From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gproxy2-pub.mail.unifiedlayer.com (gproxy2-pub.mail.unifiedlayer.com [69.89.18.3]) by sourceware.org (Postfix) with ESMTPS id 729763858D1E for ; Wed, 2 Aug 2023 20:41:40 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 729763858D1E Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=tromey.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=tromey.com Received: from cmgw11.mail.unifiedlayer.com (unknown [10.0.90.126]) by progateway4.mail.pro1.eigbox.com (Postfix) with ESMTP id C60E0100443A2 for ; Wed, 2 Aug 2023 20:41:39 +0000 (UTC) Received: from box5379.bluehost.com ([162.241.216.53]) by cmsmtp with ESMTP id RIf5q61R2mdP7RIf5q0jvi; Wed, 02 Aug 2023 20:41:39 +0000 X-Authority-Reason: nr=8 X-Authority-Analysis: v=2.4 cv=EbYN/NqC c=1 sm=1 tr=0 ts=64cabf83 a=ApxJNpeYhEAb1aAlGBBbmA==:117 a=ApxJNpeYhEAb1aAlGBBbmA==:17 a=OWjo9vPv0XrRhIrVQ50Ab3nP57M=:19 a=dLZJa+xiwSxG16/P+YVxDGlgEgI=:19 a=UttIx32zK-AA:10:nop_rcvd_month_year a=Qbun_eYptAEA:10:endurance_base64_authed_username_1 a=CCpqsmhAAAAA:8 a=E7o_n_k3-KLvGMThL3AA:9 a=ul9cdbp4aOFLsgKbc677:22 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=tromey.com; s=default; h=Content-Type:MIME-Version:Message-ID:In-Reply-To:Date:References :Subject:Cc:To:From:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=wSX/GIGeHermT7asQa+m3CTqTdD4xFODMdFyitcH6h4=; b=p0O+NKH56y27/2h0UNxmdYhx+v 9uSf+Kv2+xe+2iI3cp0cca3DY274N1PAS4Mz9utXf0nNFcCM2+gtpnT9hgcJWKvh9yDsGBGWVu8Yo cZHDL02bFBg7dAipYgsbKWTBN; Received: from 75-166-148-59.hlrn.qwest.net ([75.166.148.59]:35414 helo=murgatroyd) by box5379.bluehost.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1qRIf5-0035bK-1T; Wed, 02 Aug 2023 14:41:39 -0600 From: Tom Tromey To: Abdul Basit Ijaz via Gdb-patches Cc: Abdul Basit Ijaz , JiniSusan.George@amd.com, tom@tromey.com, eliz@gnu.org, blarsen@redhat.com Subject: Re: [PATCH v4 4/4] gdb: Skip trampoline frames in the stack for printing or finish command. References: <20230801224744.24433-1-abdul.b.ijaz@intel.com> <20230801224744.24433-5-abdul.b.ijaz@intel.com> X-Attribution: Tom Date: Wed, 02 Aug 2023 14:41:38 -0600 In-Reply-To: <20230801224744.24433-5-abdul.b.ijaz@intel.com> (Abdul Basit Ijaz via Gdb-patches's message of "Wed, 2 Aug 2023 00:47:44 +0200") Message-ID: <87h6phch31.fsf@tromey.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - box5379.bluehost.com X-AntiAbuse: Original Domain - sourceware.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - tromey.com X-BWhitelist: no X-Source-IP: 75.166.148.59 X-Source-L: No X-Exim-ID: 1qRIf5-0035bK-1T X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: 75-166-148-59.hlrn.qwest.net (murgatroyd) [75.166.148.59]:35414 X-Source-Auth: tom+tromey.com X-Email-Count: 25 X-Source-Cap: ZWx5bnJvYmk7ZWx5bnJvYmk7Ym94NTM3OS5ibHVlaG9zdC5jb20= X-Local-Domain: yes X-Spam-Status: No, score=-3018.7 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,JMQ_SPF_NEUTRAL,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_PASS,TXREP,T_SCC_BODY_TEXT_LINE autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: >>>>> "Abdul" == Abdul Basit Ijaz via Gdb-patches writes: Abdul> Before the change, GDB prints the frames indicated by the compiler with DIE Abdul> "DW_AT_trampoline" in the backtrace and finish command, but for better user Abdul> experience, all such frames can be hidden from the user. So, after this Abdul> change, now such frames are not printed any more in the backtrace command Abdul> and also the 'finish' command skips the trampoline calls. Abdul> So far, this DIE is added to DWARF only by the IFX compiler, so Abdul> gdb.fortran/mixed-lang-stack test used to fail for this compiler because of Abdul> these extra trampoline frames in the backtrace. After the commit, those Abdul> trampoline frames are filtered so test is updated accordingly to handle the Abdul> frame level of the filtered frames. Thanks for the patch. I'm not totally sure how I feel about the stack trace part of this one. On the one hand, normally I think it makes sense to elide these frames. They aren't very interesting. On the other hand, we have frame filters for frame elision, but then this works in a totally different way. If I am stopped in a frame and go "up", will I be in the trampoline frame anyway? And will "bt" then not print the selected frame? But "frame" will? Abdul> + if (skip_trampoline_functions) Abdul> + { Abdul> + for (int i = 0; i < MAX_TRAMPOLINE_CHAIN_SIZE Abdul> + && (frame != nullptr) Abdul> + && in_trampoline_frame (frame); ++i) Abdul> + frame = get_prev_frame (frame); Formatting looks weird here. Abdul> +++ b/gdb/stack.c Abdul> @@ -2054,6 +2054,14 @@ backtrace_command_1 (const frame_print_options &fp_opts, Abdul> { Abdul> QUIT; Abdul> + if (in_trampoline_frame (fi)) Abdul> + { Abdul> + /* Trampoline frames are not printed so they are not counted in Abdul> + the backtrace limit. */ Abdul> + count++; Abdul> + continue; I guess the frame numbers will skip as well, because the frame level is a property of the frame, not of the loop displaying frames. Also this approach ignores frame filters -- if one is in use, then I think trampoline frames will show up again. You can try this by writing a dummy frame filter that just returns all frames as-is. Tom