2 files changed, 38 insertions, 11 deletions

diff --git a/clang/lib/Serialization/ASTReaderDecl.cpp b/clang/lib/Serialization/ASTReaderDecl.cpp
index 2418f3a1674..ba830d172cc 100644
--- a/clang/lib/Serialization/ASTReaderDecl.cpp
+++ b/clang/lib/Serialization/ASTReaderDecl.cpp
@@ -1486,11 +1486,18 @@ void ASTDeclReader::VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D) {
   // TemplateParmPosition.
   D->setDepth(Record[Idx++]);
   D->setPosition(Record[Idx++]);
-  // Rest of TemplateTemplateParmDecl.
-  TemplateArgumentLoc Arg = Reader.ReadTemplateArgumentLoc(F, Record, Idx);
-  bool IsInherited = Record[Idx++];
-  D->setDefaultArgument(Arg, IsInherited);
-  D->ParameterPack = Record[Idx++];
+  if (D->isExpandedParameterPack()) {
+    void **Data = reinterpret_cast<void **>(D + 1);
+    for (unsigned I = 0, N = D->getNumExpansionTemplateParameters();
+         I != N; ++I)
+      Data[I] = Reader.ReadTemplateParameterList(F, Record, Idx);
+  } else {
+    // Rest of TemplateTemplateParmDecl.
+    TemplateArgumentLoc Arg = Reader.ReadTemplateArgumentLoc(F, Record, Idx);
+    bool IsInherited = Record[Idx++];
+    D->setDefaultArgument(Arg, IsInherited);
+    D->ParameterPack = Record[Idx++];
+  }
 }
 
 void ASTDeclReader::VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D) {
@@ -2004,6 +2011,10 @@ Decl *ASTReader::ReadDeclRecord(DeclID ID) {
   case DECL_TEMPLATE_TEMPLATE_PARM:
     D = TemplateTemplateParmDecl::CreateDeserialized(Context, ID);
     break;
+  case DECL_EXPANDED_TEMPLATE_TEMPLATE_PARM_PACK:
+    D = TemplateTemplateParmDecl::CreateDeserialized(Context, ID,
+                                                     Record[Idx++]);
+    break;
   case DECL_TYPE_ALIAS_TEMPLATE:
     D = TypeAliasTemplateDecl::CreateDeserialized(Context, ID);
     break;
diff --git a/clang/lib/Serialization/ASTWriterDecl.cpp b/clang/lib/Serialization/ASTWriterDecl.cpp
index 602943b9ba5..baa8a0e4cd4 100644
--- a/clang/lib/Serialization/ASTWriterDecl.cpp
+++ b/clang/lib/Serialization/ASTWriterDecl.cpp
@@ -1172,7 +1172,8 @@ void ASTDeclWriter::VisitTemplateTypeParmDecl(TemplateTypeParmDecl *D) {
 
 void ASTDeclWriter::VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D) {
   // For an expanded parameter pack, record the number of expansion types here
-  // so that it's easier for 
+  // so that it's easier for deserialization to allocate the right amount of
+  // memory.
   if (D->isExpandedParameterPack())
     Record.push_back(D->getNumExpansionTypes());
   
@@ -1201,15 +1202,30 @@ void ASTDeclWriter::VisitNonTypeTemplateParmDecl(NonTypeTemplateParmDecl *D) {
 }
 
 void ASTDeclWriter::VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D) {
+  // For an expanded parameter pack, record the number of expansion types here
+  // so that it's easier for deserialization to allocate the right amount of
+  // memory.
+  if (D->isExpandedParameterPack())
+    Record.push_back(D->getNumExpansionTemplateParameters());
+
   VisitTemplateDecl(D);
   // TemplateParmPosition.
   Record.push_back(D->getDepth());
   Record.push_back(D->getPosition());
-  // Rest of TemplateTemplateParmDecl.
-  Writer.AddTemplateArgumentLoc(D->getDefaultArgument(), Record);
-  Record.push_back(D->defaultArgumentWasInherited());
-  Record.push_back(D->isParameterPack());
-  Code = serialization::DECL_TEMPLATE_TEMPLATE_PARM;
+
+  if (D->isExpandedParameterPack()) {
+    for (unsigned I = 0, N = D->getNumExpansionTemplateParameters();
+         I != N; ++I)
+      Writer.AddTemplateParameterList(D->getExpansionTemplateParameters(I),
+                                      Record);
+    Code = serialization::DECL_EXPANDED_TEMPLATE_TEMPLATE_PARM_PACK;
+  } else {
+    // Rest of TemplateTemplateParmDecl.
+    Writer.AddTemplateArgumentLoc(D->getDefaultArgument(), Record);
+    Record.push_back(D->defaultArgumentWasInherited());
+    Record.push_back(D->isParameterPack());
+    Code = serialization::DECL_TEMPLATE_TEMPLATE_PARM;
+  }
 }
 
 void ASTDeclWriter::VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D) {