Support 'is/as FunctionN<...>' and 'invoke' for KFunction instances

compiler/testData/codegen/box/reflection/functions/instanceOfFunction.kt

@@ -0,0 +1,36 @@
+// WITH_REFLECT
+// FILE: FromJava.java
+
+import kotlin.reflect.KCallable;
+import kotlin.jvm.functions.Function1;
+import kotlin.jvm.functions.Function2;
+import kotlin.jvm.functions.Function3;
+
+public class FromJava {
+    public static String test(KCallable<?> x) {
+        if (!(x instanceof Function1)) return "Fail 6";
+        if (!(x instanceof Function2)) return "Fail 7";
+        if (!(x instanceof Function3)) return "Fail 8";
+        return "OK";
+    }
+}
+
+// FILE: test.kt
+
+class Foo {
+    fun bar(x: Int): Int = x + 1
+}
+
+fun box(): String {
+    val bar = Foo::class.members.single { it.name == "bar" }
+
+    if (bar is Function1<*, *>) return "Fail 1"
+    if (bar !is Function2<*, *, *>) return "Fail 2"
+    if (bar is Function3<*, *, *, *>) return "Fail 3"
+
+    bar as? Function2<Foo, Int, Int> ?: return "Fail 4"
+
+    if (bar(Foo(), 42) != 43) return "Fail 5"
+
+    return FromJava.test(bar)
+}

compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java

@@ -12270,6 +12270,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("instanceOfFunction.kt")
+            public void testInstanceOfFunction() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/reflection/functions/instanceOfFunction.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("javaClassGetFunctions.kt")
             public void testJavaClassGetFunctions() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/reflection/functions/javaClassGetFunctions.kt");

core/reflection.jvm/src/kotlin/reflect/jvm/internal/FunctionCaller.kt

@@ -29,15 +29,18 @@ internal abstract class FunctionCaller<out M : Member>(
         internal val instanceClass: Class<*>?,
         valueParameterTypes: Array<Type>
 ) {
-    internal val parameterTypes: List<Type> =
+    val parameterTypes: List<Type> =
             instanceClass?.let { listOf(it, *valueParameterTypes) } ?:
             valueParameterTypes.toList()
 
+    val arity: Int
+        get() = parameterTypes.size
+
     abstract fun call(args: Array<*>): Any?
 
     protected open fun checkArguments(args: Array<*>) {
-        if (parameterTypes.size != args.size) {
+        if (arity != args.size) {
-            throw IllegalArgumentException("Callable expects ${parameterTypes.size} arguments, but ${args.size} were provided.")
+            throw IllegalArgumentException("Callable expects $arity arguments, but ${args.size} were provided.")
         }
     }
 

core/reflection.jvm/src/kotlin/reflect/jvm/internal/FunctionWithAllInvokes.kt

@@ -0,0 +1,72 @@
+/*
+ * Copyright 2010-2015 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package kotlin.reflect.jvm.internal
+
+import kotlin.reflect.KCallable
+
+internal interface FunctionWithAllInvokes :
+        // (0..22).forEach { n -> println("Function$n<" + (0..n).joinToString { "Any?" } + ">,") }
+        Function0<Any?>,
+        Function1<Any?, Any?>,
+        Function2<Any?, Any?, Any?>,
+        Function3<Any?, Any?, Any?, Any?>,
+        Function4<Any?, Any?, Any?, Any?, Any?>,
+        Function5<Any?, Any?, Any?, Any?, Any?, Any?>,
+        Function6<Any?, Any?, Any?, Any?, Any?, Any?, Any?>,
+        Function7<Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?>,
+        Function8<Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?>,
+        Function9<Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?>,
+        Function10<Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?>,
+        Function11<Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?>,
+        Function12<Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?>,
+        Function13<Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?>,
+        Function14<Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?>,
+        Function15<Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?>,
+        Function16<Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?>,
+        Function17<Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?>,
+        Function18<Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?>,
+        Function19<Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?>,
+        Function20<Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?>,
+        Function21<Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?>,
+        Function22<Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?, Any?>,
+        KCallable<Any?>
+{
+    // (0..22).forEach { n -> println("override fun invoke(" + (1..n).joinToString { "p$it: Any?" } + "): Any? = call(" + (1..n).joinToString { "p$it" } + ")") }
+    override fun invoke(): Any? = call()
+    override fun invoke(p1: Any?): Any? = call(p1)
+    override fun invoke(p1: Any?, p2: Any?): Any? = call(p1, p2)
+    override fun invoke(p1: Any?, p2: Any?, p3: Any?): Any? = call(p1, p2, p3)
+    override fun invoke(p1: Any?, p2: Any?, p3: Any?, p4: Any?): Any? = call(p1, p2, p3, p4)
+    override fun invoke(p1: Any?, p2: Any?, p3: Any?, p4: Any?, p5: Any?): Any? = call(p1, p2, p3, p4, p5)
+    override fun invoke(p1: Any?, p2: Any?, p3: Any?, p4: Any?, p5: Any?, p6: Any?): Any? = call(p1, p2, p3, p4, p5, p6)
+    override fun invoke(p1: Any?, p2: Any?, p3: Any?, p4: Any?, p5: Any?, p6: Any?, p7: Any?): Any? = call(p1, p2, p3, p4, p5, p6, p7)
+    override fun invoke(p1: Any?, p2: Any?, p3: Any?, p4: Any?, p5: Any?, p6: Any?, p7: Any?, p8: Any?): Any? = call(p1, p2, p3, p4, p5, p6, p7, p8)
+    override fun invoke(p1: Any?, p2: Any?, p3: Any?, p4: Any?, p5: Any?, p6: Any?, p7: Any?, p8: Any?, p9: Any?): Any? = call(p1, p2, p3, p4, p5, p6, p7, p8, p9)
+    override fun invoke(p1: Any?, p2: Any?, p3: Any?, p4: Any?, p5: Any?, p6: Any?, p7: Any?, p8: Any?, p9: Any?, p10: Any?): Any? = call(p1, p2, p3, p4, p5, p6, p7, p8, p9, p10)
+    override fun invoke(p1: Any?, p2: Any?, p3: Any?, p4: Any?, p5: Any?, p6: Any?, p7: Any?, p8: Any?, p9: Any?, p10: Any?, p11: Any?): Any? = call(p1, p2, p3, p4, p5, p6, p7, p8, p9, p10, p11)
+    override fun invoke(p1: Any?, p2: Any?, p3: Any?, p4: Any?, p5: Any?, p6: Any?, p7: Any?, p8: Any?, p9: Any?, p10: Any?, p11: Any?, p12: Any?): Any? = call(p1, p2, p3, p4, p5, p6, p7, p8, p9, p10, p11, p12)
+    override fun invoke(p1: Any?, p2: Any?, p3: Any?, p4: Any?, p5: Any?, p6: Any?, p7: Any?, p8: Any?, p9: Any?, p10: Any?, p11: Any?, p12: Any?, p13: Any?): Any? = call(p1, p2, p3, p4, p5, p6, p7, p8, p9, p10, p11, p12, p13)
+    override fun invoke(p1: Any?, p2: Any?, p3: Any?, p4: Any?, p5: Any?, p6: Any?, p7: Any?, p8: Any?, p9: Any?, p10: Any?, p11: Any?, p12: Any?, p13: Any?, p14: Any?): Any? = call(p1, p2, p3, p4, p5, p6, p7, p8, p9, p10, p11, p12, p13, p14)
+    override fun invoke(p1: Any?, p2: Any?, p3: Any?, p4: Any?, p5: Any?, p6: Any?, p7: Any?, p8: Any?, p9: Any?, p10: Any?, p11: Any?, p12: Any?, p13: Any?, p14: Any?, p15: Any?): Any? = call(p1, p2, p3, p4, p5, p6, p7, p8, p9, p10, p11, p12, p13, p14, p15)
+    override fun invoke(p1: Any?, p2: Any?, p3: Any?, p4: Any?, p5: Any?, p6: Any?, p7: Any?, p8: Any?, p9: Any?, p10: Any?, p11: Any?, p12: Any?, p13: Any?, p14: Any?, p15: Any?, p16: Any?): Any? = call(p1, p2, p3, p4, p5, p6, p7, p8, p9, p10, p11, p12, p13, p14, p15, p16)
+    override fun invoke(p1: Any?, p2: Any?, p3: Any?, p4: Any?, p5: Any?, p6: Any?, p7: Any?, p8: Any?, p9: Any?, p10: Any?, p11: Any?, p12: Any?, p13: Any?, p14: Any?, p15: Any?, p16: Any?, p17: Any?): Any? = call(p1, p2, p3, p4, p5, p6, p7, p8, p9, p10, p11, p12, p13, p14, p15, p16, p17)
+    override fun invoke(p1: Any?, p2: Any?, p3: Any?, p4: Any?, p5: Any?, p6: Any?, p7: Any?, p8: Any?, p9: Any?, p10: Any?, p11: Any?, p12: Any?, p13: Any?, p14: Any?, p15: Any?, p16: Any?, p17: Any?, p18: Any?): Any? = call(p1, p2, p3, p4, p5, p6, p7, p8, p9, p10, p11, p12, p13, p14, p15, p16, p17, p18)
+    override fun invoke(p1: Any?, p2: Any?, p3: Any?, p4: Any?, p5: Any?, p6: Any?, p7: Any?, p8: Any?, p9: Any?, p10: Any?, p11: Any?, p12: Any?, p13: Any?, p14: Any?, p15: Any?, p16: Any?, p17: Any?, p18: Any?, p19: Any?): Any? = call(p1, p2, p3, p4, p5, p6, p7, p8, p9, p10, p11, p12, p13, p14, p15, p16, p17, p18, p19)
+    override fun invoke(p1: Any?, p2: Any?, p3: Any?, p4: Any?, p5: Any?, p6: Any?, p7: Any?, p8: Any?, p9: Any?, p10: Any?, p11: Any?, p12: Any?, p13: Any?, p14: Any?, p15: Any?, p16: Any?, p17: Any?, p18: Any?, p19: Any?, p20: Any?): Any? = call(p1, p2, p3, p4, p5, p6, p7, p8, p9, p10, p11, p12, p13, p14, p15, p16, p17, p18, p19, p20)
+    override fun invoke(p1: Any?, p2: Any?, p3: Any?, p4: Any?, p5: Any?, p6: Any?, p7: Any?, p8: Any?, p9: Any?, p10: Any?, p11: Any?, p12: Any?, p13: Any?, p14: Any?, p15: Any?, p16: Any?, p17: Any?, p18: Any?, p19: Any?, p20: Any?, p21: Any?): Any? = call(p1, p2, p3, p4, p5, p6, p7, p8, p9, p10, p11, p12, p13, p14, p15, p16, p17, p18, p19, p20, p21)
+    override fun invoke(p1: Any?, p2: Any?, p3: Any?, p4: Any?, p5: Any?, p6: Any?, p7: Any?, p8: Any?, p9: Any?, p10: Any?, p11: Any?, p12: Any?, p13: Any?, p14: Any?, p15: Any?, p16: Any?, p17: Any?, p18: Any?, p19: Any?, p20: Any?, p21: Any?, p22: Any?): Any? = call(p1, p2, p3, p4, p5, p6, p7, p8, p9, p10, p11, p12, p13, p14, p15, p16, p17, p18, p19, p20, p21, p22)
+}

core/reflection.jvm/src/kotlin/reflect/jvm/internal/KFunctionImpl.kt

@@ -33,7 +33,7 @@ internal class KFunctionImpl private constructor(
         name: String,
         private val signature: String,
         descriptorInitialValue: FunctionDescriptor?
-) : KFunction<Any?>, KCallableImpl<Any?>, FunctionImpl {
+) : KFunction<Any?>, KCallableImpl<Any?>, FunctionImpl, FunctionWithAllInvokes {
     constructor(container: KDeclarationContainerImpl, name: String, signature: String) : this(container, name, signature, null)
 
     constructor(container: KDeclarationContainerImpl, descriptor: FunctionDescriptor) : this(
@@ -103,11 +103,7 @@ internal class KFunctionImpl private constructor(
         }
     }
 
-    override fun getArity(): Int {
+    override fun getArity() = caller.arity
-        return descriptor.valueParameters.size +
-               (if (descriptor.dispatchReceiverParameter != null) 1 else 0) +
-               (if (descriptor.extensionReceiverParameter != null) 1 else 0)
-    }
 
     override val isInline: Boolean
         get() = descriptor.isInline