Merge pull request #2158 from JamesIry/master_7006

SI-7006 Eliminate NOPs and unreachable code

4 files changed, 31 insertions, 1 deletions

diff --git a/test/files/jvm/t7006/Foo_1.flags b/test/files/jvm/t7006/Foo_1.flags
new file mode 100644
index 0000000000..72fe7b1aa0
--- /dev/null
+++ b/test/files/jvm/t7006/Foo_1.flags
@@ -0,0 +1 @@
+ -Ydead-code -Ydebug -Xfatal-warnings
diff --git a/test/files/jvm/t7006/Foo_1.scala b/test/files/jvm/t7006/Foo_1.scala
new file mode 100644
index 0000000000..995619ce6b
--- /dev/null
+++ b/test/files/jvm/t7006/Foo_1.scala
@@ -0,0 +1,10 @@
+class Foo_1 {
+  def foo {
+    try {
+      val x = 3 // this will be optimized away, leaving a useless jump only block
+    } finally {
+      print("hello")
+    }
+    while(true){} // ensure infinite loop doesn't break the algoirthm
+  }
+}
diff --git a/test/files/jvm/t7006/Test.scala b/test/files/jvm/t7006/Test.scala
new file mode 100644
index 0000000000..065a23510e
--- /dev/null
+++ b/test/files/jvm/t7006/Test.scala
@@ -0,0 +1,19 @@
+import scala.tools.partest.BytecodeTest
+import scala.tools.asm
+import asm.tree.InsnList
+import scala.collection.JavaConverters._
+
+object Test extends BytecodeTest {
+  def show: Unit = {
+    val classNode = loadClassNode("Foo_1")
+    val methodNode = getMethod(classNode, "foo")
+    assert(count(methodNode.instructions, asm.Opcodes.NOP) == 0)
+    assert(count(methodNode.instructions, asm.Opcodes.GOTO) == 1)
+  }
+
+  def count(insnList: InsnList, opcode: Int): Int = {
+    def isNop(node: asm.tree.AbstractInsnNode): Boolean =
+      (node.getOpcode == opcode)
+    insnList.iterator.asScala.count(isNop)
+  }
+}
diff --git a/test/files/run/t6102.flags b/test/files/run/t6102.flags
index e35535c8ea..72fe7b1aa0 100644
--- a/test/files/run/t6102.flags
+++ b/test/files/run/t6102.flags
@@ -1 +1 @@
- -Ydead-code 
+ -Ydead-code -Ydebug -Xfatal-warnings