[KN] CInterop: __attribute__((objc_direct)) support

Merge-request: KT-MR-8828
Merged-by: Gleb Lukianets <Gleb.Lukianets@jetbrains.com>

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

@@ -132,7 +132,7 @@ private class ObjCMethodStubBuilder(
         kotlinMethodParameters = method.getKotlinParameters(context, forConstructorOrFactory = false)
         external = (container !is ObjCProtocol)
         modality = when (container) {
-            is ObjCClass -> MemberStubModality.OPEN
+            is ObjCClass -> if (method.isDirect) MemberStubModality.FINAL else MemberStubModality.OPEN
             is ObjCProtocol -> if (method.isOptional) MemberStubModality.OPEN else MemberStubModality.ABSTRACT
             is ObjCCategory -> MemberStubModality.FINAL
         }
@@ -145,7 +145,17 @@ private class ObjCMethodStubBuilder(
     private fun buildObjCMethodAnnotations(main: AnnotationStub): List<AnnotationStub> = listOfNotNull(
             main,
             AnnotationStub.ObjC.ConsumesReceiver.takeIf { method.nsConsumesSelf },
-            AnnotationStub.ObjC.ReturnsRetained.takeIf { method.nsReturnsRetained }
+            AnnotationStub.ObjC.ReturnsRetained.takeIf { method.nsReturnsRetained },
+            if (method.isDirect) {
+                when (container) {
+                    is ObjCClass -> container.name
+                    is ObjCCategory -> container.clazz.name
+                    is ObjCProtocol -> null
+                }?.let {
+                    val prefix = if (method.isClass) '+' else '-'
+                    AnnotationStub.ObjC.Direct("$prefix[$it ${method.selector}]")
+                }
+            } else { null },
     )
 
     fun isDefaultConstructor(): Boolean =

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

@@ -185,6 +185,9 @@ sealed class AnnotationStub(val classifier: Classifier) {
         class Method(val selector: String, val encoding: String, val isStret: Boolean = false) :
                 ObjC(Classifier.topLevel(cinteropPackage, "ObjCMethod"))
 
+        class Direct(val symbol: String) :
+                ObjC(Classifier.topLevel(cinteropPackage, "ObjCDirect"))
+
         class Factory(val selector: String, val encoding: String, val isStret: Boolean = false) :
                 ObjC(Classifier.topLevel(cinteropPackage, "ObjCFactory"))
 

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

@@ -394,6 +394,9 @@ private class MappingExtensions(
                     ("encoding" to encoding).asAnnotationArgument(),
                     ("isStret" to KmAnnotationArgument.BooleanValue(isStret))
             )
+            is AnnotationStub.ObjC.Direct -> mapOfNotNull(
+                    ("symbol" to symbol).asAnnotationArgument(),
+            )
             is AnnotationStub.ObjC.Factory -> mapOfNotNull(
                     ("selector" to selector).asAnnotationArgument(),
                     ("encoding" to encoding).asAnnotationArgument(),

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

@@ -458,6 +458,7 @@ class StubIrTextEmitter(
             val encoding = annotationStub.encoding.quoteAsKotlinLiteral()
             "@ObjCMethod($selector, $encoding$stret)"
         }
+        is AnnotationStub.ObjC.Direct -> "@ObjCDirect(${annotationStub.symbol.quoteAsKotlinLiteral()})"
         is AnnotationStub.ObjC.Factory -> {
             val stret = if (annotationStub.isStret) ", true" else ""
             val selector = annotationStub.selector.quoteAsKotlinLiteral()

kotlin-native/Interop/StubGenerator/src/test/kotlin/org/jetbrains/kotlin/native/interop/gen/ObjCMethodSignaturesTest.kt

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2010-2022 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.native.interop.gen
+
+import org.jetbrains.kotlin.konan.target.HostManager
+import org.jetbrains.kotlin.native.interop.indexer.buildNativeIndex
+import org.junit.Assume
+import org.junit.BeforeClass
+import org.junit.Test
+import kotlin.test.assertNotNull
+import kotlin.test.assertTrue
+
+class ObjCMethodSignaturesTest : InteropTestsBase() {
+    companion object {
+        @BeforeClass
+        @JvmStatic
+        fun assumeMacOS() {
+            Assume.assumeTrue(HostManager.hostIsMac)
+        }
+    }
+
+    @Test
+    fun `ObjC Direct`() {
+        val files = TempFiles("ObjCDirect")
+        files.file("header.h", """
+            #import <Foundation/Foundation.h>
+            
+            @interface Foo : NSObject
+            + (void)direct __attribute__((objc_direct));
+            - (void)direct __attribute__((objc_direct));
+            @end
+            
+            @interface Foo(Ext)
+            + (void)directExt __attribute__((objc_direct));
+            - (void)directExt __attribute__((objc_direct));
+            @end
+        """.trimIndent())
+        val defFile = files.file("direct.def", """
+            language = Objective-C
+            headers = header.h
+        """.trimIndent())
+        val library = buildNativeLibraryFrom(defFile, files.directory)
+        val index = buildNativeIndex(library, false).index
+
+        index.objCClasses.find { it.name == "Foo" }.let { cls ->
+            assertNotNull(cls, "Class 'Foo' not found in native library $library")
+            assertNotNull(cls.methods.find { it.selector == "direct" && it.isClass && it.isDirect })
+            assertNotNull(cls.methods.find { it.selector == "direct" && !it.isClass && it.isDirect })
+        }
+
+        index.objCCategories.find { it.name == "Ext" && it.clazz.name == "Foo" }.let { cat ->
+            assertNotNull(cat, "Category 'Foo(Ext)' not found in native library $library")
+            assertNotNull(cat.methods.find { it.selector == "directExt" && it.isClass && it.isDirect })
+            assertNotNull(cat.methods.find { it.selector == "directExt" && !it.isClass && it.isDirect })
+        }
+    }
+}