[PATCH] Gimplify even TREE_CONSTANT VLA bounds unless they are INTEGER_CST (PR c/79413)

[Jakub Jelinek]

Hi!

The following testcase ICEs because we've failed to gimplify the array
bounds.  The array size in bytes e.g. is ((sizetype) (1 / 0) * 4) but
is TREE_CONSTANT and thus is_gimple_sizepos said that nothing needs to be
done for it.  In reality, the code actually expects INTEGER_CSTs or
VAR_DECLs (or NULL).

Fixed thusly, bootstrapped/regtested on x86_64-linux (including Ada) and
i686-linux (no Ada), ok for trunk?

2017-02-09  Jakub Jelinek  <ja...@redhat.com>

        PR c/79413
        * gimplify.h (is_gimple_sizepos): Only test for INTEGER_CST constants,
        not arbitrary TREE_CONSTANT.

        * gcc.c-torture/compile/pr79413.c: New test.

--- gcc/gimplify.h.jj   2017-01-01 12:45:34.000000000 +0100
+++ gcc/gimplify.h      2017-02-09 12:11:56.008551551 +0100
@@ -99,7 +99,7 @@ is_gimple_sizepos (tree expr)
      but that will cause problems if this type is from outside the function.
      It's OK to have that here.  */
   return (expr == NULL_TREE
-         || TREE_CONSTANT (expr)
+         || TREE_CODE (expr) == INTEGER_CST
          || TREE_CODE (expr) == VAR_DECL
          || CONTAINS_PLACEHOLDER_P (expr));
 }                                        
--- gcc/testsuite/gcc.c-torture/compile/pr79413.c.jj    2017-02-09 
12:16:01.424337042 +0100
+++ gcc/testsuite/gcc.c-torture/compile/pr79413.c       2017-02-09 
12:15:45.000000000 +0100
@@ -0,0 +1,13 @@
+/* PR c/79413 */
+
+void
+foo ()
+{
+  int a[1/0];
+}
+
+void
+bar (void)
+{
+  foo ();
+}

        Jakub