Fix using cached Kotlin subclasses of Objective-C classes (#3990)

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

@@ -15,6 +15,7 @@ import org.jetbrains.kotlin.backend.konan.descriptors.isAbstract
 import org.jetbrains.kotlin.backend.konan.ir.allParameters
 import org.jetbrains.kotlin.backend.konan.ir.isUnit
 import org.jetbrains.kotlin.backend.konan.isExternalObjCClass
+import org.jetbrains.kotlin.backend.konan.isKotlinObjCClass
 import org.jetbrains.kotlin.backend.konan.serialization.AbstractKonanIrMangler
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.util.findAnnotation
@@ -93,6 +94,14 @@ internal val IrClass.objectInstanceGetterSymbolName: String
         return "kobjget:$fqNameForIrSerialization"
     }
 
+internal val IrClass.kotlinObjCClassInfoSymbolName: String
+    get() {
+        assert (this.isExported())
+        assert (this.isKotlinObjCClass())
+
+        return "kobjcclassinfo:$fqNameForIrSerialization"
+    }
+
 val IrFunction.functionName get() = with(KonanBinaryInterface) { functionName }
 
 val IrFunction.symbolName get() = with(KonanBinaryInterface) { symbolName }

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

@@ -1005,22 +1005,19 @@ internal class FunctionGenerationContext(val function: LLVMValueRef,
                 error("type-checking against Kotlin classes inheriting Objective-C meta-classes isn't supported yet")
             }
 
-            val objCDeclarations = context.llvmDeclarations.forClass(irClass).objCDeclarations!!
+            val classInfo = codegen.kotlinObjCClassInfo(irClass)
-            val classPointerGlobal = objCDeclarations.classPointerGlobal.llvmGlobal
+            val classPointerGlobal = load(structGep(classInfo, 12 /* createdClass */))
 
             val storedClass = this.load(classPointerGlobal)
 
             val storedClassIsNotNull = this.icmpNe(storedClass, kNullInt8Ptr)
 
             return this.ifThenElse(storedClassIsNotNull, storedClass) {
-                val newClass = call(
+                call(
                         context.llvm.createKotlinObjCClass,
-                        listOf(objCDeclarations.classInfoGlobal.llvmGlobal),
+                        listOf(classInfo),
                         exceptionHandler = exceptionHandler
                 )
-
-                this.store(newClass, classPointerGlobal)
-                newClass
             }
         }
     }

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

@@ -66,12 +66,14 @@ internal class KotlinObjCClassInfoGenerator(override val context: Context) : Con
                 irClass.typeInfoPtr,
                 companionObject?.typeInfoPtr ?: NullPointer(runtime.typeInfoType),
 
-                objCLLvmDeclarations.classPointerGlobal.pointer
+                staticData.placeGlobal(
+                        "kobjcclassptr:${irClass.fqNameForIrSerialization}#internal",
+                        NullPointer(int8Type)
+                ).pointer
         )
 
         objCLLvmDeclarations.classInfoGlobal.setInitializer(info)
 
-        objCLLvmDeclarations.classPointerGlobal.setInitializer(NullPointer(int8Type))
         objCLLvmDeclarations.bodyOffsetGlobal.setInitializer(Int32(0))
     }
 
@@ -133,3 +135,16 @@ internal class KotlinObjCClassInfoGenerator(override val context: Context) : Con
                 )
             }
 }
+
+internal fun CodeGenerator.kotlinObjCClassInfo(irClass: IrClass): LLVMValueRef {
+    require(irClass.isKotlinObjCClass())
+    return if (isExternal(irClass)) {
+        importGlobal(
+                irClass.kotlinObjCClassInfoSymbolName,
+                runtime.kotlinObjCClassInfo,
+                origin = irClass.llvmSymbolOrigin
+        )
+    } else {
+        context.llvmDeclarations.forClass(irClass).objCDeclarations!!.classInfoGlobal.llvmGlobal
+    }
+}

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

@@ -70,7 +70,6 @@ internal class ClassLlvmDeclarations(
 internal class SingletonLlvmDeclarations(val instanceStorage: AddressAccess, val instanceShadowStorage: AddressAccess?)
 
 internal class KotlinObjCClassLlvmDeclarations(
-        val classPointerGlobal: StaticData.Global,
         val classInfoGlobal: StaticData.Global,
         val bodyOffsetGlobal: StaticData.Global
 )
@@ -290,18 +289,23 @@ private class DeclarationsGeneratorVisitor(override val context: Context) :
     private fun createKotlinObjCClassDeclarations(irClass: IrClass): KotlinObjCClassLlvmDeclarations {
         val internalName = qualifyInternalName(irClass)
 
-        val classPointerGlobal = staticData.createGlobal(int8TypePtr, "kobjcclassptr:$internalName")
+        val isExported = irClass.isExported()
-
+        val classInfoSymbolName = if (isExported) {
+            irClass.kotlinObjCClassInfoSymbolName
+        } else {
+            "kobjcclassinfo:$internalName"
+        }
         val classInfoGlobal = staticData.createGlobal(
                 context.llvm.runtime.kotlinObjCClassInfo,
-                "kobjcclassinfo:$internalName"
+                classInfoSymbolName,
+                isExported = isExported
         ).apply {
             setConstant(true)
         }
 
         val bodyOffsetGlobal = staticData.createGlobal(int32Type, "kobjcbodyoffs:$internalName")
 
-        return KotlinObjCClassLlvmDeclarations(classPointerGlobal, classInfoGlobal, bodyOffsetGlobal)
+        return KotlinObjCClassLlvmDeclarations(classInfoGlobal, bodyOffsetGlobal)
     }
 
     override fun visitField(declaration: IrField) {