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 0681A384859F for ; Wed, 18 May 2022 19:14:10 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 0681A384859F Received: from mail-yb1-f197.google.com (mail-yb1-f197.google.com [209.85.219.197]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-463-NV2-tSL1MqiRejeHV0DKcg-1; Wed, 18 May 2022 15:14:09 -0400 X-MC-Unique: NV2-tSL1MqiRejeHV0DKcg-1 Received: by mail-yb1-f197.google.com with SMTP id b11-20020a5b008b000000b00624ea481d55so2488573ybp.19 for ; Wed, 18 May 2022 12:14:09 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=rIQOm57Ih9ZcZ+1K7VxviOy1OgiWDC+OFYO/Wk8/rRo=; b=fUCBUgam7x3Nd4Kyk8x1fmAlWjW93GQ1FTIisYb+VAJX7sLt+zSa96JQVUzg/japGu Si2TzMQIDtYZ7hsadxJMNX5bDbjo4pO4P3j2rVNMR2eP17lyI8e1SDHjlnUSwWVAa+gA f8D/5LOoVeqfRmRvIAHqa2tHYT5LuLsnuGRJ/L2Ux0ENNNQgNUR7O0lcyTq0jW1EZlnx QdKsgAErFT96hJLuA5axAbfi8zgdcAbxKCSF+4x2UsSL+wRycA2qCEAG7wHdgbgm+dqA gagU21kvlVQSd4LWO4+VowQEiv+HdBOYyayxhv99zNdpxRPmgWNjJQp7QN85KpdenT0G S5rQ== X-Gm-Message-State: AOAM533UV6g18XQnlF1qUTvpYP2nv1p6RilOFNMPC3lEQapZ5I26wIYn oBEW59aqZiJ1oGS5g9+fiCva6EkeVs3WFlgB6i/DdFNwtQTJGeY5QdY/NVWgEpA2SV9aGtc1P87 EX61PWDDOvdx3736fELwoFS0hyLVU7ws= X-Received: by 2002:a05:690c:9:b0:2dd:1de0:7b13 with SMTP id bc9-20020a05690c000900b002dd1de07b13mr1032281ywb.450.1652901248857; Wed, 18 May 2022 12:14:08 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwkLHz64ME/+1oq3yWs/dbL7x4gQSZbbXGytYNbKiqxBUmMfO+s5l50L0/Co+hwqZeluba+XaJ7chK7apdMbEY= X-Received: by 2002:a05:690c:9:b0:2dd:1de0:7b13 with SMTP id bc9-20020a05690c000900b002dd1de07b13mr1032268ywb.450.1652901248681; Wed, 18 May 2022 12:14:08 -0700 (PDT) MIME-Version: 1.0 References: <87h75n6qgg.fsf@oldenburg.str.redhat.com> <682cd604-595b-2d02-be08-4e061e956eb0@gmail.com> In-Reply-To: <682cd604-595b-2d02-be08-4e061e956eb0@gmail.com> From: Jonathan Wakely Date: Wed, 18 May 2022 20:13:57 +0100 Message-ID: Subject: Re: Bare metal C++ with a GNU/Linux toolchain To: =?UTF-8?Q?Fran=C3=A7ois_Dumont?= Cc: Florian Weimer , "libstdc++" X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_LOW, 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 X-BeenThere: libstdc++@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libstdc++ mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 18 May 2022 19:14:12 -0000 On Wed, 18 May 2022 at 18:04, Fran=C3=A7ois Dumont via Libstdc++ wrote: > > On 18/05/22 13:16, Florian Weimer via Libstdc++ wrote: > > It seems that it is fairly straightforward to eliminate dependencies on > > libstdc++ if only a C++ subset is used (no exception handling, no RTTI, > > no operator new, etc.). > > Those C++ features are in libsup++, not libstdc++. Yes, but that's still part of the libstdc++ project and so documenting this in the libstdc++ manual is probably the right place (but I'm not sure where in the manual yet). > > You should still be able to use full C++ without libstdc++. > > I used to do so when working on STLport but it was such a long time ago > that the way we were doing it is surely outdated. > > > > But once you use abstract classes, you > > necessarily gain a reference to __cxa_pure_virtual. > > > > Would it be possible to document this symbol as interposable, so that > > developers can bring their own definition if they want? If yes, what > > would be the appropriate place for this? > > > > Thanks, > > Florian > > >