Setup overridability rules for properties built on Java fields

- They overrides each other
- They do not overrides Kotlin propeties and vice versa

compiler/testData/diagnostics/tests/j+k/fieldOverridesField.kt

@@ -0,0 +1,17 @@
+// FILE: A.java
+
+public class A {
+    public int size = 1;
+}
+
+// FILE: B.java
+
+public class B implements A {
+    public int size = 1;
+}
+
+// FILE: main.kt
+
+fun foo() {
+    B().size
+}

compiler/testData/diagnostics/tests/j+k/fieldOverridesField.txt

@@ -0,0 +1,19 @@
+package
+
+public fun foo(): kotlin.Unit
+
+public open class A {
+    public constructor A()
+    public final var size: kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public open class B : A {
+    public constructor B()
+    public final override /*1*/ var size: kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/tests/j+k/fieldOverridesNothing.kt

@@ -0,0 +1,19 @@
+// FILE: B.java
+
+abstract class B implements A {
+    public int size = 1;
+}
+
+// FILE: main.kt
+
+interface A {
+    val size: Int
+}
+
+class C : B() {
+    override val size: Int get() = 1
+}
+
+fun foo() {
+    C().<!OVERLOAD_RESOLUTION_AMBIGUITY!>size<!>
+}

compiler/testData/diagnostics/tests/j+k/fieldOverridesNothing.txt

@@ -0,0 +1,28 @@
+package
+
+public fun foo(): kotlin.Unit
+
+public interface A {
+    public abstract val size: kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public/*package*/ abstract class B : A {
+    public/*package*/ constructor B()
+    public final var size: kotlin.Int
+    public abstract override /*1*/ /*fake_override*/ val size: kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class C : B {
+    public constructor C()
+    public open override /*1*/ val size: kotlin.Int
+    public final override /*1*/ /*fake_override*/ var size: kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/tests/j+k/privateFieldOverridesNothing.kt

@@ -0,0 +1,19 @@
+// FILE: B.java
+
+abstract class B implements A {
+    private int size = 1;
+}
+
+// FILE: main.kt
+
+interface A {
+    val size: Int
+}
+
+class C : B() {
+    override val size: Int get() = 1
+}
+
+fun foo() {
+    C().size 
+}

compiler/testData/diagnostics/tests/j+k/privateFieldOverridesNothing.txt

@@ -0,0 +1,28 @@
+package
+
+public fun foo(): kotlin.Unit
+
+public interface A {
+    public abstract val size: kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public/*package*/ abstract class B : A {
+    public/*package*/ constructor B()
+    private final var size: kotlin.Int
+    public abstract override /*1*/ /*fake_override*/ val size: kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class C : B {
+    public constructor C()
+    public open override /*1*/ val size: kotlin.Int
+    invisible_fake final override /*1*/ /*fake_override*/ var size: kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/tests/org/jetbrains/kotlin/checkers/JetDiagnosticsTestGenerated.java

@@ -8694,6 +8694,18 @@ public class JetDiagnosticsTestGenerated extends AbstractJetDiagnosticsTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("fieldOverridesField.kt")
+            public void testFieldOverridesField() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/j+k/fieldOverridesField.kt");
+                doTest(fileName);
+            }
+
+            @TestMetadata("fieldOverridesNothing.kt")
+            public void testFieldOverridesNothing() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/j+k/fieldOverridesNothing.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("GenericsInSupertypes.kt")
             public void testGenericsInSupertypes() throws Exception {
                 String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/j+k/GenericsInSupertypes.kt");
@@ -8856,6 +8868,12 @@ public class JetDiagnosticsTestGenerated extends AbstractJetDiagnosticsTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("privateFieldOverridesNothing.kt")
+            public void testPrivateFieldOverridesNothing() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/j+k/privateFieldOverridesNothing.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("privateNestedClassStaticMember.kt")
             public void testPrivateNestedClassStaticMember() throws Exception {
                 String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/j+k/privateNestedClassStaticMember.kt");

core/descriptor.loader.java/src/META-INF/services/org.jetbrains.kotlin.resolve.ExternalOverridabilityCondition

@@ -0,0 +1 @@
+org.jetbrains.kotlin.load.java.FieldOverridabilityCondition

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/java/FieldOverridabilityCondition.kt

@@ -0,0 +1,33 @@
+/*
+ * 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 org.jetbrains.kotlin.load.java
+
+import org.jetbrains.kotlin.descriptors.CallableDescriptor
+import org.jetbrains.kotlin.descriptors.PropertyDescriptor
+import org.jetbrains.kotlin.resolve.ExternalOverridabilityCondition
+
+class FieldOverridabilityCondition : ExternalOverridabilityCondition {
+    override fun isOverridable(superDescriptor: CallableDescriptor, subDescriptor: CallableDescriptor): Boolean {
+        if (subDescriptor !is PropertyDescriptor || superDescriptor !is PropertyDescriptor) return true
+
+        return subDescriptor.isJavaField == superDescriptor.isJavaField
+    }
+
+    // Currently getter is null iff it's loaded from Java field
+    private val PropertyDescriptor.isJavaField: Boolean
+        get() = getter == null
+}