--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/format/ext-6.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,47 @@
+/* Test for format extensions.  Test that the C99 functions get their
+   default attributes in gnu89 mode.
+*/
+/* Origin: Joseph Myers <jsm28@cam.ac.uk> */
+/* { dg-do compile } */
+/* { dg-options "-std=gnu89 -Wformat" } */
+
+#include "format.h"
+
+void
+foo (int i, char *s, size_t n, int *ip, va_list v0, va_list v1, va_list v2,
+     va_list v3, va_list v4, va_list v5, va_list v6, va_list v7, va_list v8,
+     va_list v9, va_list v10, va_list v11, va_list v12, va_list v13)
+{
+  fprintf (stdout, "%d", i);
+  fprintf (stdout, "%ld", i); /* { dg-warning "format" "fprintf" } */
+  printf ("%d", i);
+  printf ("%ld", i); /* { dg-warning "format" "printf" } */
+  fprintf_unlocked (stdout, "%d", i);
+  fprintf_unlocked (stdout, "%ld", i); /* { dg-warning "format" "fprintf_unlocked" } */
+  printf_unlocked ("%d", i);
+  printf_unlocked ("%ld", i); /* { dg-warning "format" "printf_unlocked" } */
+  sprintf (s, "%d", i);
+  sprintf (s, "%ld", i); /* { dg-warning "format" "sprintf" } */
+  snprintf (s, n, "%d", i);
+  snprintf (s, n, "%ld", i); /* { dg-warning "format" "snprintf" } */
+  vfprintf (stdout, "%d", v0);
+  vfprintf (stdout, "%Y", v1); /* { dg-warning "format" "vfprintf" } */
+  vprintf ("%d", v2);
+  vprintf ("%Y", v3); /* { dg-warning "format" "vprintf" } */
+  vsprintf (s, "%d", v4);
+  vsprintf (s, "%Y", v5); /* { dg-warning "format" "vsprintf" } */
+  vsnprintf (s, n, "%d", v6);
+  vsnprintf (s, n, "%Y", v7); /* { dg-warning "format" "vsnprintf" } */
+  fscanf (stdin, "%d", ip);
+  fscanf (stdin, "%ld", ip); /* { dg-warning "format" "fscanf" } */
+  scanf ("%d", ip);
+  scanf ("%ld", ip); /* { dg-warning "format" "scanf" } */
+  sscanf (s, "%d", ip);
+  sscanf (s, "%ld", ip); /* { dg-warning "format" "sscanf" } */
+  vfscanf (stdin, "%d", v8);
+  vfscanf (stdin, "%Y", v9); /* { dg-warning "format" "vfscanf" } */
+  vscanf ("%d", v10);
+  vscanf ("%Y", v11); /* { dg-warning "format" "vscanf" } */
+  vsscanf (s, "%d", v12);
+  vsscanf (s, "%Y", v13); /* { dg-warning "format" "vsscanf" } */
+}