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 F0BBA385843E for ; Thu, 27 Apr 2023 09:40:53 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org F0BBA385843E 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=1682588453; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=c1mGaOXcLxtR16w0FxqcmuezajiNZOmjRTejjHlGWMM=; b=YEKt+tE+dE2oI7larJDg7p5Y9d2xU0WE5r0Dc+JnIXDp1nQpjUjEtjrq5/lZ71MZSqFWmh mBh+6jgULRBdTqMvbfu6JzCMey1TehP2HlWrQO1kzRGojRTpdkIeLURqyzZFnIyMCifvWF 8o4F3JS2AM8bdvqlSqhIZqvD3tRU9lI= 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-195-aaU9_xe8PUmvNNobtwV2pA-1; Thu, 27 Apr 2023 05:40:49 -0400 X-MC-Unique: aaU9_xe8PUmvNNobtwV2pA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 10C7A85C6E0; Thu, 27 Apr 2023 09:40:49 +0000 (UTC) Received: from tucnak.zalov.cz (unknown [10.39.194.156]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C783F1121314; Thu, 27 Apr 2023 09:40:48 +0000 (UTC) Received: from tucnak.zalov.cz (localhost [127.0.0.1]) by tucnak.zalov.cz (8.17.1/8.17.1) with ESMTPS id 33R9ekK32749357 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Thu, 27 Apr 2023 11:40:46 +0200 Received: (from jakub@localhost) by tucnak.zalov.cz (8.17.1/8.17.1/Submit) id 33R9ejOP2749355; Thu, 27 Apr 2023 11:40:45 +0200 Date: Thu, 27 Apr 2023 11:40:39 +0200 From: Jakub Jelinek To: Helmut Zeisel Cc: gcc@gcc.gnu.org Subject: Re: Aw: Re: GCC 13.1 compile error when using CXXFLAGS=-std=c++20 Message-ID: Reply-To: Jakub Jelinek References: MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-3.2 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,KAM_NUMSUBJECT,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE,TXREP,T_SCC_BODY_TEXT_LINE autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On Thu, Apr 27, 2023 at 11:35:23AM +0200, Helmut Zeisel wrote: > >Von: "Jakub Jelinek" > >An: "Helmut Zeisel" > >Cc: gcc@gcc.gnu.org > >Betreff: Re: GCC 13.1 compile error when using CXXFLAGS=-std=c++20 > >On Thu, Apr 27, 2023 at 11:09:19AM +0200, Helmut Zeisel via Gcc wrote: > >> I compiled GCC 13.1.0 with GCC 12 and had the environment variable CXXFLAGS set to -std=c++20 > >> This gives the error (both linux and cygin) > >> > >> gcc-13.1.0/libstdc++-v3/src/c++98/bitmap_allocator.cc:51:23: error: ISO C++17 does not allow dynamic exception specifications > >> 51 | _M_get(size_t __sz) throw(std::bad_alloc) > >> > >> After > >> > >> unset CXXFLAGS > >> > >> compilation works > > >Don't do it. > > Dont do *what*? > export CXXFLAGS=... ? Include explicit -std= settings in such exported variables, especially when building GCC. Packages should decide themselves in which language version they are written in, or if they are written in common subset, they should just defer to the compiler default. Note, doing that would break building even much older GCC versions. > unset CXXFLAGS ? > Compile GCC 13 with GCC 12? Jakub