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# Copyright (C) 2007, 2009, 2010 Canonical Ltd
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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_breakin_signal_number = None
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_breakin_signal_name = None
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def _debug(signal_number, interrupted_frame):
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sys.stderr.write("** %s received, entering debugger\n"
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"** Type 'c' to continue or 'q' to stop the process\n"
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"** Or %s again to quit (and possibly dump core)\n"
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% (_breakin_signal_name, _breakin_signal_name))
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# It seems that on Windows, when sys.stderr is to a PIPE, then we need to
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# flush. Not sure why it is buffered, but that seems to be the case.
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# restore default meaning so that you can kill the process by hitting it
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signal.signal(_breakin_signal_number, signal.SIG_DFL)
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signal.signal(_breakin_signal_number, _debug)
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# We import this late because breakin.py is loaded as part of the main
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# 'bzr' script, so we want it to load as little as possible until things
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from bzrlib import symbol_versioning, trace
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trace.mutter_callsite(2, 'Deprecated function called')
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symbol_versioning.warn(symbol_versioning.deprecation_string(
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hook_sigquit, symbol_versioning.deprecated_in((1, 18, 0))),
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DeprecationWarning, stacklevel=2)
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return hook_debugger_to_signal()
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def determine_signal():
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global _breakin_signal_number
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global _breakin_signal_name
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if _breakin_signal_number is not None:
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return _breakin_signal_number
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# Note: As near as I can tell, Windows is the only one to define SIGBREAK,
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# and other platforms defined SIGQUIT. There doesn't seem to be a
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# platform that defines both.
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sigquit = getattr(signal, 'SIGQUIT', None)
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sigbreak = getattr(signal, 'SIGBREAK', None)
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if sigquit is not None:
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_breakin_signal_number = sigquit
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_breakin_signal_name = 'SIGQUIT'
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elif sigbreak is not None:
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_breakin_signal_number = sigbreak
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_breakin_signal_name = 'SIGBREAK'
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return _breakin_signal_number
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def hook_debugger_to_signal():
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"""Add a signal handler so we drop into the debugger.
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On Unix, this is hooked into SIGQUIT (C-\\), and on Windows, this is
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hooked into SIGBREAK (C-Pause).
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# when sigquit (C-\) or sigbreak (C-Pause) is received go into pdb
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if os.environ.get('BZR_SIGQUIT_PDB', '1') == '0':
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# User explicitly requested we don't support this
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sig = determine_signal()
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# print 'hooking into %s' % (_breakin_signal_name,)
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signal.signal(sig, _debug)