[RTTI][Objective-C] Omit RTTI for external Obj-C classes

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

@@ -15,3 +15,20 @@ internal fun IrClass.isNonGeneratedAnnotation(): Boolean =
                 !this.annotations.hasAnnotation(serialInfoAnnotationFqName)
 
 private val serialInfoAnnotationFqName = FqName("kotlinx.serialization.SerialInfo")
+
+/**
+ * We don't need to generate RTTI in some cases, e.g. Objective-C external classes.
+ */
+internal fun IrClass.requiresRtti(): Boolean = when {
+    // TODO: Support more cases
+    // Sadly, we still need to emit RTTI for Kotlin inheritors of Obj-C classes.
+    // The reason for it is that we need to know a layout of the object to correctly
+    // deinitialize it.
+    this.isExternalObjCClass() -> false
+    else -> true
+}
+
+internal fun IrClass.requiresCodeGeneration(): Boolean =
+        // For now these two sets (classes that require RTTI and classes that require codegen)
+        // are the same, but they might diverge later.
+        requiresRtti()

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/IrToBitcode.kt

@@ -97,9 +97,9 @@ internal class RTTIGeneratorVisitor(context: Context) : IrElementVisitorVoid {
 
     override fun visitClass(declaration: IrClass) {
         super.visitClass(declaration)
-
-        generator.generate(declaration)
-
+        if (declaration.requiresRtti()) {
+            generator.generate(declaration)
+        }
         if (declaration.isKotlinObjCClass()) {
             kotlinObjCClassInfoGenerator.generate(declaration)
         }
@@ -772,7 +772,8 @@ internal class CodeGeneratorVisitor(val context: Context, val lifetimes: Map<IrE
 
     override fun visitClass(declaration: IrClass) {
         context.log{"visitClass                     : ${ir2string(declaration)}"}
-        if (declaration.isNonGeneratedAnnotation()) {
+
+        if (declaration.isNonGeneratedAnnotation() || !declaration.requiresCodeGeneration()) {
             // For non-generated annotation classes generate only nested classes.
             declaration.declarations
                     .filterIsInstance<IrClass>()

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/LlvmDeclarations.kt

@@ -157,8 +157,9 @@ private class DeclarationsGeneratorVisitor(override val context: Context) :
     }
 
     override fun visitClass(declaration: IrClass) {
-        this.classes[declaration] = createClassDeclarations(declaration)
-
+        if (declaration.requiresRtti()) {
+            this.classes[declaration] = createClassDeclarations(declaration)
+        }
         super.visitClass(declaration)
     }
 
@@ -308,6 +309,7 @@ private class DeclarationsGeneratorVisitor(override val context: Context) :
 
         val containingClass = declaration.parent as? IrClass
         if (containingClass != null) {
+            if (!containingClass.requiresRtti()) return
             val classDeclarations = this.classes[containingClass] ?:
                 error(containingClass.descriptor.toString())
             val allFields = context.getLayoutBuilder(containingClass).fields

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/RTTIGenerator.kt

@@ -185,6 +185,20 @@ internal class RTTIGenerator(override val context: Context) : ContextUtils {
         return LLVMStoreSizeOfType(llvmTargetData, classType).toInt()
     }
 
+    private fun getClassId(irClass: IrClass): Int {
+        if (irClass.isKotlinObjCClass()) return 0
+        val hierarchyInfo = if (context.ghaEnabled()) {
+            context.getLayoutBuilder(irClass).hierarchyInfo
+        } else {
+            ClassGlobalHierarchyInfo.DUMMY
+        }
+        return if (irClass.isInterface) {
+            hierarchyInfo.interfaceId
+        } else {
+            hierarchyInfo.classIdLo
+        }
+    }
+
     fun generate(irClass: IrClass) {
 
         val className = irClass.fqNameForIrSerialization
@@ -195,11 +209,16 @@ internal class RTTIGenerator(override val context: Context) : ContextUtils {
 
         val instanceSize = getInstanceSize(bodyType, className)
 
-        val superTypeOrAny = irClass.getSuperClassNotAny() ?: context.ir.symbols.any.owner
-        val superType = if (irClass.isAny()) NullPointer(runtime.typeInfoType)
-                else superTypeOrAny.typeInfoPtr
+        val superType = when {
+            irClass.isAny() -> NullPointer(runtime.typeInfoType)
+            irClass.isKotlinObjCClass() -> context.ir.symbols.any.owner.typeInfoPtr
+            else -> {
+                val superTypeOrAny = irClass.getSuperClassNotAny() ?: context.ir.symbols.any.owner
+                superTypeOrAny.typeInfoPtr
+            }
+        }
 
-        val implementedInterfaces = irClass.implementedInterfaces
+        val implementedInterfaces = irClass.implementedInterfaces.filter { it.requiresRtti() }
 
         val interfaces = implementedInterfaces.map { it.typeInfoPtr }
         val interfacesPtr = staticData.placeGlobalConstArray("kintf:$className",
@@ -235,10 +254,6 @@ internal class RTTIGenerator(override val context: Context) : ContextUtils {
 
         val reflectionInfo = getReflectionInfo(irClass)
         val typeInfoGlobal = llvmDeclarations.typeInfoGlobal
-        val hierarchyInfo =
-                if (context.ghaEnabled())
-                    context.getLayoutBuilder(irClass).hierarchyInfo
-                else ClassGlobalHierarchyInfo.DUMMY
         val typeInfo = TypeInfo(
                 irClass.typeInfoPtr,
                 makeExtendedInfo(irClass),
@@ -251,9 +266,7 @@ internal class RTTIGenerator(override val context: Context) : ContextUtils {
                 reflectionInfo.packageName,
                 reflectionInfo.relativeName,
                 flagsFromClass(irClass),
-                if (irClass.isInterface)
-                    hierarchyInfo.interfaceId
-                else hierarchyInfo.classIdLo,
+                getClassId(irClass),
                 llvmDeclarations.writableTypeInfoGlobal?.pointer,
                 associatedObjects = genAssociatedObjects(irClass)
         )