1 files changed, 13 insertions, 0 deletions
diff --git a/test/Sema/format-strings-size_t.c b/test/Sema/format-strings-size_t.c
index 7f88ff3..5058a76 100644
--- a/test/Sema/format-strings-size_t.c
+++ b/test/Sema/format-strings-size_t.c
@@ -13,3 +13,16 @@ void test(void) {
   // ptrdiff_t
   printf("%td", (double)42); // expected-warning {{format specifies type 'ptrdiff_t' (aka 'long') but the argument has type 'double'}}
 }
+
+void test_writeback(void) {
+  printf("%jn", (long*)0); // no-warning
+  printf("%jn", (unsigned long*)0); // no-warning
+  printf("%jn", (int*)0); // expected-warning{{format specifies type 'intmax_t *' (aka 'long *') but the argument has type 'int *'}}
+
+  printf("%zn", (long*)0); // no-warning
+  // FIXME: Warn about %zn with non-ssize_t argument.
+
+  printf("%tn", (long*)0); // no-warning
+  printf("%tn", (unsigned long*)0); // no-warning
+  printf("%tn", (int*)0); // expected-warning{{format specifies type 'ptrdiff_t *' (aka 'long *') but the argument has type 'int *'}}
+}