
+
+  @Test
+  def makeLMFCastExplicit(): Unit = {
+    val code =
+      """class C {
+        |  def t(l: List[String]) = {
+        |    val fun: String => String = s => s
+        |    fun(l.head)
+        |  }
+        |}
+      """.stripMargin
+    val c = compileClass(code)
+    assertSameCode(getMethod(c, "t"),
+      List(VarOp(ALOAD, 1), Invoke(INVOKEVIRTUAL, "scala/collection/immutable/List", "head", "()Ljava/lang/Object;", false),
+        TypeOp(CHECKCAST, "java/lang/String"), Invoke(INVOKESTATIC, "C", "$anonfun$t$1", "(Ljava/lang/String;)Ljava/lang/String;", false),
+        Op(ARETURN)))
+  }
+
+  @Test
+  def closureOptWithUnreachableCode(): Unit = {
+    // this example used to crash the ProdCons analysis in the closure optimizer - ProdCons
+    // expects no unreachable code.
+    val code =
+      """class C {
+        |  @inline final def m = throw new Error("")
+        |  def t = {
+        |    val f = (x: Int) => x + 1
+        |    m
+        |    f(10) // unreachable after inlining m
+        |  }
+        |}
+      """.stripMargin
+    val c = compileClass(code)
+    assertSameSummary(getMethod(c, "t"), List(NEW, DUP, LDC, "<init>", ATHROW))
+  }
+}