Source

dotfiles / python / pdb.py

Full commit
  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
"""
Pdb++, a fancier version of pdb
===============================

This module extends the stdlib pdb in numerous ways, e.g. by providing
real completion of Python values instead of pdb's own commands, or by
adding few convenience commands like ``longlist``, ``interact`` or
``watch``.

For a full explanation of each command, refer to the docstring or type
help <command> at the prompt.

Installation
------------

This module is meant to replace stdlib's pdb.py from the outsite;
simply put it in a directory in your PYTHONPATH, and you can start
using it immediately.  Since it's named pdb.py, every place which
imports pdb will now find the new module.

Dependencies
------------

To work properly, this module needs `rlcompleter_ng`_ to be installed.

To enable syntax highlighting, you must install `pygments`.

.. _pygments: http://pygments.org/
.. _`rlcompleter_ng`: http://codespeak.net/svn/user/antocuni/hack/rlcompleter_ng.py

Configuration
-------------

To customize the configuration of Pdb++, you need to put a file named
.pdbrc.py in your home directory.  The file must contain a class named
``Config`` inheriting from ``DefaultConfig`` and overridding the
desired values.

To know which options are available, look at the comment in the
source.

You can find a sample configuration file, here:
http://codespeak.net/svn/user/antocuni/hack/pdbrc.py
"""

__version__='0.1'
__author__ ='Antonio Cuni <anto.cuni@gmail.com>'
__url__='http://codespeak.net/svn/user/antocuni/hack/pdb.py'

import sys
import os.path
import inspect
import code
import types
from rlcompleter_ng import Completer, ConfigurableClass, setcolor, colors


def import_from_stdlib(name):
    import code # arbitrary module which stays in the same dir as pdb
    stdlibdir, _ = os.path.split(code.__file__)
    pyfile = os.path.join(stdlibdir, name + '.py')
    result = types.ModuleType(name)
    mydict = execfile(pyfile, result.__dict__)
    return result

pdb = import_from_stdlib('pdb')


class DefaultConfig:
    prompt = '(Pdb++) '
    completekey = 'tab'
    highlight = True
    bg = 'dark'
    colorscheme = None

    line_number_color = colors.turquoise
    current_line_color = 44 # blue

def getsourcelines(obj):
    try:
        return inspect.getsourcelines(obj)
    except IOError:
        pass

    if isinstance(obj, types.FrameType):
        filename = obj.f_code.co_filename
        if hasattr(filename, '__source__'):
            first = max(1, obj.f_lineno - 5)
            lines = [line + '\n' for line in filename.__source__.lines]
            return lines, first
    raise IOError('could not get source code')

def setbgcolor(line, color):
    # hack hack hack
    # add a bgcolor attribute to all escape sequences found
    import re
    setbg = '\x1b[%dm' % color
    regexbg = '\\1;%dm' % color
    return setbg + re.sub('(\x1b\\[.*?)m', regexbg, line) + '\x1b[00m'

CLEARSCREEN = '\033[2J\033[1;1H'

def lasti2lineno(code, lasti):
    import dis
    linestarts = list(dis.findlinestarts(code))
    linestarts.reverse()
    for i, lineno in linestarts:
        if lasti >= i:
            return lineno
    assert False, 'Invalid instruction number: %s' % lasti

class Undefined:
    def __repr__(self):
        return '<undefined>'
undefined = Undefined()

class Pdb(pdb.Pdb, ConfigurableClass):

    DefaultConfig = DefaultConfig
    config_filename = '.pdbrc.py'

    def __init__(self, *args, **kwds):
        Config = kwds.pop('Config', None)
        pdb.Pdb.__init__(self, *args, **kwds)
        self.config = self.get_config(Config)
        self.prompt = self.config.prompt
        self.completekey = self.config.completekey

        self.mycompleter = None
        self.watching = {} # frame --> (name --> last seen value)
        self.sticky = False
        self.sticky_ranges = {} # frame --> (start, end)
        self.tb_lineno = {} # frame --> lineno where the exception raised

    def interaction(self, frame, traceback, orig_traceback=None):
        self.setup(frame, traceback, orig_traceback)
        self.print_stack_entry(self.stack[self.curindex])
        self.cmdloop()
        self.forget()

    def setup(self, frame, tb, orig_tb=None):
        pdb.Pdb.setup(self, frame, tb)
        tb = orig_tb
        while tb:
            lineno = lasti2lineno(tb.tb_frame.f_code, tb.tb_lasti)
            self.tb_lineno[tb.tb_frame] = lineno
            tb = tb.tb_next

    def forget(self):
        pdb.Pdb.forget(self)
        self.raise_lineno = {}

    def complete(self, text, state):
        if state == 0:
            mydict = self.curframe.f_globals.copy()
            mydict.update(self.curframe.f_locals)
            self.mycompleter = Completer(mydict)
        return self.mycompleter.complete(text, state)

    def _init_pygments(self): 
        try:
            from pygments.lexers import PythonLexer
            from pygments.formatters import TerminalFormatter
        except ImportError:
            return False

        if hasattr(self, '_fmt'):
            return True
        
        self._fmt = TerminalFormatter(bg=self.config.bg,
                                      colorscheme=self.config.colorscheme)
        self._lexer = PythonLexer()
        return True

    def format_source(self, src):
        if not self._init_pygments():
            return src
        from pygments import highlight, lex
        return highlight(src, self._lexer, self._fmt)

    def format_line(self, lineno, marker, line):
        lineno = '%4d' % lineno
        if self.config.highlight:
            lineno = setcolor(lineno, self.config.line_number_color)
        line = '%s  %2s %s' % (lineno, marker, line)
        if self.config.highlight and marker == '->':
            line = setbgcolor(line, self.config.current_line_color)
        return line

    def parseline(self, line):
        cmd, arg, newline = pdb.Pdb.parseline(self, line)
        # don't execute short disruptive commands if a variable with
        # the name exits in the current contex; this prevents pdb to
        # quit if you type e.g. 'r[0]' by mystake.
        if cmd in ['c', 'r', 'q'] and (cmd in self.curframe.f_globals or
                                       cmd in self.curframe.f_locals):
            line = '!' + line
            return pdb.Pdb.parseline(self, line)
        return cmd, arg, newline

    def do_longlist(self, arg):
        """
        {longlist|ll}
        List source code for the current function.
        
        Differently that list, the whole function is displayed; the
        current line is marked with '->'.  In case of post-mortem
        debugging, the line which effectively raised the exception is
        marked with '>>'.

        If the 'highlight' config option is set and pygments is
        installed, the source code is colorized.
        """
        self.lastcmd = 'longlist'
        self._printlonglist()

    def _printlonglist(self, linerange=None):
        try:
            lines, lineno = getsourcelines(self.curframe)
        except IOError, e:
            print '** Error: %s **' % e
            return
        if linerange:
            start, end = linerange
            start = max(start, lineno)
            end = min(end, lineno+len(lines))
            lines = lines[start-lineno:end-lineno]
            lineno = start
        self._print_lines(lines, lineno)

    def _print_lines(self, lines, lineno, print_markers=True):
        exc_lineno = self.tb_lineno.get(self.curframe, None)
        lines = [line[:-1] for line in lines] # remove the trailing '\n'
        if self.config.highlight:
            maxlength = max(map(len, lines))
            lines = [line.ljust(maxlength) for line in lines]
            src = self.format_source('\n'.join(lines))
            lines = src.splitlines()
        for i, line in enumerate(lines):
            marker = ''
            if lineno == self.curframe.f_lineno and print_markers:
                marker = '->'
            elif lineno == exc_lineno and print_markers:
                marker = '>>'
            lines[i] = self.format_line(lineno, marker, line)
            lineno += 1
        print '\n'.join(lines)

    do_ll = do_longlist

    def do_list(self, arg):
        from StringIO import StringIO
        oldstdout = sys.stdout
        sys.stdout = StringIO()
        pdb.Pdb.do_list(self, arg)
        src = self.format_source(sys.stdout.getvalue())
        sys.stdout = oldstdout
        print src,

    do_l = do_list

    def do_interact(self, arg):
        """
        interact

        Start an interative interpreter whose global namespace
        contains all the names found in the current scope.
        """
        ns = self.curframe.f_globals.copy()
        ns.update(self.curframe.f_locals)
        code.interact("*interactive*", local=ns)

    def do_track(self, arg):
        """
        track expression

        Display a graph showing which objects are referred by the
        value of the expression.  This command requires pypy to be in
        the current PYTHONPATH.
        """
        try:
            from pypy.translator.tool.reftracker import track
        except ImportError:
            print '** cannot import pypy.translator.tool.reftracker **'
            return
        val = self._getval(arg)
        track(val)

    def _get_watching(self):
        return self.watching.setdefault(self.curframe, {})

    def _getval_or_undefined(self, arg):
        try:
            return eval(arg, self.curframe.f_globals,
                        self.curframe.f_locals)
        except NameError:
            return undefined

    def do_watch(self, arg):
        """
        watch expression

        Add expression to the watching list; expressions in this list
        are evaluated at each step, and printed every time its value
        changes.

        WARNING: since the expressions is evaluated multiple time, pay
        attention not to put expressions with side-effects in the
        watching list.
        """
        try:
            value = self._getval_or_undefined(arg)
        except:
            return
        self._get_watching()[arg] = value

    def do_unwatch(self, arg):
        """
        unwatch expression

        Remove expression from the watching list.
        """
        try:
            del self._get_watching()[arg]
        except KeyError:
            print '** not watching %s **' % arg

    def _print_if_sticky(self):
        if self.sticky:
            sys.stdout.write(CLEARSCREEN)
            frame, lineno = self.stack[self.curindex]
            filename = self.canonic(frame.f_code.co_filename)
            s = '> %s(%r)' % (filename, lineno)
            print s
            print
            sticky_range = self.sticky_ranges.get(self.curframe, None)
            self._printlonglist(sticky_range)

    def do_sticky(self, arg):
        """
        sticky [start end]

        Toggle sticky mode. When in sticky mode, it clear the screen
        and longlist the current functions, making the source
        appearing always in the same position. Useful to follow the
        flow control of a function when doing step-by-step execution.

        If ``start`` and ``end`` are given, sticky mode is enabled and
        only lines within that range (extremes included) will be
        displayed.
        """
        if arg:
            try:
                start, end = map(int, arg.split())
            except ValueError:
                print '** Error when parsing argument: %s **' % arg
                return
            self.sticky = True
            self.sticky_ranges[self.curframe] = start, end+1
        else:
            self.sticky = not self.sticky
            self.sticky_range = None
        self._print_if_sticky()

    def preloop(self):
        self._print_if_sticky()
        watching = self._get_watching()
        for expr, oldvalue in watching.iteritems():
            newvalue = self._getval_or_undefined(expr)
            # check for identity first; this prevents custom __eq__ to
            # be called at every loop, and also prevents instances
            # whose fields are changed to be displayed
            if newvalue is not oldvalue or newvalue != oldvalue:
                watching[expr] = newvalue
                print '%s: %r --> %r' % (expr, oldvalue, newvalue)

    def do_source(self, arg):
        try:
            obj = self._getval(arg)
        except:
            return
        try:
            lines, lineno = getsourcelines(obj)
        except (IOError, TypeError), e:
            print '** Error: %s **' % e
            return
        self._print_lines(lines, lineno, print_markers=False)

# Simplified interface

# copy some functions from pdb.py, but rebind the global dictionary
for name in 'run runeval runctx runcall set_trace pm'.split():
    func = getattr(pdb, name)
    newfunc = types.FunctionType(func.func_code, globals(), func.func_name)
    globals()[name] = newfunc
del name, func, newfunc

def post_mortem(t, Pdb=Pdb):
    p = Pdb()
    p.reset()
    orig_tb = t
    while t.tb_next is not None:
        t = t.tb_next
    p.interaction(t.tb_frame, t, orig_tb)

# pdb++ specific interface

def xpm(Pdb=Pdb):
    """
    To be used inside an except clause, enter a post-mortem pdb
    related to the just catched exception.
    """
    post_mortem(sys.exc_info()[2], Pdb)