--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/pr39565.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,48 @@
+/* PR39565: Static variable leaves undefined symbol in object file.
+   Variables codestrs_4 and codestrs_8 should not be undefined,
+   when this program is compiled at -O2. As a basic sanity test,
+   verify that this program compiles into an executable and runs. */
+
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+
+extern void abort (void);
+extern void exit (int);
+extern int strcmp (const char *, const char *);
+
+static const union codestrs_t_4 {
+  struct {
+    char str_2[sizeof ("Illegal opcode")];
+  };
+  char str[0];
+} codestrs_4 = { {"Illegal opcode"} };
+
+static const union codestrs_t_8 {
+  struct {
+    char str_12[sizeof ("Integer divide by zero")];
+  };
+  char str[0];
+} codestrs_8 = { {"Integer divide by zero"} };
+
+const char *
+psiginfo (int pinfo)
+{
+  const char *base = ((void *)0);
+
+  switch (pinfo)
+    {
+    case 4: base = codestrs_4.str; break;
+    case 8: base = codestrs_8.str; break;
+    }
+  return base;
+}
+
+int
+main (void)
+{
+  if (strcmp (psiginfo (4), codestrs_4.str))
+    abort ();
+  if (strcmp (psiginfo (8), codestrs_8.str))
+    abort ();
+  exit (0);
+}