From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f45.google.com (mail-wm1-f45.google.com [209.85.128.45]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DD1932BFC63; Tue, 13 May 2025 19:40:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.45 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747165242; cv=none; b=PrESXY+thO/6mEkKmVXcSMkGSSLxfqTiSfb/35X7eVKI9/N71HzVznY0WJn04VqexOLet9E42qaa0+OG3XkAQN167lVIudiN/rlaGk/dyPLbStj4bP0FYAkdSoLKn5w0Snq7tElaR0r3cuCiWdKwvPUvRSk9YwrcpdgwrjJ+mM0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747165242; c=relaxed/simple; bh=iuaXUFkdXRZwH25Aaato396egM7lKXerTYhIHS5xkvA=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=YKpJmhWV50RcPuyEoSVpojnan5bxCl0/4FKbWe5XToDUdwx3RXeHYgL58+dyxfW6Y70rB0RSzTmzzAIn7+TuLecRnOrGauV8yiAi1h+aelCfxwS6axpjBDWuma0SyJSdzeD+E6V8pqz2oZ3lOkqkNVy6X/9LUwZpC5268A0gSU0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=g2SeAb0a; arc=none smtp.client-ip=209.85.128.45 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="g2SeAb0a" Received: by mail-wm1-f45.google.com with SMTP id 5b1f17b1804b1-441d1ed82faso42310915e9.0; Tue, 13 May 2025 12:40:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1747165239; x=1747770039; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=Ge/ru0EIxCZg8y7oNNgrAg2dL5AXcq2Pmu81/bUcIDU=; b=g2SeAb0aAmLathJ8EzPnTwp7IpP4yl9EqSM1K4MmKZBhkVyKeY/NB4AhrVZOtkqSmz Amm0JNnFvSg1nKp9DLOzAQ61XUwT9W9vZw+ykWKxfaqIZGIDY7SPxmM9bPEPsHipenMI 45zwpBjG2LkBh3h2KbHpMD6xaZAu2Xt5KwLnRcLDxQ4Iv1HKwBHhBVblBkqty/WKXVAm 5/X0DterGcgXCKhC9EkPYyStKhtA03i19lyQnqZ5jnwPiFxlK4UFuvvo/7KJwlxjtqtr Nnl3nGq1uYGkYxdgWeAleV51TJraK6KkVA0W+4xvA4+DNk5UX47upVzMzMC3g+BQ4/tC 07aw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1747165239; x=1747770039; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Ge/ru0EIxCZg8y7oNNgrAg2dL5AXcq2Pmu81/bUcIDU=; b=XspRKfcnsXQxii1MSur96tSHW8kEP5PuLeYrRCkh4uev2LD+pRZUkmnZ0inn+W67xe e3Ck3RxqJeTdVXlBCsQTnEFfvX5mmmiRwxyozWPeY40csZNh7HImw3czoN6SoYLNXN9u kV6ZZDumT03G2GaHweeK3y1O9PNabUZNSU0qoM6UCv3p9sXeyVXZm2ZQfj5l05WRZbMK CKaPLOsWNRYpvmo45EwuOOA6IitrQVjAvOzsFWod+lQ7Tl1RjKebm1cKvv5BTuRqWtN6 SMZyaCSgFH+5/M3mjzlrfVdYyRHfGEuzVxeteKi2VBqw1CmZYd0xxXqknNWP/PHcwDEU j8Gw== X-Forwarded-Encrypted: i=1; AJvYcCUT+ZmXxOrBCOfAeh/ecVPSKiZZp33nk3dzvBRoRIZ0rHEmmCRliuiND/tOe2x2Dm+j8FZ5rtAa0TSBwFQ=@vger.kernel.org, AJvYcCX2Mt3kYy30Ac9jaD+gn9D2ky8qF/GHZk2eD9mT5lmx2Fxgu6kBg0ymr/l1+HsZ2Wz2aqdEFPWC6bBx@vger.kernel.org X-Gm-Message-State: AOJu0YzFUAU/qIq4PpECTOylQ2QX8knYE9ihtaizmMhaybSjyUYir36o q6XovXd5h1TKymENX/ZevKh9YO88w2yXms/b6LywEXwBV7M0IJZ0 X-Gm-Gg: ASbGncsG1bwmHwDJnn9Mj29nikKBSB9qTVcwK+Jc89BBzJ8O5WerlXkF2DhoGXQpoNw qs00CJPDowrZb5NX2MDBjfqIsEopYqRUlPq0jOoZhBcm7HGgQQdvMbPpORsPbcLDUNySp+dw1yS /TtxC+lyYlvHJOg6WH+FrGWi45nA0u+wUTNlTaqR+PdVYHwCtNQikYbeex9PRIZXkIzm0Su205J eKoSjx9AGyrhIGbvAKvK2+rcgSHGUzxX26rVqqF3BB+fGM6q+PUGlf15W3wUKKKC8UGdhvOuYv6 7+oJvDFu5TAwrinjsv12KQJJ9ePSLXMVSl89EM6OVwj1YqZpf6e+ZZAdT3OM+rdh8dMdD+a6jHN va263qrQ+fi2IoA== X-Google-Smtp-Source: AGHT+IHpoKX2J3ZRgVCXEBwGRUBbn2eTk4NSfffmKZLSzChL9Pphfa0iLpwQENfg4auVKKfGgLscfw== X-Received: by 2002:a05:600c:8507:b0:440:9b1a:cd78 with SMTP id 5b1f17b1804b1-442f20da0b5mr6159205e9.10.1747165238893; Tue, 13 May 2025 12:40:38 -0700 (PDT) Received: from pumpkin (82-69-66-36.dsl.in-addr.zen.co.uk. [82.69.66.36]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-442d685c2d7sm177560815e9.30.2025.05.13.12.40.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 13 May 2025 12:40:38 -0700 (PDT) Date: Tue, 13 May 2025 20:40:31 +0100 From: David Laight To: Alexey Dobriyan Cc: corbet@lwn.net, workflows@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 6/9] CodingStyle: recommend static_assert/_Static_assert Message-ID: <20250513204031.26f50209@pumpkin> In-Reply-To: <20250509203430.3448-6-adobriyan@gmail.com> References: <20250509203430.3448-1-adobriyan@gmail.com> <20250509203430.3448-6-adobriyan@gmail.com> X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; arm-unknown-linux-gnueabihf) Precedence: bulk X-Mailing-List: workflows@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Fri, 9 May 2025 23:34:27 +0300 Alexey Dobriyan wrote: > Linux's BUG_ON is done backwards (condition is inverted). > But it is a long story. > > However C11/C23 allow to partially transition to what all normal > programmers are used to, namely assert(). > > Deprecate BUILD_BUG_ON, recommend static_assert/_Static_assert. > And then some day BUG_ON will be flipped as well. _Static_assert() is broken by design and only usable for trival tests. clang also output the entire expansion of the conditional (even when a message is specified) which can lead to very very very very long lines. It isn't at all suitable for many of the checks in the kernel. Look at the signedness test in min() as an example. David