PR0091R3: Implement parsing support for using templates as types.

This change adds a new type node, DeducedTemplateSpecializationType, to
represent a type template name that has been used as a type. This is modeled
around AutoType, and shares a common base class for representing a deduced
placeholder type.

We allow deduced class template types in a few more places than the standard
does: in conditions and for-range-declarators, and in new-type-ids. This is
consistent with GCC and with discussion on the core reflector. This patch
does not yet support deduced class template types being named in typename
specifiers.

llvm-svn: 293207

1 files changed, 4 insertions, 2 deletions

diff --git a/clang/lib/CodeGen/ItaniumCXXABI.cpp b/clang/lib/CodeGen/ItaniumCXXABI.cpp
index 490fadbd1c4..74aabeb253f 100644
--- a/clang/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/clang/lib/CodeGen/ItaniumCXXABI.cpp
@@ -2815,7 +2815,8 @@ void ItaniumRTTIBuilder::BuildVTablePointer(const Type *Ty) {
     llvm_unreachable("References shouldn't get here");
 
   case Type::Auto:
-    llvm_unreachable("Undeduced auto type shouldn't get here");
+  case Type::DeducedTemplateSpecialization:
+    llvm_unreachable("Undeduced type shouldn't get here");
 
   case Type::Pipe:
     llvm_unreachable("Pipe types shouldn't get here");
@@ -3045,7 +3046,8 @@ llvm::Constant *ItaniumRTTIBuilder::BuildTypeInfo(QualType Ty, bool Force,
     llvm_unreachable("References shouldn't get here");
 
   case Type::Auto:
-    llvm_unreachable("Undeduced auto type shouldn't get here");
+  case Type::DeducedTemplateSpecialization:
+    llvm_unreachable("Undeduced type shouldn't get here");
 
   case Type::Pipe:
     llvm_unreachable("Pipe type shouldn't get here");