Inherit FunctionReference from CallableReference

This became possible now because FunctionImpl is no longer a class

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

@@ -105,9 +105,4 @@ public class ReflectionFactoryImpl extends ReflectionFactory {
         KDeclarationContainer owner = reference.getOwner();
         return owner instanceof KDeclarationContainerImpl ? ((KDeclarationContainerImpl) owner) : EmptyContainerForLocal.INSTANCE;
     }
-
-    private static KDeclarationContainerImpl getOwner(FunctionReference reference) {
-        KDeclarationContainer owner = reference.getOwner();
-        return owner instanceof KDeclarationContainerImpl ? ((KDeclarationContainerImpl) owner) : EmptyContainerForLocal.INSTANCE;
-    }
 }

core/runtime.jvm/src/kotlin/jvm/internal/CallableReference.java

@@ -28,14 +28,36 @@ import java.util.Map;
 /**
  * A superclass for all classes generated by Kotlin compiler for callable references.
  *
- * All methods from reflection API should be implemented here to throw informative exceptions (see KotlinReflectionNotSupportedError)
+ * All methods from KCallable should be implemented here and should delegate to the actual implementation, loaded dynamically
+ * and stored in the {@link CallableReference#reflected} field.
  */
 @SuppressWarnings({"unchecked", "NullableProblems"})
 public abstract class CallableReference implements KCallable {
-    protected KCallable reflected;
+    // This field is not volatile intentionally:
+    // 1) It's fine if the value is computed multiple times in different threads;
+    // 2) An uninitialized value cannot be observed in this field from other thread because only already initialized or safely initialized
+    //    objects are written to it. The latter is guaranteed because both KFunctionImpl and KPropertyImpl have at least one final field.
+    private KCallable reflected;
 
     protected abstract KCallable computeReflected();
 
+    public KCallable compute() {
+        KCallable result = reflected;
+        if (result == null) {
+            result = computeReflected();
+            reflected = result;
+        }
+        return result;
+    }
+
+    protected KCallable getReflected() {
+        KCallable result = compute();
+        if (result == this) {
+            throw new KotlinReflectionNotSupportedError();
+        }
+        return result;
+    }
+
     // The following methods provide the information identifying this callable, which is used by the reflection implementation.
     // They are supposed to be overridden in each subclass (each anonymous class generated for a callable reference).
 
@@ -66,8 +88,8 @@ public abstract class CallableReference implements KCallable {
         throw new AbstractMethodError();
     }
 
-    // The following methods are the stub implementations of reflection functions.
-    // They are called when you're using reflection on a property reference without the reflection implementation in the classpath.
+    // The following methods are the delegating implementations of reflection functions. They are called when you're using reflection
+    // on a callable reference. Without kotlin-reflect.jar in the classpath, getReflected() throws an exception.
 
     @Override
     public List<KParameter> getParameters() {
@@ -120,21 +142,4 @@ public abstract class CallableReference implements KCallable {
     public boolean isAbstract() {
         return getReflected().isAbstract();
     }
-
-    public KCallable compute() {
-        KCallable result = reflected;
-        if (result == null) {
-            result = computeReflected();
-            reflected = result;
-        }
-        return result;
-    }
-
-    protected KCallable getReflected() {
-        KCallable result = compute();
-        if (result == this) {
-            throw new KotlinReflectionNotSupportedError();
-        }
-        return result;
-    }
 }

core/runtime.jvm/src/kotlin/jvm/internal/FunctionReference.java

@@ -16,19 +16,11 @@
 
 package kotlin.jvm.internal;
 
-import kotlin.jvm.KotlinReflectionNotSupportedError;
-import kotlin.reflect.*;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
+import kotlin.reflect.KCallable;
+import kotlin.reflect.KFunction;
 
-import java.lang.annotation.Annotation;
-import java.util.List;
-import java.util.Map;
-
-@SuppressWarnings({"unchecked", "NullableProblems"})
-public class FunctionReference implements FunctionImpl, KFunction {
+public class FunctionReference extends CallableReference implements FunctionImpl, KFunction {
     private final int arity;
-    private KFunction reflected;
 
     public FunctionReference(int arity) {
         this.arity = arity;
@@ -39,71 +31,14 @@ public class FunctionReference implements FunctionImpl, KFunction {
         return arity;
     }
 
-    // Most of the following methods are copies from CallableReference, since this class cannot inherit from it
-
-    public KDeclarationContainer getOwner() {
-        throw new AbstractMethodError();
+    @Override
+    protected KFunction getReflected() {
+        return (KFunction) super.getReflected();
     }
 
     @Override
-    public String getName() {
-        throw new AbstractMethodError();
-    }
-
-    public String getSignature() {
-        throw new AbstractMethodError();
-    }
-
-    @Override
-    public List<KParameter> getParameters() {
-        return getReflected().getParameters();
-    }
-
-    @Override
-    public KType getReturnType() {
-        return getReflected().getReturnType();
-    }
-
-    @Override
-    public List<Annotation> getAnnotations() {
-        return getReflected().getAnnotations();
-    }
-
-    @NotNull
-    @Override
-    public List<KTypeParameter> getTypeParameters() {
-        return getReflected().getTypeParameters();
-    }
-
-    @Override
-    public Object call(@NotNull Object... args) {
-        return getReflected().call(args);
-    }
-
-    @Override
-    public Object callBy(@NotNull Map args) {
-        return getReflected().callBy(args);
-    }
-
-    @Nullable
-    @Override
-    public KVisibility getVisibility() {
-        return getReflected().getVisibility();
-    }
-
-    @Override
-    public boolean isFinal() {
-        return getReflected().isFinal();
-    }
-
-    @Override
-    public boolean isOpen() {
-        return getReflected().isOpen();
-    }
-
-    @Override
-    public boolean isAbstract() {
-        return getReflected().isAbstract();
+    protected KCallable computeReflected() {
+        return Reflection.function(this);
     }
 
     @Override
@@ -158,7 +93,7 @@ public class FunctionReference implements FunctionImpl, KFunction {
 
     @Override
     public String toString() {
-        KFunction reflected = compute();
+        KCallable reflected = compute();
         if (reflected != this) {
             return reflected.toString();
         }
@@ -168,21 +103,4 @@ public class FunctionReference implements FunctionImpl, KFunction {
                ? "constructor" + Reflection.REFLECTION_NOT_AVAILABLE
                : "function " + getName() + Reflection.REFLECTION_NOT_AVAILABLE;
     }
-
-    public KFunction compute() {
-        KFunction result = reflected;
-        if (result == null) {
-            result = Reflection.function(this);
-            reflected = result;
-        }
-        return result;
-    }
-
-    private KFunction getReflected() {
-        KFunction result = compute();
-        if (result == this) {
-            throw new KotlinReflectionNotSupportedError();
-        }
-        return result;
-    }
 }

core/runtime.jvm/src/kotlin/jvm/internal/PropertyReference.java

@@ -45,8 +45,7 @@ public abstract class PropertyReference extends CallableReference implements KPr
                    getSignature().equals(other.getSignature());
         }
         if (obj instanceof KProperty) {
-            compute();
-            return obj.equals(reflected);
+            return obj.equals(compute());
         }
         return false;
     }