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package scala.tools.nsc.backend.jvm
import org.junit.Assert._
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)))
}
@Test // wrong local variable table for methods containing while loops
def t9179(): Unit = {
val code =
"""class C {
| def t(): Unit = {
| var x = ""
| while (x != null) {
| foo()
| x = null
| }
| bar()
| }
| def foo(): Unit = ()
| def bar(): Unit = ()
|}
""".stripMargin
val c = compileClass(code)
val t = getMethod(c, "t")
val isFrameLine = (x: Instruction) => x.isInstanceOf[FrameEntry] || x.isInstanceOf[LineNumber]
assertSameCode(t.instructions.filterNot(isFrameLine), List(
Label(0), Ldc(LDC, ""), Label(3), VarOp(ASTORE, 1),
Label(5), VarOp(ALOAD, 1), Jump(IFNULL, Label(21)),
Label(10), VarOp(ALOAD, 0), Invoke(INVOKEVIRTUAL, "C", "foo", "()V", false), Label(14), Op(ACONST_NULL), VarOp(ASTORE, 1), Label(18), Jump(GOTO, Label(5)),
Label(21), VarOp(ALOAD, 0), Invoke(INVOKEVIRTUAL, "C", "bar", "()V", false), Label(26), Op(RETURN), Label(28)))
val labels = t.instructions collect { case l: Label => l }
val x = t.localVars.find(_.name == "x").get
assertEquals(x.start, labels(1))
assertEquals(x.end, labels(7))
}
@Test
def sd186_traitLineNumber(): Unit = {
val code =
"""trait T {
| def t(): Unit = {
| toString
| toString
| }
|}
""".stripMargin
val t = compileClass(code)
val tMethod = getMethod(t, "t$")
val invoke = Invoke(INVOKEVIRTUAL, "java/lang/Object", "toString", "()Ljava/lang/String;", false)
// ths static accessor is positioned at the line number of the accessed method.
assertSameCode(tMethod.instructions,
List(Label(0), LineNumber(2, Label(0)), VarOp(ALOAD, 0), Invoke(INVOKESPECIAL, "T", "t", "()V", true), Op(RETURN), Label(4))
)
}
@Test
def sd233(): Unit = {
val code = "def f = { println(1); synchronized(println(2)) }"
val m = compileMethod(code)
val List(ExceptionHandler(_, _, _, desc)) = m.handlers
assert(desc == None, desc)
}
}
|
