[Bug c++/67407] [6 regression] ice in friend_accessible_p

[trippels at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67407

--- Comment #2 from Markus Trippelsdorf <trippels at gcc dot gnu.org> ---
markus@x4 tmp % cat b.ii
template <class> class A;
template <class> struct B;
template <class X> struct B<A<X> >
{
  static int
  check ()
  {
    A<X> a;
    a.m_class->m_object;
  }
};
template <class T> class A
{
public:
  template <class X> bool operator== (const X &) const;
  T *m_class;
};
template <class T>
template <class X>
bool
A<T>::operator== (const X &) const
{
  B<X>::check;
}
class C
{
protected:
  template <class> friend struct B;
  void *m_object;
};
class F : virtual C
{
};
class G : virtual public C
{
};
class H : F, public G
{
};
class D
{
  void onBusMessage (const A<int> &);
  A<H> m_pipeline;
};
void
D::onBusMessage (const A<int> &p1)
{
  p1 == m_pipeline;
}

markus@x4 tmp % g++ -c b.ii
b.ii: In instantiation of ‘static int B<A<X> >::check() [with X = H]’:
b.ii:23:3:   required from ‘bool A< <template-parameter-1-1>
>::operator==(const X&) const [with X = A<H>; T = int]’
b.ii:48:9:   required from here
b.ii:9:5: internal compiler error: in friend_accessible_p, at cp/search.c:847
     a.m_class->m_object;
     ^
0x75973d friend_accessible_p
        ../../gcc/gcc/cp/search.c:847
0x759703 friend_accessible_p
        ../../gcc/gcc/cp/search.c:839
0x7596c2 friend_accessible_p
        ../../gcc/gcc/cp/search.c:822
0x759942 dfs_accessible_post
        ../../gcc/gcc/cp/search.c:907
0x756f66 dfs_walk_once_accessible_r
        ../../gcc/gcc/cp/search.c:1872
0x75708c dfs_walk_once_accessible_r
        ../../gcc/gcc/cp/search.c:1863
0x75708c dfs_walk_once_accessible_r
        ../../gcc/gcc/cp/search.c:1863
0x7571cc dfs_walk_once_accessible
        ../../gcc/gcc/cp/search.c:1891
0x758c69 accessible_p(tree_node*, tree_node*, bool)
        ../../gcc/gcc/cp/search.c:1015
0x5c5141 enforce_access(tree_node*, tree_node*, tree_node*, int)
        ../../gcc/gcc/cp/call.c:6091
0x76ea27 perform_or_defer_access_check(tree_node*, tree_node*, tree_node*, int)
        ../../gcc/gcc/cp/semantics.c:337
0x758585 lookup_member(tree_node*, tree_node*, int, bool, int)
        ../../gcc/gcc/cp/search.c:1337
0x72f47b finish_class_member_access_expr(tree_node*, tree_node*, bool, int)
        ../../gcc/gcc/cp/typeck.c:2782
0x643920 tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool,
bool)
        ../../gcc/gcc/cp/pt.c:16098
0x635a40 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
        ../../gcc/gcc/cp/pt.c:15031
0x636422 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
        ../../gcc/gcc/cp/pt.c:14442
0x634f43 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
        ../../gcc/gcc/cp/pt.c:14428
0x63521b tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
        ../../gcc/gcc/cp/pt.c:14614
0x6334f5 instantiate_decl(tree_node*, int, bool)
        ../../gcc/gcc/cp/pt.c:21158
0x678689 instantiate_pending_templates(int)
        ../../gcc/gcc/cp/pt.c:21275
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