From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 276CFC48292 for ; Mon, 5 Feb 2024 19:07:37 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rX4Ix-0004Ub-D7; Mon, 05 Feb 2024 14:06:55 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rX4Iw-0004UM-An for qemu-devel@nongnu.org; Mon, 05 Feb 2024 14:06:54 -0500 Received: from mail-oo1-xc29.google.com ([2607:f8b0:4864:20::c29]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1rX4Iu-0007iS-Tl for qemu-devel@nongnu.org; Mon, 05 Feb 2024 14:06:54 -0500 Received: by mail-oo1-xc29.google.com with SMTP id 006d021491bc7-59a146e8c85so42209eaf.0 for ; Mon, 05 Feb 2024 11:06:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1707160011; x=1707764811; darn=nongnu.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=Se2AYabkUjDUOt5YIJBB7lI0SdJAPGRAlIRMo2qJFyc=; b=iH53wot7nm1rPb/EBf02H6fQGHPriclz7KeA6RLiQTU3f/hxHL1FW04jpHne5La/ka p+LhqY7QaVc6H2gsQtBRJwuTGmR8UnyQksI4ktgFNhwhfQfk7E1XoZdrJV5OoJFqToP1 aZ3HmlNYU8B4UqzKj/e8JPEv8t7Fh7ZI8dccaHbfvDhuylIdpNtaTnKQYJkvgcJAhmLF mZK1pksxnZAZnZXeX5h/euqgq0696VVcFMXNCMeQ4FpPd1jGqc+NRqCb45Aaxhpulgks t6azUHd23lasItey16dhOhETonZadQkOpu1yf8yvK+lflUkXKrE30iPKz1Peap9lwyOs jXzg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1707160011; x=1707764811; h=content-transfer-encoding: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=Se2AYabkUjDUOt5YIJBB7lI0SdJAPGRAlIRMo2qJFyc=; b=h4claD+gTUtAoVgW7y+bx++GqnRwkh7zPONMznVZslTbEvhm+Jp9a740QfMM//966h CGJbYbOdW7RPRGkrs0EZ7bCui4lLWW7Se2looH3gq/4dmg4AoXJyh4IEgLA2vKiWEPuV z9X8TJc90VHN4UiLibx+Y42/AgSIg00VYwfOxIL1atvmKm7oRBVQDTy6HHOqsr5PMjhf YwqajSEGQKjf7xYKZfcUwJBJYjy53SIr/HFix1cQode8jCpCApmtNtw15+qc4M/kxajF pu/1b/LgEKLw+2Gl256CRmCk1n+8I7VlFX1HPdudpLMsNoUz3cvAGk1pBdXVVDSqaJbN qidA== X-Gm-Message-State: AOJu0YxH5DO6HCdKdLlaue1venEvyTPw6YdNgtiUGhmfYje4DHrWmizj jsTnjEe8CNTisD5XInN+lOOdAn0nF/6fFDSX5nPk7Zh85Jyeqn2WcoNO9MF7kWk5EXt4fkvhkAS dMnlGtOL+u3vsR7P7ZluBNX9sSFM= X-Google-Smtp-Source: AGHT+IGhBssTKxdPzCrXHV55WZu1jgum4IhoLs2XM9ERA/FZ3qYZVdjJ50Sn8q/IYxosAEdoT+8pfbud2jcSA8Yb8aE= X-Received: by 2002:a4a:241d:0:b0:599:49ec:6d15 with SMTP id m29-20020a4a241d000000b0059949ec6d15mr584834oof.1.1707160011436; Mon, 05 Feb 2024 11:06:51 -0800 (PST) MIME-Version: 1.0 References: <20240205171819.474283-1-stefanha@redhat.com> <877cjiaibh.fsf@rfc1149.net> In-Reply-To: <877cjiaibh.fsf@rfc1149.net> From: Stefan Hajnoczi Date: Mon, 5 Feb 2024 14:06:39 -0500 Message-ID: Subject: Re: [PATCH] docs/style: allow C99 mixed declarations To: Samuel Tardieu Cc: =?UTF-8?Q?Daniel_P=2E_Berrang=C3=A9?= , Stefan Hajnoczi , Hanna Czenczek , Markus Armbruster , =?UTF-8?Q?Philippe_Mathieu=2DDaud=C3=A9?= , Peter Maydell , Richard Henderson , Thomas Huth , =?UTF-8?B?QWxleCBCZW5uw6ll?= , qemu-devel@nongnu.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Received-SPF: pass client-ip=2607:f8b0:4864:20::c29; envelope-from=stefanha@gmail.com; helo=mail-oo1-xc29.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Mon, 5 Feb 2024 at 13:16, Samuel Tardieu wrote: > > > Daniel P. Berrang=C3=A9 writes: > > > $ gcc -Wall -Wuninitialized -o jump jump.c > > Note that many GCC warnings don't trigger if you don't enable > optimizations. In the case you exhibit, adding -O is enough to get > a sensible warning: > > $ gcc -Wall -O -o jump jump.c > jump.c: In function =E2=80=98main=E2=80=99: > jump.c:11:3: warning: =E2=80=98foo=E2=80=99 may be used uninitialized > [-Wmaybe-uninitialized] > 11 | free(foo); > | ^~~~~~~~~ > jump.c:8:9: note: =E2=80=98foo=E2=80=99 was declared here > 8 | char *foo =3D malloc(30); > | ^~~ llvm also prints a warning: jump.c:5:7: warning: variable 'foo' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] I confirmed that QEMU's current compiler flags enable these warnings so both gcc and llvm detect the issue that Daniel pointed out in QEMU code. Daniel: Does this address your concern about compiler warnings? Stefan