From 61c4d28e36cd3f1be392cb77f07436d1fa6b0f9f Mon Sep 17 00:00:00 2001
From: Douglas Gregor <dgregor@apple.com>
Date: Wed, 5 Jan 2011 15:48:55 +0000
Subject: [PATCH] Implement support for template template parameter packs,
 e.g.,

  template<template<class> class ...Metafunctions>
    struct apply_to_each;



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@122874 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/clang/AST/DeclTemplate.h              | 12 +++--
 include/clang/Sema/Sema.h                     |  3 +-
 lib/AST/ASTContext.cpp                        |  8 +--
 lib/AST/ASTImporter.cpp                       |  1 +
 lib/AST/DeclBase.cpp                          |  5 +-
 lib/AST/DeclPrinter.cpp                       |  7 ++-
 lib/AST/DeclTemplate.cpp                      |  5 +-
 lib/AST/StmtProfile.cpp                       |  3 +-
 lib/Parse/ParseTemplate.cpp                   | 31 +++++++----
 lib/Sema/SemaTemplate.cpp                     | 51 +++++++++++--------
 lib/Sema/SemaTemplateInstantiate.cpp          | 19 +++++--
 lib/Sema/SemaTemplateInstantiateDecl.cpp      |  4 +-
 lib/Sema/SemaTemplateVariadic.cpp             | 12 ++++-
 lib/Serialization/ASTReaderDecl.cpp           |  4 +-
 lib/Serialization/ASTWriterDecl.cpp           |  1 +
 .../temp.variadic/metafunctions.cpp           | 26 ++++++++++
 test/CXX/temp/temp.decls/temp.variadic/p5.cpp |  5 ++
 .../temp.variadic/parameter-matching.cpp      |  2 +
 test/CXX/temp/temp.param/p9-0x.cpp            |  4 ++
 19 files changed, 152 insertions(+), 51 deletions(-)

diff --git a/include/clang/AST/DeclTemplate.h b/include/clang/AST/DeclTemplate.h
index f2f91786bc..b20aeeb74a 100644
--- a/include/clang/AST/DeclTemplate.h
+++ b/include/clang/AST/DeclTemplate.h
@@ -1084,18 +1084,22 @@ class TemplateTemplateParmDecl
   /// Whether or not the default argument was inherited.
   bool DefaultArgumentWasInherited;
 
+  /// \brief Whether this parameter is a parameter pack.
+  bool ParameterPack;
+    
   TemplateTemplateParmDecl(DeclContext *DC, SourceLocation L,
-                           unsigned D, unsigned P,
+                           unsigned D, unsigned P, bool ParameterPack,
                            IdentifierInfo *Id, TemplateParameterList *Params)
     : TemplateDecl(TemplateTemplateParm, DC, L, Id, Params),
       TemplateParmPosition(D, P), DefaultArgument(),
-      DefaultArgumentWasInherited(false)
+      DefaultArgumentWasInherited(false), ParameterPack(ParameterPack)
     { }
 
 public:
   static TemplateTemplateParmDecl *Create(ASTContext &C, DeclContext *DC,
                                           SourceLocation L, unsigned D,
-                                          unsigned P, IdentifierInfo *Id,
+                                          unsigned P, bool ParameterPack,
+                                          IdentifierInfo *Id,
                                           TemplateParameterList *Params);
 
   using TemplateParmPosition::getDepth;
@@ -1108,7 +1112,7 @@ public:
   /// \code
   /// template<template <class T> ...MetaFunctions> struct Apply;
   /// \endcode
-  bool isParameterPack() const { return /*FIXME: variadic templates*/false; }
+  bool isParameterPack() const { return ParameterPack; }
 
   /// \brief Determine whether this template parameter has a default
   /// argument.
diff --git a/include/clang/Sema/Sema.h b/include/clang/Sema/Sema.h
index fac590a82f..3ec6f05ea4 100644
--- a/include/clang/Sema/Sema.h
+++ b/include/clang/Sema/Sema.h
@@ -2845,12 +2845,13 @@ public:
   Decl *ActOnTemplateTemplateParameter(Scope *S,
                                        SourceLocation TmpLoc,
                                        TemplateParamsTy *Params,
+                                       SourceLocation EllipsisLoc,
                                        IdentifierInfo *ParamName,
                                        SourceLocation ParamNameLoc,
                                        unsigned Depth,
                                        unsigned Position,
                                        SourceLocation EqualLoc,
-                                 const ParsedTemplateArgument &DefaultArg);
+                                       ParsedTemplateArgument DefaultArg);
 
   TemplateParamsTy *
   ActOnTemplateParameterList(unsigned Depth,
diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index 149ecbc599..b4520609ff 100644
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -51,7 +51,7 @@ ASTContext::CanonicalTemplateTemplateParm::Profile(llvm::FoldingSetNodeID &ID,
                                                TemplateTemplateParmDecl *Parm) {
   ID.AddInteger(Parm->getDepth());
   ID.AddInteger(Parm->getPosition());
-  // FIXME: Parameter pack
+  ID.AddBoolean(Parm->isParameterPack());
 
   TemplateParameterList *Params = Parm->getTemplateParameters();
   ID.AddInteger(Params->size());
@@ -66,7 +66,7 @@ ASTContext::CanonicalTemplateTemplateParm::Profile(llvm::FoldingSetNodeID &ID,
     
     if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(*P)) {
       ID.AddInteger(1);
-      // FIXME: Parameter pack
+      ID.AddBoolean(NTTP->isParameterPack());
       ID.AddPointer(NTTP->getType().getAsOpaquePtr());
       continue;
     }
@@ -119,7 +119,9 @@ ASTContext::getCanonicalTemplateTemplateParmDecl(
   TemplateTemplateParmDecl *CanonTTP
     = TemplateTemplateParmDecl::Create(*this, getTranslationUnitDecl(), 
                                        SourceLocation(), TTP->getDepth(),
-                                       TTP->getPosition(), 0,
+                                       TTP->getPosition(), 
+                                       TTP->isParameterPack(),
+                                       0,
                          TemplateParameterList::Create(*this, SourceLocation(),
                                                        SourceLocation(),
                                                        CanonParams.data(),
diff --git a/lib/AST/ASTImporter.cpp b/lib/AST/ASTImporter.cpp
index c62225ef40..70c8632047 100644
--- a/lib/AST/ASTImporter.cpp
+++ b/lib/AST/ASTImporter.cpp
@@ -3444,6 +3444,7 @@ ASTNodeImporter::VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D) {
   return TemplateTemplateParmDecl::Create(Importer.getToContext(), 
                               Importer.getToContext().getTranslationUnitDecl(), 
                                           Loc, D->getDepth(), D->getPosition(),
+                                          D->isParameterPack(),
                                           Name.getAsIdentifierInfo(), 
                                           TemplateParams);
 }
diff --git a/lib/AST/DeclBase.cpp b/lib/AST/DeclBase.cpp
index 75ea2df27e..700100507b 100644
--- a/lib/AST/DeclBase.cpp
+++ b/lib/AST/DeclBase.cpp
@@ -111,8 +111,11 @@ bool Decl::isTemplateParameterPack() const {
   if (const TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(this))
     return TTP->isParameterPack();
   if (const NonTypeTemplateParmDecl *NTTP
-                                = llvm::dyn_cast<NonTypeTemplateParmDecl>(this))
+                                = dyn_cast<NonTypeTemplateParmDecl>(this))
     return NTTP->isParameterPack();
+  if (const TemplateTemplateParmDecl *TTP
+                                    = dyn_cast<TemplateTemplateParmDecl>(this))
+    return TTP->isParameterPack();
   return false;
 }
 
diff --git a/lib/AST/DeclPrinter.cpp b/lib/AST/DeclPrinter.cpp
index 8941200969..eaa117a045 100644
--- a/lib/AST/DeclPrinter.cpp
+++ b/lib/AST/DeclPrinter.cpp
@@ -699,8 +699,11 @@ void DeclPrinter::VisitTemplateDecl(TemplateDecl *D) {
 
   Out << "> ";
 
-  if (isa<TemplateTemplateParmDecl>(D)) {
-    Out << "class " << D->getName();
+  if (TemplateTemplateParmDecl *TTP = dyn_cast<TemplateTemplateParmDecl>(D)) {
+    Out << "class ";
+    if (TTP->isParameterPack())
+      Out << "...";
+    Out << D->getName();
   } else {
     Visit(D->getTemplatedDecl());
   }
diff --git a/lib/AST/DeclTemplate.cpp b/lib/AST/DeclTemplate.cpp
index 0110e3b180..2755a9e230 100644
--- a/lib/AST/DeclTemplate.cpp
+++ b/lib/AST/DeclTemplate.cpp
@@ -412,9 +412,10 @@ SourceLocation NonTypeTemplateParmDecl::getDefaultArgumentLoc() const {
 TemplateTemplateParmDecl *
 TemplateTemplateParmDecl::Create(ASTContext &C, DeclContext *DC,
                                  SourceLocation L, unsigned D, unsigned P,
-                                 IdentifierInfo *Id,
+                                 bool ParameterPack, IdentifierInfo *Id,
                                  TemplateParameterList *Params) {
-  return new (C) TemplateTemplateParmDecl(DC, L, D, P, Id, Params);
+  return new (C) TemplateTemplateParmDecl(DC, L, D, P, ParameterPack, Id, 
+                                          Params);
 }
 
 //===----------------------------------------------------------------------===//
diff --git a/lib/AST/StmtProfile.cpp b/lib/AST/StmtProfile.cpp
index ab24a69124..17a9326cc0 100644
--- a/lib/AST/StmtProfile.cpp
+++ b/lib/AST/StmtProfile.cpp
@@ -903,7 +903,7 @@ void StmtProfiler::VisitDecl(Decl *D) {
     if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(D)) {
       ID.AddInteger(NTTP->getDepth());
       ID.AddInteger(NTTP->getIndex());
-      ID.AddInteger(NTTP->isParameterPack());
+      ID.AddBoolean(NTTP->isParameterPack());
       VisitType(NTTP->getType());
       return;
     }
@@ -921,6 +921,7 @@ void StmtProfiler::VisitDecl(Decl *D) {
     if (TemplateTemplateParmDecl *TTP = dyn_cast<TemplateTemplateParmDecl>(D)) {
       ID.AddInteger(TTP->getDepth());
       ID.AddInteger(TTP->getIndex());
+      ID.AddBoolean(TTP->isParameterPack());
       return;
     }
   }
diff --git a/lib/Parse/ParseTemplate.cpp b/lib/Parse/ParseTemplate.cpp
index afa2cc62f9..8fb6b96673 100644
--- a/lib/Parse/ParseTemplate.cpp
+++ b/lib/Parse/ParseTemplate.cpp
@@ -421,12 +421,14 @@ bool Parser::isStartOfTemplateTypeParameter() {
 ///         parameter-declaration
 ///
 ///       type-parameter: (see below)
-///         'class' ...[opt][C++0x] identifier[opt]
+///         'class' ...[opt] identifier[opt]
 ///         'class' identifier[opt] '=' type-id
-///         'typename' ...[opt][C++0x] identifier[opt]
+///         'typename' ...[opt] identifier[opt]
 ///         'typename' identifier[opt] '=' type-id
-///         'template' ...[opt][C++0x] '<' template-parameter-list '>' 'class' identifier[opt]
-///         'template' '<' template-parameter-list '>' 'class' identifier[opt] = id-expression
+///         'template' '<' template-parameter-list '>' 
+///               'class' ...[opt] identifier[opt]
+///         'template' '<' template-parameter-list '>' 'class' identifier[opt]
+///               = id-expression
 Decl *Parser::ParseTemplateParameter(unsigned Depth, unsigned Position) {
   if (isStartOfTemplateTypeParameter())
     return ParseTypeParameter(Depth, Position);
@@ -502,8 +504,10 @@ Decl *Parser::ParseTypeParameter(unsigned Depth, unsigned Position) {
 /// template parameters.
 ///
 ///       type-parameter:    [C++ temp.param]
-///         'template' '<' template-parameter-list '>' 'class' identifier[opt]
-///         'template' '<' template-parameter-list '>' 'class' identifier[opt] = id-expression
+///         'template' '<' template-parameter-list '>' 'class' 
+///                  ...[opt] identifier[opt]
+///         'template' '<' template-parameter-list '>' 'class' identifier[opt] 
+///                  = id-expression
 Decl *
 Parser::ParseTemplateTemplateParameter(unsigned Depth, unsigned Position) {
   assert(Tok.is(tok::kw_template) && "Expected 'template' keyword");
@@ -529,6 +533,15 @@ Parser::ParseTemplateTemplateParameter(unsigned Depth, unsigned Position) {
   }
   SourceLocation ClassLoc = ConsumeToken();
 
+  // Parse the ellipsis, if given.
+  SourceLocation EllipsisLoc;
+  if (Tok.is(tok::ellipsis)) {
+    EllipsisLoc = ConsumeToken();
+    
+    if (!getLang().CPlusPlus0x)
+      Diag(EllipsisLoc, diag::err_variadic_templates);
+  }
+      
   // Get the identifier, if given.
   SourceLocation NameLoc;
   IdentifierInfo* ParamName = 0;
@@ -569,9 +582,9 @@ Parser::ParseTemplateTemplateParameter(unsigned Depth, unsigned Position) {
   }
   
   return Actions.ActOnTemplateTemplateParameter(getCurScope(), TemplateLoc,
-                                                ParamList, ParamName,
-                                                NameLoc, Depth, Position,
-                                                EqualLoc, DefaultArg);
+                                                ParamList, EllipsisLoc, 
+                                                ParamName, NameLoc, Depth, 
+                                                Position, EqualLoc, DefaultArg);
 }
 
 /// ParseNonTypeTemplateParameter - Handle the parsing of non-type
diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index 419f59d588..a0c89f0fbd 100644
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -522,6 +522,14 @@ Decl *Sema::ActOnTypeParameter(Scope *S, bool Typename, bool Ellipsis,
     IdResolver.AddDecl(Param);
   }
 
+  // C++0x [temp.param]p9:
+  //   A default template-argument may be specified for any kind of
+  //   template-parameter that is not a template parameter pack.
+  if (DefaultArg && Ellipsis) {
+    Diag(EqualLoc, diag::err_template_param_pack_default_arg);
+    DefaultArg = ParsedType();
+  }
+
   // Handle the default argument, if provided.
   if (DefaultArg) {
     TypeSourceInfo *DefaultTInfo;
@@ -529,14 +537,6 @@ Decl *Sema::ActOnTypeParameter(Scope *S, bool Typename, bool Ellipsis,
     
     assert(DefaultTInfo && "expected source information for type");
     
-    // C++0x [temp.param]p9:
-    // A default template-argument may be specified for any kind of
-    // template-parameter that is not a template parameter pack.
-    if (Ellipsis) {
-      Diag(EqualLoc, diag::err_template_param_pack_default_arg);
-      return Param;
-    }
-
     // Check for unexpanded parameter packs.
     if (DiagnoseUnexpandedParameterPack(Loc, DefaultTInfo, 
                                         UPPC_DefaultArgument))
@@ -647,16 +647,16 @@ Decl *Sema::ActOnNonTypeTemplateParameter(Scope *S, Declarator &D,
     IdResolver.AddDecl(Param);
   }
   
+  // C++0x [temp.param]p9:
+  //   A default template-argument may be specified for any kind of
+  //   template-parameter that is not a template parameter pack.
+  if (Default && IsParameterPack) {
+    Diag(EqualLoc, diag::err_template_param_pack_default_arg);
+    Default = 0;
+  }
+
   // Check the well-formedness of the default template argument, if provided.
   if (Default) {
-    // C++0x [temp.param]p9:
-    //   A default template-argument may be specified for any kind of
-    //   template-parameter that is not a template parameter pack.
-    if (IsParameterPack) {
-      Diag(EqualLoc, diag::err_template_param_pack_default_arg);
-      return Param;
-    }
-
     // Check for unexpanded parameter packs.
     if (DiagnoseUnexpandedParameterPack(Default, UPPC_DefaultArgument))
       return Param;
@@ -679,21 +679,24 @@ Decl *Sema::ActOnNonTypeTemplateParameter(Scope *S, Declarator &D,
 Decl *Sema::ActOnTemplateTemplateParameter(Scope* S,
                                            SourceLocation TmpLoc,
                                            TemplateParamsTy *Params,
+                                           SourceLocation EllipsisLoc,
                                            IdentifierInfo *Name,
                                            SourceLocation NameLoc,
                                            unsigned Depth,
                                            unsigned Position,
                                            SourceLocation EqualLoc,
-                                       const ParsedTemplateArgument &Default) {
+                                           ParsedTemplateArgument Default) {
   assert(S->isTemplateParamScope() &&
          "Template template parameter not in template parameter scope!");
 
   // Construct the parameter object.
+  bool IsParameterPack = EllipsisLoc.isValid();
+  // FIXME: Pack-ness is dropped
   TemplateTemplateParmDecl *Param =
     TemplateTemplateParmDecl::Create(Context, Context.getTranslationUnitDecl(),
                                      NameLoc.isInvalid()? TmpLoc : NameLoc, 
-                                     Depth, Position, Name,
-                                     Params);
+                                     Depth, Position, IsParameterPack, 
+                                     Name, Params);
 
   // If the template template parameter has a name, then link the identifier 
   // into the scope and lookup mechanisms.
@@ -708,6 +711,14 @@ Decl *Sema::ActOnTemplateTemplateParameter(Scope* S,
     Param->setInvalidDecl();
   }
 
+  // C++0x [temp.param]p9:
+  //   A default template-argument may be specified for any kind of
+  //   template-parameter that is not a template parameter pack.
+  if (IsParameterPack && !Default.isInvalid()) {
+    Diag(EqualLoc, diag::err_template_param_pack_default_arg);
+    Default = ParsedTemplateArgument();
+  }
+  
   if (!Default.isInvalid()) {
     // Check only that we have a template template argument. We don't want to
     // try to check well-formedness now, because our template template parameter
@@ -1212,7 +1223,7 @@ bool Sema::CheckTemplateParameterList(TemplateParameterList *NewParams,
         // new declaration.
         SawDefaultArgument = true;
         // FIXME: We need to create a new kind of "default argument"
-        // expression that points to a previous template template
+        // expression that points to a previous non-type template
         // parameter.
         NewNonTypeParm->setDefaultArgument(
                                          OldNonTypeParm->getDefaultArgument(),
diff --git a/lib/Sema/SemaTemplateInstantiate.cpp b/lib/Sema/SemaTemplateInstantiate.cpp
index 5d724f3b70..a256537068 100644
--- a/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/lib/Sema/SemaTemplateInstantiate.cpp
@@ -697,9 +697,22 @@ Decl *TemplateInstantiator::TransformDecl(SourceLocation Loc, Decl *D) {
                                             TTP->getPosition()))
         return D;
 
-      // FIXME: Variadic templates index substitution.
-      TemplateName Template
-        = TemplateArgs(TTP->getDepth(), TTP->getPosition()).getAsTemplate();
+      TemplateArgument Arg = TemplateArgs(TTP->getDepth(), TTP->getPosition());
+      
+      if (TTP->isParameterPack()) {
+        assert(Arg.getKind() == TemplateArgument::Pack && 
+               "Missing argument pack");
+        
+        if (getSema().ArgumentPackSubstitutionIndex == -1) {
+          // FIXME: Variadic templates fun case.
+          getSema().Diag(Loc,  diag::err_pack_expansion_mismatch_unsupported);
+          return 0;
+        }
+        
+        Arg = Arg.pack_begin()[getSema().ArgumentPackSubstitutionIndex];
+      }
+
+      TemplateName Template = Arg.getAsTemplate();
       assert(!Template.isNull() && Template.getAsTemplateDecl() &&
              "Wrong kind of template template argument");
       return Template.getAsTemplateDecl();
diff --git a/lib/Sema/SemaTemplateInstantiateDecl.cpp b/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 60a942ac2f..92521ae16e 100644
--- a/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -1542,8 +1542,8 @@ TemplateDeclInstantiator::VisitTemplateTemplateParmDecl(
   TemplateTemplateParmDecl *Param
     = TemplateTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(),
                                    D->getDepth() - TemplateArgs.getNumLevels(), 
-                                       D->getPosition(), D->getIdentifier(), 
-                                       InstParams);
+                                       D->getPosition(), D->isParameterPack(), 
+                                       D->getIdentifier(), InstParams);
   Param->setDefaultArgument(D->getDefaultArgument(), false);
   
   // Introduce this template parameter's instantiation into the instantiation 
diff --git a/lib/Sema/SemaTemplateVariadic.cpp b/lib/Sema/SemaTemplateVariadic.cpp
index 4e01ec2407..acb73144d9 100644
--- a/lib/Sema/SemaTemplateVariadic.cpp
+++ b/lib/Sema/SemaTemplateVariadic.cpp
@@ -78,7 +78,16 @@ namespace {
       return true;
     }
     
-    // FIXME: Record occurrences of template template parameter packs.
+    /// \brief Record occurrences of template template parameter packs.
+    bool TraverseTemplateName(TemplateName Template) {
+      if (TemplateTemplateParmDecl *TTP 
+            = dyn_cast_or_null<TemplateTemplateParmDecl>(
+                                                  Template.getAsTemplateDecl()))
+        if (TTP->isParameterPack())
+          Unexpanded.push_back(std::make_pair(TTP, SourceLocation()));
+      
+      return inherited::TraverseTemplateName(Template);
+    }
 
     //------------------------------------------------------------------------
     // Pruning the search for unexpanded parameter packs.
@@ -556,7 +565,6 @@ ExprResult Sema::ActOnSizeofParameterPackExpr(Scope *S,
                                               SourceLocation RParenLoc) {
   // C++0x [expr.sizeof]p5:
   //   The identifier in a sizeof... expression shall name a parameter pack.
-  
   LookupResult R(*this, &Name, NameLoc, LookupOrdinaryName);
   LookupName(R, S);
   
diff --git a/lib/Serialization/ASTReaderDecl.cpp b/lib/Serialization/ASTReaderDecl.cpp
index 40f3ab7e1b..239abbeb39 100644
--- a/lib/Serialization/ASTReaderDecl.cpp
+++ b/lib/Serialization/ASTReaderDecl.cpp
@@ -1173,6 +1173,7 @@ void ASTDeclReader::VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D) {
   TemplateArgumentLoc Arg = Reader.ReadTemplateArgumentLoc(F, Record, Idx);
   bool IsInherited = Record[Idx++];
   D->setDefaultArgument(Arg, IsInherited);
+  D->ParameterPack = Record[Idx++];
 }
 
 void ASTDeclReader::VisitStaticAssertDecl(StaticAssertDecl *D) {
@@ -1433,7 +1434,8 @@ Decl *ASTReader::ReadDeclRecord(unsigned Index, DeclID ID) {
                                         QualType(), false, 0);
     break;
   case DECL_TEMPLATE_TEMPLATE_PARM:
-    D = TemplateTemplateParmDecl::Create(*Context, 0, SourceLocation(),0,0,0,0);
+    D = TemplateTemplateParmDecl::Create(*Context, 0, SourceLocation(), 0, 0,
+                                         false, 0, 0);
     break;
   case DECL_STATIC_ASSERT:
     D = StaticAssertDecl::Create(*Context, 0, SourceLocation(), 0, 0);
diff --git a/lib/Serialization/ASTWriterDecl.cpp b/lib/Serialization/ASTWriterDecl.cpp
index add6cd343d..ff1f4bf44b 100644
--- a/lib/Serialization/ASTWriterDecl.cpp
+++ b/lib/Serialization/ASTWriterDecl.cpp
@@ -1011,6 +1011,7 @@ void ASTDeclWriter::VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D) {
   // Rest of TemplateTemplateParmDecl.
   Writer.AddTemplateArgumentLoc(D->getDefaultArgument(), Record);
   Record.push_back(D->defaultArgumentWasInherited());
+  Record.push_back(D->isParameterPack());
   Code = serialization::DECL_TEMPLATE_TEMPLATE_PARM;
 }
 
diff --git a/test/CXX/temp/temp.decls/temp.variadic/metafunctions.cpp b/test/CXX/temp/temp.decls/temp.variadic/metafunctions.cpp
index 47b7793da0..3e9e8f5fb2 100644
--- a/test/CXX/temp/temp.decls/temp.variadic/metafunctions.cpp
+++ b/test/CXX/temp/temp.decls/temp.variadic/metafunctions.cpp
@@ -138,3 +138,29 @@ namespace Indices {
   int check0[is_same<build_indices<5>::type,
                      int_tuple<0, 1, 2, 3, 4>>::value? 1 : -1];
 }
+
+namespace TemplateTemplateApply {
+  template<typename T, template<class> class ...Meta>
+  struct apply_each {
+    typedef tuple<typename Meta<T>::type...> type;
+  };
+
+  template<typename T> 
+  struct add_reference {
+    typedef T& type;
+  };
+
+  template<typename T> 
+  struct add_pointer {
+    typedef T* type;
+  };
+
+  template<typename T> 
+  struct add_const {
+    typedef const T type;
+  };
+
+  int check0[is_same<apply_each<int, 
+                                add_reference, add_pointer, add_const>::type,
+                     tuple<int&, int*, int const>>::value? 1 : -1];
+}
diff --git a/test/CXX/temp/temp.decls/temp.variadic/p5.cpp b/test/CXX/temp/temp.decls/temp.variadic/p5.cpp
index 729a6a0bb2..f0822c3452 100644
--- a/test/CXX/temp/temp.decls/temp.variadic/p5.cpp
+++ b/test/CXX/temp/temp.decls/temp.variadic/p5.cpp
@@ -154,6 +154,11 @@ void TestPPNameFunc(int i) {
   f(static_cast<Types>(i)); // expected-error{{expression contains unexpanded parameter pack 'Types'}}
 }
 
+template<typename T, template<class> class ...Meta>
+struct TestUnexpandedTTP {
+  typedef tuple<typename Meta<T>::type> type; // expected-error{{declaration type contains unexpanded parameter pack 'Meta'}}
+};
+
 // Test for unexpanded parameter packs in declarations.
 // FIXME: Attributes?
 template<typename T, typename... Types>
diff --git a/test/CXX/temp/temp.decls/temp.variadic/parameter-matching.cpp b/test/CXX/temp/temp.decls/temp.variadic/parameter-matching.cpp
index 7352be2d72..126a0961b1 100644
--- a/test/CXX/temp/temp.decls/temp.variadic/parameter-matching.cpp
+++ b/test/CXX/temp/temp.decls/temp.variadic/parameter-matching.cpp
@@ -19,3 +19,5 @@ template<template<typename T> class> struct X1tt; // expected-error{{template ty
 
 template<template<typename T> class> struct X2tt; // expected-note{{previous template type parameter declared here}}
 template<template<typename ...T> class> struct X2tt; // expected-error{{template type parameter pack conflicts with previous template type parameter}}
+
+// FIXME: Add checks for non-type template parameter packs, template parameter packs
diff --git a/test/CXX/temp/temp.param/p9-0x.cpp b/test/CXX/temp/temp.param/p9-0x.cpp
index 42d1adf297..1980bc6eaa 100644
--- a/test/CXX/temp/temp.param/p9-0x.cpp
+++ b/test/CXX/temp/temp.param/p9-0x.cpp
@@ -8,3 +8,7 @@ struct X0;
 template<int ...Values = 0> // expected-error{{template parameter pack cannot have a default argument}}
 struct X1;
 
+template<typename T> struct vector;
+
+template<template<class> class ...Templates = vector> // expected-error{{template parameter pack cannot have a default argument}}
+struct X2; 
-- 
2.40.0