From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from simark.ca by simark.ca with LMTP id 9G2/GzXfTWFCOgAAWB0awg (envelope-from ) for ; Fri, 24 Sep 2021 10:22:45 -0400 Received: by simark.ca (Postfix, from userid 112) id 5B1811EE25; Fri, 24 Sep 2021 10:22:45 -0400 (EDT) X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on simark.ca X-Spam-Level: X-Spam-Status: No, score=-1.7 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,NICE_REPLY_A,RDNS_DYNAMIC, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.2 Received: from sourceware.org (ip-8-43-85-97.sourceware.org [8.43.85.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by simark.ca (Postfix) with ESMTPS id 884041EDDB for ; Fri, 24 Sep 2021 10:22:44 -0400 (EDT) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 0B046385803F for ; Fri, 24 Sep 2021 14:22:44 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 0B046385803F DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1632493364; bh=Ue9NClx3Jk0VjApQEzilyenaBedXTw8WHD1AG+Ah8P4=; h=Subject:To:References:Date:In-Reply-To:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To: From; b=iQZMQyNyMr7P9gvEFm4H1fksVwF3sRg8Iv6aRPTKN7SuiFiZmK4pfWkioL8qk1yKo 1LU858dMy0VmyIkrMJINIQ7ZUPNXeS++e8RnwXTGxiLSdBTeNdt3U5xqO/Du8jA3ir r2kLa3PiGXQhOZ1N8Byr4kus5gPe9ePLPUPL9tt8= Received: from smtp.polymtl.ca (smtp.polymtl.ca [132.207.4.11]) by sourceware.org (Postfix) with ESMTPS id 34C593858402 for ; Fri, 24 Sep 2021 14:22:25 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 34C593858402 Received: from simark.ca (simark.ca [158.69.221.121]) (authenticated bits=0) by smtp.polymtl.ca (8.14.7/8.14.7) with ESMTP id 18OEMHVn027244 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 24 Sep 2021 10:22:21 -0400 DKIM-Filter: OpenDKIM Filter v2.11.0 smtp.polymtl.ca 18OEMHVn027244 Received: from [10.0.0.11] (192-222-157-6.qc.cable.ebox.net [192.222.157.6]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by simark.ca (Postfix) with ESMTPSA id B47CE1EDDB; Fri, 24 Sep 2021 10:22:16 -0400 (EDT) Subject: Re: [PATCH] gdbsupport: better detection of -Wmissing-prototypes support To: Pedro Alves , Andrew Burgess , gdb-patches@sourceware.org References: <20210924122933.2714720-1-andrew.burgess@embecosm.com> <20210924131632.GC1900093@embecosm.com> <9ea18967-7c71-60a0-f265-a39634b335df@polymtl.ca> <54b146f8-f83b-67ea-d63f-ece07e7b7657@palves.net> Message-ID: <4640bbdc-4b51-dab4-a730-3549a3b75807@polymtl.ca> Date: Fri, 24 Sep 2021 10:22:16 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: <54b146f8-f83b-67ea-d63f-ece07e7b7657@palves.net> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-Poly-FromMTA: (simark.ca [158.69.221.121]) at Fri, 24 Sep 2021 14:22:17 +0000 X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Simon Marchi via Gdb-patches Reply-To: Simon Marchi Errors-To: gdb-patches-bounces+public-inbox=simark.ca@sourceware.org Sender: "Gdb-patches" On 2021-09-24 10:06 a.m., Pedro Alves wrote: > On 2021-09-24 2:40 p.m., Simon Marchi via Gdb-patches wrote: >> On 2021-09-24 9:16 a.m., Andrew Burgess wrote: >>> It has been pointed out to me on IRC (thanks Simon), that this issue >>> is not GCC, but ccache: >>> >>> https://github.com/ccache/ccache/issues/738#issuecomment-740133374 >>> >>> So this patch certainly shouldn't go in as it is currently written. >>> >>> It's still pretty annoying seeing those warnings though, so I wonder >>> if we can consider having a work around for this ccache issue in the >>> GDB configure scripts? >>> >>> Maybe something as simple as setting CCACHE_DISABLE in the environment >>> prior to running the AM_GDB_WARNINGS checks? >>> >>> All ideas welcome... >> >> Either way would be fine with me: >> >> - to use AC_LINK_IFELSE all the time (I don't think the execution time >> would be significantly higher) >> - to set CCACHE_DISABLE during the execution of AM_GDB_WARNINGS > > Does working around this in configure tests still mean that when using ccache > for really building gdb, ccache will still misreorder arguments and thus > potentially a -Wmissing-prototypes warning would not be turned into an error? I think it's only the "-Wmissing-prototypes is useless in C++" warning that has this order problem. If you were compiling something in C and was missing a prototype, that warning would be not be affected by the order bug (although I haven't tried). By working around in the problem in configure, that means -Wmissing-prototypes will not be present when compiling with GCC (as it does nothing in C++), so there's nothing to miss here. > So, here's another option, I think: > > #3 - drop -Wmissing-prototypes completely. > > As the GCC warning says, > > cc1plus: warning: command line option ‘-Wmissing-prototypes’ is valid for C/ObjC but not for C++ > > it's only valid for C, not C++. Do we compile anything with a C compiler nowadays? It's there because it does something for clang in C++, see: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=a0761e34f054767de6d6389929d27e9015fb299b If we find that the rationale for having it there isn't valid anymore, we can remove it. Simon