--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/g++.dg/lto/pr52400_0.C	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,18 @@
+// { dg-lto-do run }
+
+extern "C" {
+  static int f4(int);
+
+int f5(int a) {
+  extern int f4(int);
+  return f4(a);
+}
+}
+
+int f4(int a) { return 4+a; }
+
+int main(int argc, char *argv[])
+{
+  int a = f4(1);
+  return !(a == 5);
+}