From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-x42a.google.com (mail-pf1-x42a.google.com [IPv6:2607:f8b0:4864:20::42a]) by sourceware.org (Postfix) with ESMTPS id 4999D3875B7C for ; Tue, 6 Dec 2022 18:36:01 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 4999D3875B7C Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-pf1-x42a.google.com with SMTP id 130so15310785pfu.8 for ; Tue, 06 Dec 2022 10:36:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=80n3UBqAyp0PnXRP9P1rs6VvMsHq8kI5crOPoWQfLfI=; b=N/8KGOl49uVW6YI9gA9m+VO18LsaB6wmjKD7n8VeZEZdjXC9MupchOxFE9rInEZm4H q1G9p2j2JYorpSjrdRGIIekEaQtViFlb161VOfTgMr3LEZhR+qvUtZmkkGa0McN8tgew XXxxMxR+h2IVdmAJ6ZN3MokVvc8rI11f6Vx+g27F7bZW2q712kaS5BH+Il93snST36iJ YM2wM1arBRdl1Ne+/kRIamqYUqVb1v0P+iAQ6eut51IOy3cxaEBCjmqeaU5ULuToOGo2 FmLGo3a5cZCl9rlauimfVV47neG59wl64Em4WzNFxwAy+bnICCCEpo6qk7FaNw2AlQjw yvrQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=80n3UBqAyp0PnXRP9P1rs6VvMsHq8kI5crOPoWQfLfI=; b=rEQJBPxHlJKrRr0Dt3FaMh16fImDW5MYAmJKMfJsH6vVaLJ9uIr5RpEW9Jg/4tLDl4 Mp19iHrPXo3MW/xzu0Brg2SeotmiDoq2TpTy6mAkPMORuqPG6YAq45j6QmRbuBZLQI71 UMfRC3ev5oQEBZnFUcWmygvB7apnENXwaBt+phs6frPYGo9J0+XhnyCsEURMDW2BwcV2 tX2EWY63S5AuclX5SjxEW7xzZIY6Z79QqRbQUl/swYhdx5wFogvL8j+K1VhDrdRmaxAU LJdnppCPBI9vkkiCA/BTX8si+g7Yc77Kjw8/MQp6xU+rNbjLGxCM4C2D2ZkPjoAxHk2D 0Yvw== X-Gm-Message-State: ANoB5pkZwr7S9s4KWTk/XQLLYrZZNYLQiW1IAjf+sqcqA8nTl+rP9ZJP zsczVBCkJg5Tu7XAUkY0gNaIiMiMMT5rapeHicU= X-Google-Smtp-Source: AA0mqf6CiD172lW1GuLI6x/Rlb003+Mbye7CXTWq7AMmjpYC7zEOQSHz7xX4Q1gheHo7RUT7eVs8ZGgR5G0ZZeRK/6U= X-Received: by 2002:a63:c51:0:b0:470:4522:f64a with SMTP id 17-20020a630c51000000b004704522f64amr60525788pgm.348.1670351760154; Tue, 06 Dec 2022 10:36:00 -0800 (PST) MIME-Version: 1.0 References: <52ab45bc-cd6e-7acb-dc6f-9cddef4a926a@codesourcery.com> In-Reply-To: <52ab45bc-cd6e-7acb-dc6f-9cddef4a926a@codesourcery.com> From: Gavin Ray Date: Tue, 6 Dec 2022 13:35:48 -0500 Message-ID: Subject: Re: Using [[may_alias]] in C23/C++23 on a union works in neither post-"union" position, or at the end of the definition To: Joseph Myers Cc: gcc@gcc.gnu.org Content-Type: multipart/alternative; boundary="0000000000005066ea05ef2d1344" X-Spam-Status: No, score=-0.1 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_ENVFROM_END_DIGIT,FREEMAIL_FROM,HTML_MESSAGE,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS,TXREP 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: --0000000000005066ea05ef2d1344 Content-Type: text/plain; charset="UTF-8" Oh, D'oh! Thanks Joseph, apologies for the needless email on the list then. One final question if I could -- does that mean that in order to support "may-alias" with the bracket syntax on both Clang and GCC, it would require: union [[gnu::may_alias]] [[clang::may_alias]] foo {}; On Tue, Dec 6, 2022 at 11:54 AM Joseph Myers wrote: > On Mon, 5 Dec 2022, Gavin Ray via Gcc wrote: > > > union [[may_alias]] broken2 {}; > > With [[]] syntax it's [[gnu::may_alias]], since it's not a standard > attribute. > > -- > Joseph S. Myers > joseph@codesourcery.com > --0000000000005066ea05ef2d1344--