[C++ PATCH] PR c++/89381 - implicit copy and using-declaration.

[C++ PATCH] PR c++/89381 - implicit copy and using-declaration.

[Jason Merrill]

Here the used base<int>::operator= gets into the list of foo's bindings for
operator=, but it shouldn't make the copy ctor deleted.

Tested x86_64-pc-linux-gnu, applying to trunk.

	* class.c (classtype_has_move_assign_or_move_ctor_p): Don't consider
	op= brought in by a using-declaration.
---
 gcc/cp/class.c                          |  4 ++-
 gcc/testsuite/g++.dg/cpp0x/implicit16.C | 37 +++++++++++++++++++++++++
 gcc/cp/ChangeLog                        |  4 +++
 3 files changed, 44 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/implicit16.C

diff --git a/gcc/cp/class.c b/gcc/cp/class.c
index 0d4d35bd690..a70a852424e 100644
--- a/gcc/cp/class.c
+++ b/gcc/cp/class.c
@@ -5220,7 +5220,9 @@ classtype_has_move_assign_or_move_ctor_p (tree t, bool user_p)
     for (ovl_iterator iter (get_class_binding_direct
 			    (t, assign_op_identifier));
 	 iter; ++iter)
-      if ((!user_p || !DECL_ARTIFICIAL (*iter)) && move_fn_p (*iter))
+      if ((!user_p || !DECL_ARTIFICIAL (*iter))
+	  && DECL_CONTEXT (*iter) == t
+	  && move_fn_p (*iter))
 	return true;
   
   return false;
diff --git a/gcc/testsuite/g++.dg/cpp0x/implicit16.C b/gcc/testsuite/g++.dg/cpp0x/implicit16.C
new file mode 100644
index 00000000000..229f2b4cd81
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/implicit16.C
@@ -0,0 +1,37 @@
+// PR c++/89381
+// { dg-do compile { target c++11 } }
+
+template<typename T>
+struct base
+{
+  base() { }
+  base(const base&) { }
+  base(base&&) { }
+  base& operator=(const base&) { return *this; }
+  base& operator=(base&&) { return *this; }
+};
+
+struct foo : base<int>
+{
+    using base<int>::base;
+    using base<int>::operator=;
+};
+
+//using workaround = decltype(foo{*static_cast<foo const*>(0)});
+
+struct bar
+{
+    bar& operator=(foo ve)
+    {
+        value = ve;
+        return *this;
+    }
+
+    foo value;
+};
+
+int main()
+{
+    foo a;
+    foo b{a};
+}
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index a076fa9a255..848859e955e 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,9 @@
 2019-03-06  Jason Merrill  <jason@redhat.com>
 
+	PR c++/89381 - implicit copy and using-declaration.
+	* class.c (classtype_has_move_assign_or_move_ctor_p): Don't consider
+	op= brought in by a using-declaration.
+
 	PR c++/89576 - if constexpr of lambda capture.
 	* semantics.c (maybe_convert_cond): Do convert a non-dependent
 	condition in a template.

base-commit: 02daf5d2ca0cd851d93e4d7299a95013cb405497
-- 
2.20.1