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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))
}
}
|
