Fix missing forward declarations in framework (#3088)

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

@@ -1096,11 +1096,11 @@ abstract class ObjCExportHeaderGenerator internal constructor(
     }
 
     internal fun referenceClass(objCName: String, descriptor: ClassDescriptor? = null) {
-        if (objcGenerics || descriptor !in generatedClasses) classForwardDeclarations += objCName
+        classForwardDeclarations += objCName
     }
 
     internal fun referenceProtocol(objCName: String, descriptor: ClassDescriptor? = null) {
-        if (descriptor !in generatedClasses) protocolForwardDeclarations += objCName
+        protocolForwardDeclarations += objCName
     }
 }
 

backend.native/tests/framework/values/expectedLazy.h

@@ -542,6 +542,30 @@ __attribute__((swift_name("TestKClassI")))
 @required
 @end;
 
+__attribute__((swift_name("ForwardI2")))
+@protocol ValuesForwardI2 <ValuesForwardI1>
+@required
+@end;
+
+__attribute__((swift_name("ForwardI1")))
+@protocol ValuesForwardI1
+@required
+- (id<ValuesForwardI2>)getForwardI2 __attribute__((swift_name("getForwardI2()")));
+@end;
+
+__attribute__((swift_name("ForwardC2")))
+@interface ValuesForwardC2 : ValuesForwardC1
+- (instancetype)init __attribute__((swift_name("init()"))) __attribute__((objc_designated_initializer));
++ (instancetype)new __attribute__((availability(swift, unavailable, message="use object initializers instead")));
+@end;
+
+__attribute__((swift_name("ForwardC1")))
+@interface ValuesForwardC1 : KotlinBase
+- (instancetype)init __attribute__((swift_name("init()"))) __attribute__((objc_designated_initializer));
++ (instancetype)new __attribute__((availability(swift, unavailable, message="use object initializers instead")));
+- (ValuesForwardC2 *)getForwardC2 __attribute__((swift_name("getForwardC2()")));
+@end;
+
 @interface ValuesEnumeration (ValuesKt)
 - (ValuesEnumeration *)getAnswer __attribute__((swift_name("getAnswer()")));
 @end;

backend.native/tests/framework/values/values.kt

@@ -438,3 +438,14 @@ class TestKClass {
 
     interface I
 }
+
+// https://kotlinlang.slack.com/archives/C3SGXARS6/p1560954372179300
+interface ForwardI2 : ForwardI1
+interface ForwardI1 {
+    fun getForwardI2(): ForwardI2
+}
+
+abstract class ForwardC2 : ForwardC1()
+abstract class ForwardC1 {
+    abstract fun getForwardC2(): ForwardC2
+}