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[C++ PATCH] For -std=c++1z treat class types with inherited ctors as non-aggregate (PR c++/79143)
- From: Jakub Jelinek <jakub at redhat dot com>
- To: Jason Merrill <jason at redhat dot com>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Tue, 7 Feb 2017 22:30:36 +0100
- Subject: [C++ PATCH] For -std=c++1z treat class types with inherited ctors as non-aggregate (PR c++/79143)
- Authentication-results: sourceware.org; auth=none
- Reply-to: Jakub Jelinek <jakub at redhat dot com>
Hi!
P0017R1 added in [dcl.init.aggr]/1 that classes with inherited constructors
are not aggregate. CLASSTYPE_NON_AGGREGATE is set slightly before
add_implicitly_declared_members is called and so we don't know about the
inherited ctors yet.
Not 100% sure if we want to do this even for -std=c++1z
-fno-new-inheriting-ctors (i.e. if the below block shouldn't be guarded with
&& flag_new_inheriting_ctors too), because e.g. for
-fno-new-inheriting-ctors we actually don't set TYPE_HAS_USER_CONSTRUCTOR.
Bootstrapped/regtested on x86_64-linux and i686-linux and additionally
tested with make check-c++-all on both.
2017-02-07 Jakub Jelinek <jakub@redhat.com>
PR c++/79143
* class.c (add_implicitly_declared_members): Set
CLASSTYPE_NON_AGGREGATE and CLASSTYPE_NON_LAYOUT_POD_P on types
with inherited constructors for C++17.
* g++.dg/cpp1z/pr79143.C: New test.
--- gcc/cp/class.c.jj 2017-02-04 08:43:15.000000000 +0100
+++ gcc/cp/class.c 2017-02-07 18:00:24.479093367 +0100
@@ -3453,8 +3453,19 @@ add_implicitly_declared_members (tree t,
location_t loc = input_location;
input_location = DECL_SOURCE_LOCATION (using_decl);
if (ctor_list)
- for (; ctor_list; ctor_list = OVL_NEXT (ctor_list))
- one_inherited_ctor (OVL_CURRENT (ctor_list), t, using_decl);
+ {
+ if (cxx_dialect >= cxx1z)
+ {
+ /* [dcl.init.aggr]/1: An aggregate is an array or a class
+ with
+ - no user-provided, explicit or inherited
+ constructors. */
+ CLASSTYPE_NON_AGGREGATE (t) = 1;
+ CLASSTYPE_NON_LAYOUT_POD_P (t) = 1;
+ }
+ for (; ctor_list; ctor_list = OVL_NEXT (ctor_list))
+ one_inherited_ctor (OVL_CURRENT (ctor_list), t, using_decl);
+ }
*access_decls = TREE_CHAIN (*access_decls);
input_location = loc;
}
--- gcc/testsuite/g++.dg/cpp1z/pr79143.C.jj 2017-02-07 17:55:19.091028200 +0100
+++ gcc/testsuite/g++.dg/cpp1z/pr79143.C 2017-02-07 17:54:48.000000000 +0100
@@ -0,0 +1,28 @@
+// PR c++/79143
+// { dg-do compile }
+// { dg-options "-std=c++1z" }
+
+struct base {
+ base (int, int) {}
+};
+
+template<class>
+struct derived : base {
+ using base::base;
+};
+
+template<class>
+struct derived2 : base {
+ derived2 (int x, int y) : base (x, y) {}
+};
+
+int
+main ()
+{
+ base (13, 42);
+ derived<int> (13, 42);
+ derived2<int> (13, 42);
+ base{13, 42};
+ derived<int>{13, 42}; // { dg-bogus "too many initializers" }
+ derived2<int>{13, 42};
+}
Jakub