Native: rewrite Kotlin_Interop_getObjCClass in Objective-C

This allows calling it in "Native" thread state.

kotlin-native/Interop/Runtime/src/native/kotlin/kotlinx/cinterop/ObjectiveCImpl.kt

@@ -133,19 +133,6 @@ internal annotation class ObjCMethodImp(val selector: String, val encoding: Stri
 @TypedIntrinsic(IntrinsicType.OBJC_GET_SELECTOR)
 internal external fun objCGetSelector(selector: String): COpaquePointer
 
-@kotlin.native.internal.ExportForCppRuntime("Kotlin_Interop_getObjCClass")
-private fun getObjCClassByName(name: NativePtr): NativePtr {
-    val result = objc_lookUpClass(name)
-    if (result == nativeNullPtr) {
-        val className = interpretCPointer<ByteVar>(name)!!.toKString()
-        val message = """Objective-C class '$className' not found.
-            |Ensure that the containing framework or library was linked.""".trimMargin()
-
-        throw RuntimeException(message)
-    }
-    return result
-}
-
 @kotlin.native.internal.ExportForCompiler
 private fun allocObjCObject(clazz: NativePtr): NativePtr {
     val rawResult = objc_allocWithZone(clazz)
@@ -219,6 +206,3 @@ external fun objc_retain(ptr: NativePtr): NativePtr
 
 @GCUnsafeCall("Kotlin_objc_release")
 external fun objc_release(ptr: NativePtr)
-
-@GCUnsafeCall("Kotlin_objc_lookUpClass")
-external fun objc_lookUpClass(name: NativePtr): NativePtr

kotlin-native/runtime/src/main/cpp/ObjCInterop.mm

@@ -173,7 +173,11 @@ void releaseAsAssociatedObjectImp(id self, SEL _cmd, ReleaseMode mode) {
 
 extern "C" {
 
-Class Kotlin_Interop_getObjCClass(const char* name);
+Class Kotlin_Interop_getObjCClass(const char* name) {
+    Class result = objc_lookUpClass(name);
+    RuntimeCheck(result != nil, "Objective-C class '%s' not found. Ensure that the containing framework or library was linked.", name);
+    return result;
+}
 
 const TypeInfo* GetObjCKotlinTypeInfo(ObjHeader* obj) RUNTIME_NOTHROW;
 
@@ -391,10 +395,6 @@ void Kotlin_objc_release(id ptr) {
   objc_release(ptr);
 }
 
-Class Kotlin_objc_lookUpClass(const char* name) {
-  return objc_lookUpClass(name);
-}
-
 } // extern "C"
 
 #else  // KONAN_OBJC_INTEROP
@@ -426,11 +426,6 @@ void Kotlin_objc_release(void* ptr) {
   RuntimeAssert(false, "Objective-C interop is disabled");
 }
 
-void* Kotlin_objc_lookUpClass(const char* name) {
-  RuntimeAssert(false, "Objective-C interop is disabled");
-  return nullptr;
-}
-
 } // extern "C"
 
 #endif // KONAN_OBJC_INTEROP

kotlin-native/runtime/src/test_support/cpp/CompilerGeneratedObjC.mm

@@ -14,15 +14,6 @@
 
 extern "C" {
 
-Class Kotlin_Interop_getObjCClass(const char* name) {
-    Class result = objc_lookUpClass(name);
-    if (result == nil) {
-        // GTest can display error messages of C++ exceptions so we use them instead of ObjC ones.
-        throw std::invalid_argument("Incorrect class name");
-    }
-    return result;
-}
-
 RUNTIME_NORETURN OBJ_GETTER0(Kotlin_NSEnumeratorAsKIterator_create) {
     throw std::runtime_error("Not implemented for tests");
 }