1 files changed, 30 insertions, 3 deletions
diff --git a/clang/lib/AST/MicrosoftMangle.cpp b/clang/lib/AST/MicrosoftMangle.cpp
index 81bdb6708d6..9b395a7a11c 100644
--- a/clang/lib/AST/MicrosoftMangle.cpp
+++ b/clang/lib/AST/MicrosoftMangle.cpp
@@ -2450,9 +2450,36 @@ void MicrosoftCXXNameMangler::mangleType(const ObjCInterfaceType *T, Qualifiers,
 
 void MicrosoftCXXNameMangler::mangleType(const ObjCObjectType *T, Qualifiers,
                                          SourceRange Range) {
-  // We don't allow overloading by different protocol qualification,
-  // so mangling them isn't necessary.
-  mangleType(T->getBaseType(), Range, QMM_Drop);
+  if (T->qual_empty())
+    return mangleType(T->getBaseType(), Range, QMM_Drop);
+
+  ArgBackRefMap OuterArgsContext;
+  BackRefVec OuterTemplateContext;
+
+  TypeBackReferences.swap(OuterArgsContext);
+  NameBackReferences.swap(OuterTemplateContext);
+
+  mangleTagTypeKind(TTK_Struct);
+
+  Out << "?$";
+  if (T->isObjCId())
+    mangleSourceName("objc_object");
+  else if (T->isObjCClass())
+    mangleSourceName("objc_class");
+  else
+    mangleSourceName(T->getInterface()->getName());
+
+  for (const auto &Q : T->quals()) {
+    Out << 'Y'; // cointerface
+    mangleSourceName(Q->getName());
+    Out << '@';
+  }
+  Out << '@';
+
+  Out << '@';
+
+  TypeBackReferences.swap(OuterArgsContext);
+  NameBackReferences.swap(OuterTemplateContext);
 }
 
 void MicrosoftCXXNameMangler::mangleType(const BlockPointerType *T,