On 03/13/2017 06:20 PM, Nathan Sidwell wrote:
On 03/13/2017 05:05 PM, Jason Merrill wrote:
It looks like you're ignoring the access for all base destructors;
handling this in synthesized_method_base_walk would let you limit the
change to vbases with virtual destructors. That function also already
handles ignoring access control for an inherited constructor.
Committed this. It looked to me that the inheriting ctor case should be
using dk_no_check rather than dk_deferring, given the comment. But I
didn't want to change that in this patch.
nathan
--
Nathan Sidwell
2017-03-14 Nathan Sidwell <nat...@acm.org>
PR c++/79393 DR 1658 workaround
* method.c (synthesized_method_base_walk): Inihibit abstract class
virtual base access check here.
(synthesized_method_walk): Not here.
Index: cp/method.c
===================================================================
--- cp/method.c (revision 246120)
+++ cp/method.c (working copy)
@@ -1420,10 +1420,10 @@ walk_field_subobs (tree fields, tree fnn
}
}
-// Base walker helper for synthesized_method_walk. Inspect a direct
-// or virtual base. BINFO is the parent type's binfo. BASE_BINFO is
-// the base binfo of interests. All other parms are as for
-// synthesized_method_walk, or its local vars.
+/* Base walker helper for synthesized_method_walk. Inspect a direct
+ or virtual base. BINFO is the parent type's binfo. BASE_BINFO is
+ the base binfo of interests. All other parms are as for
+ synthesized_method_walk, or its local vars. */
static tree
synthesized_method_base_walk (tree binfo, tree base_binfo,
@@ -1436,7 +1436,8 @@ synthesized_method_base_walk (tree binfo
{
bool inherited_binfo = false;
tree argtype = NULL_TREE;
-
+ deferring_kind defer = dk_no_deferred;
+
if (copy_arg_p)
argtype = build_stub_type (BINFO_TYPE (base_binfo), quals, move_p);
else if ((inherited_binfo
@@ -1445,11 +1446,21 @@ synthesized_method_base_walk (tree binfo
argtype = inherited_parms;
/* Don't check access on the inherited constructor. */
if (flag_new_inheriting_ctors)
- push_deferring_access_checks (dk_deferred);
+ defer = dk_deferred;
}
+ /* To be conservative, ignore access to the base dtor that
+ DR1658 instructs us to ignore. See the comment in
+ synthesized_method_walk. */
+ else if (cxx_dialect >= cxx14 && fnname == complete_dtor_identifier
+ && BINFO_VIRTUAL_P (base_binfo)
+ && ABSTRACT_CLASS_TYPE_P (BINFO_TYPE (binfo)))
+ defer = dk_no_check;
+
+ if (defer != dk_no_deferred)
+ push_deferring_access_checks (defer);
tree rval = locate_fn_flags (base_binfo, fnname, argtype, flags,
diag ? tf_warning_or_error : tf_none);
- if (inherited_binfo && flag_new_inheriting_ctors)
+ if (defer != dk_no_deferred)
pop_deferring_access_checks ();
process_subob_fn (rval, spec_p, trivial_p, deleted_p,
@@ -1677,13 +1688,6 @@ synthesized_method_walk (tree ctype, spe
if (constexpr_p)
*constexpr_p = false;
- /* To be conservative, ignore access to the base dtor that
- DR1658 instructs us to ignore. */
- bool no_access_check = (cxx_dialect >= cxx14
- && ABSTRACT_CLASS_TYPE_P (ctype));
-
- if (no_access_check)
- push_deferring_access_checks (dk_no_check);
FOR_EACH_VEC_ELT (*vbases, i, base_binfo)
synthesized_method_base_walk (binfo, base_binfo, quals,
copy_arg_p, move_p, ctor_p,
@@ -1691,8 +1695,6 @@ synthesized_method_walk (tree ctype, spe
fnname, flags, diag,
spec_p, trivial_p,
deleted_p, constexpr_p);
- if (no_access_check)
- pop_deferring_access_checks ();
}
/* Now handle the non-static data members. */
Index: testsuite/g++.dg/cpp1y/pr79393-2.C
===================================================================
--- testsuite/g++.dg/cpp1y/pr79393-2.C (revision 0)
+++ testsuite/g++.dg/cpp1y/pr79393-2.C (working copy)
@@ -0,0 +1,22 @@
+// { dg-do compile { target c++14 } }
+
+// DR 1658, inaccessible dtor of virtual base doesn't affect an
+// abstract class. But we should stil check access to non-virtual bases.
+
+class C;
+
+struct A {
+private:
+ ~A (){ }
+ friend class C;
+};
+
+struct B : A { // { dg-error "is private" }
+ virtual bool Ok () = 0; // abstract
+};
+
+struct C : B {
+ ~C ()
+ { } // { dg-error "use of deleted" }
+ virtual bool Ok ();
+};
