binutils-gdb/gdb/testsuite/gdb.base/multi-line-starts-subshell.exp

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# Copyright (C) 2014-2018 Free Software Foundation, Inc.
PR python/17372 - Python hangs when displaying help() This is more of a readline/terminal issue than a Python one. PR17372 is a regression in 7.8 caused by the fix for PR17072: commit 0017922d0292d8c374584f6100874580659c9973 Author: Pedro Alves <palves@redhat.com> Date: Mon Jul 14 19:55:32 2014 +0100 Background execution + pagination aborts readline/gdb 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. ... gdb/ 2014-07-14 Pedro Alves <palves@redhat.com> PR gdb/17072 * top.c (gdb_readline_wrapper_line): Tweak comment. (gdb_readline_wrapper_cleanup): If readline is enabled, reinstall the input handler callback. The problem is that installing the input handler callback also preps the terminal, putting it in raw mode and with echo disabled, which is bad if we're going to call a command that assumes cooked/canonical mode, and echo enabled, like in the case of the PR, Python's interactive shell. Another example I came up with that doesn't depend on Python is starting a subshell with "(gdb) shell /bin/sh" from a multi-line command. Tests covering both these examples are added. The fix is to revert the original fix for PR gdb/17072, and instead restore the callback handler after processing an asynchronous target event. Furthermore, calling rl_callback_handler_install when we already have some input in readline's line buffer discards that input, which is obviously a bad thing to do while the user is typing. No specific test is added for that, because I first tried calling it even if the callback handler was still installed and that resulted in hundreds of failures in the testsuite. gdb/ 2014-10-29 Pedro Alves <palves@redhat.com> PR python/17372 * event-top.c (change_line_handler): Call gdb_rl_callback_handler_remove instead of rl_callback_handler_remove. (callback_handler_installed): New global. (gdb_rl_callback_handler_remove, gdb_rl_callback_handler_install) (gdb_rl_callback_handler_reinstall): New functions. (display_gdb_prompt): Call gdb_rl_callback_handler_remove and gdb_rl_callback_handler_install instead of rl_callback_handler_remove and rl_callback_handler_install. (gdb_disable_readline): Call gdb_rl_callback_handler_remove instead of rl_callback_handler_remove. * event-top.h (gdb_rl_callback_handler_remove) (gdb_rl_callback_handler_install) (gdb_rl_callback_handler_reinstall): New declarations. * infrun.c (reinstall_readline_callback_handler_cleanup): New cleanup function. (fetch_inferior_event): Install it. * top.c (gdb_readline_wrapper_line) Call gdb_rl_callback_handler_remove instead of rl_callback_handler_remove. (gdb_readline_wrapper_cleanup): Don't call rl_callback_handler_install. gdb/testsuite/ 2014-10-29 Pedro Alves <palves@redhat.com> PR python/17372 * gdb.python/python.exp: Test a multi-line command that spawns interactive Python. * gdb.base/multi-line-starts-subshell.exp: New file.
2014-10-23 18:13:35 +02:00
#
# 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 <http://www.gnu.org/licenses/>.
# Test spawning a subshell from a multi-line command, where the last
# prompt displayed is a secondary prompt. GDB used to have a bug
# where in this case the subshell would start with the wrong terminal
# settings. See PR python/17372.
gdb_exit
gdb_start
# The subshell's prompt.
set shell_prompt "gdb-subshell$ "
set shell_prompt_re [string_to_regexp $shell_prompt]
# Point HOME nowhere to avoid the shell sourcing the user's init
# scripts.
set shell_cmd "HOME=/dev/null PS1=\"$shell_prompt\" /bin/sh"
set test "spawn subshell from multi-line"
gdb_test_multiple "if 1\nshell ${shell_cmd}\nend" $test {
-re "$shell_prompt_re$" {
pass $test
# Now check that shell input works and that echo is enabled.
set test "shell input works"
send_gdb "echo foo\n"
gdb_expect {
-re "^echo foo\r\nfoo\r\n$shell_prompt_re$" {
pass $test
}
timeout {
fail "$test (timeout)"
}
}
# Exit the subshell, back to GDB
gdb_test "exit" ".*" "exit shell"
}
}
# Check that we restore input in GDB correctly.
gdb_test "print 1" "^print 1\r\n.. = 1" "gdb input still works"