[gcc r15-5570] c++: modules and tsubst_friend_class

[Jason Merrill via Gcc-cvs]

https://gcc.gnu.org/g:03c7145a4175c452362b5d1e2fa5f83dc8a01d18

commit r15-5570-g03c7145a4175c452362b5d1e2fa5f83dc8a01d18
Author: Jason Merrill <ja...@redhat.com>
Date:   Wed Nov 20 13:51:10 2024 +0100

    c++: modules and tsubst_friend_class
    
    In 20_util/function_objects/mem_fn/constexpr.cc we start to instantiate
    _Mem_fn_base's friend declaration of _Bind_check_arity before we've loaded
    the namespace-scope declaration, so lookup_imported_hidden_friend doesn't
    find it.  But then we load the namespace-scope declaration in
    lookup_template_class during substitution, and so when we get around to
    pushing the result of substitution, they conflict.  Fixed by calling
    lazy_load_pendings in lookup_imported_hidden_friend.
    
    gcc/cp/ChangeLog:
    
            * name-lookup.cc (lookup_imported_hidden_friend): Call
            lazy_load_pendings.

Diff:
---
 gcc/cp/name-lookup.cc | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/gcc/cp/name-lookup.cc b/gcc/cp/name-lookup.cc
index 2dca57a14fd8..769879976420 100644
--- a/gcc/cp/name-lookup.cc
+++ b/gcc/cp/name-lookup.cc
@@ -4569,6 +4569,8 @@ lookup_imported_hidden_friend (tree friend_tmpl)
       || !DECL_MODULE_IMPORT_P (inner))
     return NULL_TREE;
 
+  lazy_load_pendings (friend_tmpl);
+
   tree bind = get_mergeable_namespace_binding
     (current_namespace, DECL_NAME (inner), DECL_MODULE_ATTACH_P (inner));
   if (!bind)