diff --git a/clang/lib/StaticAnalyzer/Checkers/CallAndMessageChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/CallAndMessageChecker.cpp
--- a/clang/lib/StaticAnalyzer/Checkers/CallAndMessageChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/CallAndMessageChecker.cpp
@@ -262,7 +262,9 @@
         if (T->getAsStructureType()) {
           if (Find(FR))
             return true;
-        } else {
+        } else if (!I->isUnnamedBitfield()){
+          // unnamed bitfields are skipped during aggregate initialization
+          // Since they are not supposed to be used, warnings should not be reported
           const SVal &V = StoreMgr.getBinding(store, loc::MemRegionVal(FR));
           if (V.isUndef())
             return true;