IPython/core/crashhandler.py

# -*- coding: utf-8 -*-
"""sys.excepthook for IPython itself, leaves a detailed report on disk.


Authors
-------
- Fernando Perez <[e-mail]>
"""

#*****************************************************************************
#       Copyright (C) 2008-2009 The IPython Development Team
#       Copyright (C) 2001-2007 Fernando Perez. <[e-mail]>
#
#  Distributed under the terms of the BSD License.  The full license is in
#  the file COPYING, distributed as part of this software.
#*****************************************************************************

#****************************************************************************
# Required modules

# From the standard library
import os
import sys
from pprint import pformat

# Our own
from IPython.core import release
from IPython.core import ultratb
from IPython.utils.genutils import sys_info

from IPython.external.Itpl import itpl

#****************************************************************************

class CrashHandler(object):
    """Customizable crash handlers for IPython-based systems.

    Instances of this class provide a __call__ method which can be used as a
    sys.excepthook, i.e., the __call__ signature is:

        def __call__(self,etype, evalue, etb)

    """

    def __init__(self,app, app_name, contact_name=None, contact_email=None, 
                 bug_tracker=None, crash_report_fname='CrashReport.txt', 
                 show_crash_traceback=True, call_pdb=False):
        """New crash handler.

        Inputs:

        - app: a running application instance, which will be queried at crash
        time for internal information.

        - app_name: a string containing the name of your application.

        - contact_name: a string with the name of the person to contact.

        - contact_email: a string with the email address of the contact.

        - bug_tracker: a string with the URL for your project's bug tracker.

        - crash_report_fname: a string with the filename for the crash report
        to be saved in.  These reports are left in the ipython user directory
        as determined by the running IPython instance.

        Optional inputs:
        
        - show_crash_traceback(True): if false, don't print the crash
        traceback on stderr, only generate the on-disk report


        Non-argument instance attributes:

        These instances contain some non-argument attributes which allow for 
        further customization of the crash handler's behavior.  Please see the
        source for further details.
        """

        # apply args into instance
        self.app = app
        self.app_name = app_name
        self.contact_name = contact_name
        self.contact_email = contact_email
        self.bug_tracker = bug_tracker
        self.crash_report_fname = crash_report_fname
        self.show_crash_traceback = show_crash_traceback
        self.section_sep = '\n\n'+'*'*75+'\n\n'
        self.call_pdb = call_pdb
        #self.call_pdb = True # dbg
        
        # Hardcoded defaults, which can be overridden either by subclasses or
        # at runtime for the instance.

        # Template for the user message.  Subclasses which completely override
        # this, or user apps, can modify it to suit their tastes.  It gets
        # expanded using itpl, so calls of the kind $self.foo are valid.
        self.user_message_template = """
Oops, $self.app_name crashed. We do our best to make it stable, but...

A crash report was automatically generated with the following information:
  - A verbatim copy of the crash traceback.
  - A copy of your input history during this session.
  - Data on your current $self.app_name configuration.

It was left in the file named:
\t'$self.crash_report_fname'
If you can email this file to the developers, the information in it will help
them in understanding and correcting the problem.

You can mail it to: $self.contact_name at $self.contact_email
with the subject '$self.app_name Crash Report'.

If you want to do it now, the following command will work (under Unix):
mail -s '$self.app_name Crash Report' $self.contact_email < $self.crash_report_fname

To ensure accurate tracking of this issue, please file a report about it at:
$self.bug_tracker
"""

    def __call__(self,etype, evalue, etb):
        """Handle an exception, call for compatible with sys.excepthook"""

        # Report tracebacks shouldn't use color in general (safer for users)
        color_scheme = 'NoColor'

        # Use this ONLY for developer debugging (keep commented out for release)
        #color_scheme = 'Linux'   # dbg
        
        try:
            rptdir = self.app.ipython_dir
        except:
            rptdir = os.getcwd()
        if not os.path.isdir(rptdir):
            rptdir = os.getcwd()
        report_name = os.path.join(rptdir,self.crash_report_fname)
        # write the report filename into the instance dict so it can get
        # properly expanded out in the user message template
        self.crash_report_fname = report_name
        TBhandler = ultratb.VerboseTB(color_scheme=color_scheme,
                                      long_header=1,
                                      call_pdb=self.call_pdb,
                                      )
        if self.call_pdb:
            TBhandler(etype,evalue,etb)
            return
        else:
            traceback = TBhandler.text(etype,evalue,etb,context=31)

        # print traceback to screen
        if self.show_crash_traceback:
            print >> sys.stderr, traceback

        # and generate a complete report on disk
        try:
            report = open(report_name,'w')
        except:
            print >> sys.stderr, 'Could not create crash report on disk.'
            return

        # Inform user on stderr of what happened
        msg = itpl('\n'+'*'*70+'\n'+self.user_message_template)
        print >> sys.stderr, msg

        # Construct report on disk
        report.write(self.make_report(traceback))
        report.close()
        raw_input("Hit <Enter> to quit this message (your terminal may close):")

    def make_report(self,traceback):
        """Return a string containing a crash report."""
        
        sec_sep = self.section_sep
        
        report = ['*'*75+'\n\n'+'IPython post-mortem report\n\n']
        rpt_add = report.append
        rpt_add(sys_info())
        
        try:
            config = pformat(self.app.config)
            rpt_add(sec_sep+'Current user configuration structure:\n\n')
            rpt_add(config)
        except:
            pass
        rpt_add(sec_sep+'Crash traceback:\n\n' + traceback)

        return ''.join(report)


class IPythonCrashHandler(CrashHandler):
    """sys.excepthook for IPython itself, leaves a detailed report on disk."""
    
    def __init__(self, app, app_name='IPython'):

        # Set here which of the IPython authors should be listed as contact
        AUTHOR_CONTACT = 'Fernando'
        
        # Set argument defaults
        bug_tracker = 'https://bugs.launchpad.net/ipython/+filebug'
        contact_name,contact_email = release.authors[AUTHOR_CONTACT][:2]
        crash_report_fname = 'IPython_crash_report.txt'
        # Call parent constructor
        CrashHandler.__init__(self,app,app_name,contact_name,contact_email,
                              bug_tracker,crash_report_fname)

    def make_report(self,traceback):
        """Return a string containing a crash report."""

        sec_sep = self.section_sep
        # Start with parent report
        report = [super(IPythonCrashHandler, self).make_report(traceback)]
        # Add interactive-specific info we may have
        rpt_add = report.append
        try:
            rpt_add(sec_sep+"History of session input:")
            for line in self.app.shell.user_ns['_ih']:
                rpt_add(line)
            rpt_add('\n*** Last line of input (may not be in above history):\n')
            rpt_add(self.app.shell._last_input_line+'\n')
        except:
            pass

        return ''.join(report)