NCGenerics: reenable round-trip for mangling

Author: kavon

lib/Frontend/CompilerInvocation.cpp

@@ -2641,9 +2641,6 @@ static bool ParseIRGenArgs(IRGenOptions &Opts, ArgList &Args,
   if (Args.hasArg(OPT_no_clang_module_breadcrumbs))
     Opts.DisableClangModuleSkeletonCUs = true;
 
-  if (SWIFT_ENABLE_EXPERIMENTAL_NONCOPYABLE_GENERICS)
-    Opts.DisableRoundTripDebugTypes = true; // temporary until we fix mangling!
-
   if (auto A = Args.getLastArg(OPT_enable_round_trip_debug_types,
                                OPT_disable_round_trip_debug_types)) {
     Opts.DisableRoundTripDebugTypes =

lib/IRGen/IRGenDebugInfo.cpp

@@ -1817,6 +1817,10 @@ class IRGenDebugInfoImpl : public IRGenDebugInfo {
       // Emit the protocols the archetypes conform to.
       SmallVector<llvm::Metadata *, 4> Protocols;
       for (auto *ProtocolDecl : Archetype->getConformsTo()) {
+        // Skip marker protocols, as they are not available at runtime.
+        if (ProtocolDecl->isMarkerProtocol())
+          continue;
+
         auto PTy =
             IGM.getLoweredType(ProtocolDecl->getInterfaceType()).getASTType();
         auto PDbgTy = DebugTypeInfo::getFromTypeInfo(

stdlib/cmake/modules/SwiftSource.cmake

@@ -610,7 +610,6 @@ function(_compile_swift_files
   if(SWIFT_ENABLE_EXPERIMENTAL_NONCOPYABLE_GENERICS)
     list(APPEND swift_flags "-enable-experimental-feature" "NoncopyableGenerics")
     list(APPEND swift_flags "-Xfrontend" "-enable-experimental-associated-type-inference")
-    list(APPEND swift_flags "-Xfrontend" "-disable-round-trip-debug-types") # NOTE: temporary until we fix mangling!
   endif()
 
   if (SWIFT_STDLIB_ENABLE_STRICT_CONCURRENCY_COMPLETE)