1 files changed, 140 insertions, 0 deletions
diff --git a/test/junit/scala/tools/nsc/backend/jvm/BytecodeTest.scala b/test/junit/scala/tools/nsc/backend/jvm/BytecodeTest.scala
new file mode 100644
index 0000000000..7954fe2360
--- /dev/null
+++ b/test/junit/scala/tools/nsc/backend/jvm/BytecodeTest.scala
@@ -0,0 +1,140 @@
+package scala.tools.nsc.backend.jvm
+
+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 BytecodeTest extends BytecodeTesting {
+  import compiler._
+
+  @Test
+  def t6288bJumpPosition(): Unit = {
+    val code =
+      """object Case3 {                                 // 01
+        | def unapply(z: Any): Option[Int] = Some(-1)   // 02
+        | def main(args: Array[String]) {               // 03
+        |    ("": Any) match {                          // 04
+        |      case x : String =>                       // 05
+        |        println("case 0")                      // 06 println and jump at 6
+        |      case _ =>                                // 07
+        |        println("default")                     // 08 println and jump at 8
+        |    }                                          // 09
+        |    println("done")                            // 10
+        |  }
+        |}
+      """.stripMargin
+    val List(mirror, module) = compileClasses(code)
+
+    val unapplyLineNumbers = getInstructions(module, "unapply").filter(_.isInstanceOf[LineNumber])
+    assert(unapplyLineNumbers == List(LineNumber(2, Label(0))), unapplyLineNumbers)
+
+    val expected = List(
+      LineNumber(4, Label(0)),
+      LineNumber(5, Label(5)),
+      Jump(IFEQ, Label(20)),
+
+      LineNumber(6, Label(11)),
+      Invoke(INVOKEVIRTUAL, "scala/Predef$", "println", "(Ljava/lang/Object;)V", false),
+      Jump(GOTO, Label(33)),
+
+      LineNumber(5, Label(20)),
+      Jump(GOTO, Label(24)),
+
+      LineNumber(8, Label(24)),
+      Invoke(INVOKEVIRTUAL, "scala/Predef$", "println", "(Ljava/lang/Object;)V", false),
+      Jump(GOTO, Label(33)),
+
+      LineNumber(10, Label(33)),
+      Invoke(INVOKEVIRTUAL, "scala/Predef$", "println", "(Ljava/lang/Object;)V", false)
+    )
+
+    val mainIns = getInstructions(module, "main") filter {
+      case _: LineNumber | _: Invoke | _: Jump => true
+      case _ => false
+    }
+    assertSameCode(mainIns, expected)
+  }
+
+  @Test
+  def bytecodeForBranches(): Unit = {
+    val code =
+      """class C {
+        |  def t1(b: Boolean) = if (b) 1 else 2
+        |  def t2(x: Int) = if (x == 393) 1 else 2
+        |  def t3(a: Array[String], b: AnyRef) = a != b && b == a
+        |  def t4(a: AnyRef) = a == null || null != a
+        |  def t5(a: AnyRef) = (a eq null) || (null ne a)
+        |  def t6(a: Int, b: Boolean) = if ((a == 10) && b || a != 1) 1 else 2
+        |  def t7(a: AnyRef, b: AnyRef) = a == b
+        |  def t8(a: AnyRef) = Nil == a || "" != a
+        |}
+      """.stripMargin
+
+    val c = compileClass(code)
+
+    // t1: no unnecessary GOTOs
+    assertSameCode(getMethod(c, "t1"), List(
+      VarOp(ILOAD, 1), Jump(IFEQ, Label(6)),
+      Op(ICONST_1), Jump(GOTO, Label(9)),
+      Label(6), Op(ICONST_2),
+      Label(9), Op(IRETURN)))
+
+    // t2: no unnecessary GOTOs
+    assertSameCode(getMethod(c, "t2"), List(
+      VarOp(ILOAD, 1), IntOp(SIPUSH, 393), Jump(IF_ICMPNE, Label(7)),
+      Op(ICONST_1), Jump(GOTO, Label(10)),
+      Label(7), Op(ICONST_2),
+      Label(10), Op(IRETURN)))
+
+    // t3: Array == is translated to reference equality, AnyRef == to null checks and equals
+    assertSameCode(getMethod(c, "t3"), List(
+      // Array ==
+      VarOp(ALOAD, 1), VarOp(ALOAD, 2), Jump(IF_ACMPEQ, Label(23)),
+      // AnyRef ==
+      VarOp(ALOAD, 2), VarOp(ALOAD, 1), VarOp(ASTORE, 3), Op(DUP), Jump(IFNONNULL, Label(14)),
+      Op(POP), VarOp(ALOAD, 3), Jump(IFNULL, Label(19)), Jump(GOTO, Label(23)),
+      Label(14), VarOp(ALOAD, 3), Invoke(INVOKEVIRTUAL, "java/lang/Object", "equals", "(Ljava/lang/Object;)Z", false), Jump(IFEQ, Label(23)),
+      Label(19), Op(ICONST_1), Jump(GOTO, Label(26)),
+      Label(23), Op(ICONST_0),
+      Label(26), Op(IRETURN)))
+
+    val t4t5 = List(
+      VarOp(ALOAD, 1), Jump(IFNULL, Label(6)),
+      VarOp(ALOAD, 1), Jump(IFNULL, Label(10)),
+      Label(6), Op(ICONST_1), Jump(GOTO, Label(13)),
+      Label(10), Op(ICONST_0),
+      Label(13), Op(IRETURN))
+
+    // t4: one side is known null, so just a null check on the other
+    assertSameCode(getMethod(c, "t4"), t4t5)
+
+    // t5: one side known null, so just a null check on the other
+    assertSameCode(getMethod(c, "t5"), t4t5)
+
+    // t6: no unnecessary GOTOs
+    assertSameCode(getMethod(c, "t6"), List(
+      VarOp(ILOAD, 1), IntOp(BIPUSH, 10), Jump(IF_ICMPNE, Label(7)),
+      VarOp(ILOAD, 2), Jump(IFNE, Label(12)),
+      Label(7), VarOp(ILOAD, 1), Op(ICONST_1), Jump(IF_ICMPEQ, Label(16)),
+      Label(12), Op(ICONST_1), Jump(GOTO, Label(19)),
+      Label(16), Op(ICONST_2),
+      Label(19), Op(IRETURN)))
+
+    // t7: universal equality
+    assertInvoke(getMethod(c, "t7"), "scala/runtime/BoxesRunTime", "equals")
+
+    // t8: no null checks invoking equals on modules and constants
+    assertSameCode(getMethod(c, "t8"), List(
+      Field(GETSTATIC, "scala/collection/immutable/Nil$", "MODULE$", "Lscala/collection/immutable/Nil$;"), VarOp(ALOAD, 1), Invoke(INVOKEVIRTUAL, "java/lang/Object", "equals", "(Ljava/lang/Object;)Z", false), Jump(IFNE, Label(10)),
+      Ldc(LDC, ""), VarOp(ALOAD, 1), Invoke(INVOKEVIRTUAL, "java/lang/Object", "equals", "(Ljava/lang/Object;)Z", false), Jump(IFNE, Label(14)),
+      Label(10), Op(ICONST_1), Jump(GOTO, Label(17)),
+      Label(14), Op(ICONST_0),
+      Label(17), Op(IRETURN)))
+  }
+}