Start implementing support for substitution into pack expansions that

involve template parameter packs at multiple template levels that
occur within the signatures members of class templates (and partial
specializations thereof). This is a work-in-progress that is deficient
in several ways, notably:
  - It only works for template type parameter packs, but we need to
  also support non-type template parameter packs and template template
  parameter packs.
  - It doesn't keep track of the lengths of the substituted argument
  packs in the expansion, so it can't properly diagnose length
  mismatches.

However, this is a concrete step in the right direction.

llvm-svn: 123425

1 files changed, 12 insertions, 0 deletions

diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index d3b103f56c1..52cf3829dc9 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -244,6 +244,14 @@ ASTTypeWriter::VisitSubstTemplateTypeParmType(
 }
 
 void
+ASTTypeWriter::VisitSubstTemplateTypeParmPackType(
+                                      const SubstTemplateTypeParmPackType *T) {
+  Writer.AddTypeRef(QualType(T->getReplacedParameter(), 0), Record);
+  Writer.AddTemplateArgument(T->getArgumentPack(), Record);
+  Code = TYPE_SUBST_TEMPLATE_TYPE_PARM_PACK;
+}
+
+void
 ASTTypeWriter::VisitTemplateSpecializationType(
                                        const TemplateSpecializationType *T) {
   Record.push_back(T->isDependentType());
@@ -491,6 +499,10 @@ void TypeLocWriter::VisitSubstTemplateTypeParmTypeLoc(
                                             SubstTemplateTypeParmTypeLoc TL) {
   Writer.AddSourceLocation(TL.getNameLoc(), Record);
 }
+void TypeLocWriter::VisitSubstTemplateTypeParmPackTypeLoc(
+                                          SubstTemplateTypeParmPackTypeLoc TL) {
+  Writer.AddSourceLocation(TL.getNameLoc(), Record);
+}
 void TypeLocWriter::VisitTemplateSpecializationTypeLoc(
                                            TemplateSpecializationTypeLoc TL) {
   Writer.AddSourceLocation(TL.getTemplateNameLoc(), Record);