Introduce a new representation for template template

parameters. Rather than storing them as either declarations (for the
non-dependent case) or expressions (for the dependent case), we now
(always) store them as TemplateNames. 

The primary change here is to add a new kind of TemplateArgument,
which stores a TemplateName. However, making that change ripples to
every switch on a TemplateArgument's kind, also affecting
TemplateArgumentLocInfo/TemplateArgumentLoc, default template
arguments for template template parameters, type-checking of template
template arguments, etc.

This change is light on testing. It should fix several pre-existing
problems with template template parameters, such as:
  - the inability to use dependent template names as template template
  arguments
  - template template parameter default arguments cannot be
  instantiation

However, there are enough pieces missing that more implementation is
required before we can adequately test template template parameters. 



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@86777 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 3 insertions, 1 deletions

diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index bb3559b50f..b5d9cac9fa 100644
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -2357,12 +2357,14 @@ ASTContext::getCanonicalTemplateArgument(const TemplateArgument &Arg) {
       return Arg;
 
     case TemplateArgument::Expression:
-      // FIXME: Build canonical expression?
       return Arg;
 
     case TemplateArgument::Declaration:
       return TemplateArgument(Arg.getAsDecl()->getCanonicalDecl());
 
+    case TemplateArgument::Template:
+      return TemplateArgument(getCanonicalTemplateName(Arg.getAsTemplate()));
+      
     case TemplateArgument::Integral:
       return TemplateArgument(*Arg.getAsIntegral(),
                               getCanonicalType(Arg.getIntegralType()));