| Message ID | 20200316225435.GA3755249@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | [committed] libstdc++: Add default constructor to net::service_already_exists (PR 94199) | expand |
Hi, On Mon, 16 Mar 2020 at 23:54, Jonathan Wakely via Gcc-patches <gcc-patches@gcc.gnu.org> wrote: > > The service_already_exists exception type specified in the TS doesn't > have any constructors defined. Since its base class isn't default > constructible, that means has no usable constructors. This may be a > defect in the TS. > > This patch fixes it by adding a default constructor, but making it > private. The make_service function is declared as a friend to be able to > call that private constructor. > > PR libstdc++/94199 > * include/experimental/executor (service_already_exists): Add default > constructor. Declare make_service to be a friend. > * testsuite/experimental/net/execution_context/make_service.cc: New > test. > The new test fails on arm-eabi / aarch64-elf (aka bare-metal / newlib targets), because: /arm-none-eabi/libstdc++-v3/include/experimental/executor:514: error: 'mutex' in namespace 'std' does not name a type /arm-none-eabi/libstdc++-v3/include/experimental/executor:561: error: 'mutex' is not a member of 'std' [...] I don't remember what's the usual "fix" for this Thanks, Christophe > Tested powerpc64le-linux, committed to master. > > I'll backport it to gcc-9 too. >
On 17/03/20 12:01 +0100, Christophe Lyon wrote: >Hi, > > >On Mon, 16 Mar 2020 at 23:54, Jonathan Wakely via Gcc-patches ><gcc-patches@gcc.gnu.org> wrote: >> >> The service_already_exists exception type specified in the TS doesn't >> have any constructors defined. Since its base class isn't default >> constructible, that means has no usable constructors. This may be a >> defect in the TS. >> >> This patch fixes it by adding a default constructor, but making it >> private. The make_service function is declared as a friend to be able to >> call that private constructor. >> >> PR libstdc++/94199 >> * include/experimental/executor (service_already_exists): Add default >> constructor. Declare make_service to be a friend. >> * testsuite/experimental/net/execution_context/make_service.cc: New >> test. >> > >The new test fails on arm-eabi / aarch64-elf (aka bare-metal / newlib >targets), because: >/arm-none-eabi/libstdc++-v3/include/experimental/executor:514: error: >'mutex' in namespace 'std' does not name a type >/arm-none-eabi/libstdc++-v3/include/experimental/executor:561: error: >'mutex' is not a member of 'std' >[...] > >I don't remember what's the usual "fix" for this I think they are just failing on some targets: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89760
On 16/03/20 22:54 +0000, Jonathan Wakely wrote: >The service_already_exists exception type specified in the TS doesn't >have any constructors defined. Since its base class isn't default >constructible, that means has no usable constructors. This may be a >defect in the TS. > >This patch fixes it by adding a default constructor, but making it >private. The make_service function is declared as a friend to be able to >call that private constructor. > > PR libstdc++/94199 > * include/experimental/executor (service_already_exists): Add default > constructor. Declare make_service to be a friend. > * testsuite/experimental/net/execution_context/make_service.cc: New > test. LWG preferred to make the constrcutor public, so this patch does that. Tested x86_64-linux, committed to master.
diff --git a/libstdc++-v3/include/experimental/executor b/libstdc++-v3/include/experimental/executor index 5577623bb47..6955ead6bf5 100644 --- a/libstdc++-v3/include/experimental/executor +++ b/libstdc++-v3/include/experimental/executor @@ -127,7 +127,14 @@ inline namespace v1 /// An extensible, type-safe, polymorphic set of services. class execution_context; - class service_already_exists : public logic_error { }; + class service_already_exists : public logic_error + { + template<typename _Service, typename... _Args> + friend _Service& + make_service(execution_context&, _Args&&...); + + service_already_exists() : logic_error("service already exists") { } + }; template<typename _Tp> struct is_executor; diff --git a/libstdc++-v3/testsuite/experimental/net/execution_context/make_service.cc b/libstdc++-v3/testsuite/experimental/net/execution_context/make_service.cc new file mode 100644 index 00000000000..f134add48b5 --- /dev/null +++ b/libstdc++-v3/testsuite/experimental/net/execution_context/make_service.cc @@ -0,0 +1,36 @@ +// Copyright (C) 2020 Free Software Foundation, Inc. +// +// This file is part of the GNU ISO C++ Library. This library is free +// software; you can redistribute it and/or modify it under the +// terms of the GNU General Public License as published by the +// Free Software Foundation; either version 3, or (at your option) +// any later version. + +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. + +// You should have received a copy of the GNU General Public License along +// with this library; see the file COPYING3. If not see +// <http://www.gnu.org/licenses/>. + +// { dg-do compile { target c++14 } } + +#include <experimental/executor> + +namespace net = std::experimental::net; + +struct S : net::execution_context::service +{ + using key_type = S; + + S(net::execution_context&); + + void shutdown() noexcept override { } +}; + +void test01(net::execution_context& c) +{ + net::make_service<S>(c); +}
The service_already_exists exception type specified in the TS doesn't have any constructors defined. Since its base class isn't default constructible, that means has no usable constructors. This may be a defect in the TS. This patch fixes it by adding a default constructor, but making it private. The make_service function is declared as a friend to be able to call that private constructor. PR libstdc++/94199 * include/experimental/executor (service_already_exists): Add default constructor. Declare make_service to be a friend. * testsuite/experimental/net/execution_context/make_service.cc: New test. Tested powerpc64le-linux, committed to master. I'll backport it to gcc-9 too. commit c62f5e6e1f457462b1cea74792833821bbea64bb Author: Jonathan Wakely <jwakely@redhat.com> Date: Mon Mar 16 22:53:42 2020 +0000 libstdc++: Add default constructor to net::service_already_exists (PR 94199) The service_already_exists exception type specified in the TS doesn't have any constructors defined. Since its base class isn't default constructible, that means has no usable constructors. This may be a defect in the TS. This patch fixes it by adding a default constructor, but making it private. The make_service function is declared as a friend to be able to call that private constructor. PR libstdc++/94199 * include/experimental/executor (service_already_exists): Add default constructor. Declare make_service to be a friend. * testsuite/experimental/net/execution_context/make_service.cc: New test.