3 files changed, 48 insertions, 5 deletions
diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index f527657626..eebb11da99 100644
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -242,6 +242,24 @@ ASTContext::setInstantiatedFromStaticDataMember(VarDecl *Inst, VarDecl *Tmpl) {
   InstantiatedFromStaticDataMember[Inst] = Tmpl;
 }
 
+UnresolvedUsingDecl *
+ASTContext::getInstantiatedFromUnresolvedUsingDecl(UsingDecl *UUD) {
+  llvm::DenseMap<UsingDecl *, UnresolvedUsingDecl *>::iterator Pos 
+    = InstantiatedFromUnresolvedUsingDecl.find(UUD);
+  if (Pos == InstantiatedFromUnresolvedUsingDecl.end())
+    return 0;
+  
+  return Pos->second;
+}
+
+void
+ASTContext::setInstantiatedFromUnresolvedUsingDecl(UsingDecl *UD,
+                                                   UnresolvedUsingDecl *UUD) {
+  assert(!InstantiatedFromUnresolvedUsingDecl[UD] &&
+         "Already noted what using decl what instantiated from");
+  InstantiatedFromUnresolvedUsingDecl[UD] = UUD;
+}
+
 namespace {
   class BeforeInTranslationUnit 
     : std::binary_function<SourceRange, SourceRange, bool> {
diff --git a/lib/Sema/SemaTemplateInstantiate.cpp b/lib/Sema/SemaTemplateInstantiate.cpp
index 521394b978..b1cc328a2d 100644
--- a/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/lib/Sema/SemaTemplateInstantiate.cpp
@@ -477,6 +477,11 @@ TemplateInstantiator::TransformDeclRefExpr(DeclRefExpr *E) {
   if (!InstD)
     return SemaRef.ExprError();
   
+  // If we instantiated an UnresolvedUsingDecl and got back an UsingDecl,
+  // we need to get the underlying decl. 
+  // FIXME: Is this correct? Maybe FindInstantiatedDecl should do this?
+  InstD = InstD->getUnderlyingDecl();
+  
   // FIXME: nested-name-specifier for QualifiedDeclRefExpr
   return SemaRef.BuildDeclarationNameExpr(E->getLocation(), InstD, 
                                           /*FIXME:*/false,
@@ -685,6 +690,8 @@ Sema::InstantiateClass(SourceLocation PointOfInstantiation,
         Invalid = true;
       else if (FieldDecl *Field = dyn_cast<FieldDecl>(NewMember))
         Fields.push_back(DeclPtrTy::make(Field));
+      else if (UsingDecl *UD = dyn_cast<UsingDecl>(NewMember))
+        Instantiation->addDecl(UD);
     } else {
       // FIXME: Eventually, a NULL return will mean that one of the
       // instantiations was a semantic disaster, and we'll want to set Invalid =
diff --git a/lib/Sema/SemaTemplateInstantiateDecl.cpp b/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 6c1f0115b6..5978dae311 100644
--- a/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -757,9 +757,14 @@ TemplateDeclInstantiator::VisitUnresolvedUsingDecl(UnresolvedUsingDecl *D) {
   SS.setRange(D->getTargetNestedNameRange());
   SS.setScopeRep(NNS);
   
-  return SemaRef.BuildUsingDeclaration(D->getLocation(), SS, 
-                                       D->getTargetNameLocation(), 
-                                       D->getTargetName(), 0, D->isTypeName());
+  NamedDecl *UD = 
+    SemaRef.BuildUsingDeclaration(D->getLocation(), SS, 
+                                  D->getTargetNameLocation(), 
+                                  D->getTargetName(), 0, D->isTypeName());
+  if (UD)
+    SemaRef.Context.setInstantiatedFromUnresolvedUsingDecl(cast<UsingDecl>(UD), 
+                                                           D);
+  return UD;
 }
 
 Decl *Sema::SubstDecl(Decl *D, DeclContext *Owner,
@@ -1220,6 +1225,12 @@ static bool isInstantiationOf(EnumDecl *Pattern,
   return false;
 }
 
+static bool isInstantiationOf(UnresolvedUsingDecl *Pattern,
+                              UsingDecl *Instance,
+                              ASTContext &C) {
+  return C.getInstantiatedFromUnresolvedUsingDecl(Instance) == Pattern;
+}
+
 static bool isInstantiationOfStaticDataMember(VarDecl *Pattern,
                                               VarDecl *Instance) {
   assert(Instance->isStaticDataMember());
@@ -1236,9 +1247,16 @@ static bool isInstantiationOfStaticDataMember(VarDecl *Pattern,
 }
 
 static bool isInstantiationOf(ASTContext &Ctx, NamedDecl *D, Decl *Other) {
-  if (D->getKind() != Other->getKind())
-    return false;
+  if (D->getKind() != Other->getKind()) {
+    if (UnresolvedUsingDecl *UUD = dyn_cast<UnresolvedUsingDecl>(D)) {
+      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) {
+        return isInstantiationOf(UUD, UD, Ctx);
+      }
+    }
 
+    return false;
+  }
+  
   if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Other))
     return isInstantiationOf(cast<CXXRecordDecl>(D), Record);