diff --git a/Interop/Indexer/prebuilt/nativeInteropStubs/kotlin/clang/Clang.kt b/Interop/Indexer/prebuilt/nativeInteropStubs/kotlin/clang/Clang.kt
index 49cde2d3db9..03d658f40de 100644
--- a/Interop/Indexer/prebuilt/nativeInteropStubs/kotlin/clang/Clang.kt
+++ b/Interop/Indexer/prebuilt/nativeInteropStubs/kotlin/clang/Clang.kt
@@ -3570,7 +3570,7 @@ enum class CXIndexOptFlags(val value: Int) {
     }
 }
 
-object NativeFunctionType1 : NativeFunctionType<(CXCursor, CXCursor, NativePtr?) -> CXChildVisitResult>(UInt32, Struct(UInt32, SInt32, Pointer), Struct(UInt32, SInt32, Pointer), Pointer) {
+object NativeFunctionType1 : NativeFunctionType<(CXCursor, CXCursor, NativePtr?) -> CXChildVisitResult>(UInt32, Struct(UInt32, SInt32, Struct(Pointer, Pointer, Pointer)), Struct(UInt32, SInt32, Struct(Pointer, Pointer, Pointer)), Pointer) {
     override fun invoke(function: (CXCursor, CXCursor, NativePtr?) -> CXChildVisitResult, args: NativeArray<NativePtrBox>, ret: NativePtr) {
         val res = function(args[0].value.asRef(CXCursor)!!, args[1].value.asRef(CXCursor)!!, args[2].value.asRef(NativePtrBox)!!.value)
         CXChildVisitResult.ref.byPtr(ret).value = res
@@ -3589,14 +3589,14 @@ object NativeFunctionType3 : NativeFunctionType<(NativePtr?, CXSourceLocation?,
     }
 }
 
-object NativeFunctionType4 : NativeFunctionType<(CXCursor, NativePtr?) -> CXVisitorResult>(UInt32, Struct(UInt32, SInt32, Pointer), Pointer) {
+object NativeFunctionType4 : NativeFunctionType<(CXCursor, NativePtr?) -> CXVisitorResult>(UInt32, Struct(UInt32, SInt32, Struct(Pointer, Pointer, Pointer)), Pointer) {
     override fun invoke(function: (CXCursor, NativePtr?) -> CXVisitorResult, args: NativeArray<NativePtrBox>, ret: NativePtr) {
         val res = function(args[0].value.asRef(CXCursor)!!, args[1].value.asRef(NativePtrBox)!!.value)
         CXVisitorResult.ref.byPtr(ret).value = res
     }
 }
 
-object NativeFunctionType5 : NativeFunctionType<(NativePtr?, CXCursor, CXSourceRange) -> CXVisitorResult>(UInt32, Pointer, Struct(UInt32, SInt32, Pointer), Struct(Pointer, UInt32, UInt32)) {
+object NativeFunctionType5 : NativeFunctionType<(NativePtr?, CXCursor, CXSourceRange) -> CXVisitorResult>(UInt32, Pointer, Struct(UInt32, SInt32, Struct(Pointer, Pointer, Pointer)), Struct(Struct(Pointer, Pointer), UInt32, UInt32)) {
     override fun invoke(function: (NativePtr?, CXCursor, CXSourceRange) -> CXVisitorResult, args: NativeArray<NativePtrBox>, ret: NativePtr) {
         val res = function(args[0].value.asRef(NativePtrBox)!!.value, args[1].value.asRef(CXCursor)!!, args[2].value.asRef(CXSourceRange)!!)
         CXVisitorResult.ref.byPtr(ret).value = res
diff --git a/Interop/Indexer/src/main/kotlin/org/jetbrains/kotlin/native/interop/indexer/Indexer.kt b/Interop/Indexer/src/main/kotlin/org/jetbrains/kotlin/native/interop/indexer/Indexer.kt
index ab0ac552182..86dcdb37ad4 100644
--- a/Interop/Indexer/src/main/kotlin/org/jetbrains/kotlin/native/interop/indexer/Indexer.kt
+++ b/Interop/Indexer/src/main/kotlin/org/jetbrains/kotlin/native/interop/indexer/Indexer.kt
@@ -98,16 +98,27 @@ private class NativeIndexImpl : NativeIndex() {
      * Computes [StructDef.hasNaturalLayout] property.
      */
     fun structHasNaturalLayout(structDefCursor: CXCursor): Boolean {
-        val hasAttributes = malloc(Int32Box)
-        hasAttributes.value = 0
-        clang_visitChildren(structDefCursor, { cursor, parent, clientData ->
-            if (clang_isAttribute(cursor.kind.value) != 0) {
-                clientData.asRef(Int32Box)!!.value = 1
-            }
-            CXChildVisitResult.CXChildVisit_Continue
-        }, hasAttributes.ptr)
+        val defKind = structDefCursor.kind.value
 
-        return hasAttributes.value == 0
+        when (defKind) {
+
+            CXCursorKind.CXCursor_UnionDecl -> return false
+
+            CXCursorKind.CXCursor_StructDecl -> {
+                val hasAttributes = arena.alloc(Int32Box)
+                hasAttributes.value = 0
+                clang_visitChildren(structDefCursor, { cursor, parent, clientData ->
+                    if (clang_isAttribute(cursor.kind.value) != 0) {
+                        clientData.asRef(Int32Box)!!.value = 1
+                    }
+                    CXChildVisitResult.CXChildVisit_Continue
+                }, hasAttributes.ptr)
+
+                return hasAttributes.value == 0
+            }
+
+            else -> throw IllegalArgumentException(defKind.toString())
+        }
     }
 
     fun convertType(type: CXType): Type {
@@ -253,6 +264,7 @@ fun CXString.convertAndDispose(): String {
 }
 
 fun buildNativeIndexImpl(headerFile: File, args: List<String>): NativeIndex {
+    // TODO: dispose all allocated memory and resources
     val args1 = args.map { CString.fromString(it)!!.asCharPtr() }.toTypedArray()
 
     val index = clang_createIndex(0, 0)
diff --git a/Interop/Runtime/src/callbacks/c/callbacks.c b/Interop/Runtime/src/callbacks/c/callbacks.c
index d4a5b30b9f7..44f90608f65 100644
--- a/Interop/Runtime/src/callbacks/c/callbacks.c
+++ b/Interop/Runtime/src/callbacks/c/callbacks.c
@@ -101,6 +101,8 @@ JNIEXPORT jlong JNICALL Java_kotlin_1native_interop_CallbacksKt_ffiTypePointer(J
 JNIEXPORT jlong JNICALL Java_kotlin_1native_interop_CallbacksKt_ffiTypeStruct0(JNIEnv *env, jclass cls, jlong elements) {
     ffi_type* res = malloc(sizeof(ffi_type));
     if (res != NULL) {
+        res->size = 0;
+        res->alignment = 0;
         res->elements = (ffi_type**) elements;
         res->type = FFI_TYPE_STRUCT;
     }
@@ -164,7 +166,11 @@ static void ffi_fun(ffi_cif *cif, void *ret, void **args, void *user_data) {
     static jmethodID ffiFunImpl0 = NULL;
     static jclass cls = NULL;
     if (ffiFunImpl0 == NULL) {
-        cls = (*env)->FindClass(env, "kotlin_native/interop/CallbacksKt");
+        jclass clsLocal = (*env)->FindClass(env, "kotlin_native/interop/CallbacksKt");
+        checkException(env);
+        assert(clsLocal != NULL);
+
+        cls = (jclass) (*env)->NewGlobalRef(env, clsLocal);
         checkException(env);
         assert(cls != NULL);
 
diff --git a/Interop/StubGenerator/src/main/kotlin/org/jetbrains/kotlin/native/interop/gen/jvm/StubGenerator.kt b/Interop/StubGenerator/src/main/kotlin/org/jetbrains/kotlin/native/interop/gen/jvm/StubGenerator.kt
index 72bce02dbfb..3939343b015 100644
--- a/Interop/StubGenerator/src/main/kotlin/org/jetbrains/kotlin/native/interop/gen/jvm/StubGenerator.kt
+++ b/Interop/StubGenerator/src/main/kotlin/org/jetbrains/kotlin/native/interop/gen/jvm/StubGenerator.kt
@@ -374,7 +374,7 @@ class StubGenerator(
 
             is RecordType -> {
                 val refType = getKotlinTypeForRefTo(type)
-                InValueBinding(
+                return InValueBinding(
                         kotlinJniBridgeType = "Long",
                         conv = { "NativePtr.byValue($it).asRef(${refType.typeExpr})!!" },
                         kotlinType = refType.typeName
@@ -386,6 +386,16 @@ class StubGenerator(
     }
 
     fun getCallbackParamBinding(type: Type): InValueBinding {
+        when (type) {
+            is RecordType -> {
+                val refType = getKotlinTypeForRefTo(type)
+                return InValueBinding(
+                        kotlinJniBridgeType = "Long",
+                        conv = { throw UnsupportedOperationException() },
+                        kotlinType = refType.typeName
+                )
+            }
+        }
         return getInValueBinding(type)
     }
 
@@ -578,6 +588,11 @@ class StubGenerator(
         out("}")
     }
 
+    private fun getFfiStructType(elementTypes: List<Type>) =
+            "Struct(" +
+                    elementTypes.map { getFfiType(it) }.joinToString(", ") +
+                    ")"
+
     private fun getFfiType(type: Type): String {
         return when(type) {
             is VoidType -> "Void"
@@ -588,29 +603,38 @@ class StubGenerator(
             is Int32Type -> "SInt32"
             is UInt32Type -> "UInt32"
             is IntPtrType, is UIntPtrType, // TODO
-            is PointerType, is ArrayType -> "Pointer"
+            is PointerType -> "Pointer"
+            is ConstArrayType -> getFfiStructType(
+                    Array(type.length.toInt(), { type.elemType }).toList()
+            )
             is EnumType -> getFfiType(type.def.baseType)
             is RecordType -> {
                 val def = type.decl.def!!
                 if (!def.hasNaturalLayout) {
                     throw NotImplementedError() // TODO: represent pointer to function as NativePtr instead
                 }
-                "Struct(" + def.fields.map {
-                    getFfiType(it.type)
-                }.joinToString(", ") + ")"
+                getFfiStructType(def.fields.map { it.type })
             }
             else -> throw NotImplementedError(type.toString())
         }
     }
 
+    private fun getArgFfiType(type: Type) = when (type) {
+        is ArrayType -> "Pointer"
+        else -> getFfiType(type)
+    }
+
+    private fun getRetValFfiType(type: Type) = getArgFfiType(type)
+
     private fun generateFunctionType(type: FunctionType, name: String) {
         val kotlinFunctionType = getKotlinFunctionType(type)
 
-        val constructorArgs = listOf(type.returnType, *type.parameterTypes.toTypedArray()).map {
-            getFfiType(it)
-        }.joinToString(", ")
+        val constructorArgs = listOf(getRetValFfiType(type.returnType)) +
+                type.parameterTypes.map { getArgFfiType(it) }
 
-        out("object $name : NativeFunctionType<$kotlinFunctionType>($constructorArgs) {")
+        val constructorArgsStr = constructorArgs.joinToString(", ")
+
+        out("object $name : NativeFunctionType<$kotlinFunctionType>($constructorArgsStr) {")
         indent {
             out("override fun invoke(function: $kotlinFunctionType, args: NativeArray<NativePtrBox>, ret: NativePtr) {")
             indent {