--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/Walloca-7.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,18 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target alloca } */
+/* { dg-options "-Walloca -O0" } */
+
+extern void f(void *);
+
+void foo(void)
+{
+  // Test that strict -Walloca works even without optimization.
+  f (__builtin_alloca(500)); // { dg-warning "use of 'alloca'" }
+}
+
+void bar(void)
+{
+  // Test that we warn on alloca() calls, not just __builtin_alloca calls.
+  extern void *alloca(__SIZE_TYPE__);
+  f (alloca (123)); // { dg-warning "use of 'alloca'" }
+}