--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/format/c90-strftime-2.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,31 @@
+/* Test for strftime formats.  Rejection of formats using C99 features in
+   pedantic C90 mode.  */
+/* Origin: Joseph Myers <jsm28@cam.ac.uk> */
+/* { dg-do compile } */
+/* { dg-options "-std=iso9899:1990 -pedantic -Wformat -Wformat-y2k" } */
+
+#include "format.h"
+
+void
+foo (char *s, size_t m, const struct tm *tp)
+{
+  strftime (s, m, "%C", tp); /* { dg-warning "C" "%C not in C90" } */
+  strftime (s, m, "%D", tp); /* { dg-warning "C" "%D not in C90" } */
+  /* { dg-warning "only last 2" "2-digit year" { target *-*-* } .-1 } */
+  strftime (s, m, "%e", tp); /* { dg-warning "C" "%e not in C90" } */
+  strftime (s, m, "%F", tp); /* { dg-warning "C" "%F not in C90" } */
+  strftime (s, m, "%g", tp); /* { dg-warning "C" "%g not in C90" } */
+  /* { dg-warning "only last 2" "2-digit year" { target *-*-* } .-1 } */
+  strftime (s, m, "%G", tp); /* { dg-warning "C" "%G not in C90" } */
+  strftime (s, m, "%h", tp); /* { dg-warning "C" "%h not in C90" } */
+  strftime (s, m, "%n", tp); /* { dg-warning "C" "%n not in C90" } */
+  strftime (s, m, "%r", tp); /* { dg-warning "C" "%r not in C90" } */
+  strftime (s, m, "%R", tp); /* { dg-warning "C" "%R not in C90" } */
+  strftime (s, m, "%t", tp); /* { dg-warning "C" "%t not in C90" } */
+  strftime (s, m, "%T", tp); /* { dg-warning "C" "%T not in C90" } */
+  strftime (s, m, "%u", tp); /* { dg-warning "C" "%u not in C90" } */
+  strftime (s, m, "%V", tp); /* { dg-warning "C" "%V not in C90" } */
+  strftime (s, m, "%z", tp); /* { dg-warning "C" "%z not in C90" } */
+  strftime (s, m, "%EX", tp); /* { dg-warning "C" "%E not in C90" } */
+  strftime (s, m, "%OW", tp); /* { dg-warning "C" "%O not in C90" } */
+}