Teach Type::getAs<TemplateSpecializationType> that a TemplateSpecializationType

for a type alias template can appear as sugar at any level of desugaring, just
like a TypedefType.

llvm-svn: 164655

1 files changed, 15 insertions, 8 deletions

diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index 529c90603c2..9db41c4b1e9 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -288,18 +288,17 @@ QualType QualType::IgnoreParens(QualType T) {
   return T;
 }
 
-/// \brief This will check for a TypedefType by removing any existing sugar
-/// until it reaches a TypedefType or a non-sugared type.
-template <> const TypedefType *Type::getAs() const {
-  const Type *Cur = this;
-
+/// \brief This will check for a T (which should be a Type which can act as
+/// sugar, such as a TypedefType) by removing any existing sugar until it
+/// reaches a T or a non-sugared type.
+template<typename T> static const T *getAsSugar(const Type *Cur) {
   while (true) {
-    if (const TypedefType *TDT = dyn_cast<TypedefType>(Cur))
-      return TDT;
+    if (const T *Sugar = dyn_cast<T>(Cur))
+      return Sugar;
     switch (Cur->getTypeClass()) {
 #define ABSTRACT_TYPE(Class, Parent)
 #define TYPE(Class, Parent) \
-    case Class: { \
+    case Type::Class: { \
       const Class##Type *Ty = cast<Class##Type>(Cur); \
       if (!Ty->isSugared()) return 0; \
       Cur = Ty->desugar().getTypePtr(); \
@@ -310,6 +309,14 @@ template <> const TypedefType *Type::getAs() const {
   }
 }
 
+template <> const TypedefType *Type::getAs() const {
+  return getAsSugar<TypedefType>(this);
+}
+
+template <> const TemplateSpecializationType *Type::getAs() const {
+  return getAsSugar<TemplateSpecializationType>(this);
+}
+
 /// getUnqualifiedDesugaredType - Pull any qualifiers and syntactic
 /// sugar off the given type.  This should produce an object of the
 /// same dynamic type as the canonical type.