[transferring] Fix mangling for reabstraction thunks with a transferring result.

include/swift/Basic/Mangler.h

@@ -21,6 +21,7 @@
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/StringMap.h"
+#include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
 
 namespace swift {
@@ -100,14 +101,24 @@ class Mangler {
     return StringRef(Storage.data(), Storage.size());
   }
 
+  void print(llvm::raw_ostream &os) const {
+    os << getBufferStr() << '\n';
+  }
+
+public:
+  /// Dump the current stored state in the Mangler. Only for use in the debugger!
+  SWIFT_DEBUG_DUMPER(dumpBufferStr()) {
+    print(llvm::dbgs());
+  }
+
+protected:
   /// Removes the last characters of the buffer by setting it's size to a
   /// smaller value.
   void resetBuffer(size_t toPos) {
     assert(toPos <= Storage.size());
     Storage.resize(toPos);
   }
 
-protected:
   Mangler() : Buffer(Storage) { }
 
   /// Begins a new mangling but does not add the mangling prefix.

include/swift/Demangling/DemangleNodes.def

@@ -132,6 +132,7 @@ NODE(ImplEscaping)
 NODE(ImplConvention)
 NODE(ImplDifferentiabilityKind)
 NODE(ImplErasedIsolation)
+NODE(ImplTransferringResult)
 NODE(ImplParameterResultDifferentiability)
 NODE(ImplParameterTransferring)
 NODE(ImplFunctionAttribute)

lib/AST/ASTMangler.cpp

@@ -1987,9 +1987,6 @@ void ASTMangler::appendImplFunctionType(SILFunctionType *fn,
   if (!fn->isNoEscape())
     OpArgs.push_back('e');
 
-  if (fn->hasTransferringResult())
-    OpArgs.push_back('T');
-
   switch (fn->getIsolation()) {
   case SILFunctionTypeIsolation::Unknown:
     break;
@@ -2097,6 +2094,10 @@ void ASTMangler::appendImplFunctionType(SILFunctionType *fn,
     appendType(param.getInterfaceType(), sig, forDecl);
   }
 
+  // Mangle if we have a transferring result.
+  if (fn->hasTransferringResult())
+    OpArgs.push_back('T');
+
   // Mangle the results.
   for (auto result : fn->getResults()) {
     OpArgs.push_back(getResultConvention(result.getConvention()));

lib/Demangling/Demangler.cpp

@@ -2319,6 +2319,11 @@ NodePointer Demangler::demangleImplFunctionType() {
       Param = addChild(Param, Transferring);
     ++NumTypesToAdd;
   }
+
+  if (nextIf('T')) {
+    type->addChild(createNode(Node::Kind::ImplTransferringResult), *this);
+  }
+
   while (NodePointer Result = demangleImplResultConvention(
                                                     Node::Kind::ImplResult)) {
     type = addChild(type, Result);

lib/Demangling/NodePrinter.cpp

@@ -425,6 +425,7 @@ class NodePrinter {
     case Node::Kind::ImplDifferentiabilityKind:
     case Node::Kind::ImplEscaping:
     case Node::Kind::ImplErasedIsolation:
+    case Node::Kind::ImplTransferringResult:
     case Node::Kind::ImplConvention:
     case Node::Kind::ImplParameterResultDifferentiability:
     case Node::Kind::ImplParameterTransferring:
@@ -975,6 +976,7 @@ class NodePrinter {
   void printImplFunctionType(NodePointer fn, unsigned depth) {
     NodePointer patternSubs = nullptr;
     NodePointer invocationSubs = nullptr;
+    NodePointer transferringResult = nullptr;
     enum State { Attrs, Inputs, Results } curState = Attrs;
     auto transitionTo = [&](State newState) {
       assert(newState >= curState);
@@ -988,7 +990,14 @@ class NodePrinter {
           }
           Printer << '(';
           continue;
-        case Inputs: Printer << ") -> ("; continue;
+        case Inputs:
+          Printer << ") -> ";
+          if (transferringResult) {
+            print(transferringResult, depth + 1);
+            Printer << " ";
+          }
+          Printer << "(";
+          continue;
         case Results: printer_unreachable("no state after Results");
         }
         printer_unreachable("bad state");
@@ -1010,6 +1019,8 @@ class NodePrinter {
         patternSubs = child;
       } else if (child->getKind() == Node::Kind::ImplInvocationSubstitutions) {
         invocationSubs = child;
+      } else if (child->getKind() == Node::Kind::ImplTransferringResult) {
+        transferringResult = child;
       } else {
         assert(curState == Attrs);
         print(child, depth + 1);
@@ -2748,6 +2759,9 @@ NodePointer NodePrinter::print(NodePointer Node, unsigned depth,
   case Node::Kind::ImplErasedIsolation:
     Printer << "@isolated(any)";
     return nullptr;
+  case Node::Kind::ImplTransferringResult:
+    Printer << "transferring";
+    return nullptr;
   case Node::Kind::ImplConvention:
     Printer << Node->getText();
     return nullptr;

lib/Demangling/OldRemangler.cpp

@@ -1736,6 +1736,12 @@ ManglingError Remangler::mangleImplErasedIsolation(Node *node, unsigned depth) {
   return ManglingError::Success;
 }
 
+ManglingError Remangler::mangleImplTransferringResult(Node *node,
+                                                      unsigned depth) {
+  // The old mangler does not encode transferring result
+  return ManglingError::Success;
+}
+
 ManglingError Remangler::mangleImplPatternSubstitutions(Node *node,
                                                         unsigned depth) {
   // The old mangler does not encode substituted function types.

lib/Demangling/Remangler.cpp

@@ -1781,6 +1781,12 @@ ManglingError Remangler::mangleImplErasedIsolation(Node *node, unsigned depth) {
   return ManglingError::Success;
 }
 
+ManglingError Remangler::mangleImplTransferringResult(Node *node,
+                                                      unsigned depth) {
+  Buffer << 'T';
+  return ManglingError::Success;
+}
+
 ManglingError Remangler::mangleImplConvention(Node *node, unsigned depth) {
   char ConvCh = llvm::StringSwitch<char>(node->getText())
                   .Case("@callee_unowned", 'y')
@@ -1955,6 +1961,9 @@ ManglingError Remangler::mangleImplFunctionType(Node *node, unsigned depth) {
       case Node::Kind::ImplErasedIsolation:
         Buffer << 'A';
         break;
+      case Node::Kind::ImplTransferringResult:
+        Buffer << 'T';
+        break;
       case Node::Kind::ImplConvention: {
         char ConvCh = llvm::StringSwitch<char>(Child->getText())
                         .Case("@callee_unowned", 'y')

test/Demangle/Inputs/manglings.txt

@@ -467,3 +467,4 @@ $sS3fIedgyyTd_D ---> @escaping @differentiable @callee_guaranteed (@unowned Swif
 $s4testA2A5KlassCyYTF ---> test.test() -> transferring test.Klass
 $s4main5KlassCACYTcMD ---> demangling cache variable for type metadata for (main.Klass) -> transferring main.Klass
 $s4null19transferAsyncResultAA16NonSendableKlassCyYaYTF ---> null.transferAsyncResult() -> transferring null.NonSendableKlass
+$s4null16NonSendableKlassCIegHo_ACs5Error_pIegHTrzo_TR ---> {T:} reabstraction thunk helper from @escaping @callee_guaranteed @async () -> (@owned null.NonSendableKlass) to @escaping @callee_guaranteed @async () -> transferring (@out null.NonSendableKlass, @error @owned Swift.Error)