Reflection: refactor property construction and fix memory leak

Properties obtained by KClass.properties were having strong references to
descriptors (captured by closures, which are strongly retained by
DescriptorBasedProperty). Support initial value in lazy soft properties

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

@@ -18,6 +18,7 @@ package kotlin.reflect.jvm.internal
 
 import org.jetbrains.kotlin.descriptors.PropertyDescriptor
 import org.jetbrains.kotlin.descriptors.Visibilities
+import org.jetbrains.kotlin.load.java.structure.reflect.desc
 import org.jetbrains.kotlin.resolve.DescriptorUtils
 import org.jetbrains.kotlin.serialization.ProtoBuf
 import org.jetbrains.kotlin.serialization.deserialization.NameResolver
@@ -26,10 +27,22 @@ import org.jetbrains.kotlin.serialization.jvm.JvmProtoBuf
 import java.lang.reflect.Field
 import java.lang.reflect.Method
 
-abstract class DescriptorBasedProperty(computeDescriptor: () -> PropertyDescriptor) {
+abstract class DescriptorBasedProperty private(
-    protected abstract val container: KCallableContainerImpl
+        container: KCallableContainerImpl,
+        name: String,
+        receiverParameterDesc: String?,
+        descriptorInitialValue: PropertyDescriptor?
+) {
+    constructor(container: KCallableContainerImpl, name: String, receiverParameterClass: Class<*>?) : this(
+            container, name, receiverParameterClass?.desc, null
+    )
 
-    protected abstract val name: String
+    constructor(container: KCallableContainerImpl, descriptor: PropertyDescriptor) : this(
+            container,
+            descriptor.getName().asString(),
+            descriptor.getExtensionReceiverParameter()?.getType()?.let { type -> RuntimeTypeMapper.mapTypeToJvmDesc(type) },
+            descriptor
+    )
 
     private data class PropertyProtoData(
             val proto: ProtoBuf.Callable,
@@ -37,7 +50,9 @@ abstract class DescriptorBasedProperty(computeDescriptor: () -> PropertyDescript
             val signature: JvmProtoBuf.JvmPropertySignature
     )
 
-    protected val descriptor: PropertyDescriptor by ReflectProperties.lazySoft(computeDescriptor)
+    protected val descriptor: PropertyDescriptor by ReflectProperties.lazySoft<PropertyDescriptor>(descriptorInitialValue) {
+        container.findPropertyDescriptor(name, receiverParameterDesc)
+    }
 
     // null if this is a property declared in a foreign (Java) class
     private val protoData: PropertyProtoData? by ReflectProperties.lazyWeak {

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

@@ -20,7 +20,6 @@ import org.jetbrains.kotlin.descriptors.PropertyDescriptor
 import org.jetbrains.kotlin.load.java.structure.reflect.classId
 import org.jetbrains.kotlin.load.java.structure.reflect.classLoader
 import org.jetbrains.kotlin.load.java.structure.reflect.createArrayType
-import org.jetbrains.kotlin.load.java.structure.reflect.desc
 import org.jetbrains.kotlin.name.ClassId
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.resolve.scopes.JetScope
@@ -42,9 +41,7 @@ abstract class KCallableContainerImpl {
 
     abstract val scope: JetScope
 
-    protected fun findPropertyDescriptor(name: String, receiverParameterClass: Class<*>? = null): () -> PropertyDescriptor = {
+    fun findPropertyDescriptor(name: String, receiverDesc: String? = null): PropertyDescriptor {
-        val receiverDesc = receiverParameterClass?.desc
-
         val properties = scope
                 .getProperties(Name.identifier(name))
                 .filter { descriptor ->
@@ -57,14 +54,14 @@ abstract class KCallableContainerImpl {
                 }
 
         if (properties.size() != 1) {
-            val debugText = if (receiverParameterClass == null) name else "${receiverParameterClass.getSimpleName()}.$name"
+            val debugText = if (receiverDesc == null) name else "$receiverDesc.$name"
             throw KotlinReflectionInternalError(
                     if (properties.isEmpty()) "Property '$debugText' not resolved in $this"
                     else "${properties.size()} properties '$debugText' resolved in $this"
             )
         }
 
-        properties.single() as PropertyDescriptor
+        return properties.single() as PropertyDescriptor
     }
 
     // TODO: check resulting method's return type

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

@@ -69,14 +69,14 @@ class KClassImpl<T>(override val jClass: Class<T>) : KCallableContainerImpl(), K
 
     fun getProperties(declared: Boolean): Collection<KMemberProperty<T, *>> =
             getProperties(extension = false, declared = declared) { descriptor ->
-                if (descriptor.isVar()) KMutableMemberPropertyImpl<T, Any?>(this) { descriptor }
+                if (descriptor.isVar()) KMutableMemberPropertyImpl<T, Any?>(this, descriptor)
-                else KMemberPropertyImpl<T, Any?>(this) { descriptor }
+                else KMemberPropertyImpl<T, Any?>(this, descriptor)
             }
 
     fun getExtensionProperties(declared: Boolean): Collection<KMemberExtensionProperty<T, *, *>> =
             getProperties(extension = true, declared = declared) { descriptor ->
-                if (descriptor.isVar()) KMutableMemberExtensionPropertyImpl<T, Any?, Any?>(this) { descriptor }
+                if (descriptor.isVar()) KMutableMemberExtensionPropertyImpl<T, Any?, Any?>(this, descriptor)
-                else KMemberExtensionPropertyImpl<T, Any?, Any?>(this) { descriptor }
+                else KMemberExtensionPropertyImpl<T, Any?, Any?>(this, descriptor)
             }
 
     private fun <P : KProperty<*>> getProperties(extension: Boolean, declared: Boolean, create: (PropertyDescriptor) -> P): Collection<P> =
@@ -91,10 +91,10 @@ class KClassImpl<T>(override val jClass: Class<T>) : KCallableContainerImpl(), K
                     .toList()
 
     fun memberProperty(name: String): KMemberProperty<T, *> =
-            KMemberPropertyImpl<T, Any>(this, findPropertyDescriptor(name))
+            KMemberPropertyImpl<T, Any>(this, name)
 
     fun mutableMemberProperty(name: String): KMutableMemberProperty<T, *> =
-            KMutableMemberPropertyImpl<T, Any>(this, findPropertyDescriptor(name))
+            KMutableMemberPropertyImpl<T, Any>(this, name)
 
     override fun equals(other: Any?): Boolean =
             other is KClassImpl<*> && jClass == other.jClass

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

@@ -23,10 +23,11 @@ import kotlin.reflect.IllegalPropertyAccessException
 import kotlin.reflect.KMemberExtensionProperty
 import kotlin.reflect.KMutableMemberExtensionProperty
 
-open class KMemberExtensionPropertyImpl<D : Any, E, out R>(
+open class KMemberExtensionPropertyImpl<D : Any, E, out R> : DescriptorBasedProperty, KMemberExtensionProperty<D, E, R>, KPropertyImpl<R> {
-        override val container: KClassImpl<D>,
+    constructor(container: KClassImpl<D>, name: String, receiverParameterClass: Class<E>) : super(container, name, receiverParameterClass)
-        computeDescriptor: () -> PropertyDescriptor
+
-) : DescriptorBasedProperty(computeDescriptor), KMemberExtensionProperty<D, E, R>, KPropertyImpl<R> {
+    constructor(container: KClassImpl<D>, descriptor: PropertyDescriptor) : super(container, descriptor)
+
     override val name: String get() = descriptor.getName().asString()
 
     override val getter: Method get() = super<DescriptorBasedProperty>.getter!!
@@ -45,10 +46,14 @@ open class KMemberExtensionPropertyImpl<D : Any, E, out R>(
 }
 
 
-class KMutableMemberExtensionPropertyImpl<D : Any, E, R>(
+class KMutableMemberExtensionPropertyImpl<D : Any, E, R> :
-        container: KClassImpl<D>,
+        KMemberExtensionPropertyImpl<D, E, R>,
-        computeDescriptor: () -> PropertyDescriptor
+        KMutableMemberExtensionProperty<D, E, R>,
-) : KMemberExtensionPropertyImpl<D, E, R>(container, computeDescriptor), KMutableMemberExtensionProperty<D, E, R>, KMutablePropertyImpl<R> {
+        KMutablePropertyImpl<R> {
+    constructor(container: KClassImpl<D>, name: String, receiverParameterClass: Class<E>) : super(container, name, receiverParameterClass)
+
+    constructor(container: KClassImpl<D>, descriptor: PropertyDescriptor) : super(container, descriptor)
+
     override val setter: Method get() = super<KMemberExtensionPropertyImpl>.setter!!
 
     override fun set(instance: D, extensionReceiver: E, value: R) {

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

@@ -21,10 +21,11 @@ import kotlin.reflect.IllegalPropertyAccessException
 import kotlin.reflect.KMemberProperty
 import kotlin.reflect.KMutableMemberProperty
 
-open class KMemberPropertyImpl<T : Any, out R>(
+open class KMemberPropertyImpl<T : Any, out R> : DescriptorBasedProperty, KMemberProperty<T, R>, KPropertyImpl<R> {
-        override val container: KClassImpl<T>,
+    constructor(container: KClassImpl<T>, name: String) : super(container, name, null)
-        computeDescriptor: () -> PropertyDescriptor
+
-) : DescriptorBasedProperty(computeDescriptor), KMemberProperty<T, R>, KPropertyImpl<R> {
+    constructor(container: KClassImpl<T>, descriptor: PropertyDescriptor) : super(container, descriptor)
+
     override val name: String get() = descriptor.getName().asString()
 
     override fun get(instance: T): R {
@@ -40,10 +41,11 @@ open class KMemberPropertyImpl<T : Any, out R>(
 }
 
 
-class KMutableMemberPropertyImpl<T : Any, R>(
+class KMutableMemberPropertyImpl<T : Any, R> : KMemberPropertyImpl<T, R>, KMutableMemberProperty<T, R>, KMutablePropertyImpl<R> {
-        container: KClassImpl<T>,
+    constructor(container: KClassImpl<T>, name: String) : super(container, name)
-        computeDescriptor: () -> PropertyDescriptor
+
-) : KMemberPropertyImpl<T, R>(container, computeDescriptor), KMutableMemberProperty<T, R>, KMutablePropertyImpl<R> {
+    constructor(container: KClassImpl<T>, descriptor: PropertyDescriptor) : super(container, descriptor)
+
     override fun set(instance: T, value: R) {
         try {
             val setter = setter

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

@@ -31,21 +31,17 @@ class KPackageImpl(override val jClass: Class<*>) : KCallableContainerImpl(), KP
 
     override val scope: JetScope get() = descriptor.getMemberScope()
 
-    fun topLevelVariable(name: String): KTopLevelVariable<*> {
+    fun topLevelVariable(name: String): KTopLevelVariable<*> =
-        return KTopLevelVariableImpl<Any?>(this, findPropertyDescriptor(name))
+            KTopLevelVariableImpl<Any?>(this, name)
-    }
 
-    fun mutableTopLevelVariable(name: String): KMutableTopLevelVariable<*> {
+    fun mutableTopLevelVariable(name: String): KMutableTopLevelVariable<*> =
-        return KMutableTopLevelVariableImpl<Any?>(this, findPropertyDescriptor(name))
+            KMutableTopLevelVariableImpl<Any?>(this, name)
-    }
 
-    fun <T> topLevelExtensionProperty(name: String, receiver: Class<T>): KTopLevelExtensionProperty<T, *> {
+    fun <T> topLevelExtensionProperty(name: String, receiver: Class<T>): KTopLevelExtensionProperty<T, *> =
-        return KTopLevelExtensionPropertyImpl<T, Any?>(this, findPropertyDescriptor(name, receiver))
+            KTopLevelExtensionPropertyImpl<T, Any?>(this, name, receiver)
-    }
 
-    fun <T> mutableTopLevelExtensionProperty(name: String, receiver: Class<T>): KMutableTopLevelExtensionProperty<T, *> {
+    fun <T> mutableTopLevelExtensionProperty(name: String, receiver: Class<T>): KMutableTopLevelExtensionProperty<T, *> =
-        return KMutableTopLevelExtensionPropertyImpl<T, Any?>(this, findPropertyDescriptor(name, receiver))
+            KMutableTopLevelExtensionPropertyImpl<T, Any?>(this, name, receiver)
-    }
 
     override fun equals(other: Any?): Boolean =
             other is KPackageImpl && jClass == other.jClass

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

@@ -16,16 +16,14 @@
 
 package kotlin.reflect.jvm.internal
 
-import org.jetbrains.kotlin.descriptors.PropertyDescriptor
 import java.lang.reflect.Method
 import kotlin.reflect.IllegalPropertyAccessException
 import kotlin.reflect.KMutableTopLevelExtensionProperty
 import kotlin.reflect.KTopLevelExtensionProperty
 
-open class KTopLevelExtensionPropertyImpl<T, out R>(
+open class KTopLevelExtensionPropertyImpl<T, out R> : DescriptorBasedProperty, KTopLevelExtensionProperty<T, R>, KPropertyImpl<R> {
-        override val container: KPackageImpl,
+    constructor(container: KPackageImpl, name: String, receiverParameterClass: Class<T>) : super(container, name, receiverParameterClass)
-        computeDescriptor: () -> PropertyDescriptor
+
-) : DescriptorBasedProperty(computeDescriptor), KTopLevelExtensionProperty<T, R>, KPropertyImpl<R> {
     override val name: String get() = descriptor.getName().asString()
 
     override val getter: Method get() = super<DescriptorBasedProperty>.getter!!
@@ -41,10 +39,12 @@ open class KTopLevelExtensionPropertyImpl<T, out R>(
     }
 }
 
-class KMutableTopLevelExtensionPropertyImpl<T, R>(
+class KMutableTopLevelExtensionPropertyImpl<T, R> :
-        container: KPackageImpl,
+        KTopLevelExtensionPropertyImpl<T, R>,
-        computeDescriptor: () -> PropertyDescriptor
+        KMutableTopLevelExtensionProperty<T, R>,
-) : KTopLevelExtensionPropertyImpl<T, R>(container, computeDescriptor), KMutableTopLevelExtensionProperty<T, R>, KMutablePropertyImpl<R> {
+        KMutablePropertyImpl<R> {
+    constructor(container: KPackageImpl, name: String, receiverParameterClass: Class<T>) : super(container, name, receiverParameterClass)
+
     override val setter: Method get() = super<KTopLevelExtensionPropertyImpl>.setter!!
 
     override fun set(receiver: T, value: R) {

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

@@ -16,16 +16,14 @@
 
 package kotlin.reflect.jvm.internal
 
-import org.jetbrains.kotlin.descriptors.PropertyDescriptor
 import java.lang.reflect.Method
 import kotlin.reflect.IllegalPropertyAccessException
 import kotlin.reflect.KMutableTopLevelVariable
 import kotlin.reflect.KTopLevelVariable
 
-open class KTopLevelVariableImpl<out R>(
+open class KTopLevelVariableImpl<out R> : DescriptorBasedProperty, KTopLevelVariable<R>, KVariableImpl<R> {
-        override val container: KPackageImpl,
+    constructor(container: KPackageImpl, name: String) : super(container, name, null)
-        computeDescriptor: () -> PropertyDescriptor
+
-) : DescriptorBasedProperty(computeDescriptor), KTopLevelVariable<R>, KVariableImpl<R> {
     override val name: String get() = descriptor.getName().asString()
 
     override val getter: Method get() = super<DescriptorBasedProperty>.getter!!
@@ -41,10 +39,9 @@ open class KTopLevelVariableImpl<out R>(
     }
 }
 
-class KMutableTopLevelVariableImpl<R>(
+class KMutableTopLevelVariableImpl<R> : KTopLevelVariableImpl<R>, KMutableTopLevelVariable<R>, KMutableVariableImpl<R> {
-        container: KPackageImpl,
+    constructor(container: KPackageImpl, name: String) : super(container, name)
-        computeDescriptor: () -> PropertyDescriptor
+
-) : KTopLevelVariableImpl<R>(container, computeDescriptor), KMutableTopLevelVariable<R>, KMutableVariableImpl<R> {
     override val setter: Method get() = super<KTopLevelVariableImpl>.setter!!
 
     override fun set(value: R) {

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

@@ -18,6 +18,7 @@ package kotlin.reflect.jvm.internal;
 
 import kotlin.Function0;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.lang.ref.SoftReference;
 import java.lang.ref.WeakReference;
@@ -67,8 +68,11 @@ import java.lang.ref.WeakReference;
         private final Function0<T> initializer;
         private SoftReference<Object> value = null;
 
-        public LazySoftVal(@NotNull Function0<T> initializer) {
+        public LazySoftVal(@Nullable T initialValue, @NotNull Function0<T> initializer) {
             this.initializer = initializer;
+            if (initialValue != null) {
+                this.value = new SoftReference<Object>(escape(initialValue));
+            }
         }
 
         @Override
@@ -120,9 +124,14 @@ import java.lang.ref.WeakReference;
         return new LazyVal<T>(initializer);
     }
 
+    @NotNull
+    public static <T> LazySoftVal<T> lazySoft(@Nullable T initialValue, @NotNull Function0<T> initializer) {
+        return new LazySoftVal<T>(initialValue, initializer);
+    }
+
     @NotNull
     public static <T> LazySoftVal<T> lazySoft(@NotNull Function0<T> initializer) {
-        return new LazySoftVal<T>(initializer);
+        return lazySoft(null, initializer);
     }
 
     @NotNull