Interop, backend: refactor and reorder interop lowering

* Do not break type compatibility when lowering interop intrinsics.
* Place interop lowering before callable reference lowering.
* Add other improvements to interop implementation.

Interop/Indexer/prebuilt/nativeInteropStubs/kotlin/clang/Clang.kt

@@ -5,7 +5,7 @@ import kotlinx.cinterop.*
 fun asctime(arg0: CPointer<tm>?): CPointer<CInt8Var>? {
     val _arg0 = arg0.rawValue
     val res = externals.asctime(_arg0)
-    return CPointer.createNullable<CInt8Var>(res)
+    return interpretCPointer<CInt8Var>(res)
 }
 
 fun clock(): clock_t {
@@ -16,7 +16,7 @@ fun clock(): clock_t {
 fun ctime(arg0: CPointer<time_tVar>?): CPointer<CInt8Var>? {
     val _arg0 = arg0.rawValue
     val res = externals.ctime(_arg0)
-    return CPointer.createNullable<CInt8Var>(res)
+    return interpretCPointer<CInt8Var>(res)
 }
 
 fun difftime(arg0: time_t, arg1: time_t): Double {
@@ -30,20 +30,20 @@ fun getdate(arg0: String?): CPointer<tm>? {
     return memScoped {
         val _arg0 = arg0?.toCString(memScope).rawPtr
         val res = externals.getdate(_arg0)
-        CPointer.createNullable<tm>(res)
+        interpretCPointer<tm>(res)
     }
 }
 
 fun gmtime(arg0: CPointer<time_tVar>?): CPointer<tm>? {
     val _arg0 = arg0.rawValue
     val res = externals.gmtime(_arg0)
-    return CPointer.createNullable<tm>(res)
+    return interpretCPointer<tm>(res)
 }
 
 fun localtime(arg0: CPointer<time_tVar>?): CPointer<tm>? {
     val _arg0 = arg0.rawValue
     val res = externals.localtime(_arg0)
-    return CPointer.createNullable<tm>(res)
+    return interpretCPointer<tm>(res)
 }
 
 fun mktime(arg0: CPointer<tm>?): time_t {
@@ -69,7 +69,7 @@ fun strptime(arg0: String?, arg1: String?, arg2: CPointer<tm>?): CPointer<CInt8V
         val _arg1 = arg1?.toCString(memScope).rawPtr
         val _arg2 = arg2.rawValue
         val res = externals.strptime(_arg0, _arg1, _arg2)
-        CPointer.createNullable<CInt8Var>(res)
+        interpretCPointer<CInt8Var>(res)
     }
 }
 
@@ -89,7 +89,7 @@ fun asctime_r(arg0: CPointer<tm>?, arg1: String?): CPointer<CInt8Var>? {
         val _arg0 = arg0.rawValue
         val _arg1 = arg1?.toCString(memScope).rawPtr
         val res = externals.asctime_r(_arg0, _arg1)
-        CPointer.createNullable<CInt8Var>(res)
+        interpretCPointer<CInt8Var>(res)
     }
 }
 
@@ -98,7 +98,7 @@ fun ctime_r(arg0: CPointer<time_tVar>?, arg1: String?): CPointer<CInt8Var>? {
         val _arg0 = arg0.rawValue
         val _arg1 = arg1?.toCString(memScope).rawPtr
         val res = externals.ctime_r(_arg0, _arg1)
-        CPointer.createNullable<CInt8Var>(res)
+        interpretCPointer<CInt8Var>(res)
     }
 }
 
@@ -106,14 +106,14 @@ fun gmtime_r(arg0: CPointer<time_tVar>?, arg1: CPointer<tm>?): CPointer<tm>? {
     val _arg0 = arg0.rawValue
     val _arg1 = arg1.rawValue
     val res = externals.gmtime_r(_arg0, _arg1)
-    return CPointer.createNullable<tm>(res)
+    return interpretCPointer<tm>(res)
 }
 
 fun localtime_r(arg0: CPointer<time_tVar>?, arg1: CPointer<tm>?): CPointer<tm>? {
     val _arg0 = arg0.rawValue
     val _arg1 = arg1.rawValue
     val res = externals.localtime_r(_arg0, _arg1)
-    return CPointer.createNullable<tm>(res)
+    return interpretCPointer<tm>(res)
 }
 
 fun posix2time(arg0: time_t): time_t {
@@ -182,7 +182,7 @@ fun clock_settime(__clock_id: clockid_t, __tp: CPointer<timespec>?): Int {
 fun clang_getCString(string: CXString): CPointer<CInt8Var>? {
     val _string = string.rawPtr
     val res = externals.clang_getCString(_string)
-    return CPointer.createNullable<CInt8Var>(res)
+    return interpretCPointer<CInt8Var>(res)
 }
 
 fun clang_disposeString(string: CXString): Unit {
@@ -205,7 +205,7 @@ fun clang_getBuildSessionTimestamp(): Long {
 fun clang_VirtualFileOverlay_create(options: Int): CXVirtualFileOverlay? {
     val _options = options
     val res = externals.clang_VirtualFileOverlay_create(_options)
-    return CPointer.createNullable<CXVirtualFileOverlayImpl>(res)
+    return interpretCPointer<CXVirtualFileOverlayImpl>(res)
 }
 
 fun clang_VirtualFileOverlay_addFileMapping(arg0: CXVirtualFileOverlay?, virtualPath: String?, realPath: String?): CXErrorCode {
@@ -249,7 +249,7 @@ fun clang_VirtualFileOverlay_dispose(arg0: CXVirtualFileOverlay?): Unit {
 fun clang_ModuleMapDescriptor_create(options: Int): CXModuleMapDescriptor? {
     val _options = options
     val res = externals.clang_ModuleMapDescriptor_create(_options)
-    return CPointer.createNullable<CXModuleMapDescriptorImpl>(res)
+    return interpretCPointer<CXModuleMapDescriptorImpl>(res)
 }
 
 fun clang_ModuleMapDescriptor_setFrameworkModuleName(arg0: CXModuleMapDescriptor?, name: String?): CXErrorCode {
@@ -289,7 +289,7 @@ fun clang_createIndex(excludeDeclarationsFromPCH: Int, displayDiagnostics: Int):
     val _excludeDeclarationsFromPCH = excludeDeclarationsFromPCH
     val _displayDiagnostics = displayDiagnostics
     val res = externals.clang_createIndex(_excludeDeclarationsFromPCH, _displayDiagnostics)
-    return CPointer.createNullable<COpaque>(res)
+    return interpretCPointer<COpaque>(res)
 }
 
 fun clang_disposeIndex(index: CXIndex?): Unit {
@@ -343,7 +343,7 @@ fun clang_getFile(tu: CXTranslationUnit?, file_name: String?): CXFile? {
         val _tu = tu.rawValue
         val _file_name = file_name?.toCString(memScope).rawPtr
         val res = externals.clang_getFile(_tu, _file_name)
-        CPointer.createNullable<COpaque>(res)
+        interpretCPointer<COpaque>(res)
     }
 }
 
@@ -492,7 +492,7 @@ fun clang_getSkippedRanges(tu: CXTranslationUnit?, file: CXFile?): CPointer<CXSo
     val _tu = tu.rawValue
     val _file = file.rawValue
     val res = externals.clang_getSkippedRanges(_tu, _file)
-    return CPointer.createNullable<CXSourceRangeList>(res)
+    return interpretCPointer<CXSourceRangeList>(res)
 }
 
 fun clang_disposeSourceRangeList(ranges: CPointer<CXSourceRangeList>?): Unit {
@@ -511,7 +511,7 @@ fun clang_getDiagnosticInSet(Diags: CXDiagnosticSet?, Index: Int): CXDiagnostic?
     val _Diags = Diags.rawValue
     val _Index = Index
     val res = externals.clang_getDiagnosticInSet(_Diags, _Index)
-    return CPointer.createNullable<COpaque>(res)
+    return interpretCPointer<COpaque>(res)
 }
 
 fun clang_loadDiagnostics(file: String?, error: CPointer<CXLoadDiag_Error.Var>?, errorString: CPointer<CXString>?): CXDiagnosticSet? {
@@ -520,7 +520,7 @@ fun clang_loadDiagnostics(file: String?, error: CPointer<CXLoadDiag_Error.Var>?,
         val _error = error.rawValue
         val _errorString = errorString.rawValue
         val res = externals.clang_loadDiagnostics(_file, _error, _errorString)
-        CPointer.createNullable<COpaque>(res)
+        interpretCPointer<COpaque>(res)
     }
 }
 
@@ -533,7 +533,7 @@ fun clang_disposeDiagnosticSet(Diags: CXDiagnosticSet?): Unit {
 fun clang_getChildDiagnostics(D: CXDiagnostic?): CXDiagnosticSet? {
     val _D = D.rawValue
     val res = externals.clang_getChildDiagnostics(_D)
-    return CPointer.createNullable<COpaque>(res)
+    return interpretCPointer<COpaque>(res)
 }
 
 fun clang_getNumDiagnostics(Unit: CXTranslationUnit?): Int {
@@ -546,13 +546,13 @@ fun clang_getDiagnostic(Unit: CXTranslationUnit?, Index: Int): CXDiagnostic? {
     val _Unit = Unit.rawValue
     val _Index = Index
     val res = externals.clang_getDiagnostic(_Unit, _Index)
-    return CPointer.createNullable<COpaque>(res)
+    return interpretCPointer<COpaque>(res)
 }
 
 fun clang_getDiagnosticSetFromTU(Unit: CXTranslationUnit?): CXDiagnosticSet? {
     val _Unit = Unit.rawValue
     val res = externals.clang_getDiagnosticSetFromTU(_Unit)
-    return CPointer.createNullable<COpaque>(res)
+    return interpretCPointer<COpaque>(res)
 }
 
 fun clang_disposeDiagnostic(Diagnostic: CXDiagnostic?): Unit {
@@ -667,7 +667,7 @@ fun clang_createTranslationUnitFromSourceFile(CIdx: CXIndex?, source_filename: S
         val _num_unsaved_files = num_unsaved_files
         val _unsaved_files = unsaved_files.rawValue
         val res = externals.clang_createTranslationUnitFromSourceFile(_CIdx, _source_filename, _num_clang_command_line_args, _clang_command_line_args, _num_unsaved_files, _unsaved_files)
-        CPointer.createNullable<CXTranslationUnitImpl>(res)
+        interpretCPointer<CXTranslationUnitImpl>(res)
     }
 }
 
@@ -676,7 +676,7 @@ fun clang_createTranslationUnit(CIdx: CXIndex?, ast_filename: String?): CXTransl
         val _CIdx = CIdx.rawValue
         val _ast_filename = ast_filename?.toCString(memScope).rawPtr
         val res = externals.clang_createTranslationUnit(_CIdx, _ast_filename)
-        CPointer.createNullable<CXTranslationUnitImpl>(res)
+        interpretCPointer<CXTranslationUnitImpl>(res)
     }
 }
 
@@ -705,7 +705,7 @@ fun clang_parseTranslationUnit(CIdx: CXIndex?, source_filename: String?, command
         val _num_unsaved_files = num_unsaved_files
         val _options = options
         val res = externals.clang_parseTranslationUnit(_CIdx, _source_filename, _command_line_args, _num_command_line_args, _unsaved_files, _num_unsaved_files, _options)
-        CPointer.createNullable<CXTranslationUnitImpl>(res)
+        interpretCPointer<CXTranslationUnitImpl>(res)
     }
 }
 
@@ -779,7 +779,7 @@ fun clang_reparseTranslationUnit(TU: CXTranslationUnit?, num_unsaved_files: Int,
 fun clang_getTUResourceUsageName(kind: CXTUResourceUsageKind): CPointer<CInt8Var>? {
     val _kind = kind.value
     val res = externals.clang_getTUResourceUsageName(_kind)
-    return CPointer.createNullable<CInt8Var>(res)
+    return interpretCPointer<CInt8Var>(res)
 }
 
 fun clang_getCXTUResourceUsage(TU: CXTranslationUnit?, retValPlacement: NativePlacement): CXTUResourceUsage {
@@ -938,12 +938,12 @@ fun clang_getCursorLanguage(cursor: CXCursor): CXLanguageKind {
 fun clang_Cursor_getTranslationUnit(arg0: CXCursor): CXTranslationUnit? {
     val _arg0 = arg0.rawPtr
     val res = externals.clang_Cursor_getTranslationUnit(_arg0)
-    return CPointer.createNullable<CXTranslationUnitImpl>(res)
+    return interpretCPointer<CXTranslationUnitImpl>(res)
 }
 
 fun clang_createCXCursorSet(): CXCursorSet? {
     val res = externals.clang_createCXCursorSet()
-    return CPointer.createNullable<CXCursorSetImpl>(res)
+    return interpretCPointer<CXCursorSetImpl>(res)
 }
 
 fun clang_disposeCXCursorSet(cset: CXCursorSet?): Unit {
@@ -997,7 +997,7 @@ fun clang_disposeOverriddenCursors(overridden: CPointer<CXCursor>?): Unit {
 fun clang_getIncludedFile(cursor: CXCursor): CXFile? {
     val _cursor = cursor.rawPtr
     val res = externals.clang_getIncludedFile(_cursor)
-    return CPointer.createNullable<COpaque>(res)
+    return interpretCPointer<COpaque>(res)
 }
 
 fun clang_getCursor(arg0: CXTranslationUnit?, arg1: CXSourceLocation, retValPlacement: NativePlacement): CXCursor {
@@ -1585,32 +1585,32 @@ fun clang_Cursor_getMangling(arg0: CXCursor, retValPlacement: NativePlacement):
 fun clang_Cursor_getCXXManglings(arg0: CXCursor): CPointer<CXStringSet>? {
     val _arg0 = arg0.rawPtr
     val res = externals.clang_Cursor_getCXXManglings(_arg0)
-    return CPointer.createNullable<CXStringSet>(res)
+    return interpretCPointer<CXStringSet>(res)
 }
 
 fun clang_Cursor_getModule(C: CXCursor): CXModule? {
     val _C = C.rawPtr
     val res = externals.clang_Cursor_getModule(_C)
-    return CPointer.createNullable<COpaque>(res)
+    return interpretCPointer<COpaque>(res)
 }
 
 fun clang_getModuleForFile(arg0: CXTranslationUnit?, arg1: CXFile?): CXModule? {
     val _arg0 = arg0.rawValue
     val _arg1 = arg1.rawValue
     val res = externals.clang_getModuleForFile(_arg0, _arg1)
-    return CPointer.createNullable<COpaque>(res)
+    return interpretCPointer<COpaque>(res)
 }
 
 fun clang_Module_getASTFile(Module: CXModule?): CXFile? {
     val _Module = Module.rawValue
     val res = externals.clang_Module_getASTFile(_Module)
-    return CPointer.createNullable<COpaque>(res)
+    return interpretCPointer<COpaque>(res)
 }
 
 fun clang_Module_getParent(Module: CXModule?): CXModule? {
     val _Module = Module.rawValue
     val res = externals.clang_Module_getParent(_Module)
-    return CPointer.createNullable<COpaque>(res)
+    return interpretCPointer<COpaque>(res)
 }
 
 fun clang_Module_getName(Module: CXModule?, retValPlacement: NativePlacement): CXString {
@@ -1645,7 +1645,7 @@ fun clang_Module_getTopLevelHeader(arg0: CXTranslationUnit?, Module: CXModule?,
     val _Module = Module.rawValue
     val _Index = Index
     val res = externals.clang_Module_getTopLevelHeader(_arg0, _Module, _Index)
-    return CPointer.createNullable<COpaque>(res)
+    return interpretCPointer<COpaque>(res)
 }
 
 fun clang_CXXConstructor_isConvertingConstructor(C: CXCursor): Int {
@@ -1837,7 +1837,7 @@ fun clang_getCompletionChunkCompletionString(completion_string: CXCompletionStri
     val _completion_string = completion_string.rawValue
     val _chunk_number = chunk_number
     val res = externals.clang_getCompletionChunkCompletionString(_completion_string, _chunk_number)
-    return CPointer.createNullable<COpaque>(res)
+    return interpretCPointer<COpaque>(res)
 }
 
 fun clang_getNumCompletionChunks(completion_string: CXCompletionString?): Int {
@@ -1890,7 +1890,7 @@ fun clang_getCompletionBriefComment(completion_string: CXCompletionString?, retV
 fun clang_getCursorCompletionString(cursor: CXCursor): CXCompletionString? {
     val _cursor = cursor.rawPtr
     val res = externals.clang_getCursorCompletionString(_cursor)
-    return CPointer.createNullable<COpaque>(res)
+    return interpretCPointer<COpaque>(res)
 }
 
 fun clang_defaultCodeCompleteOptions(): Int {
@@ -1908,7 +1908,7 @@ fun clang_codeCompleteAt(TU: CXTranslationUnit?, complete_filename: String?, com
         val _num_unsaved_files = num_unsaved_files
         val _options = options
         val res = externals.clang_codeCompleteAt(_TU, _complete_filename, _complete_line, _complete_column, _unsaved_files, _num_unsaved_files, _options)
-        CPointer.createNullable<CXCodeCompleteResults>(res)
+        interpretCPointer<CXCodeCompleteResults>(res)
     }
 }
 
@@ -1935,7 +1935,7 @@ fun clang_codeCompleteGetDiagnostic(Results: CPointer<CXCodeCompleteResults>?, I
     val _Results = Results.rawValue
     val _Index = Index
     val res = externals.clang_codeCompleteGetDiagnostic(_Results, _Index)
-    return CPointer.createNullable<COpaque>(res)
+    return interpretCPointer<COpaque>(res)
 }
 
 fun clang_codeCompleteGetContexts(Results: CPointer<CXCodeCompleteResults>?): Long {
@@ -1988,7 +1988,7 @@ fun clang_getInclusions(tu: CXTranslationUnit?, visitor: CXInclusionVisitor?, cl
 fun clang_Cursor_Evaluate(C: CXCursor): CXEvalResult? {
     val _C = C.rawPtr
     val res = externals.clang_Cursor_Evaluate(_C)
-    return CPointer.createNullable<COpaque>(res)
+    return interpretCPointer<COpaque>(res)
 }
 
 fun clang_EvalResult_getKind(E: CXEvalResult?): CXEvalResultKind {
@@ -2012,7 +2012,7 @@ fun clang_EvalResult_getAsDouble(E: CXEvalResult?): Double {
 fun clang_EvalResult_getAsStr(E: CXEvalResult?): CPointer<CInt8Var>? {
     val _E = E.rawValue
     val res = externals.clang_EvalResult_getAsStr(_E)
-    return CPointer.createNullable<CInt8Var>(res)
+    return interpretCPointer<CInt8Var>(res)
 }
 
 fun clang_EvalResult_dispose(E: CXEvalResult?): Unit {
@@ -2025,7 +2025,7 @@ fun clang_getRemappings(path: String?): CXRemapping? {
     return memScoped {
         val _path = path?.toCString(memScope).rawPtr
         val res = externals.clang_getRemappings(_path)
-        CPointer.createNullable<COpaque>(res)
+        interpretCPointer<COpaque>(res)
     }
 }
 
@@ -2033,7 +2033,7 @@ fun clang_getRemappingsFromFileList(filePaths: CPointer<CPointerVar<CInt8Var>>?,
     val _filePaths = filePaths.rawValue
     val _numFiles = numFiles
     val res = externals.clang_getRemappingsFromFileList(_filePaths, _numFiles)
-    return CPointer.createNullable<COpaque>(res)
+    return interpretCPointer<COpaque>(res)
 }
 
 fun clang_remap_getNumFiles(arg0: CXRemapping?): Int {
@@ -2082,49 +2082,49 @@ fun clang_index_isEntityObjCContainerKind(arg0: CXIdxEntityKind): Int {
 fun clang_index_getObjCContainerDeclInfo(arg0: CPointer<CXIdxDeclInfo>?): CPointer<CXIdxObjCContainerDeclInfo>? {
     val _arg0 = arg0.rawValue
     val res = externals.clang_index_getObjCContainerDeclInfo(_arg0)
-    return CPointer.createNullable<CXIdxObjCContainerDeclInfo>(res)
+    return interpretCPointer<CXIdxObjCContainerDeclInfo>(res)
 }
 
 fun clang_index_getObjCInterfaceDeclInfo(arg0: CPointer<CXIdxDeclInfo>?): CPointer<CXIdxObjCInterfaceDeclInfo>? {
     val _arg0 = arg0.rawValue
     val res = externals.clang_index_getObjCInterfaceDeclInfo(_arg0)
-    return CPointer.createNullable<CXIdxObjCInterfaceDeclInfo>(res)
+    return interpretCPointer<CXIdxObjCInterfaceDeclInfo>(res)
 }
 
 fun clang_index_getObjCCategoryDeclInfo(arg0: CPointer<CXIdxDeclInfo>?): CPointer<CXIdxObjCCategoryDeclInfo>? {
     val _arg0 = arg0.rawValue
     val res = externals.clang_index_getObjCCategoryDeclInfo(_arg0)
-    return CPointer.createNullable<CXIdxObjCCategoryDeclInfo>(res)
+    return interpretCPointer<CXIdxObjCCategoryDeclInfo>(res)
 }
 
 fun clang_index_getObjCProtocolRefListInfo(arg0: CPointer<CXIdxDeclInfo>?): CPointer<CXIdxObjCProtocolRefListInfo>? {
     val _arg0 = arg0.rawValue
     val res = externals.clang_index_getObjCProtocolRefListInfo(_arg0)
-    return CPointer.createNullable<CXIdxObjCProtocolRefListInfo>(res)
+    return interpretCPointer<CXIdxObjCProtocolRefListInfo>(res)
 }
 
 fun clang_index_getObjCPropertyDeclInfo(arg0: CPointer<CXIdxDeclInfo>?): CPointer<CXIdxObjCPropertyDeclInfo>? {
     val _arg0 = arg0.rawValue
     val res = externals.clang_index_getObjCPropertyDeclInfo(_arg0)
-    return CPointer.createNullable<CXIdxObjCPropertyDeclInfo>(res)
+    return interpretCPointer<CXIdxObjCPropertyDeclInfo>(res)
 }
 
 fun clang_index_getIBOutletCollectionAttrInfo(arg0: CPointer<CXIdxAttrInfo>?): CPointer<CXIdxIBOutletCollectionAttrInfo>? {
     val _arg0 = arg0.rawValue
     val res = externals.clang_index_getIBOutletCollectionAttrInfo(_arg0)
-    return CPointer.createNullable<CXIdxIBOutletCollectionAttrInfo>(res)
+    return interpretCPointer<CXIdxIBOutletCollectionAttrInfo>(res)
 }
 
 fun clang_index_getCXXClassDeclInfo(arg0: CPointer<CXIdxDeclInfo>?): CPointer<CXIdxCXXClassDeclInfo>? {
     val _arg0 = arg0.rawValue
     val res = externals.clang_index_getCXXClassDeclInfo(_arg0)
-    return CPointer.createNullable<CXIdxCXXClassDeclInfo>(res)
+    return interpretCPointer<CXIdxCXXClassDeclInfo>(res)
 }
 
 fun clang_index_getClientContainer(arg0: CPointer<CXIdxContainerInfo>?): CXIdxClientContainer? {
     val _arg0 = arg0.rawValue
     val res = externals.clang_index_getClientContainer(_arg0)
-    return CPointer.createNullable<COpaque>(res)
+    return interpretCPointer<COpaque>(res)
 }
 
 fun clang_index_setClientContainer(arg0: CPointer<CXIdxContainerInfo>?, arg1: CXIdxClientContainer?): Unit {
@@ -2137,7 +2137,7 @@ fun clang_index_setClientContainer(arg0: CPointer<CXIdxContainerInfo>?, arg1: CX
 fun clang_index_getClientEntity(arg0: CPointer<CXIdxEntityInfo>?): CXIdxClientEntity? {
     val _arg0 = arg0.rawValue
     val res = externals.clang_index_getClientEntity(_arg0)
-    return CPointer.createNullable<COpaque>(res)
+    return interpretCPointer<COpaque>(res)
 }
 
 fun clang_index_setClientEntity(arg0: CPointer<CXIdxEntityInfo>?, arg1: CXIdxClientEntity?): Unit {
@@ -2150,7 +2150,7 @@ fun clang_index_setClientEntity(arg0: CPointer<CXIdxEntityInfo>?, arg1: CXIdxCli
 fun clang_IndexAction_create(CIdx: CXIndex?): CXIndexAction? {
     val _CIdx = CIdx.rawValue
     val res = externals.clang_IndexAction_create(_CIdx)
-    return CPointer.createNullable<COpaque>(res)
+    return interpretCPointer<COpaque>(res)
 }
 
 fun clang_IndexAction_dispose(arg0: CXIndexAction?): Unit {

Interop/Runtime/src/jvm/kotlin/kotlinx/cinterop/JvmCallbacks.kt

@@ -15,7 +15,7 @@ data class StableObjPtr private constructor(val value: COpaquePointer) {
          */
         fun create(any: Any) = fromValue(newGlobalRef(any))
 
-        private fun fromValue(value: NativePtr) = fromValue(CPointer.create(value))
+        private fun fromValue(value: NativePtr) = fromValue(interpretCPointer(value)!!)
 
         /**
          * Creates [StableObjPtr] from given raw value.
@@ -219,7 +219,7 @@ private fun ffiCreateCif(returnType: ffi_type, paramTypes: List<ffi_type>): ffi_
 
 private fun ffiFunImpl0(ffiCif: Long, ret: Long, args: Long, userData: Any) {
     ffiFunImpl(interpretPointed(ffiCif),
-            CPointer.create(ret),
+            interpretCPointer(ret)!!,
             interpretPointed(args),
             userData as UserData)
 }

Interop/Runtime/src/jvm/kotlin/kotlinx/cinterop/JvmTypes.kt

@@ -11,21 +11,30 @@ val nativeNullPtr: NativePtr = 0L
 inline fun <reified T : CVariable> typeOf() = T::class.companionObjectInstance as CVariable.Type
 
 /**
- * Returns interpretation of entity with given pointer.
+ * Returns interpretation of entity with given pointer, or `null` if it is null.
  *
  * @param T must not be abstract
  */
-inline fun <reified T : NativePointed> interpretPointed(ptr: NativePtr): T {
+inline fun <reified T : NativePointed> interpretNullablePointed(ptr: NativePtr): T? {
-    return ensuringNotNull(ptr) {
+    if (ptr == nativeNullPtr) {
+        return null
+    } else {
         val kClass = T::class
         val primaryConstructor = kClass.primaryConstructor
         if (primaryConstructor == null) {
             throw IllegalArgumentException("${kClass.simpleName} doesn't have a constructor")
         }
-        (primaryConstructor as (NativePtr) -> T)(ptr)
+        return (primaryConstructor as (NativePtr) -> T)(ptr)
     }
 }
 
+fun <T : CPointed> interpretCPointer(rawValue: NativePtr) =
+        if (rawValue == nativeNullPtr) {
+            null
+        } else {
+            CPointer<T>(rawValue)
+        }
+
 inline fun <reified T : CAdaptedFunctionType<*>> CAdaptedFunctionType.Companion.getInstanceOf(): T =
         T::class.objectInstance!!
 

Interop/Runtime/src/main/kotlin/kotlinx/cinterop/Types.kt

@@ -12,40 +12,14 @@ interface NativePointed {
 
 // `null` value of `NativePointed?` is mapped to `nativeNullPtr`.
 val NativePointed?.rawPtr: NativePtr
-    get() = this?.rawPtr ?: nativeNullPtr
+    get() = if (this != null) this.rawPtr else nativeNullPtr
 
 /**
- * Returns interpretation of entity with given pointer, or `null` if it is null.
+ * Returns interpretation of entity with given pointer.
  *
  * @param T must not be abstract
  */
-inline fun <reified T : NativePointed> interpretNullablePointed(ptr: NativePtr): T? {
+inline fun <reified T : NativePointed> interpretPointed(ptr: NativePtr): T = interpretNullablePointed<T>(ptr)!!
-    return ifNotNull(ptr) {
-        interpretPointed<T>(it)
-    }
-}
-
-/**
- * Applies the function to the pointer if it is not null, otherwise returns `null`.
- */
-inline fun <T> ifNotNull(ptr: NativePtr, function: (NativePtr)->T): T? {
-    return if (ptr == nativeNullPtr) {
-        null
-    } else {
-        function(ptr)
-    }
-}
-
-/**
- * Applies the function to the pointer ensuring that it is not null.
- */
-inline fun <T> ensuringNotNull(ptr: NativePtr, function: (NativePtr)->T): T {
-    if (ptr == nativeNullPtr) {
-        throw IllegalArgumentException()
-    } else {
-        return function(ptr)
-    }
-}
 
 /**
  * Changes the interpretation of the pointed data or code.
@@ -60,16 +34,7 @@ interface CPointed : NativePointed
 /**
  * C pointer.
  */
-class CPointer<T : CPointed> private constructor(val rawValue: NativePtr) {
+class CPointer<T : CPointed> internal constructor(val rawValue: NativePtr) {
-    companion object {
-        fun <T : CPointed> create(rawValue: NativePtr) = ensuringNotNull(rawValue) {
-            CPointer<T>(rawValue)
-        }
-
-        fun <T : CPointed> createNullable(rawValue: NativePtr) = ifNotNull(rawValue) {
-            CPointer<T>(it)
-        }
-    }
 
     override fun equals(other: Any?): Boolean {
         if (this === other) {
@@ -90,7 +55,7 @@ class CPointer<T : CPointed> private constructor(val rawValue: NativePtr) {
  * Returns the pointer to this data or code.
  */
 val <T : CPointed> T.ptr: CPointer<T>
-    get() = CPointer.create(this.rawPtr)
+    get() = interpretCPointer(this.rawPtr)!!
 
 /**
  * Returns the corresponding [CPointed].
@@ -104,7 +69,7 @@ inline val <reified T : CPointed> CPointer<T>.pointed: T
 val CPointer<*>?.rawValue: NativePtr
     get() = this?.rawValue ?: nativeNullPtr
 
-fun <T : CPointed> CPointer<*>.reinterpret(): CPointer<T> = CPointer.create(this.rawValue)
+fun <T : CPointed> CPointer<*>.reinterpret(): CPointer<T> = interpretCPointer(this.rawValue)!!
 
 /**
  * The [CPointed] without any specified interpretation.
@@ -251,7 +216,7 @@ typealias CPointerVar<T> = CPointerVarWithValueMappedTo<CPointer<T>>
  * The value of this variable.
  */
 inline var <reified P : CPointer<*>> CPointerVarWithValueMappedTo<P>.value: P?
-    get() = CPointer.createNullable<CPointed>(nativeMemUtils.getNativePtr(this)) as P?
+    get() = interpretCPointer<CPointed>(nativeMemUtils.getNativePtr(this)) as P?
     set(value) = nativeMemUtils.putNativePtr(this, value.rawValue)
 
 /**

Interop/Runtime/src/main/kotlin/kotlinx/cinterop/Utils.kt

@@ -151,10 +151,10 @@ fun <T : CPointed> NativePlacement.allocPointerTo() = alloc<CPointerVar<T>>()
 /**
  * The zero-terminated string.
  */
-class CString private constructor(override val rawPtr: NativePtr) : CPointed {
+class CString(override val rawPtr: NativePtr) : CPointed {
 
     companion object {
-        fun fromArray(array: CArray<CInt8Var>) = CString(array.rawPtr)
+        fun fromArray(array: CArray<CInt8Var>) = array.reinterpret<CString>()
     }
 
     fun length(): Int {

Interop/Runtime/src/native/kotlin/kotlinx/cinterop/NativeMem.kt

@@ -51,7 +51,7 @@ object nativeMemUtils {
         if (ptr == nativeNullPtr) {
             throw OutOfMemoryError("unable to allocate native memory")
         }
-        return NativeAllocated(ptr)
+        return interpretPointed<NativeAllocated>(ptr)
     }
 
     fun free(mem: NativePointed) {

Interop/Runtime/src/native/kotlin/kotlinx/cinterop/NativeTypes.kt

@@ -14,11 +14,17 @@ inline val nativeNullPtr: NativePtr
 fun <T : CVariable> typeOf(): CVariable.Type = throw Error("typeOf() is called with erased argument")
 
 /**
- * Returns interpretation of entity with given pointer.
+ * Returns interpretation of entity with given pointer, or `null` if it is null.
  *
  * @param T must not be abstract
  */
-@Intrinsic external fun <T : NativePointed> interpretPointed(ptr: NativePtr): T
+@Intrinsic external fun <T : NativePointed> interpretNullablePointed(ptr: NativePtr): T?
+
+@Intrinsic external fun <T : CPointed> interpretCPointer(rawValue: NativePtr): CPointer<T>?
+
+@Intrinsic external fun NativePointed.getRawPointer(): NativePtr
+
+@Intrinsic external fun CPointer<*>.getRawValue(): NativePtr
 
 inline fun <reified T : CAdaptedFunctionType<*>> CAdaptedFunctionType.Companion.getInstanceOf(): T =
         TODO("CAdaptedFunctionType.getInstanceOf")

Interop/StubGenerator/src/main/kotlin/org/jetbrains/kotlin/native/interop/gen/jvm/StubGenerator.kt

@@ -276,7 +276,7 @@ class StubGenerator(
         class Pointer(val pointee: String) : TypeInfo() {
             override fun argToJni(name: String) = "$name.rawValue"
 
-            override fun argFromJni(name: String) = "CPointer.createNullable<$pointee>($name)"
+            override fun argFromJni(name: String) = "interpretCPointer<$pointee>($name)"
 
             override val jniType: String
                 get() = "NativePtr"

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/InteropUtils.kt

@@ -6,6 +6,7 @@ import org.jetbrains.kotlin.incremental.components.NoLookupLocation
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.resolve.scopes.MemberScope
+import org.jetbrains.kotlin.types.TypeUtils
 
 private val cPointerName = "CPointer"
 private val nativePointedName = "NativePointed"
@@ -37,12 +38,26 @@ internal class InteropBuiltIns(builtIns: KonanBuiltIns) {
 
     val cPointerRawValue = cPointer.unsubstitutedMemberScope.getContributedVariables("rawValue").single()
 
+    val cPointerGetRawValue = packageScope.getContributedFunctions("getRawValue").single {
+        val extensionReceiverParameter = it.extensionReceiverParameter
+        extensionReceiverParameter != null &&
+                TypeUtils.getClassDescriptor(extensionReceiverParameter.type) == cPointer
+    }
+
     val nativePointedRawPtrGetter =
             nativePointed.unsubstitutedMemberScope.getContributedVariables("rawPtr").single().getter!!
 
+    val nativePointedGetRawPointer = packageScope.getContributedFunctions("getRawPointer").single {
+        val extensionReceiverParameter = it.extensionReceiverParameter
+        extensionReceiverParameter != null &&
+                TypeUtils.getClassDescriptor(extensionReceiverParameter.type) == nativePointed
+    }
+
     val memberAt = packageScope.getContributedFunctions("memberAt").single()
 
-    val interpretPointed = packageScope.getContributedFunctions("interpretPointed").single()
+    val interpretNullablePointed = packageScope.getContributedFunctions("interpretNullablePointed").single()
+
+    val interpretCPointer = packageScope.getContributedFunctions("interpretCPointer").single()
 
     val arrayGetByIntIndex = packageScope.getContributedFunctions("get").single {
         KotlinBuiltIns.isInt(it.valueParameters.single().type)

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/KonanLower.kt

@@ -48,6 +48,9 @@ internal class KonanLower(val context: Context) {
         phaser.phase(KonanPhase.LOWER_INNER_CLASSES) {
             InnerClassLowering(context).runOnFilePostfix(irFile)
         }
+        phaser.phase(KonanPhase.LOWER_INTEROP) {
+            InteropLowering(context).lower(irFile)
+        }
         phaser.phase(KonanPhase.LOWER_CALLABLES) {
             CallableReferenceLowering(context).runOnFilePostfix(irFile)
         }
@@ -62,8 +65,5 @@ internal class KonanLower(val context: Context) {
         phaser.phase(KonanPhase.AUTOBOX) {
             Autoboxing(context).lower(irFile)
         }
-        phaser.phase(KonanPhase.LOWER_INTEROP) {
-            InteropLowering(context).lower(irFile)
-        }
     }
 }

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/IrToBitcode.kt

@@ -1661,6 +1661,9 @@ internal class CodeGeneratorVisitor(val context: Context) : IrElementVisitorVoid
         val interop = context.interopBuiltIns
 
         return when (descriptor) {
+            interop.interpretNullablePointed, interop.interpretCPointer,
+            interop.nativePointedGetRawPointer, interop.cPointerGetRawValue -> args.single()
+
             in interop.readPrimitive -> {
                 val pointerType = pointerType(codegen.getLLVMType(descriptor.returnType!!))
                 val rawPointer = args.last()

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/lower/InteropLowering.kt

@@ -148,20 +148,25 @@ private class InteropTransformer(val context: Context) : IrBuildingTransformer(c
         if (descriptor is ClassConstructorDescriptor) {
             val type = descriptor.constructedClass.defaultType
             if (type.isRepresentedAs(ValueType.C_POINTER) || type.isRepresentedAs(ValueType.NATIVE_POINTED)) {
-                return expression.getValueArgument(0)!!
+                throw Error("Native interop types constructors must not be called directly")
             }
         }
 
         if (descriptor == interop.nativePointedRawPtrGetter ||
                 OverridingUtil.overrides(descriptor, interop.nativePointedRawPtrGetter)) {
 
-            return expression.dispatchReceiver!!
+            // Replace by the intrinsic call to be handled by code generator:
+            return builder.irCall(interop.nativePointedGetRawPointer).apply {
+                extensionReceiver = expression.dispatchReceiver
+            }
         }
 
         return when (descriptor) {
-            interop.cPointerRawValue.getter -> expression.dispatchReceiver!!
+            interop.cPointerRawValue.getter ->
-
+                // Replace by the intrinsic call to be handled by code generator:
-            interop.interpretPointed -> expression.getValueArgument(0)!!
+                builder.irCall(interop.cPointerGetRawValue).apply {
+                    extensionReceiver = expression.dispatchReceiver
+                }
 
             interop.arrayGetByIntIndex, interop.arrayGetByLongIndex -> {
                 val array = expression.extensionReceiver!!