[DefaultOverrides] Mangling.

Author: nate-chandler

docs/ABI/Mangling.rst

@@ -239,6 +239,7 @@ types where the metadata itself has unknown layout.)
   global ::= global 'Twb'                // back deployment thunk
   global ::= global 'TwB'                // back deployment fallback function
   global ::= global 'Twc'                // coro function pointer of a function
+  global ::= global 'Twd'                // default override of a function
   global ::= entity entity 'TV'          // vtable override thunk, derived followed by base
   global ::= type label-list? 'D'        // type mangling for the debugger with label list for function types.
   global ::= type 'TC'                   // continuation prototype (not actually used for real symbols)

include/swift/Demangling/DemangleNodes.def

@@ -411,6 +411,7 @@ NODE(Integer)
 NODE(NegativeInteger)
 NODE(DependentGenericParamValueMarker)
 NODE(CoroFunctionPointer)
+NODE(DefaultOverride)
 
 #undef CONTEXT_NODE
 #undef NODE

lib/Demangling/Demangler.cpp

@@ -156,6 +156,7 @@ bool swift::Demangle::isFunctionAttr(Node::Kind kind) {
     case Node::Kind::BackDeploymentFallback:
     case Node::Kind::HasSymbolQuery:
     case Node::Kind::CoroFunctionPointer:
+    case Node::Kind::DefaultOverride:
       return true;
     default:
       return false;
@@ -3142,6 +3143,8 @@ NodePointer Demangler::demangleThunkOrSpecialization() {
       case 'B': return createNode(Node::Kind::BackDeploymentFallback);
       case 'c':
         return createNode(Node::Kind::CoroFunctionPointer);
+      case 'd':
+        return createNode(Node::Kind::DefaultOverride);
       case 'S': return createNode(Node::Kind::HasSymbolQuery);
       default:
         return nullptr;

lib/Demangling/NodePrinter.cpp

@@ -660,6 +660,7 @@ class NodePrinter {
     case Node::Kind::DependentGenericInverseConformanceRequirement:
     case Node::Kind::DependentGenericParamValueMarker:
     case Node::Kind::CoroFunctionPointer:
+    case Node::Kind::DefaultOverride:
       return false;
     }
     printer_unreachable("bad node kind");
@@ -3494,6 +3495,9 @@ NodePointer NodePrinter::print(NodePointer Node, unsigned depth,
   case Node::Kind::CoroFunctionPointer:
     Printer << "coro function pointer to ";
     return nullptr;
+  case Node::Kind::DefaultOverride:
+    Printer << "default override of ";
+    return nullptr;
   }
 
   printer_unreachable("bad node kind!");

lib/Demangling/OldRemangler.cpp

@@ -1203,6 +1203,11 @@ ManglingError Remangler::mangleCoroFunctionPointer(Node *node, unsigned depth) {
   return ManglingError::Success;
 }
 
+ManglingError Remangler::mangleDefaultOverride(Node *node, unsigned depth) {
+  Buffer << "Twd";
+  return ManglingError::Success;
+}
+
 ManglingError Remangler::mangleDeallocator(Node *node, EntityContext &ctx,
                                            unsigned depth) {
   return mangleSimpleEntity(node, 'F', "D", ctx, depth + 1);

lib/Demangling/Remangler.cpp

@@ -1056,6 +1056,11 @@ ManglingError Remangler::mangleCoroFunctionPointer(Node *node, unsigned depth) {
   return ManglingError::Success;
 }
 
+ManglingError Remangler::mangleDefaultOverride(Node *node, unsigned depth) {
+  Buffer << "Twd";
+  return ManglingError::Success;
+}
+
 ManglingError Remangler::mangleDependentAssociatedTypeRef(Node *node,
                                                           unsigned depth) {
   RETURN_IF_ERROR(mangleIdentifier(node->getFirstChild(), depth));
@@ -1842,6 +1847,7 @@ ManglingError Remangler::mangleGlobal(Node *node, unsigned depth) {
       case Node::Kind::BackDeploymentFallback:
       case Node::Kind::HasSymbolQuery:
       case Node::Kind::CoroFunctionPointer:
+      case Node::Kind::DefaultOverride:
         mangleInReverseOrder = true;
         break;
       default:

test/Demangle/Inputs/manglings.txt

@@ -489,9 +489,10 @@ $s7ToolKit10TypedValueOACs5Error_pIgHTnTrzo_A2CsAD_pIegHiTrzr_TR ---> {T:} reabs
 $s16sending_mangling16NonSendableKlassCACIegTiTr_A2CIegTxTo_TR ---> {T:} reabstraction thunk helper from @escaping @callee_guaranteed (@in sending sending_mangling.NonSendableKlass) -> sending (@out sending_mangling.NonSendableKlass) to @escaping @callee_guaranteed (@owned sending sending_mangling.NonSendableKlass) -> sending (@owned sending_mangling.NonSendableKlass)
 $s3red7MyActorC3runyxxyYaKYCXEYaKlFZ ---> static red.MyActor.run<A>(@execution(caller) () async throws -> A) async throws -> A
 $s5thing1PP1sAA1SVvxTwc ---> coro function pointer to thing.P.s.modify2 : thing.S
-
 _$s15raw_identifiers0020foospace_liaADEDGcjayyF ---> raw_identifiers.`foo space`() -> ()
 _$s15raw_identifiers0018_3times_pgaIGJCFbhayyF ---> raw_identifiers.`3 times`() -> ()
 _$s15raw_identifiers0019test_yeaIIBCEapkagayyF ---> raw_identifiers.`test +`() -> ()
 _$s15raw_identifiers0020pathfoo_yuEHaaCiJskayyF ---> raw_identifiers.`path://foo`() -> ()
 _$s15raw_identifiers10FontWeightO009_100_FpEpdyyFZ ---> static raw_identifiers.FontWeight.`100`() -> ()
+$s7Library1BC1iSivxTwd ---> default override of Library.B.i.modify2 : Swift.Int
+$s7Library1BC1iSivxTwdTwc ---> coro function pointer to default override of Library.B.i.modify2 : Swift.Int