KT-4138: java.lang.VerifyError: (class: kotlin/sql/tests/h2/Foo, method: getA$b$0 signature: ()Lkotlin/sql/tests/h2/Foo;) Wrong return type in function

#KT-4138 Fixed

compiler/backend/src/org/jetbrains/jet/codegen/AccessorForPropertyBackingFieldInOuterClass.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2010-2013 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.jet.codegen;
+
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+import org.jetbrains.jet.lang.descriptors.DeclarationDescriptor;
+import org.jetbrains.jet.lang.descriptors.PropertyDescriptor;
+import org.jetbrains.jet.lang.types.JetType;
+
+public class AccessorForPropertyBackingFieldInOuterClass extends AccessorForPropertyDescriptor {
+
+    public AccessorForPropertyBackingFieldInOuterClass(
+            @NotNull PropertyDescriptor pd,
+            @NotNull DeclarationDescriptor containingDeclaration,
+            int index,
+            @Nullable JetType delegationType
+    ) {
+        super(pd, delegationType != null ? delegationType :  pd.getType(), null, null, containingDeclaration, index);
+    }
+}

compiler/backend/src/org/jetbrains/jet/codegen/AccessorForPropertyDescriptor.java

@@ -16,6 +16,8 @@
 
 package org.jetbrains.jet.codegen;
 
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 import org.jetbrains.jet.lang.descriptors.*;
 import org.jetbrains.jet.lang.descriptors.annotations.AnnotationDescriptor;
 import org.jetbrains.jet.lang.descriptors.impl.PropertyDescriptorImpl;
@@ -29,17 +31,23 @@ import org.jetbrains.jet.lang.types.JetType;
 import java.util.Collections;
 
 public class AccessorForPropertyDescriptor extends PropertyDescriptorImpl {
-    public AccessorForPropertyDescriptor(PropertyDescriptor pd, DeclarationDescriptor containingDeclaration, int index) {
+    public AccessorForPropertyDescriptor(@NotNull PropertyDescriptor pd, @NotNull DeclarationDescriptor containingDeclaration, int index) {
+        this(pd, pd.getType(), DescriptorUtils.getReceiverParameterType(pd.getReceiverParameter()), pd.getExpectedThisObject(), containingDeclaration, index);
+    }
+
+    protected AccessorForPropertyDescriptor(
+            @NotNull PropertyDescriptor original,
+            @NotNull JetType propertyType,
+            @Nullable JetType receiverType,
+            @Nullable ReceiverParameterDescriptor expectedThisObject,
+            @NotNull DeclarationDescriptor containingDeclaration,
+            int index
+    ) {
         super(containingDeclaration, Collections.<AnnotationDescriptor>emptyList(), Modality.FINAL, Visibilities.LOCAL,
-              pd.isVar(), Name.identifier(pd.getName() + "$b$" + index),
+              original.isVar(), Name.identifier(original.getName() + "$b$" + index),
               Kind.DECLARATION);
 
-        boolean isStaticProperty = AsmUtil.isPropertyWithBackingFieldInOuterClass(pd)
-                                   && !AsmUtil.isClassObjectWithBackingFieldsInOuter(containingDeclaration);
-        JetType receiverType = !isStaticProperty ? DescriptorUtils.getReceiverParameterType(pd.getReceiverParameter()) : null;
-
-        setType(pd.getType(), Collections.<TypeParameterDescriptorImpl>emptyList(), isStaticProperty ? null : pd.getExpectedThisObject(),
-                receiverType);
+        setType(propertyType, Collections.<TypeParameterDescriptorImpl>emptyList(), expectedThisObject, receiverType);
         initialize(new Getter(this), new Setter(this));
     }
 

compiler/backend/src/org/jetbrains/jet/codegen/ExpressionCodegen.java

@@ -1811,7 +1811,7 @@ public class ExpressionCodegen extends JetVisitor<StackValue, StackValue> implem
             int flags = AsmUtil.getVisibilityForSpecialPropertyBackingField(propertyDescriptor, isDelegatedProperty);
             skipPropertyAccessors = (flags & ACC_PRIVATE) == 0 || methodKind == MethodKind.SYNTHETIC_ACCESSOR || methodKind == MethodKind.INITIALIZER;
             if (!skipPropertyAccessors) {
-                propertyDescriptor = (PropertyDescriptor) backingFieldContext.getAccessor(propertyDescriptor);
+                propertyDescriptor = (PropertyDescriptor) backingFieldContext.getAccessor(propertyDescriptor, true, delegateType);
             }
         }
 

compiler/backend/src/org/jetbrains/jet/codegen/context/CodegenContext.java

@@ -29,6 +29,7 @@ import org.jetbrains.jet.lang.descriptors.annotations.AnnotationDescriptor;
 import org.jetbrains.jet.lang.descriptors.impl.ConstructorDescriptorImpl;
 import org.jetbrains.jet.lang.resolve.BindingContext;
 import org.jetbrains.jet.lang.resolve.DescriptorUtils;
+import org.jetbrains.jet.lang.types.JetType;
 
 import java.util.Collections;
 import java.util.HashMap;
@@ -247,21 +248,35 @@ public abstract class CodegenContext<T extends DeclarationDescriptor> {
         return c;
     }
 
-    public DeclarationDescriptor getAccessor(DeclarationDescriptor descriptor) {
+    @NotNull
+    public DeclarationDescriptor getAccessor(@NotNull DeclarationDescriptor descriptor) {
+        return getAccessor(descriptor, false, null);
+    }
+
+    @NotNull
+    public DeclarationDescriptor getAccessor(@NotNull DeclarationDescriptor descriptor, boolean isForBackingFieldInOuterClass, @Nullable JetType delegateType) {
         if (accessors == null) {
             accessors = new HashMap<DeclarationDescriptor, DeclarationDescriptor>();
         }
         descriptor = descriptor.getOriginal();
         DeclarationDescriptor accessor = accessors.get(descriptor);
         if (accessor != null) {
+            assert !isForBackingFieldInOuterClass ||
+                   accessor instanceof AccessorForPropertyBackingFieldInOuterClass : "There is already exists accessor with isForBackingFieldInOuterClass = false in this context";
             return accessor;
         }
 
+        int accessorIndex = accessors.size();
         if (descriptor instanceof SimpleFunctionDescriptor || descriptor instanceof ConstructorDescriptor) {
-            accessor = new AccessorForFunctionDescriptor((FunctionDescriptor) descriptor, contextDescriptor, accessors.size());
+            accessor = new AccessorForFunctionDescriptor((FunctionDescriptor) descriptor, contextDescriptor, accessorIndex);
         }
         else if (descriptor instanceof PropertyDescriptor) {
-            accessor = new AccessorForPropertyDescriptor((PropertyDescriptor) descriptor, contextDescriptor, accessors.size());
+            if (isForBackingFieldInOuterClass) {
+                accessor = new AccessorForPropertyBackingFieldInOuterClass((PropertyDescriptor) descriptor, contextDescriptor,
+                                                                           accessorIndex, delegateType);
+            } else {
+                accessor = new AccessorForPropertyDescriptor((PropertyDescriptor) descriptor, contextDescriptor, accessorIndex);
+            }
         }
         else {
             throw new UnsupportedOperationException("Do not know how to create accessor for descriptor " + descriptor);

compiler/testData/codegen/box/delegatedProperty/kt4138.kt

@@ -0,0 +1,35 @@
+class Delegate<T>(var inner: T) {
+    fun get(t: Any?, p: PropertyMetadata): T = inner
+    fun set(t: Any?, p: PropertyMetadata, i: T) { inner = i }
+}
+
+
+class Foo (val f: Int) {
+    class object {
+        val A: Foo by Delegate(Foo(11))
+        var B: Foo by Delegate(Foo(11))
+    }
+}
+
+trait FooTrait {
+    class object {
+        val A: Foo by Delegate(Foo(11))
+        var B: Foo by Delegate(Foo(11))
+    }
+}
+
+fun box() : String {
+    if (Foo.A.f != 11) return "fail 1"
+    if (Foo.B.f != 11) return "fail 2"
+
+    Foo.B = Foo(12)
+    if (Foo.B.f != 12) return "fail 3"
+
+    if (FooTrait.A.f != 11) return "fail 4"
+    if (FooTrait.B.f != 11) return "fail 5"
+
+    FooTrait.B = Foo(12)
+    if (FooTrait.B.f != 12) return "fail 6"
+
+    return "OK"
+}

compiler/tests/org/jetbrains/jet/codegen/generated/BlackBoxCodegenTestGenerated.java

@@ -1877,6 +1877,11 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             doTest("compiler/testData/codegen/box/delegatedProperty/inferredPropertyType.kt");
         }
         
+        @TestMetadata("kt4138.kt")
+        public void testKt4138() throws Exception {
+            doTest("compiler/testData/codegen/box/delegatedProperty/kt4138.kt");
+        }
+        
         @TestMetadata("privateVar.kt")
         public void testPrivateVar() throws Exception {
             doTest("compiler/testData/codegen/box/delegatedProperty/privateVar.kt");