1 files changed, 3 insertions, 4 deletions
diff --git a/clang/lib/ASTMatchers/ASTMatchFinder.cpp b/clang/lib/ASTMatchers/ASTMatchFinder.cpp
index 571e7dac240..8807b13c5ed 100644
--- a/clang/lib/ASTMatchers/ASTMatchFinder.cpp
+++ b/clang/lib/ASTMatchers/ASTMatchFinder.cpp
@@ -621,6 +621,9 @@ private:
     if (Node.get<TranslationUnitDecl>() ==
         ActiveASTContext->getTranslationUnitDecl())
       return false;
+    assert(Node.getMemoizationData() &&
+           "Invariant broken: only nodes that support memoization may be "
+           "used in the parent map.");
 
     MatchKey Key;
     Key.MatcherID = Matcher.getID();
@@ -864,11 +867,7 @@ bool MatchASTVisitor::TraverseNestedNameSpecifier(NestedNameSpecifier *NNS) {
 
 bool MatchASTVisitor::TraverseNestedNameSpecifierLoc(
     NestedNameSpecifierLoc NNS) {
-  if (!NNS)
-    return true;
-
   match(NNS);
-
   // We only match the nested name specifier here (as opposed to traversing it)
   // because the traversal is already done in the parallel "Loc"-hierarchy.
   if (NNS.hasQualifier())