[ObjCExport] Fix visibility of private companion

^KT-79767 Fixed

Author: elevenetc

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

@@ -6,14 +6,18 @@
 package org.jetbrains.kotlin.objcexport
 
 import org.jetbrains.kotlin.analysis.api.KaSession
+import org.jetbrains.kotlin.analysis.api.export.utilities.isCompanion
 import org.jetbrains.kotlin.analysis.api.symbols.KaClassSymbol
 import org.jetbrains.kotlin.analysis.api.symbols.KaClassifierSymbol
-import org.jetbrains.kotlin.analysis.api.export.utilities.isCompanion
+import org.jetbrains.kotlin.objcexport.analysisApiUtils.isVisibleInObjC
 
 /**
  * [org.jetbrains.kotlin.backend.konan.objcexport.ObjCExportTranslator.needCompanionObjectProperty]
  */
 internal fun KaSession.hasCompanionObject(symbol: KaClassSymbol): Boolean = getCompanion(symbol) != null
 
+internal fun KaSession.hasVisibleCompanionObject(symbol: KaClassSymbol): Boolean =
+    getCompanion(symbol) != null && isVisibleInObjC(getCompanion(symbol))
+
 internal fun KaSession.getCompanion(symbol: KaClassSymbol): KaClassifierSymbol? =
     symbol.staticMemberScope.classifiers.toList().firstOrNull { (it as? KaClassSymbol)?.isCompanion == true }

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

@@ -42,7 +42,7 @@ fun ObjCExportContext.translateToObjCClass(symbol: KaClassSymbol): ObjCClass? =
         /* The order of members tries to replicate the K1 implementation explicitly */
         this += translateToObjCConstructors(symbol)
 
-        if (symbol.isCompanion || analysisSession.hasCompanionObject(symbol)) {
+        if (symbol.isCompanion || analysisSession.hasVisibleCompanionObject(symbol)) {
             this += buildCompanionProperty(symbol)
         }
 

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

@@ -670,6 +670,11 @@ class ObjCExportHeaderGeneratorTest(private val generator: HeaderGenerator) {
         doTest(headersTestDataDir.resolve("propertyGetter"))
     }
 
+    @Test
+    fun `test - private companion`() {
+        doTest(headersTestDataDir.resolve("privateCompanion"))
+    }
+
     @Test
     fun `test - extensions mangling`() {
         doTest(headersTestDataDir.resolve("extensionsMangling"))

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

@@ -0,0 +1,29 @@
+#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>
+
+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 Foo : Base
+- (instancetype)init __attribute__((swift_name("init()"))) __attribute__((objc_designated_initializer));
++ (instancetype)new __attribute__((availability(swift, unavailable, message="use object initializers instead")));
+@end
+
+#pragma pop_macro("_Nullable_result")
+#pragma clang diagnostic pop
+NS_ASSUME_NONNULL_END

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

@@ -0,0 +1,5 @@
+class Foo {
+    private companion object {
+        const val bar = 42
+    }
+}