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 369AE386F44E for ; Wed, 5 Jul 2023 06:41:09 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 369AE386F44E 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=1688539268; 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=2qTT6OTweDcWwViwqdEd6UQJCjwc22iFyR93kidMuj8=; b=C4KmLeyqZcwlIEzIPnxhD0RHEKTyFWwKmgFKP2iWdsT0uPDqTj+senqT36uT9RNMqV0AtN YRovl/DijgL+uR+lJ8WSQf+NURwla8MA5D5u4WNgHPkWwZ1WWTWyCdul9qS5Li7O06TsFH SU4vn7y1QJrtbigsOdjR1qL6ZLqH6s8= 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-424-fxmIH_pOMKmm-2RlQLuaMA-1; Wed, 05 Jul 2023 02:41:07 -0400 X-MC-Unique: fxmIH_pOMKmm-2RlQLuaMA-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 3D368873210; Wed, 5 Jul 2023 06:41:07 +0000 (UTC) Received: from localhost (unknown [10.42.28.54]) by smtp.corp.redhat.com (Postfix) with ESMTP id 06D8C2166B25; Wed, 5 Jul 2023 06:41:06 +0000 (UTC) From: Jonathan Wakely To: libstdc++@gcc.gnu.org, gcc-patches@gcc.gnu.org Subject: [committed] libstdc++: Fix std::__uninitialized_default_n for constant evaluation [PR110542] Date: Wed, 5 Jul 2023 07:40:11 +0100 Message-ID: <20230705064106.1143618-1-jwakely@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.6 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-11.8 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 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: This is a weird one as described in the PR. GCC doesn't complain about this bug, but seems to have a bogus error elsewhere. I'll add a testcase once I've understood/fixed the GCC error. Tested x86_64-linux. Pushed to trunk. -- >8 -- libstdc++-v3/ChangeLog: PR libstdc++/110542 * include/bits/stl_uninitialized.h (__uninitialized_default_n): Do not use std::fill_n during constant evaluation. --- libstdc++-v3/include/bits/stl_uninitialized.h | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/libstdc++-v3/include/bits/stl_uninitialized.h b/libstdc++-v3/include/bits/stl_uninitialized.h index 6752c6b5746..be7b4afdd05 100644 --- a/libstdc++-v3/include/bits/stl_uninitialized.h +++ b/libstdc++-v3/include/bits/stl_uninitialized.h @@ -695,6 +695,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION inline _ForwardIterator __uninitialized_default_n(_ForwardIterator __first, _Size __n) { +#ifdef __cpp_lib_is_constant_evaluated + if (std::is_constant_evaluated()) + return __uninitialized_default_n_1:: + __uninit_default_n(__first, __n); +#endif + typedef typename iterator_traits<_ForwardIterator>::value_type _ValueType; // See uninitialized_fill_n for the conditions for using std::fill_n. -- 2.41.0