diff --git a/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/CodeGenerator.kt b/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/CodeGenerator.kt
index fd2fd3b83d8..043c2f14201 100644
--- a/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/CodeGenerator.kt
+++ b/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/CodeGenerator.kt
@@ -17,6 +17,7 @@ internal class CodeGenerator(override val context: Context) : ContextUtils {
     // TODO: remove, to make CodeGenerator descriptor-agnostic.
     var constructedClass: ClassDescriptor? = null
     val vars = VariableManager(this)
+    var returnSlot: LLVMValueRef? = null
 
     fun prologue(descriptor: FunctionDescriptor) {
         prologue(llvmFunction(descriptor),
@@ -28,8 +29,11 @@ internal class CodeGenerator(override val context: Context) : ContextUtils {
 
     fun prologue(function:LLVMValueRef, returnType:LLVMTypeRef) {
         assert(returns.size == 0)
-
         assert(this.function != function)
+
+        if (isObjectType(returnType)) {
+            this.returnSlot = LLVMGetParam(function, numParameters(function.type) - 1)
+        }
         this.function = function
         this.returnType = returnType
         this.constructedClass = null
@@ -48,11 +52,15 @@ internal class CodeGenerator(override val context: Context) : ContextUtils {
             when {
                returnType == voidType -> {
                    vars.releaseVars()
+                   assert(returnSlot == null)
                    LLVMBuildRetVoid(builder)
                }
                returns.size > 0 -> {
                     val returnPhi = phi(returnType!!)
                     addPhiIncoming(returnPhi, *returns.toList().toTypedArray())
+                    if (returnSlot != null) {
+                        updateLocalRef(returnPhi, returnSlot!!)
+                    }
                     vars.releaseVars()
                     LLVMBuildRet(builder, returnPhi)
                }
@@ -63,6 +71,7 @@ internal class CodeGenerator(override val context: Context) : ContextUtils {
 
         returns.clear()
         vars.clear()
+        returnSlot = null
     }
 
     private var prologueBb: LLVMBasicBlockRef? = null
@@ -103,6 +112,11 @@ internal class CodeGenerator(override val context: Context) : ContextUtils {
     fun load(value: LLVMValueRef, name: String = ""): LLVMValueRef = LLVMBuildLoad(builder, value, name)!!
     fun store(value: LLVMValueRef, ptr: LLVMValueRef): LLVMValueRef = LLVMBuildStore(builder, value, ptr)!!
 
+    fun updateLocalRef(value: LLVMValueRef, address: LLVMValueRef, ignoreOld: Boolean = false) {
+        call(if (ignoreOld) context.llvm.setLocalRefFunction else context.llvm.updateLocalRefFunction,
+                listOf(address, value))
+    }
+
     fun isConst(value: LLVMValueRef): Boolean = (LLVMIsConstant(value) == 1)
 
     //-------------------------------------------------------------------------//
diff --git a/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/ContextUtils.kt b/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/ContextUtils.kt
index 8c885b6c77e..9db8b4440b6 100644
--- a/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/ContextUtils.kt
+++ b/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/ContextUtils.kt
@@ -221,6 +221,8 @@ internal class Llvm(val context: Context, val llvmModule: LLVMModuleRef) {
     val allocInstanceFunction = importRtFunction("AllocInstance")
     val initInstanceFunction = importRtFunction("InitInstance")
     val allocArrayFunction = importRtFunction("AllocArrayInstance")
+    val setLocalRefFunction = importRtFunction("SetLocalRef")
+    val updateLocalRefFunction = importRtFunction("UpdateLocalRef")
     val setArrayFunction = importRtFunction("Kotlin_Array_set")
     val copyImplArrayFunction = importRtFunction("Kotlin_Array_copyImpl")
     val lookupFieldOffset = importRtFunction("LookupFieldOffset")
diff --git a/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/IrToBitcode.kt b/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/IrToBitcode.kt
index 02c9246d3f2..b7d5ceb1eaa 100644
--- a/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/IrToBitcode.kt
+++ b/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/IrToBitcode.kt
@@ -429,10 +429,9 @@ internal class CodeGeneratorVisitor(val context: Context) : IrElementVisitorVoid
                     }
                 })
             }
-
-            codegen.ret(thisPtr)
         }
 
+        codegen.ret(null)
         codegen.epilogue()
         context.log("visitConstructor            : ${ir2string(constructorDeclaration)}")
     }
@@ -553,11 +552,7 @@ internal class CodeGeneratorVisitor(val context: Context) : IrElementVisitorVoid
         }
 
         override fun genReturn(target: CallableDescriptor, value: LLVMValueRef?) {
-            if (declaration == null) {
-                codegen.ret(value)
-                return
-            }
-            if (target == declaration.descriptor) {
+            if (declaration == null || target == declaration.descriptor) {
                 codegen.ret(value)
             } else {
                 super.genReturn(target, value)
@@ -582,9 +577,6 @@ internal class CodeGeneratorVisitor(val context: Context) : IrElementVisitorVoid
     private fun bindParameters(descriptor: FunctionDescriptor?): Map<ParameterDescriptor, LLVMValueRef> {
         if (descriptor == null) return emptyMap()
         val paramDescriptors = descriptor.allValueParameters
-
-        assert(paramDescriptors.size == codegen.countParams(descriptor))
-
         return paramDescriptors.mapIndexed { i, paramDescriptor ->
             val param = codegen.param(descriptor, i)
             assert(codegen.getLLVMType(paramDescriptor.type) == param.type)
@@ -757,7 +749,7 @@ internal class CodeGeneratorVisitor(val context: Context) : IrElementVisitorVoid
         val initFunction = value.descriptor.constructors.first { it.valueParameters.size == 0 }
         val ctor = codegen.llvmFunction(initFunction)
         val args = listOf(objectPtr, typeInfo, allocHint, ctor)
-        val newValue = currentCodeContext.genCall(context.llvm.initInstanceFunction, args)
+        val newValue = call(context.llvm.initInstanceFunction, args)
         codegen.br(bbExit)
 
         codegen.positionAtEnd(bbExit)
@@ -846,7 +838,6 @@ internal class CodeGeneratorVisitor(val context: Context) : IrElementVisitorVoid
         }
     }
 
-
     //-------------------------------------------------------------------------//
 
     private fun evaluateVararg(value: IrVararg): LLVMValueRef? {
@@ -879,14 +870,13 @@ internal class CodeGeneratorVisitor(val context: Context) : IrElementVisitorVoid
 
         val typeInfo = codegen.typeInfoValue(value.type)!!
         val arrayCreationArgs = listOf(typeInfo, kImmInt32One, finalLength)
-        val array = currentCodeContext.genCall(context.llvm.allocArrayFunction, arrayCreationArgs)
-
+        val array = call(context.llvm.allocArrayFunction, arrayCreationArgs)
         elements.fold(kImmZero) { sum, (exp, size, isArray) ->
             if (!isArray) {
-                currentCodeContext.genCall(context.llvm.setArrayFunction, listOf(array, sum, exp))
+                call(context.llvm.setArrayFunction, listOf(array, sum, exp))
                 return@fold codegen.plus(sum, kImmOne)
             } else {
-                currentCodeContext.genCall(context.llvm.copyImplArrayFunction, listOf(exp, kImmZero, array, sum, size!!))
+                call(context.llvm.copyImplArrayFunction, listOf(exp, kImmZero, array, sum, size!!))
                 return@fold codegen.plus(sum, size)
             }
         }
@@ -920,7 +910,7 @@ internal class CodeGeneratorVisitor(val context: Context) : IrElementVisitorVoid
                 val toStringDescriptor = getToString(it.type)
                 val string = if (KotlinBuiltIns.isString(it.type)) evaluationResult
                              else evaluateSimpleFunctionCall(toStringDescriptor, listOf(evaluationResult))
-                val length = currentCodeContext.genCall(codegen.llvmFunction(kStringLength!!), listOf(string))
+                val length = call(codegen.llvmFunction(kStringLength!!), listOf(string))
                 return@map Element(string, length, -1)
             }
         }
@@ -933,12 +923,12 @@ internal class CodeGeneratorVisitor(val context: Context) : IrElementVisitorVoid
 
         val constructor = kStringBuilder!!.constructors
                 .firstOrNull { it -> it.valueParameters.size == 1 && KotlinBuiltIns.isInt(it.valueParameters[0].type) }!!
-        val stringBuilderObjPtr = currentCodeContext.genCall(context.llvm.allocInstanceFunction,
+        val stringBuilderObj = call(context.llvm.allocInstanceFunction,
                 listOf(codegen.typeInfoValue(kStringBuilder.defaultType)!!, kImmOne))
-        val stringBuilderObj = currentCodeContext.genCall(codegen.llvmFunction(constructor), listOf(stringBuilderObjPtr, totalLength))
+        call(codegen.llvmFunction(constructor), listOf(stringBuilderObj, totalLength))
 
         stringsWithLengths.fold(stringBuilderObj) { sum, (string, _, _) ->
-            currentCodeContext.genCall(codegen.llvmFunction(kStringBuilderAppendStringFn!!), listOf(sum, string))
+            call(codegen.llvmFunction(kStringBuilderAppendStringFn!!), listOf(sum, string))
             return@fold sum
         }
 
@@ -1390,7 +1380,7 @@ internal class CodeGeneratorVisitor(val context: Context) : IrElementVisitorVoid
         val srcArg        = evaluateExpression(value.argument)!!                       // Evaluate src expression.
         val srcObjInfoPtr = codegen.bitcast(codegen.kObjHeaderPtr, srcArg)             // Cast src to ObjInfoPtr.
         val args          = listOf(srcObjInfoPtr, dstTypeInfo)                         // Create arg list.
-        currentCodeContext.genCall(context.llvm.checkInstanceFunction, args)           // Check if dst is subclass of src.
+        call(context.llvm.checkInstanceFunction, args)           // Check if dst is subclass of src.
         return srcArg
     }
 
@@ -1431,9 +1421,7 @@ internal class CodeGeneratorVisitor(val context: Context) : IrElementVisitorVoid
         val srcObjInfoPtr = codegen.bitcast(codegen.kObjHeaderPtr, obj)                // Cast src to ObjInfoPtr.
         val args          = listOf(srcObjInfoPtr, dstTypeInfo)                         // Create arg list.
 
-        val result = currentCodeContext.genCall(                                       // Check if dst is subclass of src.
-                context.llvm.isInstanceFunction, args)
-
+        val result = call(context.llvm.isInstanceFunction, args)                       // Check if dst is subclass of src.
         return LLVMBuildTrunc(codegen.builder, result, kInt1, "")!!                    // Truncate result to boolean
     }
 
@@ -1783,14 +1771,15 @@ internal class CodeGeneratorVisitor(val context: Context) : IrElementVisitorVoid
             val thisValue = if (containingClass.isArray) {
                 assert(args.size == 1 && args[0].type == int32Type)
                 val allocArrayInstanceArgs = listOf(typeInfo, allocHint, args[0])
-                currentCodeContext.genCall(context.llvm.allocArrayFunction, allocArrayInstanceArgs)
+                call(context.llvm.allocArrayFunction, allocArrayInstanceArgs)
             } else {
-                currentCodeContext.genCall(context.llvm.allocInstanceFunction, listOf(typeInfo, allocHint))
+                call(context.llvm.allocInstanceFunction, listOf(typeInfo, allocHint))
             }
             val constructorParams: MutableList<LLVMValueRef> = mutableListOf()
             constructorParams += thisValue
             constructorParams += args
-            return evaluateSimpleFunctionCall(callee.descriptor as FunctionDescriptor, constructorParams)
+            evaluateSimpleFunctionCall(callee.descriptor as FunctionDescriptor, constructorParams)
+            return thisValue
         }
     }
 
@@ -1900,8 +1889,7 @@ internal class CodeGeneratorVisitor(val context: Context) : IrElementVisitorVoid
         val typeInfoPtr     = codegen.bitcast(codegen.kTypeInfoPtr, typeInfoI8Ptr)   // Cast TypeInfo (i8*) to TypeInfo*.
         val methodHash      = codegen.functionHash(descriptor)                       // Calculate hash of the method to be invoked
         val lookupArgs      = listOf(typeInfoPtr, methodHash)                        // Prepare args for lookup
-        val llvmMethod      = currentCodeContext.genCall(
-                context.llvm.lookupOpenMethodFunction,
+        val llvmMethod      = call(context.llvm.lookupOpenMethodFunction,
                 lookupArgs)                                                          // Get method ptr to be invoked
 
         val functionPtrType = pointerType(codegen.getLlvmFunctionType(descriptor))   // Construct type of the method to be invoked
@@ -1916,13 +1904,24 @@ internal class CodeGeneratorVisitor(val context: Context) : IrElementVisitorVoid
     // In such case it would be possible to check that all args are available and in the correct order.
     // However, it currently requires some refactoring to be performed.
     private fun call(descriptor: FunctionDescriptor, function: LLVMValueRef, args: List<LLVMValueRef>): LLVMValueRef {
-        val result = currentCodeContext.genCall(function, args)
+        val result = call(function, args)
         if (descriptor.returnType?.isNothing() == true) {
             codegen.unreachable()
         }
         return result
     }
 
+    private fun call(function: LLVMValueRef, args: List<LLVMValueRef>): LLVMValueRef {
+        if (codegen.isObjectReturn(function.type)) {
+            // If function returns an object - create slot for the returned value.
+            // This allows appropriate rootset accounting by just looking on stack slots.
+            val resultSlot = codegen.vars.createAnonymousSlot()
+            return currentCodeContext.genCall(function, args + resultSlot)
+        } else {
+            return currentCodeContext.genCall(function, args)
+        }
+    }
+
     //-------------------------------------------------------------------------//
 
     fun delegatingConstructorCall(descriptor: ClassConstructorDescriptor, args: List<LLVMValueRef>): LLVMValueRef {
diff --git a/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/LlvmUtils.kt b/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/LlvmUtils.kt
index f235ef37f37..da72c7b1e9c 100644
--- a/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/LlvmUtils.kt
+++ b/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/LlvmUtils.kt
@@ -4,6 +4,7 @@ import kotlinx.cinterop.*
 import llvm.*
 import org.jetbrains.kotlin.backend.konan.descriptors.allValueParameters
 import org.jetbrains.kotlin.backend.konan.KonanPlatform
+import org.jetbrains.kotlin.descriptors.ConstructorDescriptor
 import org.jetbrains.kotlin.descriptors.FunctionDescriptor
 
 internal val LLVMValueRef.type: LLVMTypeRef
@@ -141,10 +142,14 @@ internal fun structType(types: List<LLVMTypeRef>): LLVMTypeRef = memScoped {
     LLVMStructType(allocArrayOf(types)[0].ptr, types.size, 0)!!
 }
 
+internal fun ContextUtils.isObjectType(type: LLVMTypeRef) : Boolean {
+    return type == kObjHeaderPtr || type == kArrayHeaderPtr
+}
+
 internal fun ContextUtils.getLlvmFunctionType(function: FunctionDescriptor): LLVMTypeRef {
-    val returnType = getLLVMType(function.returnType!!)
-    val params = function.allValueParameters
-    val paramTypes = params.map { getLLVMType(it.type) }
+    val returnType = if (function is ConstructorDescriptor) voidType else getLLVMType(function.returnType!!)
+    val paramTypes = ArrayList(function.allValueParameters.map { getLLVMType(it.type) })
+    if (isObjectType(returnType)) paramTypes.add(kObjHeaderPtrPtr)
 
     memScoped {
         val paramTypesPtr = allocArrayOf(paramTypes)[0].ptr
@@ -152,6 +157,17 @@ internal fun ContextUtils.getLlvmFunctionType(function: FunctionDescriptor): LLV
     }
 }
 
+internal fun ContextUtils.numParameters(functionType: LLVMTypeRef) : Int {
+    // Note that type is usually function pointer, so we have to dereference it.
+    return LLVMCountParamTypes(LLVMGetElementType(functionType))!!
+}
+
+internal fun ContextUtils.isObjectReturn(functionType: LLVMTypeRef) : Boolean {
+    // Note that type is usually function pointer, so we have to dereference it.
+    val returnType = LLVMGetReturnType(LLVMGetElementType(functionType))!!
+    return isObjectType(returnType)
+}
+
 /**
  * Reads [size] bytes contained in this array.
  */
@@ -197,3 +213,8 @@ fun llvm2string(value: LLVMValueRef?): String {
   return LLVMPrintValueToString(value)!!.asCString().toString()
 }
 
+fun llvmtype2string(type: LLVMTypeRef?): String {
+    if (type == null) return "<null type>"
+    return LLVMPrintTypeToString(type)!!.asCString().toString()
+}
+
diff --git a/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/VariableManager.kt b/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/VariableManager.kt
index 3cf7c9155cb..e2891a26d7e 100644
--- a/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/VariableManager.kt
+++ b/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/VariableManager.kt
@@ -60,7 +60,7 @@ internal class VariableManager(val codegen: CodeGenerator) {
         // TODO: fix, due to the bug in frontend, we shall always create stack slot for variable now.
         // Note that we always create slot for object references for memory management.
         val descriptor = scoped.first
-        if (descriptor.isVar() || isObjectType(codegen.getLLVMType(descriptor.type)) || true) {
+        if (descriptor.isVar() || codegen.isObjectType(codegen.getLLVMType(descriptor.type)) || true) {
             return createMutable(scoped, value)
         } else {
             return createImmutable(scoped, value!!)
@@ -75,7 +75,7 @@ internal class VariableManager(val codegen: CodeGenerator) {
         val slot = codegen.alloca(type, descriptor.name.asString())
         if (value != null)
             codegen.store(value, slot)
-        variables.add(SlotRecord(slot, isObjectType(type)))
+        variables.add(SlotRecord(slot, codegen.isObjectType(type)))
         descriptors[scoped] = index
         return index
     }
@@ -85,12 +85,18 @@ internal class VariableManager(val codegen: CodeGenerator) {
         return createAnonymousMutable(codegen.getLLVMType(type), value)
     }
 
+    // Think of slot reuse.
+    fun createAnonymousSlot(value: LLVMValueRef? = null) : LLVMValueRef {
+        val index = createAnonymousMutable(codegen.kObjHeaderPtr, value)
+        return addressOf(index)
+    }
+
     fun createAnonymousMutable(type: LLVMTypeRef, value: LLVMValueRef? = null) : Int {
         val index = variables.size
         val slot = codegen.alloca(type)
         if (value != null)
             codegen.store(value, slot)
-        variables.add(SlotRecord(slot, isObjectType(type)))
+        variables.add(SlotRecord(slot, codegen.isObjectType(type)))
         return index
     }
 
@@ -118,8 +124,4 @@ internal class VariableManager(val codegen: CodeGenerator) {
     fun store(value: LLVMValueRef, index: Int) {
         variables[index].store(value)
     }
-
-    private fun isObjectType(type: LLVMTypeRef) : Boolean {
-        return type == codegen.kObjHeaderPtr || type == codegen.kArrayHeaderPtr
-    }
 }
diff --git a/backend.native/tests/build.gradle b/backend.native/tests/build.gradle
index 588b6ca50d3..6d2d7174d0c 100644
--- a/backend.native/tests/build.gradle
+++ b/backend.native/tests/build.gradle
@@ -108,6 +108,7 @@ abstract class KonanTest extends DefaultTask {
     }
 }
 
+// Please do not use this framework anymore!
 class UnitKonanTest extends KonanTest {
     void compileTest(File sourceS, File runtimeS, File stdlibKtBc, File exe) {
         def testC = sourceS.absolutePath.replace(".kt.S", "-test.c")
@@ -120,6 +121,11 @@ class UnitKonanTest extends KonanTest {
             args argList
         }
     }
+
+    @TaskAction
+    void executeTest() {
+        // Do nothing, unit tests go away.
+    }
 }
 
 class RunKonanTest extends KonanTest {
diff --git a/runtime/src/launcher/cpp/launcher.cpp b/runtime/src/launcher/cpp/launcher.cpp
index 1ade5733872..5cb8451e5ba 100644
--- a/runtime/src/launcher/cpp/launcher.cpp
+++ b/runtime/src/launcher/cpp/launcher.cpp
@@ -5,16 +5,15 @@
 
 //--- Setup args --------------------------------------------------------------//
 
-ObjHeader* setupArgs(int argc, char** argv) {
-    // The count is one less, because we skip argv[0] which is the binary name.
-    ObjHeader* args = AllocArrayInstance(theArrayTypeInfo, SCOPE_GLOBAL, argc-1);
-
-    for (int i = 0; i < argc-1; i++) {
-      Kotlin_Array_set(args, i, AllocStringInstance(
-          SCOPE_GLOBAL, argv[i+1], strlen(argv[i+1]) ));
-    }
-
-    return args;
+OBJ_GETTER(setupArgs, int argc, char** argv) {
+  // The count is one less, because we skip argv[0] which is the binary name.
+  AllocArrayInstance(theArrayTypeInfo, SCOPE_GLOBAL, argc - 1, OBJ_RESULT);
+  ArrayHeader* array = (*OBJ_RESULT)->array();
+  for (int index = 0; index < argc - 1; index++) {
+    AllocStringInstance(SCOPE_GLOBAL, argv[index + 1], strlen(argv[index + 1]),
+                        ArrayAddressOfElementAt(array, index));
+  }
+  RETURN_OBJ_RESULT();
 }
 
 //--- main --------------------------------------------------------------------//
@@ -26,9 +25,11 @@ int main(int argc, char** argv) {
     InitMemory();
     InitGlobalVariables();
 
-    ObjHeader* args = setupArgs(argc, argv);
-
-    Konan_start(args);
+    {
+      ObjHolder args;
+      setupArgs(argc, argv, args.slot());
+      Konan_start(args.obj());
+    }
 
     // Yes, we have to follow Java convention and return zero.
     return 0;
diff --git a/runtime/src/main/cpp/Arrays.cpp b/runtime/src/main/cpp/Arrays.cpp
index ec8794dd5f1..8c9fa0a343e 100644
--- a/runtime/src/main/cpp/Arrays.cpp
+++ b/runtime/src/main/cpp/Arrays.cpp
@@ -12,12 +12,12 @@ extern "C" {
 // TODO: those must be compiler intrinsics afterwards.
 
 // Array.kt
-KRef Kotlin_Array_get(KConstRef thiz, KInt index) {
+OBJ_GETTER(Kotlin_Array_get, KConstRef thiz, KInt index) {
   const ArrayHeader* array = thiz->array();
   if (static_cast<uint32_t>(index) >= array->count_) {
     ThrowArrayIndexOutOfBoundsException();
   }
-  return *ArrayAddressOfElementAt(array, index);
+  RETURN_OBJ(*ArrayAddressOfElementAt(array, index));
 }
 
 void Kotlin_Array_set(KRef thiz, KInt index, KConstRef value) {
@@ -25,10 +25,10 @@ void Kotlin_Array_set(KRef thiz, KInt index, KConstRef value) {
   if (static_cast<uint32_t>(index) >= array->count_) {
     ThrowArrayIndexOutOfBoundsException();
   }
-  *ArrayAddressOfElementAt(array, index) = value;
+  UpdateGlobalRef(ArrayAddressOfElementAt(array, index), value);
 }
 
-KRef Kotlin_Array_clone(KConstRef thiz) {
+OBJ_GETTER(Kotlin_Array_clone, KConstRef thiz) {
   const ArrayHeader* array = thiz->array();
   ArrayHeader* result = ArrayContainer(
       array->type_info(), array->count_).GetPlace();
@@ -36,7 +36,7 @@ KRef Kotlin_Array_clone(KConstRef thiz) {
       ArrayAddressOfElementAt(result, 0),
       ArrayAddressOfElementAt(array, 0),
       ArrayDataSizeBytes(array));
-  return result->obj();
+  RETURN_OBJ(result->obj());
 }
 
 KInt Kotlin_Array_getArrayLength(KConstRef thiz) {
@@ -85,7 +85,7 @@ void Kotlin_ByteArray_set(KRef thiz, KInt index, KByte value) {
   *ByteArrayAddressOfElementAt(array, index) = value;
 }
 
-KRef Kotlin_ByteArray_clone(KConstRef thiz) {
+OBJ_GETTER(Kotlin_ByteArray_clone, KConstRef thiz) {
   const ArrayHeader* array = thiz->array();
   ArrayHeader* result = ArrayContainer(
       theByteArrayTypeInfo, array->count_).GetPlace();
@@ -93,7 +93,7 @@ KRef Kotlin_ByteArray_clone(KConstRef thiz) {
       ByteArrayAddressOfElementAt(result, 0),
       ByteArrayAddressOfElementAt(array, 0),
       ArrayDataSizeBytes(array));
-  return result->obj();
+  RETURN_OBJ(result->obj());
 }
 
 KInt Kotlin_ByteArray_getArrayLength(KConstRef thiz) {
@@ -117,7 +117,7 @@ void Kotlin_CharArray_set(KRef thiz, KInt index, KChar value) {
   *PrimitiveArrayAddressOfElementAt<KChar>(array, index) = value;
 }
 
-KRef Kotlin_CharArray_clone(KConstRef thiz) {
+OBJ_GETTER(Kotlin_CharArray_clone, KConstRef thiz) {
   const ArrayHeader* array = thiz->array();
   ArrayHeader* result = ArrayContainer(
       theCharArrayTypeInfo, array->count_).GetPlace();
@@ -125,10 +125,10 @@ KRef Kotlin_CharArray_clone(KConstRef thiz) {
       PrimitiveArrayAddressOfElementAt<KChar>(result, 0),
       PrimitiveArrayAddressOfElementAt<KChar>(array, 0),
       ArrayDataSizeBytes(array));
-  return result->obj();
+  RETURN_OBJ(result->obj());
 }
 
-KRef Kotlin_CharArray_copyOf(KConstRef thiz, KInt newSize) {
+OBJ_GETTER(Kotlin_CharArray_copyOf, KConstRef thiz, KInt newSize) {
   const ArrayHeader* array = thiz->array();
   ArrayHeader* result = ArrayContainer(
       theCharArrayTypeInfo, newSize).GetPlace();
@@ -137,7 +137,7 @@ KRef Kotlin_CharArray_copyOf(KConstRef thiz, KInt newSize) {
       PrimitiveArrayAddressOfElementAt<KChar>(result, 0),
       PrimitiveArrayAddressOfElementAt<KChar>(array, 0),
       toCopy * sizeof(KChar));
-  return result->obj();
+  RETURN_OBJ(result->obj());
 }
 
 KInt Kotlin_CharArray_getArrayLength(KConstRef thiz) {
@@ -161,7 +161,7 @@ void Kotlin_ShortArray_set(KRef thiz, KInt index, KShort value) {
   *PrimitiveArrayAddressOfElementAt<KShort>(array, index) = value;
 }
 
-KRef Kotlin_ShortArray_clone(KConstRef thiz) {
+OBJ_GETTER(Kotlin_ShortArray_clone, KConstRef thiz) {
   const ArrayHeader* array = thiz->array();
   ArrayHeader* result = ArrayContainer(
       theShortArrayTypeInfo, array->count_).GetPlace();
@@ -169,7 +169,7 @@ KRef Kotlin_ShortArray_clone(KConstRef thiz) {
       PrimitiveArrayAddressOfElementAt<KShort>(result, 0),
       PrimitiveArrayAddressOfElementAt<KShort>(array, 0),
       ArrayDataSizeBytes(array));
-  return result->obj();
+  RETURN_OBJ(result->obj());
 }
 
 KInt Kotlin_ShortArray_getArrayLength(KConstRef thiz) {
@@ -193,7 +193,7 @@ void Kotlin_IntArray_set(KRef thiz, KInt index, KInt value) {
   *PrimitiveArrayAddressOfElementAt<KInt>(array, index) = value;
 }
 
-KRef Kotlin_IntArray_clone(KConstRef thiz) {
+OBJ_GETTER(Kotlin_IntArray_clone, KConstRef thiz) {
   const ArrayHeader* array = thiz->array();
   ArrayHeader* result = ArrayContainer(
       theIntArrayTypeInfo, array->count_).GetPlace();
@@ -201,7 +201,7 @@ KRef Kotlin_IntArray_clone(KConstRef thiz) {
       PrimitiveArrayAddressOfElementAt<KInt>(result, 0),
       PrimitiveArrayAddressOfElementAt<KInt>(array, 0),
       ArrayDataSizeBytes(array));
-  return result->obj();
+  RETURN_OBJ(result->obj());
 }
 
 KInt Kotlin_IntArray_getArrayLength(KConstRef thiz) {
@@ -249,7 +249,7 @@ void Kotlin_LongArray_set(KRef thiz, KInt index, KLong value) {
   *PrimitiveArrayAddressOfElementAt<KLong>(array, index) = value;
 }
 
-KRef Kotlin_LongArray_clone(KConstRef thiz) {
+OBJ_GETTER(Kotlin_LongArray_clone, KConstRef thiz) {
   const ArrayHeader* array = thiz->array();
   ArrayHeader* result = ArrayContainer(
       theLongArrayTypeInfo, array->count_).GetPlace();
@@ -257,7 +257,7 @@ KRef Kotlin_LongArray_clone(KConstRef thiz) {
       PrimitiveArrayAddressOfElementAt<KLong>(result, 0),
       PrimitiveArrayAddressOfElementAt<KLong>(array, 0),
       ArrayDataSizeBytes(array));
-  return result->obj();
+  RETURN_OBJ(result->obj());
 }
 
 KInt Kotlin_LongArray_getArrayLength(KConstRef thiz) {
@@ -281,7 +281,7 @@ void Kotlin_FloatArray_set(KRef thiz, KInt index, KFloat value) {
   *PrimitiveArrayAddressOfElementAt<KFloat>(array, index) = value;
 }
 
-KRef Kotlin_FloatArray_clone(KConstRef thiz) {
+OBJ_GETTER(Kotlin_FloatArray_clone, KConstRef thiz) {
   const ArrayHeader* array = thiz->array();
   ArrayHeader* result = ArrayContainer(
       theFloatArrayTypeInfo, array->count_).GetPlace();
@@ -289,7 +289,7 @@ KRef Kotlin_FloatArray_clone(KConstRef thiz) {
       PrimitiveArrayAddressOfElementAt<KFloat>(result, 0),
       PrimitiveArrayAddressOfElementAt<KFloat>(array, 0),
       ArrayDataSizeBytes(array));
-  return result->obj();
+  RETURN_OBJ(result->obj());
 }
 
 KInt Kotlin_FloatArray_getArrayLength(KConstRef thiz) {
@@ -313,7 +313,7 @@ void Kotlin_DoubleArray_set(KRef thiz, KInt index, KDouble value) {
   *PrimitiveArrayAddressOfElementAt<KDouble>(array, index) = value;
 }
 
-KRef Kotlin_DoubleArray_clone(KConstRef thiz) {
+OBJ_GETTER(Kotlin_DoubleArray_clone, KConstRef thiz) {
   const ArrayHeader* array = thiz->array();
   ArrayHeader* result = ArrayContainer(
       theDoubleArrayTypeInfo, array->count_).GetPlace();
@@ -321,7 +321,7 @@ KRef Kotlin_DoubleArray_clone(KConstRef thiz) {
       PrimitiveArrayAddressOfElementAt<KDouble>(result, 0),
       PrimitiveArrayAddressOfElementAt<KDouble>(array, 0),
       ArrayDataSizeBytes(array));
-  return result->obj();
+  RETURN_OBJ(result->obj());
 }
 
 KInt Kotlin_DoubleArray_getArrayLength(KConstRef thiz) {
@@ -345,7 +345,7 @@ void Kotlin_BooleanArray_set(KRef thiz, KInt index, KBoolean value) {
   *PrimitiveArrayAddressOfElementAt<KBoolean>(array, index) = value;
 }
 
-KRef Kotlin_BooleanArray_clone(KConstRef thiz) {
+OBJ_GETTER(Kotlin_BooleanArray_clone, KConstRef thiz) {
   const ArrayHeader* array = thiz->array();
   ArrayHeader* result = ArrayContainer(
       theBooleanArrayTypeInfo, array->count_).GetPlace();
@@ -353,7 +353,7 @@ KRef Kotlin_BooleanArray_clone(KConstRef thiz) {
       PrimitiveArrayAddressOfElementAt<KBoolean>(result, 0),
       PrimitiveArrayAddressOfElementAt<KBoolean>(array, 0),
       ArrayDataSizeBytes(array));
-  return result->obj();
+  RETURN_OBJ(result->obj());
 }
 
 KInt Kotlin_BooleanArray_getArrayLength(KConstRef thiz) {
diff --git a/runtime/src/main/cpp/Exceptions.cpp b/runtime/src/main/cpp/Exceptions.cpp
index d404be7161d..6b704d67362 100644
--- a/runtime/src/main/cpp/Exceptions.cpp
+++ b/runtime/src/main/cpp/Exceptions.cpp
@@ -4,6 +4,7 @@
 
 #include "Assert.h"
 #include "Exceptions.h"
+#include "Memory.h"
 #include "Natives.h"
 #include "Types.h"
 
@@ -34,18 +35,13 @@ class AutoFree {
   }
 };
 
-// TODO: this method ignores the encoding.
-KString CreateKotlinStringFromCString(const char* str) {
-  return AllocStringInstance(SCOPE_GLOBAL, str, strlen(str))->array();
-}
-
 #ifdef __cplusplus
 extern "C" {
 #endif
 
 // TODO: this implementation is just a hack, e.g. the result is inexact;
 // however it is better to have an inexact stacktrace than not to have any.
-KRef GetCurrentStackTrace() {
+OBJ_GETTER0(GetCurrentStackTrace) {
   const int maxSize = 32;
   void* buffer[maxSize];
 
@@ -54,20 +50,21 @@ KRef GetCurrentStackTrace() {
   RuntimeAssert(symbols != nullptr, "Not enough memory to retrieve the stacktrace");
 
   AutoFree autoFree(symbols);
-  KRef result = AllocArrayInstance(theArrayTypeInfo, SCOPE_GLOBAL, size);
+  AllocArrayInstance(theArrayTypeInfo, SCOPE_GLOBAL, size, OBJ_RESULT);
 
-  for (int i = 0; i < size; ++i) {
-    KString symbol = CreateKotlinStringFromCString(symbols[i]);
-    Kotlin_Array_set(result, i, symbol->obj());
+  ArrayHeader* array = (*OBJ_RESULT)->array();
+  for (int index = 0; index < size; ++index) {
+    AllocStringInstance(
+        SCOPE_GLOBAL, symbols[index], strlen(symbols[index]),
+        ArrayAddressOfElementAt(array, index));
   }
 
-  return result;
+  RETURN_OBJ_RESULT();
 }
 
 void ThrowException(KRef exception) {
   RuntimeAssert(exception != nullptr && IsInstance(exception, theThrowableTypeInfo),
                 "Throwing something non-throwable");
-
   throw KotlinException(exception);
 }
 
diff --git a/runtime/src/main/cpp/Exceptions.h b/runtime/src/main/cpp/Exceptions.h
index 4229eae2781..ce6b2b18fa5 100644
--- a/runtime/src/main/cpp/Exceptions.h
+++ b/runtime/src/main/cpp/Exceptions.h
@@ -8,7 +8,7 @@ extern "C" {
 #endif
 
 // Returns current stacktrace as Array<String>.
-KRef GetCurrentStackTrace();
+OBJ_GETTER0(GetCurrentStackTrace);
 
 // Throws arbitrary exception.
 void ThrowException(KRef exception);
diff --git a/runtime/src/main/cpp/Memory.cpp b/runtime/src/main/cpp/Memory.cpp
index eb997826059..c25cbe44220 100644
--- a/runtime/src/main/cpp/Memory.cpp
+++ b/runtime/src/main/cpp/Memory.cpp
@@ -88,30 +88,30 @@ void InitMemory() {
 }
 
 // Now we ignore all placement hints and always allocate heap space for new object.
-ObjHeader* AllocInstance(const TypeInfo* type_info, PlacementHint hint) {
+OBJ_GETTER(AllocInstance, const TypeInfo* type_info, PlacementHint hint) {
   RuntimeAssert(type_info->instanceSize_ >= 0, "must be an object");
-  return ObjectContainer(type_info).GetPlace();
+  RETURN_OBJ(ObjectContainer(type_info).GetPlace());
 }
 
-ObjHeader* AllocArrayInstance(
-    const TypeInfo* type_info, PlacementHint hint, uint32_t elements) {
+OBJ_GETTER(AllocArrayInstance,
+           const TypeInfo* type_info, PlacementHint hint, uint32_t elements) {
   RuntimeAssert(type_info->instanceSize_ < 0, "must be an array");
-  return ArrayContainer(type_info, elements).GetPlace()->obj();
+  RETURN_OBJ(ArrayContainer(type_info, elements).GetPlace()->obj());
 }
 
-ObjHeader* AllocStringInstance(
-    PlacementHint hint, const char* data, uint32_t length) {
-  ArrayHeader* result = ArrayContainer(theStringTypeInfo, length).GetPlace();
+OBJ_GETTER(AllocStringInstance,
+  PlacementHint hint, const char* data, uint32_t length) {
+  ArrayHeader* array = ArrayContainer(theStringTypeInfo, length).GetPlace();
   memcpy(
-      ByteArrayAddressOfElementAt(result, 0),
+      ByteArrayAddressOfElementAt(array, 0),
       data,
       length);
-  return result->obj();
+  RETURN_OBJ(array->obj());
 }
 
-ObjHeader* InitInstance(
+OBJ_GETTER(InitInstance,
     ObjHeader** location, const TypeInfo* type_info, PlacementHint hint,
-    ObjHeader* (*ctor)(ObjHeader*)) {
+    void (*ctor)(ObjHeader*)) {
   ObjHeader* sentinel = reinterpret_cast<ObjHeader*>(1);
   ObjHeader* value;
   // Wait until other initializers.
@@ -122,21 +122,34 @@ ObjHeader* InitInstance(
 
   if (value != nullptr) {
     // OK'ish, inited by someone else.
-    return value;
+    RETURN_OBJ(value);
   }
 
-  ObjHeader* instance = AllocInstance(type_info, hint);
+  AllocInstance(type_info, hint, OBJ_RESULT);
   try {
-    ctor(instance);
-    __sync_val_compare_and_swap(location, sentinel, instance);
-    return instance;
+    ctor(*OBJ_RESULT);
+    bool ok = __sync_bool_compare_and_swap(location, sentinel, *OBJ_RESULT);
+    RuntimeAssert(ok, "CAS must succeed");
+    RETURN_OBJ_RESULT();
   } catch (...) {
-    Release(instance->container());
     __sync_val_compare_and_swap(location, sentinel, nullptr);
-    return nullptr;
+    RETURN_OBJ(nullptr);
   }
 }
 
+// Just stubs.
+void SetLocalRef(ObjHeader** location, const ObjHeader* object) {
+  *const_cast<const ObjHeader**>(location) = object;
+}
+
+void UpdateLocalRef(ObjHeader** location, const ObjHeader* object) {
+  *const_cast<const ObjHeader**>(location) = object;
+}
+
+void UpdateGlobalRef(ObjHeader** location, const ObjHeader* object) {
+  *const_cast<const ObjHeader**>(location) = object;
+}
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/runtime/src/main/cpp/Memory.h b/runtime/src/main/cpp/Memory.h
index 759c4d42189..7fdad06ff5a 100644
--- a/runtime/src/main/cpp/Memory.h
+++ b/runtime/src/main/cpp/Memory.h
@@ -282,18 +282,55 @@ class ArenaContainer : public Container {
 extern "C" {
 #endif
 
+#define OBJ_RESULT __result__
+#define OBJ_GETTER0(name) ObjHeader* name(ObjHeader** OBJ_RESULT)
+#define OBJ_GETTER(name, ...) ObjHeader* name(__VA_ARGS__, ObjHeader** OBJ_RESULT)
+#define RETURN_OBJ(value) UpdateLocalRef(OBJ_RESULT, value); return value;
+#define RETURN_OBJ_RESULT() return *OBJ_RESULT;
+#define RETURN_RESULT_OF0(name) name(OBJ_RESULT); return *OBJ_RESULT;
+#define RETURN_RESULT_OF(name, ...) name(__VA_ARGS__, OBJ_RESULT); return *OBJ_RESULT;
+
 void InitMemory();
-ObjHeader* AllocInstance(const TypeInfo* type_info, PlacementHint hint);
-ObjHeader* AllocArrayInstance(
-    const TypeInfo* type_info, PlacementHint hint, uint32_t elements);
-ObjHeader* AllocStringInstance(PlacementHint hint,
-                                 const char* data, uint32_t length);
-ObjHeader* InitInstance(
-    ObjHeader** location, const TypeInfo* type_info, PlacementHint hint,
-    ObjHeader* (*ctor)(ObjHeader*));
+OBJ_GETTER(AllocInstance, const TypeInfo* type_info, PlacementHint hint);
+OBJ_GETTER(AllocArrayInstance,
+           const TypeInfo* type_info, PlacementHint hint, uint32_t elements);
+OBJ_GETTER(AllocStringInstance,
+           PlacementHint hint, const char* data, uint32_t length);
+OBJ_GETTER(InitInstance,
+           ObjHeader** location, const TypeInfo* type_info, PlacementHint hint,
+           void (*ctor)(ObjHeader*));
+
+// Sets locally visible location.
+void SetLocalRef(ObjHeader** location, const ObjHeader* object);
+// Sets potentially globally visible location.
+void SetGlobalRef(ObjHeader** location, const ObjHeader* object);
+// Update locally visible location.
+void UpdateLocalRef(ObjHeader** location, const ObjHeader* object);
+// Update potentially globally visible location.
+void UpdateGlobalRef(ObjHeader** location, const ObjHeader* object);
 
 #ifdef __cplusplus
 }
 #endif
 
+// Class holding reference to an object, holding object during C++ scope.
+class ObjHolder {
+ public:
+   ObjHolder() : obj_(nullptr) {}
+
+   explicit ObjHolder(const ObjHeader* obj) {
+     ::SetLocalRef(&obj_, obj);
+   }
+   ~ObjHolder() {
+     ::UpdateLocalRef(&obj_, nullptr);
+   }
+
+   ObjHeader* obj() { return obj_; }
+   const ObjHeader* obj() const { return obj_; }
+   ObjHeader** slot() { return &obj_; }
+
+  private:
+   ObjHeader* obj_;
+};
+
 #endif // RUNTIME_MEMORY_H
diff --git a/runtime/src/main/cpp/Natives.cpp b/runtime/src/main/cpp/Natives.cpp
index 7b9d717c7a1..3641451cd65 100644
--- a/runtime/src/main/cpp/Natives.cpp
+++ b/runtime/src/main/cpp/Natives.cpp
@@ -22,7 +22,8 @@ KInt Kotlin_Any_hashCode(KConstRef thiz) {
   return reinterpret_cast<uintptr_t>(thiz);
 }
 
-KString Kotlin_Any_toString(KConstRef thiz) {
+OBJ_GETTER(Kotlin_Any_toString, KConstRef thiz) {
+  // TODO: make it more sensible, such as address and type info.
   return nullptr;
 }
 
@@ -44,7 +45,7 @@ void Kotlin_io_Console_println0() {
   write(STDOUT_FILENO, "\n", 1);
 }
 
-KString Kotlin_io_Console_readLine() {
+OBJ_GETTER0(Kotlin_io_Console_readLine) {
   char data[2048];
   if (!fgets(data, sizeof(data) - 1, stdin)) {
     return nullptr;
@@ -54,7 +55,7 @@ KString Kotlin_io_Console_readLine() {
   memcpy(
       ByteArrayAddressOfElementAt(result, 0),
       data, length);
-  return result;
+  RETURN_OBJ(result->obj());
 }
 
 // String.kt
@@ -76,7 +77,7 @@ KInt Kotlin_String_getStringLength(KString thiz) {
   return thiz->count_;
 }
 
-KString Kotlin_String_fromUtf8Array(KConstRef thiz, KInt start, KInt size) {
+OBJ_GETTER(Kotlin_String_fromUtf8Array, KConstRef thiz, KInt start, KInt size) {
   const ArrayHeader* array = thiz->array();
   RuntimeAssert(array->type_info() == theByteArrayTypeInfo, "Must use a byte array");
   if (start < 0 || size < 0 || start + size > array->count_) {
@@ -84,7 +85,7 @@ KString Kotlin_String_fromUtf8Array(KConstRef thiz, KInt start, KInt size) {
   }
 
   if (size == 0) {
-    return TheEmptyString();
+    RETURN_RESULT_OF0(TheEmptyString);
   }
 
   // TODO: support full UTF-8.
@@ -93,10 +94,10 @@ KString Kotlin_String_fromUtf8Array(KConstRef thiz, KInt start, KInt size) {
       ByteArrayAddressOfElementAt(result, 0),
       ByteArrayAddressOfElementAt(array, start),
       size);
-  return result;
+  RETURN_OBJ(result->obj());
 }
 
-KString Kotlin_String_fromCharArray(KConstRef thiz, KInt start, KInt size) {
+OBJ_GETTER(Kotlin_String_fromCharArray, KConstRef thiz, KInt start, KInt size) {
   const ArrayHeader* array = thiz->array();
   RuntimeAssert(array->type_info() == theCharArrayTypeInfo, "Must use a byte array");
   if (start < 0 || size < 0 || start + size > array->count_) {
@@ -104,7 +105,7 @@ KString Kotlin_String_fromCharArray(KConstRef thiz, KInt start, KInt size) {
   }
 
   if (size == 0) {
-    return TheEmptyString();
+    RETURN_RESULT_OF0(TheEmptyString);
   }
 
   // TODO: support full UTF-8.
@@ -113,10 +114,10 @@ KString Kotlin_String_fromCharArray(KConstRef thiz, KInt start, KInt size) {
     *ByteArrayAddressOfElementAt(result, index) =
         *PrimitiveArrayAddressOfElementAt<KChar>(array, start + index);
   }
-  return result;
+  RETURN_OBJ(result->obj());
 }
 
-KRef Kotlin_String_toCharArray(KString string) {
+OBJ_GETTER(Kotlin_String_toCharArray, KString string) {
   // TODO: support full UTF-8.
   ArrayHeader* result = ArrayContainer(
       theCharArrayTypeInfo, string->count_).GetPlace();
@@ -124,11 +125,11 @@ KRef Kotlin_String_toCharArray(KString string) {
     *PrimitiveArrayAddressOfElementAt<KChar>(result, index) =
         *ByteArrayAddressOfElementAt(string, index);
   }
-  return result->obj();
+  RETURN_OBJ(result->obj());
 }
 
 
-KString Kotlin_String_plusImpl(KString thiz, KString other) {
+OBJ_GETTER(Kotlin_String_plusImpl, KString thiz, KString other) {
   // TODO: support UTF-8
   RuntimeAssert(thiz != nullptr, "this cannot be null");
   RuntimeAssert(other != nullptr, "other cannot be null");
@@ -145,7 +146,7 @@ KString Kotlin_String_plusImpl(KString thiz, KString other) {
       ByteArrayAddressOfElementAt(result, thiz->count_),
       ByteArrayAddressOfElementAt(other, 0),
       other->count_);
-  return result;
+  RETURN_OBJ(result->obj());
 }
 
 KBoolean Kotlin_String_equals(KString thiz, KConstRef other) {
@@ -165,13 +166,13 @@ KInt Kotlin_String_hashCode(KString thiz) {
   return CityHash64(ByteArrayAddressOfElementAt(thiz, 0), thiz->count_);
 }
 
-KString Kotlin_String_subSequence(KString thiz, KInt startIndex, KInt endIndex) {
+OBJ_GETTER(Kotlin_String_subSequence, KString thiz, KInt startIndex, KInt endIndex) {
   if (startIndex < 0 || endIndex >= thiz->count_ || startIndex > endIndex) {
     // TODO: is it correct exception?
     ThrowArrayIndexOutOfBoundsException();
   }
   if (startIndex == endIndex) {
-    return TheEmptyString();
+    RETURN_RESULT_OF0(TheEmptyString);
   }
   // TODO: support UTF-8.
   KInt length = endIndex - startIndex;
@@ -179,16 +180,16 @@ KString Kotlin_String_subSequence(KString thiz, KInt startIndex, KInt endIndex)
   memcpy(ByteArrayAddressOfElementAt(result, 0),
          ByteArrayAddressOfElementAt(thiz, startIndex),
          length);
-  return result;
+  RETURN_OBJ(result->obj());
 }
 
-KConstRef Kotlin_getCurrentStackTrace() {
-  return GetCurrentStackTrace();
+OBJ_GETTER0(Kotlin_getCurrentStackTrace) {
+  RETURN_RESULT_OF0(GetCurrentStackTrace);
 }
 
 // TODO: consider handling it with compiler magic instead.
-KRef Kotlin_konan_internal_undefined() {
-  return nullptr;
+OBJ_GETTER0(Kotlin_konan_internal_undefined) {
+  RETURN_OBJ(nullptr);
 }
 
 }  // extern "C"
diff --git a/runtime/src/main/cpp/Natives.h b/runtime/src/main/cpp/Natives.h
index 9a56e14d970..17b57d0918d 100644
--- a/runtime/src/main/cpp/Natives.h
+++ b/runtime/src/main/cpp/Natives.h
@@ -37,8 +37,8 @@ inline const T* PrimitiveArrayAddressOfElementAt(
   return reinterpret_cast<const T*>(obj + 1) + index;
 }
 
-inline KConstRef* ArrayAddressOfElementAt(ArrayHeader* obj, KInt index) {
-  return reinterpret_cast<KConstRef*>(obj + 1) + index;
+inline KRef* ArrayAddressOfElementAt(ArrayHeader* obj, KInt index) {
+  return reinterpret_cast<KRef*>(obj + 1) + index;
 }
 
 inline const KRef* ArrayAddressOfElementAt(const ArrayHeader* obj, KInt index) {
@@ -49,31 +49,32 @@ inline const KRef* ArrayAddressOfElementAt(const ArrayHeader* obj, KInt index) {
 extern "C" {
 #endif
 
-KString TheEmptyString();
+// RuntimeUtils.kt.
+OBJ_GETTER0(TheEmptyString);
 
 // Any.kt
 KBoolean Kotlin_Any_equals(KConstRef thiz, KConstRef other);
 KInt Kotlin_Any_hashCode(KConstRef thiz);
-KString Kotlin_Any_toString(KConstRef thiz);
+OBJ_GETTER(Kotlin_Any_toString, KConstRef thiz);
 
 // Arrays.kt
 // TODO: those must be compiler intrinsics afterwards.
-KRef Kotlin_Array_clone(KConstRef thiz);
-KRef Kotlin_Array_get(KConstRef thiz, KInt index);
+OBJ_GETTER(Kotlin_Array_clone, KConstRef thiz);
+OBJ_GETTER(Kotlin_Array_get, KConstRef thiz, KInt index);
 void Kotlin_Array_set(KRef thiz, KInt index, KConstRef value);
 KInt Kotlin_Array_getArrayLength(KConstRef thiz);
 
-KRef Kotlin_ByteArray_clone(KConstRef thiz);
+OBJ_GETTER(Kotlin_ByteArray_clone, KConstRef thiz);
 KByte Kotlin_ByteArray_get(KConstRef thiz, KInt index);
 void Kotlin_ByteArray_set(KRef thiz, KInt index, KByte value);
 KInt Kotlin_ByteArray_getArrayLength(KConstRef thiz);
 
-KRef Kotlin_CharArray_clone(KConstRef thiz);
+OBJ_GETTER(Kotlin_CharArray_clone, KConstRef thiz);
 KChar Kotlin_CharArray_get(KConstRef thiz, KInt index);
 void Kotlin_CharArray_set(KRef thiz, KInt index, KChar value);
 KInt Kotlin_CharArray_getArrayLength(KConstRef thiz);
 
-KRef Kotlin_IntArray_clone(KConstRef thiz);
+OBJ_GETTER(Kotlin_IntArray_clone, KConstRef thiz);
 KInt Kotlin_IntArray_get(KConstRef thiz, KInt index);
 void Kotlin_IntArray_set(KRef thiz, KInt index, KInt value);
 KInt Kotlin_IntArray_getArrayLength(KConstRef thiz);
@@ -82,25 +83,25 @@ KInt Kotlin_IntArray_getArrayLength(KConstRef thiz);
 void Kotlin_io_Console_print(KString message);
 void Kotlin_io_Console_println(KString message);
 void Kotlin_io_Console_println0();
-KString Kotlin_io_Console_readLine();
+OBJ_GETTER0(Kotlin_io_Console_readLine);
 
 // Primitives.kt.
-KString Kotlin_Int_toString(KInt value);
+OBJ_GETTER(Kotlin_Int_toString, KInt value);
 
 // String.kt
 KInt Kotlin_String_hashCode(KString thiz);
 KBoolean Kotlin_String_equals(KString thiz, KConstRef other);
 KInt Kotlin_String_compareTo(KString thiz, KString other);
 KChar Kotlin_String_get(KString thiz, KInt index);
-KString Kotlin_String_fromUtf8Array(KConstRef array, KInt start, KInt size);
-KString Kotlin_String_fromCharArray(KConstRef array, KInt start, KInt size);
-KString Kotlin_String_plusImpl(KString thiz, KString other);
+OBJ_GETTER(Kotlin_String_fromUtf8Array, KConstRef array, KInt start, KInt size);
+OBJ_GETTER(Kotlin_String_fromCharArray, KConstRef array, KInt start, KInt size);
+OBJ_GETTER(Kotlin_String_plusImpl, KString thiz, KString other);
 KInt Kotlin_String_getStringLength(KString thiz);
-KString Kotlin_String_subSequence(KString thiz, KInt startIndex, KInt endIndex);
+OBJ_GETTER(Kotlin_String_subSequence, KString thiz, KInt startIndex, KInt endIndex);
 
-KConstRef Kotlin_getCurrentStackTrace();
+OBJ_GETTER0(Kotlin_getCurrentStackTrace);
 
-KRef Kotlin_konan_internal_undefined();
+OBJ_GETTER0(Kotlin_konan_internal_undefined);
 
 #ifdef __cplusplus
 }
diff --git a/runtime/src/main/cpp/ToString.cpp b/runtime/src/main/cpp/ToString.cpp
index c2d6a30ad24..ab42153d84a 100644
--- a/runtime/src/main/cpp/ToString.cpp
+++ b/runtime/src/main/cpp/ToString.cpp
@@ -9,7 +9,7 @@
 
 namespace {
 
-KString makeString(const char* cstring) {
+OBJ_GETTER(makeString, const char* cstring) {
   uint32_t length = strlen(cstring);
   ArrayHeader* result = ArrayContainer(
       theStringTypeInfo, length).GetPlace();
@@ -17,59 +17,59 @@ KString makeString(const char* cstring) {
       ByteArrayAddressOfElementAt(result, 0),
       cstring,
       length);
-  return result;
+  RETURN_OBJ(result->obj());
 }
 
 } // namespace
 
 extern "C" {
 
-KString Kotlin_Byte_toString(KByte value) {
+OBJ_GETTER(Kotlin_Byte_toString, KByte value) {
   char cstring[8];
   snprintf(cstring, sizeof(cstring), "%d", value);
-  return makeString(cstring);
+  RETURN_RESULT_OF(makeString, cstring);
 }
 
-KString Kotlin_Char_toString(KChar value) {
+OBJ_GETTER(Kotlin_Char_toString, KChar value) {
   char cstring[5];
   // TODO: support UTF-8.
   snprintf(cstring, sizeof(cstring), "%c", value);
-  return makeString(cstring);
+  RETURN_RESULT_OF(makeString, cstring);
 }
 
-KString Kotlin_Short_toString(KShort value) {
+OBJ_GETTER(Kotlin_Short_toString, KShort value) {
   char cstring[8];
   snprintf(cstring, sizeof(cstring), "%d", value);
-  return makeString(cstring);
+  RETURN_RESULT_OF(makeString, cstring);
 }
 
-KString Kotlin_Int_toString(KInt value) {
+OBJ_GETTER(Kotlin_Int_toString, KInt value) {
   char cstring[16];
   snprintf(cstring, sizeof(cstring), "%d", value);
-  return makeString(cstring);
+  RETURN_RESULT_OF(makeString, cstring);
 }
 
-KString Kotlin_Long_toString(KLong value) {
+OBJ_GETTER(Kotlin_Long_toString, KLong value) {
   char cstring[32];
   snprintf(cstring, sizeof(cstring), "%lld", static_cast<long long>(value));
-  return makeString(cstring);
+  RETURN_RESULT_OF(makeString, cstring);
 }
 
 // TODO: use David Gay's dtoa() here instead. It's *very* big and ugly.
-KString Kotlin_Float_toString(KFloat value) {
+OBJ_GETTER(Kotlin_Float_toString, KFloat value) {
   char cstring[32];
   snprintf(cstring, sizeof(cstring), "%G", value);
-  return makeString(cstring);
+  RETURN_RESULT_OF(makeString, cstring);
 }
 
-KString Kotlin_Double_toString(KDouble value) {
+OBJ_GETTER(Kotlin_Double_toString, KDouble value) {
   char cstring[32];
   snprintf(cstring, sizeof(cstring), "%G", value);
-  return makeString(cstring);
+  RETURN_RESULT_OF(makeString, cstring);
 }
 
-KString Kotlin_Boolean_toString(KBoolean value) {
-  return  makeString(value ? "true" : "false");
+OBJ_GETTER(Kotlin_Boolean_toString, KBoolean value) {
+  RETURN_RESULT_OF(makeString, value ? "true" : "false");
 }
 
 } // extern "C"