1 files changed, 31 insertions, 0 deletions
diff --git a/gcc/testsuite/g++.dg/ext/strncpy-chk1.C b/gcc/testsuite/g++.dg/ext/strncpy-chk1.C
new file mode 100644
index 00000000000..7770ba93127
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/strncpy-chk1.C
@@ -0,0 +1,31 @@
+// PR c++/40502
+// { dg-do compile }
+// { dg-options "-O2" }
+
+struct A { char x[12], y[35]; };
+struct B { char z[50]; };
+
+inline void
+foo (char *dest, const char *__restrict src, __SIZE_TYPE__ n)
+{
+  __builtin___strncpy_chk (dest, src, n, __builtin_object_size (dest, 0));	// { dg-warning "will always overflow" }
+}
+
+void bar (const char *, int);
+
+inline void
+baz (int i)
+{
+  char s[128], t[32];
+  bar (s, 0);
+  bar (t, i);
+  A a;
+  B b;
+  foo (a.y, b.z, 36);
+}
+
+void
+test ()
+{
+  baz (0);
+}