From patchwork Thu Jul 3 15:13:23 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pedro Alves X-Patchwork-Id: 1893 Received: (qmail 8588 invoked by alias); 3 Jul 2014 15:26:56 -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 8536 invoked by uid 89); 3 Jul 2014 15:26:54 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=AWL, BAYES_00, SPF_HELO_PASS, SPF_PASS, T_RP_MATCHES_RCVD autolearn=ham version=3.3.2 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 (AES256-GCM-SHA384 encrypted) ESMTPS; Thu, 03 Jul 2014 15:26:51 +0000 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s63FDiqm026481 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Thu, 3 Jul 2014 11:13:44 -0400 Received: from brno.lan (ovpn01.gateway.prod.ext.ams2.redhat.com [10.39.146.11]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id s63FDQOq021950 for ; Thu, 3 Jul 2014 11:13:43 -0400 From: Pedro Alves To: gdb-patches@sourceware.org Subject: [PATCH 8/9] Background execution + pagination aborts readline/gdb Date: Thu, 3 Jul 2014 16:13:23 +0100 Message-Id: <1404400406-16708-16-git-send-email-palves@redhat.com> In-Reply-To: <1404400406-16708-1-git-send-email-palves@redhat.com> References: <1404400406-16708-1-git-send-email-palves@redhat.com> If pagination occurs as result of output sent as response to a target event while the target is executing in the background, subsequent input aborts readline/gdb: $ gdb program ... (gdb) continue& Continuing. (gdb) ---Type to continue, or q to quit--- *return* ---Type to continue, or q to quit--- Breakpoint 2, after_sleep () at paginate-bg-execution.c:21 ---Type to continue, or q to quit--- 21 return; /* after sleep */ p 1 readline: readline_callback_read_char() called with no handler! *abort/SIGABRT* $ gdb_readline_wrapper_line removes the handler after a line is processed. Usually, we'll end up re-displaying the prompt, and that reinstalls the handler. But if the output is coming out of handling a stop event, we don't re-display the prompt, and nothing restores the handler. So the next input wakes up the event loop and calls into readline, which aborts. We should do better with the prompt handling while the target is running (I think we should coordinate with readline, and hide/redisplay it around output), but that's a more invasive change better done post 7.8, so this patch is conservative and just reinstalls the handler as soon as we're out of the readline line callback. gdb/ 2014-07-03 Pedro Alves PR gdb/17072 * top.c (gdb_readline_wrapper_line): Tweak comment. (gdb_readline_wrapper_cleanup): If readline is enabled, reinstall the input handler callback. gdb/testsuite/ 2014-07-03 Pedro Alves PR gdb/17072 * gdb.base/paginate-bg-execution.c: New file. * gdb.base/paginate-bg-execution.exp: New file. --- gdb/testsuite/gdb.base/paginate-bg-execution.c | 30 ++++++ gdb/testsuite/gdb.base/paginate-bg-execution.exp | 121 +++++++++++++++++++++++ gdb/top.c | 9 +- 3 files changed, 159 insertions(+), 1 deletion(-) create mode 100644 gdb/testsuite/gdb.base/paginate-bg-execution.c create mode 100644 gdb/testsuite/gdb.base/paginate-bg-execution.exp diff --git a/gdb/testsuite/gdb.base/paginate-bg-execution.c b/gdb/testsuite/gdb.base/paginate-bg-execution.c new file mode 100644 index 0000000..7457b18 --- /dev/null +++ b/gdb/testsuite/gdb.base/paginate-bg-execution.c @@ -0,0 +1,30 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2014 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . */ + +static void +after_sleep (void) +{ + return; /* after sleep */ +} + +int +main (void) +{ + sleep (3); + after_sleep (); + return 0; +} diff --git a/gdb/testsuite/gdb.base/paginate-bg-execution.exp b/gdb/testsuite/gdb.base/paginate-bg-execution.exp new file mode 100644 index 0000000..ac62727 --- /dev/null +++ b/gdb/testsuite/gdb.base/paginate-bg-execution.exp @@ -0,0 +1,121 @@ +# Copyright (C) 2014 Free Software Foundation, Inc. + +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 3 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see . + +# A collection of tests related to running execution commands directly +# from the command line, with "-ex". + +standard_testfile + +if {[build_executable "failed to prepare" $testfile $srcfile debug] == -1} { + return -1 +} + +# Check that we handle pagination correctly when it triggers due to an +# background execution command entered directly on the command line. + +proc test_bg_execution_pagination_return {} { + global binfile + global pagination_prompt + + with_test_prefix "paginate" { + clean_restart $binfile + + if ![runto_main] then { + fail "Can't run to main" + return 0 + } + + gdb_test "b after_sleep" + + gdb_test_no_output "set height 2" + + gdb_test "continue&" "Continuing\." + + set test "pagination handled, breakpoint hit" + set saw_pagination_prompt 0 + gdb_test_multiple "" $test { + -re "$pagination_prompt$" { + set saw_pagination_prompt 1 + send_gdb "\n" + exp_continue + } + -notransfer -re "" { + # Otherwise gdb_test_multiple considers this an + # error. + exp_continue + } + -re "after sleep\[^\r\n\]+\r\n$" { + gdb_assert $saw_pagination_prompt $test + } + } + + # GDB used to crash here. + gdb_test "p 1" " = 1" "GDB accepts further input" + } +} + +# Check that we handle canceling pagination correctly when it triggers +# due to a background execution command entered directly on the +# command line. + +proc test_bg_execution_pagination_cancel { how } { + global binfile + global gdb_prompt pagination_prompt + + with_test_prefix "cancel with $how" { + clean_restart $binfile + + if ![runto_main] then { + fail "Can't run to main" + return 0 + } + + gdb_test "b after_sleep" + + gdb_test_no_output "set height 2" + + gdb_test "continue&" "Continuing\." + + set test "continue& paginates" + gdb_test_multiple "" $test { + -re "$pagination_prompt$" { + pass $test + } + -notransfer -re "" { + # Otherwise gdb_test_multiple considers this an error. + exp_continue + } + } + + set test "cancel pagination" + if { $how == "ctrl-c" } { + send_gdb "\003" + } else { + send_gdb "q\n" + + } + gdb_test_multiple "" $test { + -re "Quit\r\n$gdb_prompt $" { + pass $test + } + } + + gdb_test "p 1" " = 1" "GDB accepts further input" + } +} + +test_bg_execution_pagination_return +test_bg_execution_pagination_cancel "ctrl-c" +test_bg_execution_pagination_cancel "quit" diff --git a/gdb/top.c b/gdb/top.c index 722eb55..93a4a16 100644 --- a/gdb/top.c +++ b/gdb/top.c @@ -756,7 +756,8 @@ gdb_readline_wrapper_line (char *line) after_char_processing_hook = NULL; /* Prevent parts of the prompt from being redisplayed if annotations - are enabled, and readline's state getting out of sync. */ + are enabled, and readline's state getting out of sync. We'll + restore it in gdb_readline_wrapper_cleanup. */ if (async_command_editing_p) rl_callback_handler_remove (); } @@ -776,6 +777,12 @@ gdb_readline_wrapper_cleanup (void *arg) gdb_assert (input_handler == gdb_readline_wrapper_line); input_handler = cleanup->handler_orig; + + /* Reinstall INPUT_HANDLER in readline, without displaying a + prompt. */ + if (async_command_editing_p) + rl_callback_handler_install (NULL, input_handler); + gdb_readline_wrapper_result = NULL; gdb_readline_wrapper_done = 0;