Index: lib/Sema/SemaChecking.cpp
===================================================================
--- lib/Sema/SemaChecking.cpp
+++ lib/Sema/SemaChecking.cpp
@@ -1348,7 +1348,8 @@
   }
 
   if (FDecl || Proto) {
-    CheckNonNullArguments(*this, FDecl, Proto, Args, Loc);
+    if (!isUnevaluatedContext())
+      CheckNonNullArguments(*this, FDecl, Proto, Args, Loc);
 
     // Type safety checking.
     if (FDecl) {
Index: test/Sema/non-null-warning.c
===================================================================
--- test/Sema/non-null-warning.c
+++ test/Sema/non-null-warning.c
@@ -39,4 +39,5 @@
 
 int main () {
   foo(0); // expected-warning {{null passed to a callee that requires a non-null argument}}
+  (void)sizeof(foo(0)); // expect no warning when in an unevaluated context.
 }