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Diffstat (limited to 'test/junit/scala/tools/nsc/backend/jvm/opt/UnreachableCodeTest.scala')
-rw-r--r-- | test/junit/scala/tools/nsc/backend/jvm/opt/UnreachableCodeTest.scala | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/test/junit/scala/tools/nsc/backend/jvm/opt/UnreachableCodeTest.scala b/test/junit/scala/tools/nsc/backend/jvm/opt/UnreachableCodeTest.scala new file mode 100644 index 0000000000..4e62cc64e4 --- /dev/null +++ b/test/junit/scala/tools/nsc/backend/jvm/opt/UnreachableCodeTest.scala @@ -0,0 +1,162 @@ +package scala.tools.nsc +package backend.jvm +package opt + +import org.junit.runner.RunWith +import org.junit.runners.JUnit4 +import org.junit.Test +import scala.tools.asm.Opcodes._ +import org.junit.Assert._ + +import scala.tools.testing.AssertUtil._ + +import CodeGenTools._ +import scala.tools.partest.ASMConverters +import ASMConverters._ + +@RunWith(classOf[JUnit4]) +class UnreachableCodeTest { + import UnreachableCodeTest._ + + @Test + def basicElimination(): Unit = { + assertEliminateDead( + Op(ACONST_NULL), + Op(ATHROW), + Op(RETURN).dead + ) + + assertEliminateDead( + Op(RETURN) + ) + + assertEliminateDead( + Op(RETURN), + Op(ACONST_NULL).dead, + Op(ATHROW).dead + ) + } + + @Test + def eliminateNop(): Unit = { + assertEliminateDead( + // not dead, since visited by data flow analysis. need a different opt to eliminate it. + Op(NOP), + Op(RETURN), + Op(NOP).dead + ) + } + + @Test + def eliminateBranchOver(): Unit = { + assertEliminateDead( + Jump(GOTO, Label(1)), + Op(ACONST_NULL).dead, + Op(ATHROW).dead, + Label(1), + Op(RETURN) + ) + + assertEliminateDead( + Jump(GOTO, Label(1)), + Label(1), + Op(RETURN) + ) + } + + @Test + def deadLabelsRemain(): Unit = { + assertEliminateDead( + Op(RETURN), + Jump(GOTO, Label(1)).dead, + // not dead - labels may be referenced from other places in a classfile (eg exceptions table). + // will need a different opt to get rid of them + Label(1) + ) + } + + @Test + def pushPopNotEliminated(): Unit = { + assertEliminateDead( + // not dead, visited by data flow analysis. + Op(ACONST_NULL), + Op(POP), + Op(RETURN) + ) + } + + @Test + def nullnessNotConsidered(): Unit = { + assertEliminateDead( + Op(ACONST_NULL), + Jump(IFNULL, Label(1)), + Op(RETURN), // not dead + Label(1), + Op(RETURN) + ) + } + + @Test + def metaTest(): Unit = { + assertEliminateDead() // no instructions + + assertThrows[AssertionError]( + assertEliminateDead(Op(RETURN).dead), + _.contains("Expected: List()\nActual : List(Op(RETURN))") + ) + + assertThrows[AssertionError]( + assertEliminateDead(Op(RETURN), Op(RETURN)), + _.contains("Expected: List(Op(RETURN), Op(RETURN))\nActual : List(Op(RETURN))") + ) + } + + @Test + def bytecodeEquivalence: Unit = { + assertTrue(List(VarOp(ILOAD, 1)) === + List(VarOp(ILOAD, 2))) + assertTrue(List(VarOp(ILOAD, 1), VarOp(ISTORE, 1)) === + List(VarOp(ILOAD, 2), VarOp(ISTORE, 2))) + + // the first Op will associate 1->2, then the 2->2 will fail + assertFalse(List(VarOp(ILOAD, 1), VarOp(ISTORE, 2)) === + List(VarOp(ILOAD, 2), VarOp(ISTORE, 2))) + + // will associate 1->2 and 2->1, which is OK + assertTrue(List(VarOp(ILOAD, 1), VarOp(ISTORE, 2)) === + List(VarOp(ILOAD, 2), VarOp(ISTORE, 1))) + + assertTrue(List(Label(1), Label(2), Label(1)) === + List(Label(2), Label(4), Label(2))) + assertTrue(List(LineNumber(1, Label(1)), Label(1)) === + List(LineNumber(1, Label(3)), Label(3))) + assertFalse(List(LineNumber(1, Label(1)), Label(1)) === + List(LineNumber(1, Label(3)), Label(1))) + + assertTrue(List(TableSwitch(TABLESWITCH, 1, 3, Label(4), List(Label(5), Label(6))), Label(4), Label(5), Label(6)) === + List(TableSwitch(TABLESWITCH, 1, 3, Label(9), List(Label(3), Label(4))), Label(9), Label(3), Label(4))) + + assertTrue(List(FrameEntry(F_FULL, List(INTEGER, DOUBLE, Label(3)), List("java/lang/Object", Label(4))), Label(3), Label(4)) === + List(FrameEntry(F_FULL, List(INTEGER, DOUBLE, Label(1)), List("java/lang/Object", Label(3))), Label(1), Label(3))) + } +} + +object UnreachableCodeTest { + import scala.language.implicitConversions + implicit def aliveInstruction(ins: Instruction): (Instruction, Boolean) = (ins, true) + + implicit class MortalInstruction(val ins: Instruction) extends AnyVal { + def dead: (Instruction, Boolean) = (ins, false) + } + + def assertEliminateDead(code: (Instruction, Boolean)*): Unit = { + val cls = wrapInClass(genMethod()(code.map(_._1): _*)) + LocalOpt.removeUnreachableCode(cls) + val nonEliminated = instructionsFromMethod(cls.methods.get(0)) + + val expectedLive = code.filter(_._2).map(_._1).toList + + assertTrue(s"\nExpected: $expectedLive\nActual : $nonEliminated", nonEliminated === expectedLive) + } + +} |