From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 2181) id 5589A3887F77; Mon, 14 Nov 2022 18:34:54 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 5589A3887F77 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1668450894; bh=lJzfDCOfBlKzGUDI3fxXAJfrTfW1VwVBv/D6zkcA1Gw=; h=From:To:Subject:Date:From; b=ojPicqtrBbiUwkZ/s+bIYWPT/6U9CB5YAQPewv6NdpFgF/WdJnbP0wkRCbn1NRAGL 7sKomLFtmPTsFLKcYJC0JEnqxmTRtJXtuOCoWGn7eSlHMEkBBCNwXrh8Hlvcu8Ze9r Cj6ovWJy5fyf/ukg/ITDOZkmKUdpmAxIo0P+mgrM= MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Jonathan Wakely To: gcc-cvs@gcc.gnu.org, libstdc++-cvs@gcc.gnu.org Subject: [gcc r12-8910] libstdc++: Fix std::move_only_function for incomplete parameter types X-Act-Checkin: gcc X-Git-Author: Jonathan Wakely X-Git-Refname: refs/heads/releases/gcc-12 X-Git-Oldrev: c6bd8fac5e3bc6003f889fbd6042c0d8aa9c40ed X-Git-Newrev: 9c45321cdbf48419ced5d7d442e2f033ab8f476e Message-Id: <20221114183454.5589A3887F77@sourceware.org> Date: Mon, 14 Nov 2022 18:34:54 +0000 (GMT) List-Id: https://gcc.gnu.org/g:9c45321cdbf48419ced5d7d442e2f033ab8f476e commit r12-8910-g9c45321cdbf48419ced5d7d442e2f033ab8f476e Author: Jonathan Wakely Date: Tue Oct 18 20:49:42 2022 +0100 libstdc++: Fix std::move_only_function for incomplete parameter types The std::move_only_function::__param_t alias template attempts to optimize argument passing for the invoker, by passing by rvalue reference for types that are non-trivial or large. However, the precondition for is_trivally_copyable makes it unsuitable for using here, and can cause ODR violations. Just use is_scalar instead, and pass all class types (even small, trivial ones) by value. libstdc++-v3/ChangeLog: * include/bits/mofunc_impl.h (move_only_function::__param_t): Use __is_scalar instead of is_trivially_copyable. * testsuite/20_util/move_only_function/call.cc: Check parameters involving incomplete types. Diff: --- libstdc++-v3/include/bits/mofunc_impl.h | 5 +---- libstdc++-v3/testsuite/20_util/move_only_function/call.cc | 11 +++++++++++ 2 files changed, 12 insertions(+), 4 deletions(-) diff --git a/libstdc++-v3/include/bits/mofunc_impl.h b/libstdc++-v3/include/bits/mofunc_impl.h index 405c4054642..47e1e506306 100644 --- a/libstdc++-v3/include/bits/mofunc_impl.h +++ b/libstdc++-v3/include/bits/mofunc_impl.h @@ -205,10 +205,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION private: template - using __param_t - = __conditional_t - && sizeof(_Tp) <= sizeof(long), - _Tp, _Tp&&>; + using __param_t = __conditional_t, _Tp, _Tp&&>; using _Invoker = _Res (*)(_Mofunc_base _GLIBCXX_MOF_CV*, __param_t<_ArgTypes>...) noexcept(_Noex); diff --git a/libstdc++-v3/testsuite/20_util/move_only_function/call.cc b/libstdc++-v3/testsuite/20_util/move_only_function/call.cc index 9ca0a60a24e..0c7f58d77a0 100644 --- a/libstdc++-v3/testsuite/20_util/move_only_function/call.cc +++ b/libstdc++-v3/testsuite/20_util/move_only_function/call.cc @@ -190,10 +190,21 @@ test04() VERIFY( std::move(std::as_const(f5))() == 3 ); } +struct Incomplete; + +void +test_params() +{ + std::move_only_function f1; + std::move_only_function f2; + std::move_only_function f3; +} + int main() { test01(); test02(); test03(); test04(); + test_params(); }