Implement the Objective-C __kindof type qualifier.

The __kindof type qualifier can be applied to Objective-C object
(pointer) types to indicate id-like behavior, which includes implicit
"downcasting" of __kindof types to subclasses and id-like message-send
behavior. __kindof types provide better type bounds for substitutions
into unspecified generic types, which preserves more type information.

llvm-svn: 241548

1 files changed, 13 insertions, 0 deletions

diff --git a/clang/lib/AST/ItaniumMangle.cpp b/clang/lib/AST/ItaniumMangle.cpp
index 0134c090d67..dac803e5d2f 100644
--- a/clang/lib/AST/ItaniumMangle.cpp
+++ b/clang/lib/AST/ItaniumMangle.cpp
@@ -2379,6 +2379,10 @@ void CXXNameMangler::mangleType(const ObjCInterfaceType *T) {
 }
 
 void CXXNameMangler::mangleType(const ObjCObjectType *T) {
+  // Treat __kindof as a vendor extended type qualifier.
+  if (T->isKindOfType())
+    Out << "U8__kindof";
+
   if (!T->qual_empty()) {
     // Mangle protocol qualifiers.
     SmallString<64> QualStr;
@@ -2391,7 +2395,16 @@ void CXXNameMangler::mangleType(const ObjCObjectType *T) {
     QualOS.flush();
     Out << 'U' << QualStr.size() << QualStr;
   }
+
   mangleType(T->getBaseType());
+
+  if (T->isSpecialized()) {
+    // Mangle type arguments as I <type>+ E
+    Out << 'I';
+    for (auto typeArg : T->getTypeArgs())
+      mangleType(typeArg);
+    Out << 'E';
+  }
 }
 
 void CXXNameMangler::mangleType(const BlockPointerType *T) {