[ObjCExport] Add suspend function and @Throws tests

KT-66115, KT-66239

native/objcexport-header-generator/impl/analysis-api/src/org/jetbrains/kotlin/objcexport/analysisApiUtils/hasThrowsAnnotation.kt

@@ -4,7 +4,23 @@ import org.jetbrains.kotlin.analysis.api.symbols.KtCallableSymbol
 import org.jetbrains.kotlin.backend.konan.KonanFqNames
 import org.jetbrains.kotlin.name.ClassId
 
-
+/**
+ * Returns if this callable has [Throws] annotation.
+ * Super callables aren't included.
+ *
+ * ```kotlin
+ * class A {
+ *   @Throws
+ *   fun foo()
+ * }
+ * class B: A() {
+ *   override fun foo()
+ * }
+ *
+ * A.foo.hasThrowsAnnotation = true
+ * B.foo.hasThrowsAnnotation = false
+ * ```
+ */
 internal val KtCallableSymbol.hasThrowsAnnotation: Boolean
     get() {
         return annotationsList.hasAnnotation(ClassId.topLevel(KonanFqNames.throws))

native/objcexport-header-generator/impl/analysis-api/src/org/jetbrains/kotlin/objcexport/analysisApiUtils/isThrowable.kt

@@ -2,9 +2,6 @@ package org.jetbrains.kotlin.objcexport.analysisApiUtils
 
 import org.jetbrains.kotlin.analysis.api.KtAnalysisSession
 import org.jetbrains.kotlin.analysis.api.symbols.KtClassOrObjectSymbol
-import org.jetbrains.kotlin.backend.konan.objcexport.ObjCClassType
-import org.jetbrains.kotlin.backend.konan.objcexport.ObjCMethod
-import org.jetbrains.kotlin.backend.konan.objcexport.swiftNameAttribute
 import org.jetbrains.kotlin.builtins.StandardNames
 import org.jetbrains.kotlin.name.ClassId
 
@@ -19,16 +16,4 @@ context(KtAnalysisSession)
 internal val ClassId.isThrowable: Boolean
     get() {
         return StandardNames.FqNames.throwable == this.asSingleFqName()
-    }
+    }
-
-internal fun buildThrowableAsErrorMethod(): ObjCMethod {
-    return ObjCMethod(
-        comment = null,
-        isInstanceMethod = true,
-        returnType = ObjCClassType("NSError"),
-        selectors = listOf("asError"),
-        parameters = emptyList(),
-        attributes = listOf(swiftNameAttribute("asError()")),
-        origin = null
-    )
-}

native/objcexport-header-generator/impl/analysis-api/src/org/jetbrains/kotlin/objcexport/buildThrowableAsErrorMethod.kt

@@ -0,0 +1,20 @@
+package org.jetbrains.kotlin.objcexport
+
+import org.jetbrains.kotlin.backend.konan.objcexport.ObjCClassType
+import org.jetbrains.kotlin.backend.konan.objcexport.ObjCMethod
+import org.jetbrains.kotlin.backend.konan.objcexport.swiftNameAttribute
+
+/**
+ * See K1: [org.jetbrains.kotlin.backend.konan.objcexport.ObjCExportTranslatorImpl.buildThrowableAsErrorMethod]
+ */
+internal fun buildThrowableAsErrorMethod(): ObjCMethod {
+    return ObjCMethod(
+        comment = null,
+        isInstanceMethod = true,
+        returnType = ObjCClassType("NSError"),
+        selectors = listOf("asError"),
+        parameters = emptyList(),
+        attributes = listOf(swiftNameAttribute("asError()")),
+        origin = null
+    )
+}

native/objcexport-header-generator/impl/analysis-api/src/org/jetbrains/kotlin/objcexport/translateToObjCClass.kt

@@ -6,8 +6,6 @@ import org.jetbrains.kotlin.analysis.api.symbols.markers.KtSymbolWithModality
 import org.jetbrains.kotlin.analysis.api.types.KtNonErrorClassType
 import org.jetbrains.kotlin.backend.konan.objcexport.*
 import org.jetbrains.kotlin.descriptors.Modality
-import org.jetbrains.kotlin.name.StandardClassIds
-import org.jetbrains.kotlin.objcexport.analysisApiUtils.buildThrowableAsErrorMethod
 import org.jetbrains.kotlin.objcexport.analysisApiUtils.isThrowable
 import org.jetbrains.kotlin.objcexport.analysisApiUtils.isVisibleInObjC
 

native/objcexport-header-generator/impl/analysis-api/test/org/jetbrains/kotlin/objcexport/tests/IsThrowableTest.kt

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2010-2024 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.objcexport.tests
+
+import org.jetbrains.kotlin.analysis.api.analyze
+import org.jetbrains.kotlin.objcexport.analysisApiUtils.isThrowable
+import org.jetbrains.kotlin.objcexport.testUtils.InlineSourceCodeAnalysis
+import org.jetbrains.kotlin.objcexport.testUtils.getClassOrFail
+import org.jetbrains.kotlin.objcexport.testUtils.getPropertyOrFail
+import org.junit.jupiter.api.Test
+import kotlin.test.assertFalse
+import kotlin.test.assertTrue
+
+class IsThrowableTest(
+    private val inlineSourceCodeAnalysis: InlineSourceCodeAnalysis,
+) {
+    @Test
+    fun `test - fake throwable`() {
+        val file = inlineSourceCodeAnalysis.createKtFile(
+            """
+            class Throwable
+        """.trimIndent()
+        )
+
+        analyze(file) {
+            assertFalse(file.getClassOrFail("Throwable").isThrowable)
+        }
+    }
+
+    @Test
+    fun `test - true throwable`() {
+        val file = inlineSourceCodeAnalysis.createKtFile(
+            """
+            var foo: Throwable? = null
+        """.trimIndent()
+        )
+
+        analyze(file) {
+            val isThrowable = file.getPropertyOrFail("foo").returnType.expandedClassSymbol?.isThrowable ?: false
+            assertTrue(isThrowable)
+        }
+    }
+}

native/objcexport-header-generator/test/org/jetbrains/kotlin/backend/konan/tests/ObjCExportHeaderGeneratorTest.kt

@@ -137,7 +137,6 @@ class ObjCExportHeaderGeneratorTest(private val generator: HeaderGenerator) {
     }
 
     @Test
-    @TodoAnalysisApi
     fun `test - functionWithThrowsAnnotation`() {
         doTest(headersTestDataDir.resolve("functionWithThrowsAnnotation"))
     }
@@ -340,6 +339,21 @@ class ObjCExportHeaderGeneratorTest(private val generator: HeaderGenerator) {
         doTest(headersTestDataDir.resolve("privateGenericSuperInterface"))
     }
 
+    @Test
+    fun `test - throwable`() {
+        doTest(headersTestDataDir.resolve("throwable"))
+    }
+
+    @Test
+    fun `test - illegalStateException`() {
+        doTest(headersTestDataDir.resolve("illegalStateException"))
+    }
+
+    @Test
+    fun `test - suspend function`() {
+        doTest(headersTestDataDir.resolve("suspendFunction"))
+    }
+
     private fun doTest(root: File, configuration: Configuration = Configuration()) {
         if (!root.isDirectory) fail("Expected ${root.absolutePath} to be directory")
         val generatedHeaders = generator.generateHeaders(root, configuration).toString()

native/objcexport-header-generator/testData/headers/illegalStateException/!illegalStateException.h

@@ -0,0 +1,92 @@
+#import <Foundation/NSArray.h>
+#import <Foundation/NSDictionary.h>
+#import <Foundation/NSError.h>
+#import <Foundation/NSObject.h>
+#import <Foundation/NSSet.h>
+#import <Foundation/NSString.h>
+#import <Foundation/NSValue.h>
+
+@class KotlinIllegalStateException, KotlinThrowable, KotlinArray<T>, KotlinException, KotlinRuntimeException;
+
+@protocol KotlinIterator;
+
+NS_ASSUME_NONNULL_BEGIN
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunknown-warning-option"
+#pragma clang diagnostic ignored "-Wincompatible-property-type"
+#pragma clang diagnostic ignored "-Wnullability"
+
+#pragma push_macro("_Nullable_result")
+#if !__has_feature(nullability_nullable_result)
+#undef _Nullable_result
+#define _Nullable_result _Nullable
+#endif
+
+__attribute__((objc_subclassing_restricted))
+@interface FooKt : Base
+@property (class, readonly) KotlinIllegalStateException * _Nullable exception __attribute__((swift_name("exception")));
+@end
+
+@interface KotlinThrowable : Base
+- (instancetype)init __attribute__((swift_name("init()"))) __attribute__((objc_designated_initializer));
++ (instancetype)new __attribute__((availability(swift, unavailable, message="use object initializers instead")));
+- (instancetype)initWithMessage:(NSString * _Nullable)message __attribute__((swift_name("init(message:)"))) __attribute__((objc_designated_initializer));
+- (instancetype)initWithCause:(KotlinThrowable * _Nullable)cause __attribute__((swift_name("init(cause:)"))) __attribute__((objc_designated_initializer));
+- (instancetype)initWithMessage:(NSString * _Nullable)message cause:(KotlinThrowable * _Nullable)cause __attribute__((swift_name("init(message:cause:)"))) __attribute__((objc_designated_initializer));
+
+/**
+ * @note annotations
+ *   kotlin.experimental.ExperimentalNativeApi
+*/
+- (KotlinArray<NSString *> *)getStackTrace __attribute__((swift_name("getStackTrace()")));
+- (void)printStackTrace __attribute__((swift_name("printStackTrace()")));
+- (NSString *)description __attribute__((swift_name("description()")));
+@property (readonly) KotlinThrowable * _Nullable cause __attribute__((swift_name("cause")));
+@property (readonly) NSString * _Nullable message __attribute__((swift_name("message")));
+- (NSError *)asError __attribute__((swift_name("asError()")));
+@end
+
+@interface KotlinException : KotlinThrowable
+- (instancetype)init __attribute__((swift_name("init()"))) __attribute__((objc_designated_initializer));
++ (instancetype)new __attribute__((availability(swift, unavailable, message="use object initializers instead")));
+- (instancetype)initWithMessage:(NSString * _Nullable)message __attribute__((swift_name("init(message:)"))) __attribute__((objc_designated_initializer));
+- (instancetype)initWithCause:(KotlinThrowable * _Nullable)cause __attribute__((swift_name("init(cause:)"))) __attribute__((objc_designated_initializer));
+- (instancetype)initWithMessage:(NSString * _Nullable)message cause:(KotlinThrowable * _Nullable)cause __attribute__((swift_name("init(message:cause:)"))) __attribute__((objc_designated_initializer));
+@end
+
+@interface KotlinRuntimeException : KotlinException
+- (instancetype)init __attribute__((swift_name("init()"))) __attribute__((objc_designated_initializer));
++ (instancetype)new __attribute__((availability(swift, unavailable, message="use object initializers instead")));
+- (instancetype)initWithMessage:(NSString * _Nullable)message __attribute__((swift_name("init(message:)"))) __attribute__((objc_designated_initializer));
+- (instancetype)initWithCause:(KotlinThrowable * _Nullable)cause __attribute__((swift_name("init(cause:)"))) __attribute__((objc_designated_initializer));
+- (instancetype)initWithMessage:(NSString * _Nullable)message cause:(KotlinThrowable * _Nullable)cause __attribute__((swift_name("init(message:cause:)"))) __attribute__((objc_designated_initializer));
+@end
+
+@interface KotlinIllegalStateException : KotlinRuntimeException
+- (instancetype)init __attribute__((swift_name("init()"))) __attribute__((objc_designated_initializer));
++ (instancetype)new __attribute__((availability(swift, unavailable, message="use object initializers instead")));
+- (instancetype)initWithMessage:(NSString * _Nullable)message __attribute__((swift_name("init(message:)"))) __attribute__((objc_designated_initializer));
+- (instancetype)initWithCause:(KotlinThrowable * _Nullable)cause __attribute__((swift_name("init(cause:)"))) __attribute__((objc_designated_initializer));
+- (instancetype)initWithMessage:(NSString * _Nullable)message cause:(KotlinThrowable * _Nullable)cause __attribute__((swift_name("init(message:cause:)"))) __attribute__((objc_designated_initializer));
+@end
+
+__attribute__((objc_subclassing_restricted))
+@interface KotlinArray<T> : Base
++ (instancetype)arrayWithSize:(int32_t)size init:(T _Nullable (^)(Int *))init __attribute__((swift_name("init(size:init:)")));
++ (instancetype)alloc __attribute__((unavailable));
++ (instancetype)allocWithZone:(struct _NSZone *)zone __attribute__((unavailable));
+- (T _Nullable)getIndex:(int32_t)index __attribute__((swift_name("get(index:)")));
+- (id<KotlinIterator>)iterator __attribute__((swift_name("iterator()")));
+- (void)setIndex:(int32_t)index value:(T _Nullable)value __attribute__((swift_name("set(index:value:)")));
+@property (readonly) int32_t size __attribute__((swift_name("size")));
+@end
+
+@protocol KotlinIterator
+@required
+- (BOOL)hasNext __attribute__((swift_name("hasNext()")));
+- (id _Nullable)next __attribute__((swift_name("next()")));
+@end
+
+#pragma pop_macro("_Nullable_result")
+#pragma clang diagnostic pop
+NS_ASSUME_NONNULL_END

native/objcexport-header-generator/testData/headers/illegalStateException/Foo.kt

@@ -0,0 +1 @@
+val exception: IllegalStateException? = null

native/objcexport-header-generator/testData/headers/suspendFunction/!suspendFunction.h

@@ -0,0 +1,110 @@
+#import <Foundation/NSArray.h>
+#import <Foundation/NSDictionary.h>
+#import <Foundation/NSError.h>
+#import <Foundation/NSObject.h>
+#import <Foundation/NSSet.h>
+#import <Foundation/NSString.h>
+#import <Foundation/NSValue.h>
+
+@class KotlinThrowable, KotlinArray<T>, KotlinException, KotlinRuntimeException, KotlinIllegalStateException;
+
+@protocol KotlinIterator;
+
+NS_ASSUME_NONNULL_BEGIN
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunknown-warning-option"
+#pragma clang diagnostic ignored "-Wincompatible-property-type"
+#pragma clang diagnostic ignored "-Wnullability"
+
+#pragma push_macro("_Nullable_result")
+#if !__has_feature(nullability_nullable_result)
+#undef _Nullable_result
+#define _Nullable_result _Nullable
+#endif
+
+__attribute__((objc_subclassing_restricted))
+@interface FooKt : Base
+
+/**
+ * @note This method converts instances of CancellationException to errors.
+ * Other uncaught Kotlin exceptions are fatal.
+*/
++ (void)fooWithCompletionHandler:(void (^)(NSError * _Nullable))completionHandler __attribute__((swift_name("foo(completionHandler:)")));
+@end
+
+@interface KotlinThrowable : Base
+- (instancetype)init __attribute__((swift_name("init()"))) __attribute__((objc_designated_initializer));
++ (instancetype)new __attribute__((availability(swift, unavailable, message="use object initializers instead")));
+- (instancetype)initWithMessage:(NSString * _Nullable)message __attribute__((swift_name("init(message:)"))) __attribute__((objc_designated_initializer));
+- (instancetype)initWithCause:(KotlinThrowable * _Nullable)cause __attribute__((swift_name("init(cause:)"))) __attribute__((objc_designated_initializer));
+- (instancetype)initWithMessage:(NSString * _Nullable)message cause:(KotlinThrowable * _Nullable)cause __attribute__((swift_name("init(message:cause:)"))) __attribute__((objc_designated_initializer));
+
+/**
+ * @note annotations
+ *   kotlin.experimental.ExperimentalNativeApi
+*/
+- (KotlinArray<NSString *> *)getStackTrace __attribute__((swift_name("getStackTrace()")));
+- (void)printStackTrace __attribute__((swift_name("printStackTrace()")));
+- (NSString *)description __attribute__((swift_name("description()")));
+@property (readonly) KotlinThrowable * _Nullable cause __attribute__((swift_name("cause")));
+@property (readonly) NSString * _Nullable message __attribute__((swift_name("message")));
+- (NSError *)asError __attribute__((swift_name("asError()")));
+@end
+
+@interface KotlinException : KotlinThrowable
+- (instancetype)init __attribute__((swift_name("init()"))) __attribute__((objc_designated_initializer));
++ (instancetype)new __attribute__((availability(swift, unavailable, message="use object initializers instead")));
+- (instancetype)initWithMessage:(NSString * _Nullable)message __attribute__((swift_name("init(message:)"))) __attribute__((objc_designated_initializer));
+- (instancetype)initWithCause:(KotlinThrowable * _Nullable)cause __attribute__((swift_name("init(cause:)"))) __attribute__((objc_designated_initializer));
+- (instancetype)initWithMessage:(NSString * _Nullable)message cause:(KotlinThrowable * _Nullable)cause __attribute__((swift_name("init(message:cause:)"))) __attribute__((objc_designated_initializer));
+@end
+
+@interface KotlinRuntimeException : KotlinException
+- (instancetype)init __attribute__((swift_name("init()"))) __attribute__((objc_designated_initializer));
++ (instancetype)new __attribute__((availability(swift, unavailable, message="use object initializers instead")));
+- (instancetype)initWithMessage:(NSString * _Nullable)message __attribute__((swift_name("init(message:)"))) __attribute__((objc_designated_initializer));
+- (instancetype)initWithCause:(KotlinThrowable * _Nullable)cause __attribute__((swift_name("init(cause:)"))) __attribute__((objc_designated_initializer));
+- (instancetype)initWithMessage:(NSString * _Nullable)message cause:(KotlinThrowable * _Nullable)cause __attribute__((swift_name("init(message:cause:)"))) __attribute__((objc_designated_initializer));
+@end
+
+@interface KotlinIllegalStateException : KotlinRuntimeException
+- (instancetype)init __attribute__((swift_name("init()"))) __attribute__((objc_designated_initializer));
++ (instancetype)new __attribute__((availability(swift, unavailable, message="use object initializers instead")));
+- (instancetype)initWithMessage:(NSString * _Nullable)message __attribute__((swift_name("init(message:)"))) __attribute__((objc_designated_initializer));
+- (instancetype)initWithCause:(KotlinThrowable * _Nullable)cause __attribute__((swift_name("init(cause:)"))) __attribute__((objc_designated_initializer));
+- (instancetype)initWithMessage:(NSString * _Nullable)message cause:(KotlinThrowable * _Nullable)cause __attribute__((swift_name("init(message:cause:)"))) __attribute__((objc_designated_initializer));
+@end
+
+
+/**
+ * @note annotations
+ *   kotlin.SinceKotlin(version="1.4")
+*/
+@interface KotlinCancellationException : KotlinIllegalStateException
+- (instancetype)init __attribute__((swift_name("init()"))) __attribute__((objc_designated_initializer));
++ (instancetype)new __attribute__((availability(swift, unavailable, message="use object initializers instead")));
+- (instancetype)initWithMessage:(NSString * _Nullable)message __attribute__((swift_name("init(message:)"))) __attribute__((objc_designated_initializer));
+- (instancetype)initWithCause:(KotlinThrowable * _Nullable)cause __attribute__((swift_name("init(cause:)"))) __attribute__((objc_designated_initializer));
+- (instancetype)initWithMessage:(NSString * _Nullable)message cause:(KotlinThrowable * _Nullable)cause __attribute__((swift_name("init(message:cause:)"))) __attribute__((objc_designated_initializer));
+@end
+
+__attribute__((objc_subclassing_restricted))
+@interface KotlinArray<T> : Base
++ (instancetype)arrayWithSize:(int32_t)size init:(T _Nullable (^)(Int *))init __attribute__((swift_name("init(size:init:)")));
++ (instancetype)alloc __attribute__((unavailable));
++ (instancetype)allocWithZone:(struct _NSZone *)zone __attribute__((unavailable));
+- (T _Nullable)getIndex:(int32_t)index __attribute__((swift_name("get(index:)")));
+- (id<KotlinIterator>)iterator __attribute__((swift_name("iterator()")));
+- (void)setIndex:(int32_t)index value:(T _Nullable)value __attribute__((swift_name("set(index:value:)")));
+@property (readonly) int32_t size __attribute__((swift_name("size")));
+@end
+
+@protocol KotlinIterator
+@required
+- (BOOL)hasNext __attribute__((swift_name("hasNext()")));
+- (id _Nullable)next __attribute__((swift_name("next()")));
+@end
+
+#pragma pop_macro("_Nullable_result")
+#pragma clang diagnostic pop
+NS_ASSUME_NONNULL_END

native/objcexport-header-generator/testData/headers/suspendFunction/Foo.kt

@@ -0,0 +1 @@
+suspend fun foo() = Unit

native/objcexport-header-generator/testData/headers/throwable/!throwable.h

@@ -0,0 +1,68 @@
+#import <Foundation/NSArray.h>
+#import <Foundation/NSDictionary.h>
+#import <Foundation/NSError.h>
+#import <Foundation/NSObject.h>
+#import <Foundation/NSSet.h>
+#import <Foundation/NSString.h>
+#import <Foundation/NSValue.h>
+
+@class KotlinThrowable, KotlinArray<T>;
+
+@protocol KotlinIterator;
+
+NS_ASSUME_NONNULL_BEGIN
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunknown-warning-option"
+#pragma clang diagnostic ignored "-Wincompatible-property-type"
+#pragma clang diagnostic ignored "-Wnullability"
+
+#pragma push_macro("_Nullable_result")
+#if !__has_feature(nullability_nullable_result)
+#undef _Nullable_result
+#define _Nullable_result _Nullable
+#endif
+
+__attribute__((objc_subclassing_restricted))
+@interface FooKt : Base
+@property (class, readonly) KotlinThrowable * _Nullable throwable __attribute__((swift_name("throwable")));
+@end
+
+@interface KotlinThrowable : Base
+- (instancetype)init __attribute__((swift_name("init()"))) __attribute__((objc_designated_initializer));
++ (instancetype)new __attribute__((availability(swift, unavailable, message="use object initializers instead")));
+- (instancetype)initWithMessage:(NSString * _Nullable)message __attribute__((swift_name("init(message:)"))) __attribute__((objc_designated_initializer));
+- (instancetype)initWithCause:(KotlinThrowable * _Nullable)cause __attribute__((swift_name("init(cause:)"))) __attribute__((objc_designated_initializer));
+- (instancetype)initWithMessage:(NSString * _Nullable)message cause:(KotlinThrowable * _Nullable)cause __attribute__((swift_name("init(message:cause:)"))) __attribute__((objc_designated_initializer));
+
+/**
+ * @note annotations
+ *   kotlin.experimental.ExperimentalNativeApi
+*/
+- (KotlinArray<NSString *> *)getStackTrace __attribute__((swift_name("getStackTrace()")));
+- (void)printStackTrace __attribute__((swift_name("printStackTrace()")));
+- (NSString *)description __attribute__((swift_name("description()")));
+@property (readonly) KotlinThrowable * _Nullable cause __attribute__((swift_name("cause")));
+@property (readonly) NSString * _Nullable message __attribute__((swift_name("message")));
+- (NSError *)asError __attribute__((swift_name("asError()")));
+@end
+
+__attribute__((objc_subclassing_restricted))
+@interface KotlinArray<T> : Base
++ (instancetype)arrayWithSize:(int32_t)size init:(T _Nullable (^)(Int *))init __attribute__((swift_name("init(size:init:)")));
++ (instancetype)alloc __attribute__((unavailable));
++ (instancetype)allocWithZone:(struct _NSZone *)zone __attribute__((unavailable));
+- (T _Nullable)getIndex:(int32_t)index __attribute__((swift_name("get(index:)")));
+- (id<KotlinIterator>)iterator __attribute__((swift_name("iterator()")));
+- (void)setIndex:(int32_t)index value:(T _Nullable)value __attribute__((swift_name("set(index:value:)")));
+@property (readonly) int32_t size __attribute__((swift_name("size")));
+@end
+
+@protocol KotlinIterator
+@required
+- (BOOL)hasNext __attribute__((swift_name("hasNext()")));
+- (id _Nullable)next __attribute__((swift_name("next()")));
+@end
+
+#pragma pop_macro("_Nullable_result")
+#pragma clang diagnostic pop
+NS_ASSUME_NONNULL_END

native/objcexport-header-generator/testData/headers/throwable/Foo.kt

@@ -0,0 +1 @@
+val throwable: Throwable? = null