ugly and incomplete solution for using correct bytecode instruction when accessing properties inherited from traits (KT-2391)

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

@@ -1228,6 +1228,7 @@ public class ExpressionCodegen extends JetVisitor<StackValue, StackValue> {
         containingDeclaration = containingDeclaration.getOriginal();
 
         boolean isStatic = containingDeclaration instanceof NamespaceDescriptor;
+        boolean overridesTrait = isOverrideForTrait(propertyDescriptor);
         propertyDescriptor = propertyDescriptor.getOriginal();
         boolean isInsideClass = ((containingDeclaration == context.getThisDescriptor()) ||
                                  (context.getParentContext() instanceof CodegenContexts.NamespaceContext) && context.getParentContext().getContextDescriptor() == containingDeclaration)
@@ -1294,11 +1295,13 @@ public class ExpressionCodegen extends JetVisitor<StackValue, StackValue> {
         boolean isInterface;
         if (isInsideClass || isStatic || propertyDescriptor.getGetter() == null) {
             owner = ownerParam = typeMapper.getOwner(propertyDescriptor, contextKind());
-            isInterface = false;
+            isInterface = overridesTrait;
-            invokeOpcode = isStatic ? Opcodes.INVOKESTATIC : Opcodes.INVOKEVIRTUAL;
+            invokeOpcode = isStatic ? Opcodes.INVOKESTATIC :
+                           overridesTrait ? Opcodes.INVOKEINTERFACE
+                                          : Opcodes.INVOKEVIRTUAL;
         }
         else {
-            isInterface = CodegenUtil.isInterface(containingDeclaration);
+            isInterface = CodegenUtil.isInterface(containingDeclaration) || overridesTrait;
             // TODO ugly
             CallableMethod callableMethod = typeMapper.mapToCallableMethod(propertyDescriptor.getGetter(), isSuper, contextKind());
             invokeOpcode = callableMethod.getInvokeOpcode();
@@ -1309,6 +1312,18 @@ public class ExpressionCodegen extends JetVisitor<StackValue, StackValue> {
         return StackValue.property(propertyDescriptor.getName().getName(), owner, ownerParam, asmType(propertyDescriptor.getType()), isStatic, isInterface, isSuper, getter, setter, invokeOpcode);
     }
 
+    static boolean isOverrideForTrait(CallableMemberDescriptor propertyDescriptor) {
+        if (propertyDescriptor.getKind() == CallableMemberDescriptor.Kind.FAKE_OVERRIDE) {
+            final Set<? extends CallableMemberDescriptor> overriddenDescriptors = propertyDescriptor.getOverriddenDescriptors();
+            for (CallableMemberDescriptor descriptor : overriddenDescriptors) {
+                if (CodegenUtil.isInterface(descriptor.getContainingDeclaration())) {
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+
     @Override
     public StackValue visitCallExpression(JetCallExpression expression, StackValue receiver) {
         final JetExpression callee = expression.getCalleeExpression();

compiler/testData/codegen/regressions/kt2391.kt

@@ -0,0 +1,19 @@
+public trait LoggerAware {
+    public val logger: StringBuilder
+}
+
+public abstract class HttpServer(): LoggerAware {
+    public fun start() {
+        logger.append("OK")
+    }
+}
+
+public class MyHttpServer(): HttpServer() {
+    public override val logger = StringBuilder()
+}
+
+fun box(): String {
+    val server = MyHttpServer()
+    server.start()
+    return server.logger.toString()!!
+}

compiler/tests/org/jetbrains/jet/codegen/ClassGenTest.java

@@ -461,4 +461,9 @@ public class ClassGenTest extends CodegenTestCase {
         createEnvironmentWithMockJdkAndIdeaAnnotations(ConfigurationKind.JDK_ONLY);
         blackBoxFile("regressions/kt2390.kt");
     }
+
+    public void testKt2391() {
+        createEnvironmentWithMockJdkAndIdeaAnnotations(ConfigurationKind.JDK_ONLY);
+        blackBoxFile("regressions/kt2391.kt");
+    }
 }