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 [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id 86F2D3858C2F for ; Mon, 25 Sep 2023 08:54:09 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 86F2D3858C2F Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1695632049; 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=TugIaLMq5U7wUf68hWLF8HgNfNMI3f1HyeXBer3V0Kc=; b=SzuOQucNfnDX8aox6yVKlZxCm1XUNsQYGNOn3R/luU3UlM6eLek+E7o0EH8p2fKvubQbiD 3YSZH+BMcWegNI//rtBzpdINI6M/Ic/eNVAeR38J9y+EBWcLranBQ02thY497S+PdEVca3 Q2tD9BXcesQzup2ArYStS6efu9JaStY= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-609-KzCDDwY7PpuDAy7rXNemaA-1; Mon, 25 Sep 2023 04:54:07 -0400 X-MC-Unique: KzCDDwY7PpuDAy7rXNemaA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 266E98039C1; Mon, 25 Sep 2023 08:54:07 +0000 (UTC) Received: from localhost (unknown [10.42.28.103]) by smtp.corp.redhat.com (Postfix) with ESMTP id D2CB62026D4B; Mon, 25 Sep 2023 08:54:06 +0000 (UTC) From: Jonathan Wakely To: libstdc++@gcc.gnu.org, gcc-patches@gcc.gnu.org Subject: [committed] libstdc++: Prevent unwanted ADL in std::to_array [PR111512] Date: Mon, 25 Sep 2023 09:53:59 +0100 Message-ID: <20230925085406.2744040-1-jwakely@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 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=-11.7 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,URI_HEX autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: Tested x86_64-linux. Pushed to trunk. -- >8 -- As noted in PR c++/111512, GCC does ADL for __builtin_memcpy if it is unqualified, which can cause errors for template argument types which cannot be completed. Casting the memcpy arguments to void* prevents ADL from considering the problem type. libstdc++-v3/ChangeLog: PR libstdc++/111511 PR c++/111512 * include/std/array (to_array): Cast memcpy arguments to void*. * testsuite/23_containers/array/creation/111512.cc: New test. --- libstdc++-v3/include/std/array | 4 ++-- .../23_containers/array/creation/111512.cc | 24 +++++++++++++++++++ 2 files changed, 26 insertions(+), 2 deletions(-) create mode 100644 libstdc++-v3/testsuite/23_containers/array/creation/111512.cc diff --git a/libstdc++-v3/include/std/array b/libstdc++-v3/include/std/array index 0e32d7b52d0..c4d534c3a34 100644 --- a/libstdc++-v3/include/std/array +++ b/libstdc++-v3/include/std/array @@ -432,7 +432,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION { array, _Nm> __arr; if (!__is_constant_evaluated() && _Nm != 0) - __builtin_memcpy(__arr.data(), __a, sizeof(__a)); + __builtin_memcpy((void*)__arr.data(), (void*)__a, sizeof(__a)); else for (size_t __i = 0; __i < _Nm; ++__i) __arr._M_elems[__i] = __a[__i]; @@ -461,7 +461,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION { array, _Nm> __arr; if (!__is_constant_evaluated() && _Nm != 0) - __builtin_memcpy(__arr.data(), __a, sizeof(__a)); + __builtin_memcpy((void*)__arr.data(), (void*)__a, sizeof(__a)); else for (size_t __i = 0; __i < _Nm; ++__i) __arr._M_elems[__i] = __a[__i]; diff --git a/libstdc++-v3/testsuite/23_containers/array/creation/111512.cc b/libstdc++-v3/testsuite/23_containers/array/creation/111512.cc new file mode 100644 index 00000000000..b0f25a62153 --- /dev/null +++ b/libstdc++-v3/testsuite/23_containers/array/creation/111512.cc @@ -0,0 +1,24 @@ +// { dg-do compile { target c++20 } } + +// Bug libstdc++/111511 - Incorrect ADL in std::to_array in GCC 11/12/13 +// Bug c++/111512 - GCC's __builtin_memcpy can trigger ADL + +#include +#include + +struct incomplete; + +template +struct holder { + T t; // { dg-bogus "'holder::t' has incomplete type" } +}; + +// A complete type that cannot be used as an associated type for ADL. +using adl_bomb = holder*; + +int main() +{ + adl_bomb a[1]{}; + (void) std::to_array(a); + (void) std::to_array(std::move(a)); +} -- 2.41.0