c++/reflection: add assert to eval_type_trait

As discussed in
<https://gcc.gnu.org/pipermail/gcc-patches/2026-January/705756.html>.

Since we check eval_is_type in process_metafunction:

  if (eval_is_type (ht) != boolean_true_node)
     return throw_exception_nontype (loc, ctx, fun, non_constant_p,
				     jump_target);

finish_trait_expr should never return error_mark_node.  We can ensure
that it's so by adding an assert.

gcc/cp/ChangeLog:

	* reflect.cc (eval_type_trait): Assert that finish_trait_expr didn't
	return error_mark_node.

Reviewed-by: Jason Merrill <jason@redhat.com>

diff --git a/gcc/cp/reflect.cc b/gcc/cp/reflect.cc
index 4174c2ef855317343577ee51ece058d99fd10a04..141294dd2b2c5c669474e9c8d697e54a550d6b31 100644 (file)
--- a/gcc/cp/reflect.cc
+++ b/gcc/cp/reflect.cc
@@ -3920,6 +3920,7 @@ static tree
 eval_type_trait (location_t loc, tree type1, tree type2, cp_trait_kind kind)
 {
   tree r = finish_trait_expr (loc, kind, type1, type2);
+  gcc_checking_assert (r != error_mark_node);
   STRIP_ANY_LOCATION_WRAPPER (r);
   return r;
 }