On 2/6/26 6:38 PM, Jakub Jelinek wrote:
Hi!
We weren't adding the DECL_SELF_REFERENCE_P TYPE_DECL to TYPE_FIELDS of
eval_define_aggregate created aggregates, which resulted in ICE in
accessible_base_p which relies on DECL_SELF_REFERENCE_P TYPE_DECL to be
present in base classes of other classes.
Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for
trunk?
2026-02-05 Jakub Jelinek <[email protected]>
PR c++/123984
* reflect.cc (eval_define_aggregate): Set TYPE_BEING_DEFINED on type
after pushclass and call build_self_reference before finish_struct.
A bit odd to have the self-ref last instead of first, this seems like an
issue for members_of ordering?
* g++.dg/reflect/define_aggregate6.C: New test.
--- gcc/cp/reflect.cc.jj 2026-02-05 15:19:21.963084934 +0100
+++ gcc/cp/reflect.cc 2026-02-05 17:40:03.901515578 +0100
@@ -6081,6 +6081,7 @@ eval_define_aggregate (location_t loc, c
xref_basetypes (type, NULL_TREE);
pushclass (type);
gcc_assert (!TYPE_FIELDS (type));
+ TYPE_BEING_DEFINED (type) = 1;
tree fields = NULL_TREE;
for (int i = 0; i < TREE_VEC_LENGTH (rvec); ++i)
{
@@ -6121,6 +6122,7 @@ eval_define_aggregate (location_t loc, c
fields = f;
}
TYPE_FIELDS (type) = fields;
+ build_self_reference ();
finish_struct (type, NULL_TREE);
return get_reflection_raw (loc, orig_type);
}
--- gcc/testsuite/g++.dg/reflect/define_aggregate6.C.jj 2026-02-05
17:42:07.498427315 +0100
+++ gcc/testsuite/g++.dg/reflect/define_aggregate6.C 2026-02-05
17:41:55.461630714 +0100
@@ -0,0 +1,22 @@
+// PR c++/123984
+// { dg-do compile { target c++26 } }
+// { dg-additional-options "-freflection" }
+
+#include <meta>
+
+struct A;
+consteval
+{
+ define_aggregate (^^A, { data_member_spec (^^int, {.name{"_"}}) });
+}
+
+struct B : A {};
+
+constexpr int
+get (B &&d)
+{
+ constexpr auto ctx = std::meta::access_context::unchecked ();
+ return static_cast <A*> (&d)->[: nonstatic_data_members_of (^^A, ctx)[0] :];
+}
+
+static_assert (get (B { 123 }) == 123);
Jakub
