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, 3 insertions, 1 deletions

diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp
index 798d5b48fa7..00bde1c5b28 100644
--- a/clang/lib/CodeGen/CodeGenFunction.cpp
+++ b/clang/lib/CodeGen/CodeGenFunction.cpp
@@ -200,7 +200,8 @@ TypeEvaluationKind CodeGenFunction::getEvaluationKind(QualType type) {
       llvm_unreachable("non-canonical or dependent type in IR-generation");
 
     case Type::Auto:
-      llvm_unreachable("undeduced auto type in IR-generation");
+    case Type::DeducedTemplateSpecialization:
+      llvm_unreachable("undeduced type in IR-generation");
 
     // Various scalar types.
     case Type::Builtin:
@@ -1899,6 +1900,7 @@ void CodeGenFunction::EmitVariablyModifiedType(QualType type) {
     case Type::Typedef:
     case Type::Decltype:
     case Type::Auto:
+    case Type::DeducedTemplateSpecialization:
       // Stop walking: nothing to do.
       return;