From patchwork Tue Nov 21 16:11:01 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pedro Alves X-Patchwork-Id: 24412 Received: (qmail 96303 invoked by alias); 21 Nov 2017 16:11:07 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Delivered-To: mailing list gdb-patches@sourceware.org Received: (qmail 96135 invoked by uid 89); 21 Nov 2017 16:11:07 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-26.7 required=5.0 tests=BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, KB_WAM_FROM_NAME_SINGLEWORD, SPF_HELO_PASS, T_RP_MATCHES_RCVD autolearn=ham version=3.3.2 spammy= X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Tue, 21 Nov 2017 16:11:06 +0000 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 08EE976547; Tue, 21 Nov 2017 16:11:05 +0000 (UTC) Received: from cascais.lan (ovpn04.gateway.prod.ext.ams2.redhat.com [10.39.146.4]) by smtp.corp.redhat.com (Postfix) with ESMTP id 57E206C412; Tue, 21 Nov 2017 16:11:04 +0000 (UTC) From: Pedro Alves To: gdb-patches@sourceware.org, Joel Brobecker Subject: [PATCH 2/2] Don't lose language determined from the "main" name (fix gdb.ada/minsyms.exp) Date: Tue, 21 Nov 2017 16:11:01 +0000 Message-Id: <1511280661-14725-3-git-send-email-palves@redhat.com> In-Reply-To: <1511280661-14725-1-git-send-email-palves@redhat.com> References: <1511280661-14725-1-git-send-email-palves@redhat.com> gdb.ada/minsyms.exp fails like this here: FAIL: gdb.ada/minsyms.exp: print integer(some_minsym) FAIL: gdb.ada/minsyms.exp: print /x integer(&some_minsym) The problem is that if you have debug info for glibc, GDB switches the current language to C before it reaches the program's entry point, and then Ada's cast syntax doesn't work when the current language is C: print integer(some_minsym) A syntax error in expression, near `some_minsym)'. (gdb) FAIL: gdb.ada/minsyms.exp: print integer(some_minsym) I first thought of doing "set language ada" in the testcase, but looking deeper, I realized that before running to main, GDB knows the program is Ada, determined by reading __gnat_ada_main_program_name, via set_initial_language->main_language->find_main_name-> ada_main_name, and loses that when it is handling a shared library event. That looks like a bug to me. gdb/testsuite/ChangeLog: 2017-11-21 Pedro Alves * solib-svr4.c: Save/restore language around evaluating a probe argument. --- gdb/solib-svr4.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/gdb/solib-svr4.c b/gdb/solib-svr4.c index 5ec606d..e6f818a 100644 --- a/gdb/solib-svr4.c +++ b/gdb/solib-svr4.c @@ -1936,6 +1936,21 @@ svr4_handle_solib_event (void) usm_chain = make_cleanup (resume_section_map_updates_cleanup, current_program_space); + /* Make sure evaluating probe arguments doesn't cause us to switch + the user's current language to the runtime's language. + Evaluating probe arguments relies on reading registers off the + selected frame. When we're handling a shared library event, this + is going to be the first time we fetch the selected frame (as + opposed to the current frame), and if there's debug info for the + loader (e.g., glibc), this switches to its language (usually C). + Usually that ends up masked because we will usually next stop in + the main program (e.g., user did "start"), and switch to the + right language again then, if the program has debug info. + However, if the program does not have debug info, then GDB won't + switch, and we'd lose the language that was determined earlier by + sniffing the program's main name. */ + scoped_restore_current_language save_language; + TRY { val = evaluate_probe_argument (pa->probe, 1, frame);