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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B4B21C83F14 for ; Tue, 29 Aug 2023 09:29:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231916AbjH2J2s (ORCPT ); Tue, 29 Aug 2023 05:28:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59194 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234915AbjH2J2f (ORCPT ); Tue, 29 Aug 2023 05:28:35 -0400 Received: from 1wt.eu (ded1.1wt.eu [163.172.96.212]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 3FE7CE56; Tue, 29 Aug 2023 02:28:10 -0700 (PDT) Received: (from willy@localhost) by mail.home.local (8.17.1/8.17.1/Submit) id 37T9QJ8E013415; Tue, 29 Aug 2023 11:26:19 +0200 Date: Tue, 29 Aug 2023 11:26:19 +0200 From: Willy Tarreau To: Thomas =?iso-8859-1?Q?Wei=DFschuh?= Cc: Shuah Khan , Zhangjin Wu , Yuan Tan , linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH 1/2] tools/nolibc: add stdarg.h header Message-ID: References: <20230827-nolibc-nostdinc-v1-0-995d1811f1f3@weissschuh.net> <20230827-nolibc-nostdinc-v1-1-995d1811f1f3@weissschuh.net> <2b6c62f1-c1f1-4f2c-ba0c-981e066f4268@t-8ch.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <2b6c62f1-c1f1-4f2c-ba0c-981e066f4268@t-8ch.de> Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org On Tue, Aug 29, 2023 at 11:14:09AM +0200, Thomas Weißschuh wrote: > Hi Willy! > > On 2023-08-29 08:28:27+0200, Willy Tarreau wrote: > > On Sun, Aug 27, 2023 at 10:00:15AM +0200, Thomas Weißschuh wrote: > > > This allows nolic to work with `-nostdinc` avoiding any reliance on > > > system headers. > > > > > > The implementation has been lifted from musl libc 1.2.4. > > > There is already an implementation of stdarg.h in include/linux/stdarg.h > > > but that is GPL licensed and therefore not suitable for nolibc. > > > > I'm a bit confused because for me, stdarg was normally provided by the > > compiler, but I could be mistaken. It's just that it reminds me not so > > old memories. Therefore maybe we just need to include or define > > "something" to use it. > > It is indeed provided by the compiler. OK. But then, doesn't it mean that if we don't provide our stdarg.h, the compilers' will be used ? I'm asking because we're already using va_list and va_args, for example in vfprintf() in stdio.h, which precisely includes so it must indeed come from the compiler. > I could not find anybody doing this differently. > Using builtins seems to me to be the normal way to expose compiler > implementation specifics. OK but it's already what the compiler does itself in its own stdarg that is provided. That's why I don't understand what specific case we're trying to cover here, I feel like we're providing an alternate stdarg in case the compiler doesn't provide one except that I've not seen a compiler not provide it (even tcc comes with it), it's like stddef. Thanks, Willy