Start canonicalizing template names. This is not yet complete, but it

improves type identity with dependent types.

llvm-svn: 71152

2 files changed, 13 insertions, 2 deletions

diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index c1a232c88e9..3b1a11cb795 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -1700,6 +1700,17 @@ QualType ASTContext::getCanonicalType(QualType T) {
                               VAT->getIndexTypeQualifier());
 }
 
+TemplateName ASTContext::getCanonicalTemplateName(TemplateName Name) {
+  // If this template name refers to a template, the canonical
+  // template name merely stores the template itself.
+  if (TemplateDecl *Template = Name.getAsTemplateDecl())
+    return TemplateName(Template);
+
+  DependentTemplateName *DTN = Name.getAsDependentTemplateName();
+  assert(DTN && "Non-dependent template names must refer to template decls.");
+  return DTN->CanonicalTemplateName;
+}
+
 NestedNameSpecifier *
 ASTContext::getCanonicalNestedNameSpecifier(NestedNameSpecifier *NNS) {
   if (!NNS) 
diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index 3649abd9a74..6c4adbd0ae2 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -818,8 +818,8 @@ QualType Sema::CheckTemplateIdType(TemplateName Name,
     // A<T, T> have identical types when A is declared as:
     //
     //   template<typename T, typename U = T> struct A;
-
-    CanonType = Context.getTemplateSpecializationType(Name, 
+    TemplateName CanonName = Context.getCanonicalTemplateName(Name);
+    CanonType = Context.getTemplateSpecializationType(CanonName, 
                                                     &ConvertedTemplateArgs[0],
                                                 ConvertedTemplateArgs.size());
   } else if (ClassTemplateDecl *ClassTemplate