3 files changed, 28 insertions, 0 deletions

diff --git a/clang/lib/Serialization/ASTCommon.cpp b/clang/lib/Serialization/ASTCommon.cpp
index 79ccffc5abb..ecd249cc502 100644
--- a/clang/lib/Serialization/ASTCommon.cpp
+++ b/clang/lib/Serialization/ASTCommon.cpp
@@ -285,6 +285,7 @@ bool serialization::isRedeclarableDeclKind(unsigned Kind) {
   case Decl::NonTypeTemplateParm:
   case Decl::TemplateTemplateParm:
   case Decl::Using:
+  case Decl::UsingPack:
   case Decl::ObjCMethod:
   case Decl::ObjCCategory:
   case Decl::ObjCCategoryImpl:
diff --git a/clang/lib/Serialization/ASTReaderDecl.cpp b/clang/lib/Serialization/ASTReaderDecl.cpp
index 913a1419b3f..dc29a61c0a9 100644
--- a/clang/lib/Serialization/ASTReaderDecl.cpp
+++ b/clang/lib/Serialization/ASTReaderDecl.cpp
@@ -322,6 +322,7 @@ namespace clang {
     void VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D);
     void VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D);
     void VisitUsingDecl(UsingDecl *D);
+    void VisitUsingPackDecl(UsingPackDecl *D);
     void VisitUsingShadowDecl(UsingShadowDecl *D);
     void VisitConstructorUsingShadowDecl(ConstructorUsingShadowDecl *D);
     void VisitLinkageSpecDecl(LinkageSpecDecl *D);
@@ -1419,6 +1420,15 @@ void ASTDeclReader::VisitUsingDecl(UsingDecl *D) {
   mergeMergeable(D);
 }
 
+void ASTDeclReader::VisitUsingPackDecl(UsingPackDecl *D) {
+  VisitNamedDecl(D);
+  D->InstantiatedFrom = ReadDeclAs<NamedDecl>();
+  NamedDecl **Expansions = D->getTrailingObjects<NamedDecl*>();
+  for (unsigned I = 0; I != D->NumExpansions; ++I)
+    Expansions[I] = ReadDeclAs<NamedDecl>();
+  mergeMergeable(D);
+}
+
 void ASTDeclReader::VisitUsingShadowDecl(UsingShadowDecl *D) {
   RedeclarableResult Redecl = VisitRedeclarable(D);
   VisitNamedDecl(D);
@@ -1452,6 +1462,7 @@ void ASTDeclReader::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
   D->setUsingLoc(ReadSourceLocation());
   D->QualifierLoc = Record.ReadNestedNameSpecifierLoc(Idx);
   ReadDeclarationNameLoc(D->DNLoc, D->getDeclName());
+  D->EllipsisLoc = ReadSourceLocation();
   mergeMergeable(D);
 }
 
@@ -1460,6 +1471,7 @@ void ASTDeclReader::VisitUnresolvedUsingTypenameDecl(
   VisitTypeDecl(D);
   D->TypenameLocation = ReadSourceLocation();
   D->QualifierLoc = Record.ReadNestedNameSpecifierLoc(Idx);
+  D->EllipsisLoc = ReadSourceLocation();
   mergeMergeable(D);
 }
 
@@ -3297,6 +3309,9 @@ Decl *ASTReader::ReadDeclRecord(DeclID ID) {
   case DECL_USING:
     D = UsingDecl::CreateDeserialized(Context, ID);
     break;
+  case DECL_USING_PACK:
+    D = UsingPackDecl::CreateDeserialized(Context, ID, Record[Idx++]);
+    break;
   case DECL_USING_SHADOW:
     D = UsingShadowDecl::CreateDeserialized(Context, ID);
     break;
diff --git a/clang/lib/Serialization/ASTWriterDecl.cpp b/clang/lib/Serialization/ASTWriterDecl.cpp
index 21468619dba..ee220f00a81 100644
--- a/clang/lib/Serialization/ASTWriterDecl.cpp
+++ b/clang/lib/Serialization/ASTWriterDecl.cpp
@@ -107,6 +107,7 @@ namespace clang {
     void VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D);
     void VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D);
     void VisitUsingDecl(UsingDecl *D);
+    void VisitUsingPackDecl(UsingPackDecl *D);
     void VisitUsingShadowDecl(UsingShadowDecl *D);
     void VisitConstructorUsingShadowDecl(ConstructorUsingShadowDecl *D);
     void VisitLinkageSpecDecl(LinkageSpecDecl *D);
@@ -1142,6 +1143,15 @@ void ASTDeclWriter::VisitUsingDecl(UsingDecl *D) {
   Code = serialization::DECL_USING;
 }
 
+void ASTDeclWriter::VisitUsingPackDecl(UsingPackDecl *D) {
+  Record.push_back(D->NumExpansions);
+  VisitNamedDecl(D);
+  Record.AddDeclRef(D->getInstantiatedFromUsingDecl());
+  for (auto *E : D->expansions())
+    Record.AddDeclRef(E);
+  Code = serialization::DECL_USING_PACK;
+}
+
 void ASTDeclWriter::VisitUsingShadowDecl(UsingShadowDecl *D) {
   VisitRedeclarable(D);
   VisitNamedDecl(D);
@@ -1175,6 +1185,7 @@ void ASTDeclWriter::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
   Record.AddSourceLocation(D->getUsingLoc());
   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
   Record.AddDeclarationNameLoc(D->DNLoc, D->getDeclName());
+  Record.AddSourceLocation(D->getEllipsisLoc());
   Code = serialization::DECL_UNRESOLVED_USING_VALUE;
 }
 
@@ -1183,6 +1194,7 @@ void ASTDeclWriter::VisitUnresolvedUsingTypenameDecl(
   VisitTypeDecl(D);
   Record.AddSourceLocation(D->getTypenameLoc());
   Record.AddNestedNameSpecifierLoc(D->getQualifierLoc());
+  Record.AddSourceLocation(D->getEllipsisLoc());
   Code = serialization::DECL_UNRESOLVED_USING_TYPENAME;
 }