--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/c99-const-expr-11.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,46 @@
+/* Test for constant expressions: cases involving VLAs.  */
+/* Origin: Joseph Myers <joseph@codesourcery.com> */
+/* { dg-do compile } */
+/* { dg-options "-std=iso9899:1999 -pedantic-errors" } */
+
+/* It appears address constants may contain casts to variably modified
+   types.  Whether they should be permitted was discussed in
+   <http://groups.google.com/group/comp.std.c/msg/923eee5ab690fd98>
+   <LV7g2Vy3ARF$Ew9Q@romana.davros.org>; since static pointers to VLAs
+   are definitely permitted within functions and may be initialized
+   and such initialization involves implicit conversion to a variably
+   modified type, allowing explicit casts seems appropriate.  Thus,
+   GCC allows them as long as the "evaluated" size expressions do not
+   contain the various operators not permitted to be evaluated in a
+   constant expression, and as long as the result is genuinely
+   constant (meaning that pointer arithmetic using the size of the VLA
+   is generally not permitted).  */
+
+static int sa[100];
+
+volatile int nv;
+
+int
+f (int m, int n)
+{
+  static int (*a1)[n] = &sa;
+  static int (*a2)[n] = (int (*)[n])sa;
+  static int (*a3)[n] = (int (*)[(int){n}])sa;
+  static int (*a4)[n] = (int (*)[(int){m++}])sa; /* { dg-error "constant" } */
+  static int (*a5)[n] = (int (*)[(int){++m}])sa; /* { dg-error "constant" } */
+  static int (*a6)[n] = (int (*)[(int){m--}])sa; /* { dg-error "constant" } */
+  static int (*a7)[n] = (int (*)[(int){--m}])sa; /* { dg-error "constant" } */
+  static int (*a8)[n] = (int (*)[(m=n)])sa; /* { dg-error "constant" } */
+  static int (*a9)[n] = (int (*)[(m+=n)])sa; /* { dg-error "constant" } */
+  static int (*a10)[n] = (int (*)[f(m,n)])sa; /* { dg-error "constant" } */
+  static int (*a11)[n] = (int (*)[(m,n)])sa; /* { dg-error "constant" } */
+  static int (*a12)[n] = (int (*)[sizeof(int[n])])sa;
+  static int (*a13)[n] = (int (*)[sizeof(int[m++])])sa; /* { dg-error "constant" } */
+  static int (*a14)[n] = (int (*)[sizeof(*a1)])sa;
+  static int (*a15)[n] = (int (*)[sizeof(*(int (*)[n])sa)])sa;
+  static int (*a16)[n] = (int (*)[sizeof(*(int (*)[m++])sa)])sa; /* { dg-error "constant" } */
+  static int (*a17)[n] = (int (*)[nv])sa;
+  typedef int (*vmt)[m++];
+  static int (*a18)[n] = (vmt)sa;
+  return n;
+}