Fix build from r67476 and address the easy part of Doug's comments on rvalue refs.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@67480 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 6 insertions, 3 deletions

diff --git a/lib/Sema/SemaType.cpp b/lib/Sema/SemaType.cpp
index 24b32e8147..3f4e78cf28 100644
--- a/lib/Sema/SemaType.cpp
+++ b/lib/Sema/SemaType.cpp
@@ -323,10 +323,13 @@ QualType Sema::BuildReferenceType(QualType T, bool LValueRef, unsigned Quals,
                                   SourceLocation Loc, DeclarationName Entity) {
   if (LValueRef) {
     if (const RValueReferenceType *R = T->getAsRValueReferenceType()) {
-      // FIXME: Find the C++0x reference for reference collapsing.
-      // In reference collapsing, lvalue refs win over rvalue refs.
+      // C++0x [dcl.typedef]p9: If a typedef TD names a type that is a
+      //   reference to a type T, and attempt to create the type "lvalue
+      //   reference to cv TD" creates the type "lvalue reference to T".
+      // We use the qualifiers (restrict or none) of the original reference,
+      // not the new ones. This is consistent with GCC.
       return Context.getLValueReferenceType(R->getPointeeType()).
-               getQualifiedType(Quals);
+               getQualifiedType(T.getCVRQualifiers());
     }
   }
   if (T->isReferenceType()) {