From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from qproxy2-pub.mail.unifiedlayer.com (qproxy2-pub.mail.unifiedlayer.com [69.89.16.161]) by sourceware.org (Postfix) with ESMTPS id EC3983858D32 for ; Sun, 22 Jan 2023 20:52:15 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org EC3983858D32 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 gproxy4-pub.mail.unifiedlayer.com (gproxy4-pub.mail.unifiedlayer.com [69.89.23.142]) by qproxy2.mail.unifiedlayer.com (Postfix) with ESMTP id F3BF88047F8E for ; Sun, 22 Jan 2023 20:52:14 +0000 (UTC) Received: from cmgw11.mail.unifiedlayer.com (unknown [10.0.90.126]) by progateway6.mail.pro1.eigbox.com (Postfix) with ESMTP id E1C5610048F80 for ; Sun, 22 Jan 2023 20:50:44 +0000 (UTC) Received: from box5379.bluehost.com ([162.241.216.53]) by cmsmtp with ESMTP id JhIapb3aQGjYaJhIap7VrY; Sun, 22 Jan 2023 20:50:44 +0000 X-Authority-Reason: nr=8 X-Authority-Analysis: v=2.4 cv=cdgXElPM c=1 sm=1 tr=0 ts=63cda1a4 a=ApxJNpeYhEAb1aAlGBBbmA==:117 a=ApxJNpeYhEAb1aAlGBBbmA==:17 a=dLZJa+xiwSxG16/P+YVxDGlgEgI=:19 a=RvmDmJFTN0MA:10:nop_rcvd_month_year a=Qbun_eYptAEA:10:endurance_base64_authed_username_1 a=W3ieSrM6hks2yXPefzIA:9 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=DmTtZgb8Pggs1QRoZ/ARQC3goK/4YPKgmYP3K/h2alc=; b=c/+oyPq9Eh6dOzwm9njMT6ZKyX 9uouvE06f3DMGk3HN7GTYwx18JbVNz8GDu5qEON31jDtm9fJd8DGAv9v6SKKtWi0VSi07eVwpUsdv qGwffK2ba6uRIbkND/ZLSzcp9; Received: from 97-122-76-186.hlrn.qwest.net ([97.122.76.186]:42652 helo=prentzel) by box5379.bluehost.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1pJhIa-002oJF-JQ; Sun, 22 Jan 2023 13:50:44 -0700 From: Tom Tromey To: Hannes Domani Cc: Hannes Domani via Gdb-patches , Tom Tromey Subject: Re: [PATCH] Always create a new value object in valpy_do_cast References: <20230118172740.2171-1-ssbssa.ref@yahoo.de> <20230118172740.2171-1-ssbssa@yahoo.de> <87tu0ijw76.fsf@tromey.com> <861084923.719650.1674411768974@mail.yahoo.com> X-Attribution: Tom Date: Sun, 22 Jan 2023 13:50:42 -0700 In-Reply-To: <861084923.719650.1674411768974@mail.yahoo.com> (Hannes Domani's message of "Sun, 22 Jan 2023 18:22:48 +0000 (UTC)") Message-ID: <87lelujntp.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: 97.122.76.186 X-Source-L: No X-Exim-ID: 1pJhIa-002oJF-JQ X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: 97-122-76-186.hlrn.qwest.net (prentzel) [97.122.76.186]:42652 X-Source-Auth: tom+tromey.com X-Email-Count: 3 X-Source-Cap: ZWx5bnJvYmk7ZWx5bnJvYmk7Ym94NTM3OS5ibHVlaG9zdC5jb20= X-Local-Domain: yes X-Spam-Status: No, score=-3021.7 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 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: >>>>> "Hannes" == Hannes Domani writes: Hannes> The problem isn't the value that's reference by gdb.Value, instead Hannes> one of the other values in all_values before it. Hannes> But release_value removes it from all_values, and it was the exact value Hannes> that the scoped_value_mark free_values instance was using as the mark point, Hannes> and since it was then missing, all_values was cleared completely. Hannes> And one of those earlier values is still used by the printing later on. OMG. I think this is a latent bug in the value-mark API that's been there since... well I don't know exactly when, maybe forever. So, nice find! I think what we probably need is to change how the value_mark API works, so that it isn't relying on a value pointer being in all_values, but rather return some other type/object that isn't invalidated in the same way. Tom