Index: include/clang/StaticAnalyzer/Core/PathSensitive/BasicValueFactory.h
===================================================================
--- include/clang/StaticAnalyzer/Core/PathSensitive/BasicValueFactory.h
+++ include/clang/StaticAnalyzer/Core/PathSensitive/BasicValueFactory.h
@@ -233,7 +233,7 @@
   }
 
   llvm::ImmutableList<SVal> prependSVal(SVal X, llvm::ImmutableList<SVal> L) {
-    return SValListFactory.add(L, X);
+    return SValListFactory.add(X, L);
   }
 
   llvm::ImmutableList<const CXXBaseSpecifier *> getEmptyCXXBaseList() {
@@ -243,7 +243,7 @@
   llvm::ImmutableList<const CXXBaseSpecifier *> prependCXXBase(
       const CXXBaseSpecifier *CBS,
       llvm::ImmutableList<const CXXBaseSpecifier *> L) {
-    return CXXBaseListFactory.add(L, CBS);
+    return CXXBaseListFactory.add(CBS, L);
   }
 
   const PointerToMemberData *accumCXXBase(
Index: include/clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h
===================================================================
--- include/clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h
+++ include/clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h
@@ -153,7 +153,7 @@
     using context_type = typename data_type::Factory &;
 
     static data_type Add(data_type L, key_type K, context_type F) {
-      return F.add(L, K);
+      return F.add(K, L);
     }
 
     static bool Contains(data_type L, key_type K) {