Support :: references to Java instance fields in codegen

#KT-1183 In Progress

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

@@ -16,6 +16,21 @@
 
 package kotlin.reflect.jvm.internal
 
+enum class KClassOrigin {
+    BUILT_IN
+    KOTLIN
+    FOREIGN
+}
+
 class KClassImpl<out T>(
         val jClass: Class<T>
-) : KClass<T>
+) : KClass<T> {
+    val origin: KClassOrigin =
+            if (K_OBJECT_CLASS.isAssignableFrom(jClass)) {
+                KClassOrigin.KOTLIN
+            }
+            else {
+                KClassOrigin.FOREIGN
+                // TODO: built-in classes
+            }
+}

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

@@ -16,17 +16,32 @@
 
 package kotlin.reflect.jvm.internal
 
+import java.lang.reflect.Field
 import java.lang.reflect.Method
 
 open class KMemberPropertyImpl<T, out R>(
         name: String,
         protected val owner: KClassImpl<T>
 ) : KMemberProperty<T, R>, KPropertyImpl<R>(name) {
-    // TODO: extract, make lazy (weak?), use our descriptors knowledge, support Java fields
-    protected val getter: Method = owner.jClass.getMethod(getterName(name))
+    protected val field: Field? =
+            if (owner.origin == KClassOrigin.FOREIGN) {
+                owner.jClass.getField(name)
+            }
+            else null
 
+    // TODO: extract, make lazy (weak?), use our descriptors knowledge
+    protected val getter: Method? =
+            if (owner.origin == KClassOrigin.KOTLIN) {
+                owner.jClass.getMethod(getterName(name))
+            }
+            else null
+
+    // TODO: built-in classes
     override fun get(receiver: T): R {
-        return getter(receiver) as R
+        if (getter != null) {
+            return getter!!(receiver) as R
+        }
+        return field!!.get(receiver) as R
     }
 }
 
@@ -34,9 +49,17 @@ class KMutableMemberPropertyImpl<T, R>(
         name: String,
         owner: KClassImpl<T>
 ) : KMutableMemberProperty<T, R>, KMemberPropertyImpl<T, R>(name, owner) {
-    private val setter = owner.jClass.getMethod(setterName(name), getter.getReturnType()!!)
+    private val setter: Method? =
+            if (owner.origin == KClassOrigin.KOTLIN) {
+                owner.jClass.getMethod(setterName(name), getter!!.getReturnType()!!)
+            }
+            else null
 
     override fun set(receiver: T, value: R) {
-        setter.invoke(receiver, value)
+        if (setter != null) {
+            setter!!(receiver, value)
+            return
+        }
+        field!!.set(receiver, value)
     }
 }

core/runtime.jvm/src/kotlin/reflect/jvm/internal/util.kt

@@ -16,6 +16,8 @@
 
 package kotlin.reflect.jvm.internal
 
+import java.util.concurrent.ConcurrentHashMap
+
 // TODO: use stdlib?
 suppress("PLATFORM_CLASS_MAPPED_TO_KOTLIN")
 private fun String.capitalizeWithJavaBeanConvention(): String {
@@ -32,13 +34,24 @@ private fun getterName(propertyName: String): String = "get" + propertyName.capi
 private fun setterName(propertyName: String): String = "set" + propertyName.capitalizeWithJavaBeanConvention()
 
 
+// TODO: should use weak references
+private val foreignKClasses: MutableMap<Class<*>, KClassImpl<*>> = ConcurrentHashMap()
+
+fun <T> foreignKotlinClass(jClass: Class<T>): KClassImpl<T> {
+    val cached = foreignKClasses[jClass] as? KClassImpl<T>
+    if (cached != null) return cached
+    val result = KClassImpl<T>(jClass)
+    foreignKClasses.put(jClass, result)
+    return result
+}
+
 private val K_OBJECT_CLASS = Class.forName("kotlin.jvm.internal.KObject")
 
-// TODO
 fun <T> kotlinClass(jClass: Class<T>): KClassImpl<T> {
     if (K_OBJECT_CLASS.isAssignableFrom(jClass)) {
         val field = jClass.getDeclaredField("\$kotlinClass")
         return field.get(null) as KClassImpl<T>
     }
-    throw UnsupportedOperationException("Unsupported class: $jClass")
+    // TODO: built-in classes
+    return foreignKotlinClass(jClass)
 }