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
diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index bb3559b..b5d9cac 100644
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -2357,12 +2357,14 @@
       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()));
diff --git a/lib/AST/DeclTemplate.cpp b/lib/AST/DeclTemplate.cpp
index 9ebc91a..0c14714 100644
--- a/lib/AST/DeclTemplate.cpp
+++ b/lib/AST/DeclTemplate.cpp
@@ -220,7 +220,7 @@
       TemplateArgs.push_back(TemplateArgument(E));
     } else {
       TemplateTemplateParmDecl *TTP = cast<TemplateTemplateParmDecl>(*Param);
-      TemplateArgs.push_back(TemplateArgument(TTP));
+      TemplateArgs.push_back(TemplateArgument(TemplateName(TTP)));
     }
   }
 
@@ -285,11 +285,6 @@
   return new (C) TemplateTemplateParmDecl(DC, L, D, P, Id, Params);
 }
 
-SourceLocation TemplateTemplateParmDecl::getDefaultArgumentLoc() const {
-  return DefaultArgument? DefaultArgument->getSourceRange().getBegin()
-                        : SourceLocation();
-}
-
 //===----------------------------------------------------------------------===//
 // TemplateArgumentListBuilder Implementation
 //===----------------------------------------------------------------------===//
diff --git a/lib/AST/StmtProfile.cpp b/lib/AST/StmtProfile.cpp
index 02e0c74..4458c2b 100644
--- a/lib/AST/StmtProfile.cpp
+++ b/lib/AST/StmtProfile.cpp
@@ -695,6 +695,10 @@
     VisitType(Arg.getAsType());
     break;
 
+  case TemplateArgument::Template:
+    VisitTemplateName(Arg.getAsTemplate());
+    break;
+      
   case TemplateArgument::Declaration:
     VisitDecl(Arg.getAsDecl());
     break;
diff --git a/lib/AST/TemplateBase.cpp b/lib/AST/TemplateBase.cpp
index 94e1ca1..18a574c 100644
--- a/lib/AST/TemplateBase.cpp
+++ b/lib/AST/TemplateBase.cpp
@@ -58,6 +58,10 @@
     ID.AddPointer(getAsDecl()? getAsDecl()->getCanonicalDecl() : 0);
     break;
 
+  case Template:
+    ID.AddPointer(getAsTemplate().getAsVoidPointer());
+    break;
+      
   case Integral:
     getAsIntegral()->Profile(ID);
     getIntegralType().Profile(ID);
@@ -82,10 +86,19 @@
   switch (Argument.getKind()) {
   case TemplateArgument::Expression:
     return getSourceExpression()->getSourceRange();
+      
   case TemplateArgument::Declaration:
     return getSourceDeclExpression()->getSourceRange();
+      
   case TemplateArgument::Type:
     return getSourceDeclaratorInfo()->getTypeLoc().getFullSourceRange();
+      
+  case TemplateArgument::Template:
+    if (getTemplateQualifierRange().isValid())
+      return SourceRange(getTemplateQualifierRange().getBegin(),
+                         getTemplateNameLoc());
+    return SourceRange(getTemplateNameLoc());
+      
   case TemplateArgument::Integral:
   case TemplateArgument::Pack:
   case TemplateArgument::Null:
diff --git a/lib/AST/Type.cpp b/lib/AST/Type.cpp
index 844589f..5ecc33c 100644
--- a/lib/AST/Type.cpp
+++ b/lib/AST/Type.cpp
@@ -807,6 +807,9 @@
   case TemplateArgument::Type:
     return Arg.getAsType()->isDependentType();
 
+  case TemplateArgument::Template:
+    return Arg.getAsTemplate().isDependent();
+      
   case TemplateArgument::Declaration:
   case TemplateArgument::Integral:
     // Never dependent
diff --git a/lib/AST/TypePrinter.cpp b/lib/AST/TypePrinter.cpp
index 807f7d8..ed12006 100644
--- a/lib/AST/TypePrinter.cpp
+++ b/lib/AST/TypePrinter.cpp
@@ -576,6 +576,11 @@
       Buffer = cast<NamedDecl>(Arg.getAsDecl())->getNameAsString();
       break;
       
+    case TemplateArgument::Template: {
+      llvm::raw_string_ostream s(Buffer);
+      Arg.getAsTemplate().print(s, Policy);
+    }
+      
     case TemplateArgument::Integral:
       Buffer = Arg.getAsIntegral()->toString(10, true);
       break;