1 files changed, 9 insertions, 8 deletions

diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 634e699056e..b4d6175622d 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -7198,7 +7198,8 @@ Decl *Sema::ActOnStartNamespaceDef(Scope *NamespcScope,
     // as if by qualified name lookup.
     LookupResult R(*this, II, IdentLoc, LookupOrdinaryName, ForRedeclaration);
     LookupQualifiedName(R, CurContext->getRedeclContext());
-    NamedDecl *PrevDecl = R.getAsSingle<NamedDecl>();
+    NamedDecl *PrevDecl =
+        R.isSingleResult() ? R.getRepresentativeDecl() : nullptr;
     PrevNS = dyn_cast_or_null<NamespaceDecl>(PrevDecl);
 
     if (PrevNS) {
@@ -7579,9 +7580,9 @@ Decl *Sema::ActOnUsingDirective(Scope *S,
   }
   
   if (!R.empty()) {
-    NamedDecl *Named = R.getFoundDecl();
-    assert((isa<NamespaceDecl>(Named) || isa<NamespaceAliasDecl>(Named))
-        && "expected namespace decl");
+    NamedDecl *Named = R.getRepresentativeDecl();
+    NamespaceDecl *NS = R.getAsSingle<NamespaceDecl>();
+    assert(NS && "expected namespace decl");
 
     // The use of a nested name specifier may trigger deprecation warnings.
     DiagnoseUseOfDecl(Named, IdentLoc);
@@ -7598,7 +7599,6 @@ Decl *Sema::ActOnUsingDirective(Scope *S,
 
     // Find enclosing context containing both using-directive and
     // nominated namespace.
-    NamespaceDecl *NS = getNamespaceDecl(Named);
     DeclContext *CommonAncestor = cast<DeclContext>(NS);
     while (CommonAncestor && !CommonAncestor->Encloses(CurContext))
       CommonAncestor = CommonAncestor->getParent();
@@ -8669,7 +8669,7 @@ Decl *Sema::ActOnNamespaceAliasDef(Scope *S, SourceLocation NamespaceLoc,
     }
   }
   assert(!R.isAmbiguous() && !R.empty());
-  NamedDecl *ND = R.getFoundDecl();
+  NamedDecl *ND = R.getRepresentativeDecl();
 
   // Check if we have a previous declaration with the same name.
   LookupResult PrevR(*this, Alias, AliasLoc, LookupOrdinaryName,
@@ -8689,7 +8689,8 @@ Decl *Sema::ActOnNamespaceAliasDef(Scope *S, SourceLocation NamespaceLoc,
   // Find the previous declaration and check that we can redeclare it.
   NamespaceAliasDecl *Prev = nullptr; 
   if (NamedDecl *PrevDecl = PrevR.getAsSingle<NamedDecl>()) {
-    if (NamespaceAliasDecl *AD = dyn_cast<NamespaceAliasDecl>(PrevDecl)) {
+    if (NamespaceAliasDecl *AD =
+            dyn_cast<NamespaceAliasDecl>(PrevR.getRepresentativeDecl())) {
       // We already have an alias with the same name that points to the same
       // namespace; check that it matches.
       if (AD->getNamespace()->Equals(getNamespaceDecl(ND))) {
@@ -8697,7 +8698,7 @@ Decl *Sema::ActOnNamespaceAliasDef(Scope *S, SourceLocation NamespaceLoc,
       } else if (isVisible(PrevDecl)) {
         Diag(AliasLoc, diag::err_redefinition_different_namespace_alias)
           << Alias;
-        Diag(PrevDecl->getLocation(), diag::note_previous_namespace_alias)
+        Diag(AD->getLocation(), diag::note_previous_namespace_alias)
           << AD->getNamespace();
         return nullptr;
       }