From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-x52a.google.com (mail-ed1-x52a.google.com [IPv6:2a00:1450:4864:20::52a]) by sourceware.org (Postfix) with ESMTPS id 5F9A93858D1E for ; Sat, 11 Mar 2023 16:48:28 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 5F9A93858D1E 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-ed1-x52a.google.com with SMTP id s11so32750641edy.8 for ; Sat, 11 Mar 2023 08:48:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1678553307; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=IDQWYsdg0yZ3cXUAUBwHDSeTkBUfSdeCJVykOGhaFRY=; b=Azl031WvLsWPekZVkTREF0Mk25QnS883EGoY8jQmc1Kr9D1lCJf2+W4SS/WyUtytNT 2qSUQ7MOJxqofaa/dTwVQsWcrDTX2HdaFT06J5jFoOEBaUZXoDr0EDTOaiQWGRyTuU0F Al7am0ucMIYZGVCCXX5jA/KkT9jPqyT3a0SIeklxpuF0MUtwdH15GCBuGgLcFHJ0eqZi 5TsrUN0xgZe/PNk0WbbeeL/2I0zsTV+HbGAQrENX7vTRpjeBIhVuOqxKqEGx/DL3bsqX RuLsIk123PXuxnlUtZ55xA9Fsu4/pbasXo3kVQTT65ZgsIPVOAWpgNBzHCyrLbdGHZ5N xKdA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1678553307; 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=IDQWYsdg0yZ3cXUAUBwHDSeTkBUfSdeCJVykOGhaFRY=; b=PQnZJmiH2r8JPnd6ohBEsG2U3bPpGZe+U5eW/a5j7okqUA7oNMHMdl5tEbAqf+ABUk 5zCCzeW4A2K6VJrfIGcj1ebu00islgPQrSNkQdZThX0GEgb7CYPJG/44sorlpaAWNa1W XgIBtLeTtcwr19L1babqojdiPpeQkKDIy7D1RmkmBFuk0+7bibXPWkjhRyJduOWZZXLa dcu4RvIqBbH2AlIWTZYshpkcVIUFEt7Uujw4jVUzP28bUKCaYyN1Awqm5UVDywDv2JE0 5gljp3txj+A7ayOYQbGOQVgv4i+/BLsE0G7bhQNX4C/8NSRZ1siqefjd87lD7yQHq0yR H2Fg== X-Gm-Message-State: AO0yUKVy+jcr5EhPaMy7IihyfBjJZ4D1Ektj2a1KupxsPjgrnGgDXs40 UKu9n4A7KvFzedyW5QgUjhZ0IPlmeX1+RBpTQ3I= X-Google-Smtp-Source: AK7set/yaSUXKFfP+jXR5WBK0RWge9rEc7/6vts0dyPpramC7DkjWvSKRkTsJWz4ovBHY1fl61o/gEMbtazFqujl1eQ= X-Received: by 2002:a05:6402:530c:b0:4ad:739c:b38e with SMTP id eo12-20020a056402530c00b004ad739cb38emr3837144edb.1.1678553306905; Sat, 11 Mar 2023 08:48:26 -0800 (PST) MIME-Version: 1.0 References: <7785d160-cd05-01e2-e800-4bc82d630c4e@starynkevitch.net> In-Reply-To: <7785d160-cd05-01e2-e800-4bc82d630c4e@starynkevitch.net> From: Jonathan Wakely Date: Sat, 11 Mar 2023 16:48:14 +0000 Message-ID: Subject: Re: No warning about duplicate values in enum To: Basile Starynkevitch Cc: Andrea Monaco , "gcc@gcc.gnu.org" Content-Type: multipart/alternative; boundary="00000000000098405d05f6a2a500" X-Spam-Status: No, score=-0.6 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,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: --00000000000098405d05f6a2a500 Content-Type: text/plain; charset="UTF-8" On Sat, 11 Mar 2023, 12:53 Basile Starynkevitch, wrote: > Hello all, > > > Andrea observed that: > > In gcc 8.3.0, compiling > > > enum > test > { > FIRST = 1, > SECOND = 1, > THIRD = 2 > }; > > int > main (void) > { > return 0; > } > > > generates no warning even with -Wextra. > > I believe that the C standard (which I don't have here, but see also > https://port70.net/~nsz/c/c11/n1570.html or buy it from ISO) explicitly > allow duplicate values in enum. > Of course it does, it's perfectly valid. Nobody has said it should be rejected. The request is for a warning, because for *some* uses of enums duplicates are not wanted. --00000000000098405d05f6a2a500--