From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id 420153858CDB for ; Tue, 19 Mar 2024 15:59:07 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 420153858CDB Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 420153858CDB Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1710863948; cv=none; b=wiIqRhy1nyJOsm1WeWdi3lIJpSqrwzagqjpt+5ORNKno+cBTiehOsqEPPP8yrYWIjxfT3F2aJHfGte8Av3zAxRxqU4cx/fV7z0FRCyADGgqF+uXT8e027VtUbtKXMqqO9DMCNZxjp3XWZbBKdfHyTiVGjwzeoRd0zP0ZLqILUvo= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1710863948; c=relaxed/simple; bh=mVlVPFWvIbq6T3IftiRM3OxBdMDMjUqolhfXGPyfudI=; h=DKIM-Signature:From:To:Subject:Date:Message-ID:MIME-Version; b=tYw2FIVLBAh7+IqKUWTO1gn0Yd9xijWDI/OBAmbrJF/OyB+WhpAoLnTce6QBn3zblK/B7WuaEQVMtIjg6enpKcnfyLldpoSoygvRYWyZv2cG3IMRaLB8WUTugTycWeRdETgpZjRAbjkK/H6NQ3HRAY4qGN2CrpogLDkxY3jOqCA= ARC-Authentication-Results: i=1; server2.sourceware.org DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1710863947; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=EvgEESmVK3GXmVdq6t5eBnsR9z+IH9o0lxvbWtaGh2E=; b=W9Z1aPt6ZwW4X+y3W8YDQb/Uxp7TR+RocCaDSa/73pz9l496ixuR/cYPlXLivfphbQYBuQ ppwIJSvn075+Yh7LJoc3ZiH8Xhpr5OhYvEqz4LRbdCA15ryvnNu/etgqA3JJ1pHghmssQk Czug+o2gN9+w3jBxTM5qhR9RYmPjea8= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-694-L211E0ivPEKryiY6MgWcMg-1; Tue, 19 Mar 2024 11:59:03 -0400 X-MC-Unique: L211E0ivPEKryiY6MgWcMg-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 8AFE5800264; Tue, 19 Mar 2024 15:59:03 +0000 (UTC) Received: from localhost (unknown [10.42.28.8]) by smtp.corp.redhat.com (Postfix) with ESMTP id 58E6E202451F; Tue, 19 Mar 2024 15:59:03 +0000 (UTC) From: Jonathan Wakely To: libstdc++@gcc.gnu.org, gcc-patches@gcc.gnu.org Subject: [PATCH] libstdc++: Constrain std::vector default constructor [PR113841] Date: Tue, 19 Mar 2024 15:57:32 +0000 Message-ID: <20240319155858.3406992-1-jwakely@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.4 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-12.0 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,GIT_PATCH_0,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H4,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_NONE,TXREP,T_SCC_BODY_TEXT_LINE,URI_HEX autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: This fixes the problem in the PR, which is revealed by the new concept-based constraints on std::pair constructors in C++20 mode. That makes this a C++20 regression, as the PR's example compiles with C++17. We need something similar for std::basic_string too, which I'll do later. Any comments? Tested aarch64-linux. -- >8 -- This is needed to avoid errors outside the immediate context when evaluating is_default_constructible_v> when A is not default constructible. To avoid diagnostic regressions for 23_containers/vector/48101_neg.cc we need to make the std::allocator partial specializations default constructible, which they probably should have been anyway. libstdc++-v3/ChangeLog: PR libstdc++/113841 * include/bits/allocator.h (allocator): Add default constructor to partial specializations for cv-qualified types. * include/bits/stl_vector.h (_Vector_impl::_Vector_impl()): Constrain so that it's only present if the allocator is default constructible. * include/bits/stl_bvector.h (_Bvector_impl::_Bvector_impl()): Likewise. * testsuite/23_containers/vector/cons/113841.cc: New test. --- libstdc++-v3/include/bits/allocator.h | 3 ++ libstdc++-v3/include/bits/stl_bvector.h | 3 ++ libstdc++-v3/include/bits/stl_vector.h | 3 ++ .../23_containers/vector/cons/113841.cc | 34 +++++++++++++++++++ 4 files changed, 43 insertions(+) create mode 100644 libstdc++-v3/testsuite/23_containers/vector/cons/113841.cc diff --git a/libstdc++-v3/include/bits/allocator.h b/libstdc++-v3/include/bits/allocator.h index ff4f5b9137b..9e75b37fce7 100644 --- a/libstdc++-v3/include/bits/allocator.h +++ b/libstdc++-v3/include/bits/allocator.h @@ -254,6 +254,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION { public: typedef _Tp value_type; + allocator() { } template allocator(const allocator<_Up>&) { } }; @@ -262,6 +263,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION { public: typedef _Tp value_type; + allocator() { } template allocator(const allocator<_Up>&) { } }; @@ -270,6 +272,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION { public: typedef _Tp value_type; + allocator() { } template allocator(const allocator<_Up>&) { } }; /// @endcond diff --git a/libstdc++-v3/include/bits/stl_bvector.h b/libstdc++-v3/include/bits/stl_bvector.h index a3343d95b36..d567e26f4e4 100644 --- a/libstdc++-v3/include/bits/stl_bvector.h +++ b/libstdc++-v3/include/bits/stl_bvector.h @@ -593,6 +593,9 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER _GLIBCXX20_CONSTEXPR _Bvector_impl() _GLIBCXX_NOEXCEPT_IF( is_nothrow_default_constructible<_Bit_alloc_type>::value) +#if __cpp_concepts + requires is_default_constructible_v<_Bit_alloc_type> +#endif : _Bit_alloc_type() { } diff --git a/libstdc++-v3/include/bits/stl_vector.h b/libstdc++-v3/include/bits/stl_vector.h index a8d387f40a1..31169711a48 100644 --- a/libstdc++-v3/include/bits/stl_vector.h +++ b/libstdc++-v3/include/bits/stl_vector.h @@ -135,6 +135,9 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER _GLIBCXX20_CONSTEXPR _Vector_impl() _GLIBCXX_NOEXCEPT_IF( is_nothrow_default_constructible<_Tp_alloc_type>::value) +#if __cpp_lib_concepts + requires is_default_constructible_v<_Tp_alloc_type> +#endif : _Tp_alloc_type() { } diff --git a/libstdc++-v3/testsuite/23_containers/vector/cons/113841.cc b/libstdc++-v3/testsuite/23_containers/vector/cons/113841.cc new file mode 100644 index 00000000000..a7721d27f79 --- /dev/null +++ b/libstdc++-v3/testsuite/23_containers/vector/cons/113841.cc @@ -0,0 +1,34 @@ +// { dg-do compile { target c++20 } } + +#include + +template +struct Alloc +{ + using value_type = T; + + Alloc(int) { } // not default constructible + + template Alloc(const Alloc&) { } + + T* allocate(std::size_t n) { return std::allocator().allocate(n); } + void deallocate(T* p, std::size_t n) { std::allocator().deallocate(p, n); } +}; + +template struct wrap { T t; }; + +template void do_adl(T&) { } + +void test_pr113841() +{ + using test_type = std::vector>; + std::pair>* h = nullptr; + do_adl(h); +} + +void test_pr113841_bool() +{ + using test_type = std::vector>; + std::pair>* h = nullptr; + do_adl(h); +} -- 2.44.0