commit 6a4d118d9ae128791a4f043cc1e079c82bad6fb8
Author: Jason Merrill <jason@redhat.com>
Date: Wed Aug 12 17:54:04 2015 +0100
* constexpr.c (cxx_eval_store_expression): Don't set
CONSTRUCTOR_NO_IMPLICIT_ZERO if we have an enclosing CONSTRUCTOR
without it.
(cxx_eval_array_reference): Check it.
@@ -1741,6 +1741,18 @@ cxx_eval_array_reference (const constexpr_ctx *ctx, tree t,
{
if (tree_int_cst_lt (index, array_type_nelts_top (TREE_TYPE (ary))))
{
+ if (TREE_CODE (ary) == CONSTRUCTOR
+ && CONSTRUCTOR_NO_IMPLICIT_ZERO (ary))
+ {
+ /* 'ary' is part of the aggregate initializer we're currently
+ building; if there's no initializer for this element yet,
+ that's an error. */
+ if (!ctx->quiet)
+ error ("accessing uninitialized array element");
+ *non_constant_p = true;
+ return t;
+ }
+
/* If it's within the array bounds but doesn't have an explicit
initializer, it's value-initialized. */
tree val = build_value_init (elem_type, tf_warning_or_error);
@@ -2683,13 +2695,17 @@ cxx_eval_store_expression (const constexpr_ctx *ctx, tree t,
return t;
}
type = TREE_TYPE (object);
+ bool no_zero_init = true;
while (!refs->is_empty())
{
if (*valp == NULL_TREE)
{
*valp = build_constructor (type, NULL);
- CONSTRUCTOR_NO_IMPLICIT_ZERO (*valp) = true;
+ CONSTRUCTOR_NO_IMPLICIT_ZERO (*valp) = no_zero_init;
}
+ /* If the value of object is already zero-initialized, any new ctors for
+ subobjects will also be zero-initialized. */
+ no_zero_init = CONSTRUCTOR_NO_IMPLICIT_ZERO (*valp);
constructor_elt ce;
type = refs->pop();
@@ -2717,7 +2733,7 @@ cxx_eval_store_expression (const constexpr_ctx *ctx, tree t,
new_ctx.ctor = build_constructor (type, NULL);
if (*valp == NULL_TREE)
*valp = new_ctx.ctor;
- CONSTRUCTOR_NO_IMPLICIT_ZERO (new_ctx.ctor) = true;
+ CONSTRUCTOR_NO_IMPLICIT_ZERO (new_ctx.ctor) = no_zero_init;
new_ctx.object = target;
}
new file mode 100644
@@ -0,0 +1,8 @@
+// { dg-do compile { target c++11 } }
+
+struct A { int ar[3]; };
+int main()
+{
+ constexpr A a1 = { 0, a1.ar[0] };
+ constexpr A a2 = { a2.ar[0] }; // { dg-error "uninitialized" }
+}