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# Copyright (C) 2006, 2007, 2009 Canonical Ltd
#
# 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 2 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, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
import os
import signal
_breakin_signal_number = None
_breakin_signal_name = None
def _debug(signal_number, interrupted_frame):
import pdb
import sys
sys.stderr.write("** %s received, entering debugger\n"
"** Type 'c' to continue or 'q' to stop the process\n"
"** Or %s again to quit (and possibly dump core)\n"
% (_breakin_signal_name, _breakin_signal_name))
# It seems that on Windows, when sys.stderr is to a PIPE, then we need to
# flush. Not sure why it is buffered, but that seems to be the case.
sys.stderr.flush()
# restore default meaning so that you can kill the process by hitting it
# twice
signal.signal(_breakin_signal_number, signal.SIG_DFL)
try:
pdb.set_trace()
finally:
signal.signal(_breakin_signal_number, _debug)
def hook_sigquit():
# We import this late because breakin.py is loaded as part of the main
# 'bzr' script, so we want it to load as little as possible until things
# are up and running
from bzrlib import symbol_versioning, trace
trace.mutter_callsite(2, 'Deprecated function called')
symbol_versioning.warn(symbol_versioning.deprecation_string(
hook_sigquit, symbol_versioning.deprecated_in((1, 18, 0))),
DeprecationWarning, stacklevel=2)
return hook_debugger_to_signal()
def determine_signal():
global _breakin_signal_number
global _breakin_signal_name
if _breakin_signal_number is not None:
return _breakin_signal_number
# Note: As near as I can tell, Windows is the only one to define SIGBREAK,
# and other platforms defined SIGQUIT. There doesn't seem to be a
# platform that defines both.
# -- jam 2009-07-30
sigquit = getattr(signal, 'SIGQUIT', None)
sigbreak = getattr(signal, 'SIGBREAK', None)
if sigquit is not None:
_breakin_signal_number = sigquit
_breakin_signal_name = 'SIGQUIT'
elif sigbreak is not None:
_breakin_signal_number = sigbreak
_breakin_signal_name = 'SIGBREAK'
return _breakin_signal_number
def hook_debugger_to_signal():
"""Add a signal handler so we drop into the debugger.
On Linux and Mac, this is hooked into SIGQUIT (C-\\) on Windows, this is
hooked into SIGBREAK (C-Pause).
"""
# when sigquit (C-\) or sigbreak (C-Pause) is received go into pdb
if os.environ.get('BZR_SIGQUIT_PDB', '1') == '0':
# User explicitly requested we don't support this
return
sig = determine_signal()
if sig is None:
return
# print 'hooking into %s' % (_breakin_signal_name,)
signal.signal(sig, _debug)
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