Support get/set on KProperty objects for delegated properties

compiler/testData/codegen/boxWithStdlib/delegatedProperty/stackOverflowOnCallFromGetValue.kt

@@ -1,23 +1,50 @@
 // FULL_JDK
 
-import kotlin.reflect.KProperty
-import kotlin.reflect.KProperty0
-import kotlin.test.assertFailsWith
+import java.lang.reflect.InvocationTargetException
+import kotlin.reflect.*
 
-class Delegate {
+object Delegate {
     fun getValue(t: Any?, p: KProperty<*>): String {
-        return (p as KProperty0<String>).get()
+        (p as? KProperty0<String>)?.get()
+        (p as? KProperty1<O, String>)?.get(O)
+        (p as? KProperty2<O, O, String>)?.get(O, O)
+        return "Fail"
+    }
+
+    fun setValue(t: Any?, p: KProperty<*>, v: String) {
+        (p as? KMutableProperty0<String>)?.set(v)
+        (p as? KMutableProperty1<O, String>)?.set(O, v)
+        (p as? KMutableProperty2<O, O, String>)?.set(O, O, v)
     }
 }
 
-val prop: String by Delegate()
+var topLevel: String by Delegate
+object O {
+    var member: String by Delegate
+    var O.memExt: String by Delegate
+}
+
+fun check(lambda: () -> Unit) {
+    try {
+        lambda()
+        throw AssertionError("Getting the property value with .get() from getValue() or setting it with .set() in setValue() " +
+                             "is effectively an endless recursion and should fail")
+    } catch (e: Throwable) {
+        if (e !is InvocationTargetException && e !is StackOverflowError) {
+            throw AssertionError("The current implementation uses reflection to get the value of the property," +
+                                 "so either InvocationTargetException or StackOverflowError should have happened, but was: ${e}")
+        }
+    }
+}
 
 fun box(): String {
-    assertFailsWith(
-            StackOverflowError::class.java,
-            "Getting the property value with .get() from getValue is effectively an endless recursion and should fail"
-    ) {
-        prop
+    check { topLevel }
+    check { topLevel = "" }
+    check { O.member }
+    check { O.member = "" }
+    with (O) {
+        check { O.memExt }
+        check { O.memExt = "" }
     }
 
     return "OK"

compiler/testData/codegen/boxWithStdlib/delegatedProperty/useKPropertyLater.kt

@@ -0,0 +1,43 @@
+import java.util.*
+import kotlin.reflect.*
+
+val properties = HashSet<KProperty<*>>()
+
+object Delegate {
+    fun getValue(t: Any?, p: KProperty<*>): String {
+        properties.add(p)
+        return ""
+    }
+
+    fun setValue(t: Any?, p: KProperty<*>, v: String) {
+        properties.add(p)
+    }
+}
+
+var topLevel: String by Delegate
+object O {
+    var member: String by Delegate
+    var O.memExt: String by Delegate
+}
+
+fun box(): String {
+    topLevel = ""
+    O.member = ""
+    with (O) {
+        O.memExt = ""
+    }
+
+    for (p in HashSet(properties)) {
+        // None of these should fail
+
+        (p as? KProperty0<String>)?.get()
+        (p as? KProperty1<O, String>)?.get(O)
+        (p as? KProperty2<O, O, String>)?.get(O, O)
+
+        (p as? KMutableProperty0<String>)?.set("")
+        (p as? KMutableProperty1<O, String>)?.set(O, "")
+        (p as? KMutableProperty2<O, O, String>)?.set(O, O, "")
+    }
+
+    return "OK"
+}

compiler/tests/org/jetbrains/kotlin/codegen/generated/BlackBoxWithStdlibCodegenTestGenerated.java

@@ -1467,6 +1467,12 @@ public class BlackBoxWithStdlibCodegenTestGenerated extends AbstractBlackBoxCode
             String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/boxWithStdlib/delegatedProperty/stackOverflowOnCallFromGetValue.kt");
             doTestWithStdlib(fileName);
         }
+
+        @TestMetadata("useKPropertyLater.kt")
+        public void testUseKPropertyLater() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/boxWithStdlib/delegatedProperty/useKPropertyLater.kt");
+            doTestWithStdlib(fileName);
+        }
     }
 
     @TestMetadata("compiler/testData/codegen/boxWithStdlib/enum")

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

@@ -18,56 +18,65 @@ package kotlin.reflect.jvm.internal
 
 import kotlin.jvm.internal.*
 
-internal class KProperty0FromReferenceImpl(
+internal open class KProperty0Augmented(
         val reference: PropertyReference0
 ) : KProperty0Impl<Any?>(reference.owner as KDeclarationContainerImpl, reference.name, reference.signature) {
     override val name: String get() = reference.name
+}
 
+internal class KProperty0FromReferenceImpl(reference: PropertyReference0) : KProperty0Augmented(reference) {
     override fun get(): Any? = reference.get()
 }
 
-internal class KMutableProperty0FromReferenceImpl(
+internal open class KMutableProperty0Augmented(
         val reference: MutablePropertyReference0
 ) : KMutableProperty0Impl<Any?>(reference.owner as KDeclarationContainerImpl, reference.name, reference.signature) {
     override val name: String get() = reference.name
+}
 
+internal class KMutableProperty0FromReferenceImpl(reference: MutablePropertyReference0) : KMutableProperty0Augmented(reference) {
     override fun get(): Any? = reference.get()
-
     override fun set(value: Any?) = reference.set(value)
 }
 
-internal class KProperty1FromReferenceImpl(
+internal open class KProperty1Augmented(
         val reference: PropertyReference1
 ) : KProperty1Impl<Any?, Any?>(reference.owner as KDeclarationContainerImpl, reference.name, reference.signature) {
     override val name: String get() = reference.name
+}
 
+internal class KProperty1FromReferenceImpl(reference: PropertyReference1) : KProperty1Augmented(reference) {
     override fun get(receiver: Any?): Any? = reference.get(receiver)
 }
 
-internal class KMutableProperty1FromReferenceImpl(
+internal open class KMutableProperty1Augmented(
         val reference: MutablePropertyReference1
 ) : KMutableProperty1Impl<Any?, Any?>(reference.owner as KDeclarationContainerImpl, reference.name, reference.signature) {
     override val name: String get() = reference.name
+}
 
+internal class KMutableProperty1FromReferenceImpl(reference: MutablePropertyReference1) : KMutableProperty1Augmented(reference) {
     override fun get(receiver: Any?): Any? = reference.get(receiver)
-
     override fun set(receiver: Any?, value: Any?) = reference.set(receiver, value)
 }
 
-internal class KProperty2FromReferenceImpl(
+internal open class KProperty2Augmented(
         val reference: PropertyReference2
 ) : KProperty2Impl<Any?, Any?, Any?>(reference.owner as KDeclarationContainerImpl, reference.name, reference.signature) {
     override val name: String get() = reference.name
+}
 
+internal class KProperty2FromReferenceImpl(reference: PropertyReference2) : KProperty2Augmented(reference) {
     override fun get(receiver1: Any?, receiver2: Any?): Any? = reference.get(receiver1, receiver2)
 }
 
-internal class KMutableProperty2FromReferenceImpl(
+internal open class KMutableProperty2Augmented(
         val reference: MutablePropertyReference2
 ) : KMutableProperty2Impl<Any?, Any?, Any?>(reference.owner as KDeclarationContainerImpl, reference.name, reference.signature) {
     override val name: String get() = reference.name
+}
 
+internal class KMutableProperty2FromReferenceImpl(reference: MutablePropertyReference2) : KMutableProperty2Augmented(reference) {
     override fun get(receiver1: Any?, receiver2: Any?): Any? = reference.get(receiver1, receiver2)
-
     override fun set(receiver1: Any?, receiver2: Any?, value: Any?) = reference.set(receiver1, receiver2, value)
 }

core/reflection.jvm/src/kotlin/reflect/jvm/internal/ReflectionFactoryImpl.java

@@ -50,32 +50,32 @@ public class ReflectionFactoryImpl extends ReflectionFactory {
 
     @Override
     public KProperty0 property0(PropertyReference0 p) {
-        return new KProperty0FromReferenceImpl(p);
+        return p instanceof PropertyReference0Impl ? new KProperty0Augmented(p) : new KProperty0FromReferenceImpl(p);
     }
 
     @Override
     public KMutableProperty0 mutableProperty0(MutablePropertyReference0 p) {
-        return new KMutableProperty0FromReferenceImpl(p);
+        return p instanceof MutablePropertyReference0Impl ? new KMutableProperty0Augmented(p) : new KMutableProperty0FromReferenceImpl(p);
     }
 
     @Override
     public KProperty1 property1(PropertyReference1 p) {
-        return new KProperty1FromReferenceImpl(p);
+        return p instanceof PropertyReference1Impl ? new KProperty1Augmented(p) : new KProperty1FromReferenceImpl(p);
     }
 
     @Override
     public KMutableProperty1 mutableProperty1(MutablePropertyReference1 p) {
-        return new KMutableProperty1FromReferenceImpl(p);
+        return p instanceof MutablePropertyReference1Impl ? new KMutableProperty1Augmented(p) : new KMutableProperty1FromReferenceImpl(p);
     }
 
     @Override
     public KProperty2 property2(PropertyReference2 p) {
-        return new KProperty2FromReferenceImpl(p);
+        return p instanceof PropertyReference2Impl ? new KProperty2Augmented(p) : new KProperty2FromReferenceImpl(p);
     }
 
     @Override
     public KMutableProperty2 mutableProperty2(MutablePropertyReference2 p) {
-        return new KMutableProperty2FromReferenceImpl(p);
+        return p instanceof MutablePropertyReference2Impl ? new KMutableProperty2Augmented(p) : new KMutableProperty2FromReferenceImpl(p);
     }
 
     // Deprecated