[Interop][Linker] Simplify IrProviderForCEnumAndCStructStubs

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

@@ -245,12 +245,10 @@ internal val psiToIrPhase = konanUnitPhase(
             if (this.stdlibModule in modulesWithoutDCE) {
                 functionIrClassFactory.buildAllClasses()
             }
-            modulesWithoutDCE
-                    .filter(ModuleDescriptor::isFromInteropLibrary)
-                    .forEach(irProviderForCEnumsAndCStructs::buildAllEnumsAndStructsFrom)
-
             module.acceptVoid(ManglerChecker(KonanManglerIr, Ir2DescriptorManglerAdapter(KonanManglerDesc)))
 
+            module.files += irProviderForCEnumsAndCStructs.outputFiles
+
             irModule = module
             irModules = deserializer.modules.filterValues { llvmModuleSpecification.containsModule(it) }
             ir.symbols = symbols
@@ -258,8 +256,6 @@ internal val psiToIrPhase = konanUnitPhase(
             functionIrClassFactory.module =
                     (listOf(irModule!!) + deserializer.modules.values)
                             .single { it.descriptor.isKonanStdlib() }
-
-            irProviderForCEnumsAndCStructs.module = module
         },
         name = "Psi2Ir",
         description = "Psi to IR conversion",

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

@@ -60,15 +60,12 @@ internal class IrProviderForCEnumAndCStructStubs(
     private val cStructClassGenerator =
             CStructVarClassGenerator(context, interopBuiltIns)
 
-    var module: IrModuleFragment? = null
-        set(value) {
-            if (value == null)
-                error("Provide a valid non-null module")
-            if (field != null)
-                error("Module has already been set")
-            field = value
-            value.files += filesMap.values
-        }
+    /**
+     * The final output of this provider is a list of files which contain IR declarations
+     * of enums and structs that should be generated.
+     */
+    val outputFiles: List<IrFile>
+        get() = filesMap.values.toList()
 
     fun canHandleSymbol(symbol: IrSymbol): Boolean {
         if (!symbol.isPublicApi) return false
@@ -116,9 +113,7 @@ internal class IrProviderForCEnumAndCStructStubs(
     private fun irParentFor(descriptor: ClassDescriptor): IrDeclarationContainer {
         val packageFragmentDescriptor = descriptor.findPackage()
         return filesMap.getOrPut(packageFragmentDescriptor) {
-            IrFileImpl(NaiveSourceBasedFileEntryImpl(cTypeDefinitionsFileName), packageFragmentDescriptor).also {
-                this@IrProviderForCEnumAndCStructStubs.module?.files?.add(it)
-            }
+            IrFileImpl(NaiveSourceBasedFileEntryImpl(cTypeDefinitionsFileName), packageFragmentDescriptor)
         }
     }