From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from simark.ca by simark.ca with LMTP id 9u89NtHjdWpG8xAAWB0awg (envelope-from ) for ; Fri, 07 Aug 2026 09:55:29 -0400 Received: by simark.ca (Postfix, from userid 112) id B60DB1E166; Fri, 07 Aug 2026 09:55:29 -0400 (EDT) X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-25) on simark.ca X-Spam-Level: X-Spam-Status: No, score=-5.3 required=5.0 tests=ARC_SIGNED,ARC_VALID,BAYES_00, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham autolearn_force=no version=4.0.1 Received: from vm01.sourceware.org (vm01.sourceware.org [38.145.34.32]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by simark.ca (Postfix) with ESMTPS id 566201E09E for ; Fri, 07 Aug 2026 09:55:28 -0400 (EDT) Received: from vm01.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id F25CD4BB5886 for ; Fri, 7 Aug 2026 13:55:27 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org F25CD4BB5886 Received: from simark.ca (simark.ca [158.69.221.121]) by sourceware.org (Postfix) with ESMTPS id CFA184BA902A for ; Fri, 7 Aug 2026 13:55:03 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org CFA184BA902A Authentication-Results: sourceware.org; dmarc=fail (p=none dis=none) header.from=efficios.com Authentication-Results: sourceware.org; spf=fail smtp.mailfrom=efficios.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org CFA184BA902A Authentication-Results: sourceware.org; arc=none smtp.remote-ip=158.69.221.121 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1786110903; cv=none; b=uWojq5FxRzgdxLnwf1+XIVXo2VpoU9+oZ7V0laj6QChVwBfKMKRLuX92qnhckGEq6QMY5xC4vuEBCuGd8Q364zcyz5cgDmNrkswvbcADLpI4A/Iaa+wEBxrI9vLdjn2GcOrG1gUEerVpbs9beGr94SoOJNnIqa6MYkGG7dcufP0= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1786110903; c=relaxed/simple; bh=3hbXMJrRKWXCNk/HCt8/mD6sc1HQitQ9AIeh34d150k=; h=From:To:Subject:Date:Message-ID:MIME-Version; b=xDKoBd5Gew89GTtkoOQTA7sVRrFOne+sFNTb7xil22zqFxV3KNTe7n5gSLqqc/AOXdx1Ur3RPmKYmafFnyEVKJbkxBNxnBENGszI0R9VJUk5hs1ICnFTJ3QTvynULYDWRPCtc7j++m9/5y3ORbgyjz41OViKCu1c8lb/+P2wdb4= ARC-Authentication-Results: i=1; sourceware.org DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org CFA184BA902A Received: by simark.ca (Postfix) id E35E81E09E; Fri, 07 Aug 2026 09:55:02 -0400 (EDT) From: Simon Marchi To: gdb-patches@sourceware.org Cc: Simon Marchi , Tom Tromey Subject: [PATCH v4 09/10] gdb: change default objfile iteration order to start with current objfile Date: Fri, 7 Aug 2026 09:52:27 -0400 Message-ID: <20260807135259.111194-10-simon.marchi@efficios.com> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260807135259.111194-1-simon.marchi@efficios.com> References: <20260807135259.111194-1-simon.marchi@efficios.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.30 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: gdb-patches-bounces~public-inbox=simark.ca@sourceware.org From: Simon Marchi The current default objfile search strategy, defined both in solib_ops::iterate_over_objfiles_in_search_order (when the solib_ops hasn't overridden it) and in program_space::iterate_over_objfiles_in_search_order (when there is no solib_ops in the program space, for some reason), is to scan the objfile list linearly. program_space::iterate_over_objfiles_in_search_order: for (auto &objfile : this->objfiles ()) if (cb (&objfile)) return; solib_ops::iterate_over_objfiles_in_search_order: for (objfile &objfile : m_pspace->objfiles ()) if (cb (&objfile)) return; The following patch adds support for multiple concurrent solib_ops in a program space. Everything that deals with an solib_ops needs to be adapted to deal with multiple solib_ops, including program_space::iterate_over_objfiles_in_search_order. What I came up with for that method introduces a change in behavior where the current objfile will always be searched first. Rather than hide the change in behavior in that big patch, do it in this preparatory patch, in the hope that any potential problems it causes can be more easily bisected and analyzed. Concretely, the change is to check the current objfile first, in the two spots: if (current_objfile != nullptr && cb (current_objfile)) return; This happens to be what windows_solib_ops did, so remove that specialization. svr4_solib_ops already has its own iterate_over_objfiles_in_search_order that conditionally checks the current objfile first, based on the DT_SYMBOLIC dynamic tag. So it is not affected by this change. The solib_ops potentially affected by this change are (we know that rocm_solib_ops doesn't care): - frv_solib_ops - target_solib_ops - darwin_solib_ops - dsbt_solib_ops - aix_solib_ops I don't really know if searching objfiles in order (so, main objfile first typically) is essential for any of these solib_ops. Intuitively, searching the current objfile first makes sense, unless there is some fancy symbol interposition happening, in which case that solib_ops should probably implement a custom iterate_over_objfiles_in_search_order. Change-Id: I58195af6b53ca202e6061a5f36d5f74e1a0d5c17 Approved-By: Tom Tromey Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=17003 --- gdb/progspace.c | 5 ++++- gdb/solib.c | 5 ++++- gdb/windows-tdep.c | 40 ---------------------------------------- 3 files changed, 8 insertions(+), 42 deletions(-) diff --git a/gdb/progspace.c b/gdb/progspace.c index 988bb2370301..79d377056a0e 100644 --- a/gdb/progspace.c +++ b/gdb/progspace.c @@ -128,8 +128,11 @@ program_space::iterate_over_objfiles_in_search_order return m_solib_ops->iterate_over_objfiles_in_search_order (cb, current_objfile); + if (current_objfile != nullptr && cb (current_objfile)) + return; + for (auto &objfile : this->objfiles ()) - if (cb (&objfile)) + if (&objfile != current_objfile && cb (&objfile)) return; } diff --git a/gdb/solib.c b/gdb/solib.c index b9b0f11cb477..6ed56aaf5159 100644 --- a/gdb/solib.c +++ b/gdb/solib.c @@ -451,8 +451,11 @@ solib_ops::iterate_over_objfiles_in_search_order (iterate_over_objfiles_in_search_order_cb_ftype cb, objfile *current_objfile) const { + if (current_objfile != nullptr && cb (current_objfile)) + return; + for (objfile &objfile : m_pspace->objfiles ()) - if (cb (&objfile)) + if (&objfile != current_objfile && cb (&objfile)) return; } diff --git a/gdb/windows-tdep.c b/gdb/windows-tdep.c index 36ab10e0abf8..d27f403f96e5 100644 --- a/gdb/windows-tdep.c +++ b/gdb/windows-tdep.c @@ -827,9 +827,6 @@ struct windows_solib_ops : target_solib_ops using target_solib_ops::target_solib_ops; void create_inferior_hook (int from_tty) override; - void iterate_over_objfiles_in_search_order - (iterate_over_objfiles_in_search_order_cb_ftype cb, - objfile *current_objfile) const override; }; /* Return a new solib_ops for Windows systems. */ @@ -888,43 +885,6 @@ windows_solib_ops::create_inferior_hook (int from_tty) } } -/* Implement the "iterate_over_objfiles_in_search_order" gdbarch - method. It searches all objfiles, starting with CURRENT_OBJFILE - first (if not NULL). - - On Windows, the system behaves a little differently when two - objfiles each define a global symbol using the same name, compared - to other platforms such as GNU/Linux for instance. On GNU/Linux, - all instances of the symbol effectively get merged into a single - one, but on Windows, they remain distinct. - - As a result, it usually makes sense to start global symbol searches - with the current objfile before expanding it to all other objfiles. - This helps for instance when a user debugs some code in a DLL that - refers to a global variable defined inside that DLL. When trying - to print the value of that global variable, it would be unhelpful - to print the value of another global variable defined with the same - name, but in a different DLL. */ - -void -windows_solib_ops::iterate_over_objfiles_in_search_order - (iterate_over_objfiles_in_search_order_cb_ftype cb, - objfile *current_objfile) const -{ - if (current_objfile) - { - if (cb (current_objfile)) - return; - } - - for (objfile &objfile : m_pspace->objfiles ()) - if (&objfile != current_objfile) - { - if (cb (&objfile)) - return; - } -} - /* Implement the "auto_wide_charset" gdbarch method. */ static const char * -- 2.55.0