summaryrefslogtreecommitdiffstats
path: root/Lib/trace.py
blob: ae154615fa3af4a8f093b761c384e3a1ba1f86ee (plain)
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
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
#!/usr/bin/env python3

# portions copyright 2001, Autonomous Zones Industries, Inc., all rights...
# err...  reserved and offered to the public under the terms of the
# Python 2.2 license.
# Author: Zooko O'Whielacronx
# http://zooko.com/
# mailto:zooko@zooko.com
#
# Copyright 2000, Mojam Media, Inc., all rights reserved.
# Author: Skip Montanaro
#
# Copyright 1999, Bioreason, Inc., all rights reserved.
# Author: Andrew Dalke
#
# Copyright 1995-1997, Automatrix, Inc., all rights reserved.
# Author: Skip Montanaro
#
# Copyright 1991-1995, Stichting Mathematisch Centrum, all rights reserved.
#
#
# Permission to use, copy, modify, and distribute this Python software and
# its associated documentation for any purpose without fee is hereby
# granted, provided that the above copyright notice appears in all copies,
# and that both that copyright notice and this permission notice appear in
# supporting documentation, and that the name of neither Automatrix,
# Bioreason or Mojam Media be used in advertising or publicity pertaining to
# distribution of the software without specific, written prior permission.
#
"""program/module to trace Python program or function execution

Sample use, command line:
  trace.py -c -f counts --ignore-dir '$prefix' spam.py eggs
  trace.py -t --ignore-dir '$prefix' spam.py eggs
  trace.py --trackcalls spam.py eggs

Sample use, programmatically
  import sys

  # create a Trace object, telling it what to ignore, and whether to
  # do tracing or line-counting or both.
  tracer = trace.Trace(ignoredirs=[sys.base_prefix, sys.base_exec_prefix,],
                       trace=0, count=1)
  # run the new command using the given tracer
  tracer.run('main()')
  # make a report, placing output in /tmp
  r = tracer.results()
  r.write_results(show_missing=True, coverdir="/tmp")
"""
__all__ = ['Trace', 'CoverageResults']
import argparse
import linecache
import os
import re
import sys
import token
import tokenize
import inspect
import gc
import dis
import pickle
from time import monotonic as _time

try:
    import threading
except ImportError:
    _settrace = sys.settrace

    def _unsettrace():
        sys.settrace(None)
else:
    def _settrace(func):
        threading.settrace(func)
        sys.settrace(func)

    def _unsettrace():
        sys.settrace(None)
        threading.settrace(None)

PRAGMA_NOCOVER = "#pragma NO COVER"

# Simple rx to find lines with no code.
rx_blank = re.compile(r'^\s*(#.*)?$')

class _Ignore:
    def __init__(self, modules=None, dirs=None):
        self._mods = set() if not modules else set(modules)
        self._dirs = [] if not dirs else [os.path.normpath(d)
                                          for d in dirs]
        self._ignore = { '<string>': 1 }

    def names(self, filename, modulename):
        if modulename in self._ignore:
            return self._ignore[modulename]

        # haven't seen this one before, so see if the module name is
        # on the ignore list.
        if modulename in self._mods:  # Identical names, so ignore
            self._ignore[modulename] = 1
            return 1

        # check if the module is a proper submodule of something on
        # the ignore list
        for mod in self._mods:
            # Need to take some care since ignoring
            # "cmp" mustn't mean ignoring "cmpcache" but ignoring
            # "Spam" must also mean ignoring "Spam.Eggs".
            if modulename.startswith(mod + '.'):
                self._ignore[modulename] = 1
                return 1

        # Now check that filename isn't in one of the directories
        if filename is None:
            # must be a built-in, so we must ignore
            self._ignore[modulename] = 1
            return 1

        # Ignore a file when it contains one of the ignorable paths
        for d in self._dirs:
            # The '+ os.sep' is to ensure that d is a parent directory,
            # as compared to cases like:
            #  d = "/usr/local"
            #  filename = "/usr/local.py"
            # or
            #  d = "/usr/local.py"
            #  filename = "/usr/local.py"
            if filename.startswith(d + os.sep):
                self._ignore[modulename] = 1
                return 1

        # Tried the different ways, so we don't ignore this module
        self._ignore[modulename] = 0
        return 0

def _modname(path):
    """Return a plausible module name for the patch."""

    base = os.path.basename(path)
    filename, ext = os.path.splitext(base)
    return filename

def _fullmodname(path):
    """Return a plausible module name for the path."""

    # If the file 'path' is part of a package, then the filename isn't
    # enough to uniquely identify it.  Try to do the right thing by
    # looking in sys.path for the longest matching prefix.  We'll
    # assume that the rest is the package name.

    comparepath = os.path.normcase(path)
    longest = ""
    for dir in sys.path:
        dir = os.path.normcase(dir)
        if comparepath.startswith(dir) and comparepath[len(dir)] == os.sep:
            if len(dir) > len(longest):
                longest = dir

    if longest:
        base = path[len(longest) + 1:]
    else:
        base = path
    # the drive letter is never part of the module name
    drive, base = os.path.splitdrive(base)
    base = base.replace(os.sep, ".")
    if os.altsep:
        base = base.replace(os.altsep, ".")
    filename, ext = os.path.splitext(base)
    return filename.lstrip(".")

class CoverageResults:
    def __init__(self, counts=None, calledfuncs=None, infile=None,
                 callers=None, outfile=None):
        self.counts = counts
        if self.counts is None:
            self.counts = {}
        self.counter = self.counts.copy() # map (filename, lineno) to count
        self.calledfuncs = calledfuncs
        if self.calledfuncs is None:
            self.calledfuncs = {}
        self.calledfuncs = self.calledfuncs.copy()
        self.callers = callers
        if self.callers is None:
            self.callers = {}
        self.callers = self.callers.copy()
        self.infile = infile
        self.outfile = outfile
        if self.infile:
            # Try to merge existing counts file.
            try:
                with open(self.infile, 'rb') as f:
                    counts, calledfuncs, callers = pickle.load(f)
                self.update(self.__class__(counts, calledfuncs, callers))
            except (OSError, EOFError, ValueError) as err:
                print(("Skipping counts file %r: %s"
                                      % (self.infile, err)), file=sys.stderr)

    def is_ignored_filename(self, filename):
        """Return True if the filename does not refer to a file
        we want to have reported.
        """
        return filename.startswith('<') and filename.endswith('>')

    def update(self, other):
        """Merge in the data from another CoverageResults"""
        counts = self.counts
        calledfuncs = self.calledfuncs
        callers = self.callers
        other_counts = other.counts
        other_calledfuncs = other.calledfuncs
        other_callers = other.callers

        for key in other_counts:
            counts[key] = counts.get(key, 0) + other_counts[key]

        for key in other_calledfuncs:
            calledfuncs[key] = 1

        for key in other_callers:
            callers[key] = 1

    def write_results(self, show_missing=True, summary=False, coverdir=None):
        """
        Write the coverage results.

        :param show_missing: Show lines that had no hits.
        :param summary: Include coverage summary per module.
        :param coverdir: If None, the results of each module are placed in its
                         directory, otherwise it is included in the directory
                         specified.
        """
        if self.calledfuncs:
            print()
            print("functions called:")
            calls = self.calledfuncs
            for filename, modulename, funcname in sorted(calls):
                print(("filename: %s, modulename: %s, funcname: %s"
                       % (filename, modulename, funcname)))

        if self.callers:
            print()
            print("calling relationships:")
            lastfile = lastcfile = ""
            for ((pfile, pmod, pfunc), (cfile, cmod, cfunc)) \
                    in sorted(self.callers):
                if pfile != lastfile:
                    print()
                    print("***", pfile, "***")
                    lastfile = pfile
                    lastcfile = ""
                if cfile != pfile and lastcfile != cfile:
                    print("  -->", cfile)
                    lastcfile = cfile
                print("    %s.%s -> %s.%s" % (pmod, pfunc, cmod, cfunc))

        # turn the counts data ("(filename, lineno) = count") into something
        # accessible on a per-file basis
        per_file = {}
        for filename, lineno in self.counts:
            lines_hit = per_file[filename] = per_file.get(filename, {})
            lines_hit[lineno] = self.counts[(filename, lineno)]

        # accumulate summary info, if needed
        sums = {}

        for filename, count in per_file.items():
            if self.is_ignored_filename(filename):
                continue

            if filename.endswith(".pyc"):
                filename = filename[:-1]

            if coverdir is None:
                dir = os.path.dirname(os.path.abspath(filename))
                modulename = _modname(filename)
            else:
                dir = coverdir
                if not os.path.exists(dir):
                    os.makedirs(dir)
                modulename = _fullmodname(filename)

            # If desired, get a list of the line numbers which represent
            # executable content (returned as a dict for better lookup speed)
            if show_missing:
                lnotab = _find_executable_linenos(filename)
            else:
                lnotab = {}
            if lnotab:
                source = linecache.getlines(filename)
                coverpath = os.path.join(dir, modulename + ".cover")
                with open(filename, 'rb') as fp:
                    encoding, _ = tokenize.detect_encoding(fp.readline)
                n_hits, n_lines = self.write_results_file(coverpath, source,
                                                          lnotab, count, encoding)
                if summary and n_lines:
                    percent = int(100 * n_hits / n_lines)
                    sums[modulename] = n_lines, percent, modulename, filename


        if summary and sums:
            print("lines   cov%   module   (path)")
            for m in sorted(sums):
                n_lines, percent, modulename, filename = sums[m]
                print("%5d   %3d%%   %s   (%s)" % sums[m])

        if self.outfile:
            # try and store counts and module info into self.outfile
            try:
                pickle.dump((self.counts, self.calledfuncs, self.callers),
                            open(self.outfile, 'wb'), 1)
            except OSError as err:
                print("Can't save counts files because %s" % err, file=sys.stderr)

    def write_results_file(self, path, lines, lnotab, lines_hit, encoding=None):
        """Return a coverage results file in path."""

        try:
            outfile = open(path, "w", encoding=encoding)
        except OSError as err:
            print(("trace: Could not open %r for writing: %s"
                                  "- skipping" % (path, err)), file=sys.stderr)
            return 0, 0

        n_lines = 0
        n_hits = 0
        with outfile:
            for lineno, line in enumerate(lines, 1):
                # do the blank/comment match to try to mark more lines
                # (help the reader find stuff that hasn't been covered)
                if lineno in lines_hit:
                    outfile.write("%5d: " % lines_hit[lineno])
                    n_hits += 1
                    n_lines += 1
                elif rx_blank.match(line):
                    outfile.write("       ")
                else:
                    # lines preceded by no marks weren't hit
                    # Highlight them if so indicated, unless the line contains
                    # #pragma: NO COVER
                    if lineno in lnotab and not PRAGMA_NOCOVER in line:
                        outfile.write(">>>>>> ")
                        n_lines += 1
                    else:
                        outfile.write("       ")
                outfile.write(line.expandtabs(8))

        return n_hits, n_lines

def _find_lines_from_code(code, strs):
    """Return dict where keys are lines in the line number table."""
    linenos = {}

    for _, lineno in dis.findlinestarts(code):
        if lineno not in strs:
            linenos[lineno] = 1

    return linenos

def _find_lines(code, strs):
    """Return lineno dict for all code objects reachable from code."""
    # get all of the lineno information from the code of this scope level
    linenos = _find_lines_from_code(code, strs)

    # and check the constants for references to other code objects
    for c in code.co_consts:
        if inspect.iscode(c):
            # find another code object, so recurse into it
            linenos.update(_find_lines(c, strs))
    return linenos

def _find_strings(filename, encoding=None):
    """Return a dict of possible docstring positions.

    The dict maps line numbers to strings.  There is an entry for
    line that contains only a string or a part of a triple-quoted
    string.
    """
    d = {}
    # If the first token is a string, then it's the module docstring.
    # Add this special case so that the test in the loop passes.
    prev_ttype = token.INDENT
    with open(filename, encoding=encoding) as f:
        tok = tokenize.generate_tokens(f.readline)
        for ttype, tstr, start, end, line in tok:
            if ttype == token.STRING:
                if prev_ttype == token.INDENT:
                    sline, scol = start
                    eline, ecol = end
                    for i in range(sline, eline + 1):
                        d[i] = 1
            prev_ttype = ttype
    return d

def _find_executable_linenos(filename):
    """Return dict where keys are line numbers in the line number table."""
    try:
        with tokenize.open(filename) as f:
            prog = f.read()
            encoding = f.encoding
    except OSError as err:
        print(("Not printing coverage data for %r: %s"
                              % (filename, err)), file=sys.stderr)
        return {}
    code = compile(prog, filename, "exec")
    strs = _find_strings(filename, encoding)
    return _find_lines(code, strs)

class Trace:
    def __init__(self, count=1, trace=1, countfuncs=0, countcallers=0,
                 ignoremods=(), ignoredirs=(), infile=None, outfile=None,
                 timing=False):
        """
        @param count true iff it should count number of times each
                     line is executed
        @param trace true iff it should print out each line that is
                     being counted
        @param countfuncs true iff it should just output a list of
                     (filename, modulename, funcname,) for functions
                     that were called at least once;  This overrides
                     `count' and `trace'
        @param ignoremods a list of the names of modules to ignore
        @param ignoredirs a list of the names of directories to ignore
                     all of the (recursive) contents of
        @param infile file from which to read stored counts to be
                     added into the results
        @param outfile file in which to write the results
        @param timing true iff timing information be displayed
        """
        self.infile = infile
        self.outfile = outfile
        self.ignore = _Ignore(ignoremods, ignoredirs)
        self.counts = {}   # keys are (filename, linenumber)
        self.pathtobasename = {} # for memoizing os.path.basename
        self.donothing = 0
        self.trace = trace
        self._calledfuncs = {}
        self._callers = {}
        self._caller_cache = {}
        self.start_time = None
        if timing:
            self.start_time = _time()
        if countcallers:
            self.globaltrace = self.globaltrace_trackcallers
        elif countfuncs:
            self.globaltrace = self.globaltrace_countfuncs
        elif trace and count:
            self.globaltrace = self.globaltrace_lt
            self.localtrace = self.localtrace_trace_and_count
        elif trace:
            self.globaltrace = self.globaltrace_lt
            self.localtrace = self.localtrace_trace
        elif count:
            self.globaltrace = self.globaltrace_lt
            self.localtrace = self.localtrace_count
        else:
            # Ahem -- do nothing?  Okay.
            self.donothing = 1

    def run(self, cmd):
        import __main__
        dict = __main__.__dict__
        self.runctx(cmd, dict, dict)

    def runctx(self, cmd, globals=None, locals=None):
        if globals is None: globals = {}
        if locals is None: locals = {}
        if not self.donothing:
            _settrace(self.globaltrace)
        try:
            exec(cmd, globals, locals)
        finally:
            if not self.donothing:
                _unsettrace()

    def runfunc(self, func, *args, **kw):
        result = None
        if not self.donothing:
            sys.settrace(self.globaltrace)
        try:
            result = func(*args, **kw)
        finally:
            if not self.donothing:
                sys.settrace(None)
        return result

    def file_module_function_of(self, frame):
        code = frame.f_code
        filename = code.co_filename
        if filename:
            modulename = _modname(filename)
        else:
            modulename = None

        funcname = code.co_name
        clsname = None
        if code in self._caller_cache:
            if self._caller_cache[code] is not None:
                clsname = self._caller_cache[code]
        else:
            self._caller_cache[code] = None
            ## use of gc.get_referrers() was suggested by Michael Hudson
            # all functions which refer to this code object
            funcs = [f for f in gc.get_referrers(code)
                         if inspect.isfunction(f)]
            # require len(func) == 1 to avoid ambiguity caused by calls to
            # new.function(): "In the face of ambiguity, refuse the
            # temptation to guess."
            if len(funcs) == 1:
                dicts = [d for d in gc.get_referrers(funcs[0])
                             if isinstance(d, dict)]
                if len(dicts) == 1:
                    classes = [c for c in gc.get_referrers(dicts[0])
                                   if hasattr(c, "__bases__")]
                    if len(classes) == 1:
                        # ditto for new.classobj()
                        clsname = classes[0].__name__
                        # cache the result - assumption is that new.* is
                        # not called later to disturb this relationship
                        # _caller_cache could be flushed if functions in
                        # the new module get called.
                        self._caller_cache[code] = clsname
        if clsname is not None:
            funcname = "%s.%s" % (clsname, funcname)

        return filename, modulename, funcname

    def globaltrace_trackcallers(self, frame, why, arg):
        """Handler for call events.

        Adds information about who called who to the self._callers dict.
        """
        if why == 'call':
            # XXX Should do a better job of identifying methods
            this_func = self.file_module_function_of(frame)
            parent_func = self.file_module_function_of(frame.f_back)
            self._callers[(parent_func, this_func)] = 1

    def globaltrace_countfuncs(self, frame, why, arg):
        """Handler for call events.

        Adds (filename, modulename, funcname) to the self._calledfuncs dict.
        """
        if why == 'call':
            this_func = self.file_module_function_of(frame)
            self._calledfuncs[this_func] = 1

    def globaltrace_lt(self, frame, why, arg):
        """Handler for call events.

        If the code block being entered is to be ignored, returns `None',
        else returns self.localtrace.
        """
        if why == 'call':
            code = frame.f_code
            filename = frame.f_globals.get('__file__', None)
            if filename:
                # XXX _modname() doesn't work right for packages, so
                # the ignore support won't work right for packages
                modulename = _modname(filename)
                if modulename is not None:
                    ignore_it = self.ignore.names(filename, modulename)
                    if not ignore_it:
                        if self.trace:
                            print((" --- modulename: %s, funcname: %s"
                                   % (modulename, code.co_name)))
                        return self.localtrace
            else:
                return None

    def localtrace_trace_and_count(self, frame, why, arg):
        if why == "line":
            # record the file name and line number of every trace
            filename = frame.f_code.co_filename
            lineno = frame.f_lineno
            key = filename, lineno
            self.counts[key] = self.counts.get(key, 0) + 1

            if self.start_time:
                print('%.2f' % (_time() - self.start_time), end=' ')
            bname = os.path.basename(filename)
            print("%s(%d): %s" % (bname, lineno,
                                  linecache.getline(filename, lineno)), end='')
        return self.localtrace

    def localtrace_trace(self, frame, why, arg):
        if why == "line":
            # record the file name and line number of every trace
            filename = frame.f_code.co_filename
            lineno = frame.f_lineno

            if self.start_time:
                print('%.2f' % (_time() - self.start_time), end=' ')
            bname = os.path.basename(filename)
            print("%s(%d): %s" % (bname, lineno,
                                  linecache.getline(filename, lineno)), end='')
        return self.localtrace

    def localtrace_count(self, frame, why, arg):
        if why == "line":
            filename = frame.f_code.co_filename
            lineno = frame.f_lineno
            key = filename, lineno
            self.counts[key] = self.counts.get(key, 0) + 1
        return self.localtrace

    def results(self):
        return CoverageResults(self.counts, infile=self.infile,
                               outfile=self.outfile,
                               calledfuncs=self._calledfuncs,
                               callers=self._callers)

def main():

    parser = argparse.ArgumentParser()
    parser.add_argument('--version', action='version', version='trace 2.0')

    grp = parser.add_argument_group('Main options',
            'One of these (or --report) must be given')

    grp.add_argument('-c', '--count', action='store_true',
            help='Count the number of times each line is executed and write '
                 'the counts to <module>.cover for each module executed, in '
                 'the module\'s directory. See also --coverdir, --file, '
                 '--no-report below.')
    grp.add_argument('-t', '--trace', action='store_true',
            help='Print each line to sys.stdout before it is executed')
    grp.add_argument('-l', '--listfuncs', action='store_true',
            help='Keep track of which functions are executed at least once '
                 'and write the results to sys.stdout after the program exits. '
                 'Cannot be specified alongside --trace or --count.')
    grp.add_argument('-T', '--trackcalls', action='store_true',
            help='Keep track of caller/called pairs and write the results to '
                 'sys.stdout after the program exits.')

    grp = parser.add_argument_group('Modifiers')

    _grp = grp.add_mutually_exclusive_group()
    _grp.add_argument('-r', '--report', action='store_true',
            help='Generate a report from a counts file; does not execute any '
                 'code. --file must specify the results file to read, which '
                 'must have been created in a previous run with --count '
                 '--file=FILE')
    _grp.add_argument('-R', '--no-report', action='store_true',
            help='Do not generate the coverage report files. '
                 'Useful if you want to accumulate over several runs.')

    grp.add_argument('-f', '--file',
            help='File to accumulate counts over several runs')
    grp.add_argument('-C', '--coverdir',
            help='Directory where the report files go. The coverage report '
                 'for <package>.<module> will be written to file '
                 '<dir>/<package>/<module>.cover')
    grp.add_argument('-m', '--missing', action='store_true',
            help='Annotate executable lines that were not executed with '
                 '">>>>>> "')
    grp.add_argument('-s', '--summary', action='store_true',
            help='Write a brief summary for each file to sys.stdout. '
                 'Can only be used with --count or --report')
    grp.add_argument('-g', '--timing', action='store_true',
            help='Prefix each line with the time since the program started. '
                 'Only used while tracing')

    grp = parser.add_argument_group('Filters',
            'Can be specified multiple times')
    grp.add_argument('--ignore-module', action='append', default=[],
            help='Ignore the given module(s) and its submodules'
                 '(if it is a package). Accepts comma separated list of '
                 'module names.')
    grp.add_argument('--ignore-dir', action='append', default=[],
            help='Ignore files in the given directory '
                 '(multiple directories can be joined by os.pathsep).')

    parser.add_argument('filename', nargs='?',
            help='file to run as main program')
    parser.add_argument('arguments', nargs=argparse.REMAINDER,
            help='arguments to the program')

    opts = parser.parse_args()

    if opts.ignore_dir:
        rel_path = 'lib', 'python{0.major}.{0.minor}'.format(sys.version_info)
        _prefix = os.path.join(sys.base_prefix, *rel_path)
        _exec_prefix = os.path.join(sys.base_exec_prefix, *rel_path)

    def parse_ignore_dir(s):
        s = os.path.expanduser(os.path.expandvars(s))
        s = s.replace('$prefix', _prefix).replace('$exec_prefix', _exec_prefix)
        return os.path.normpath(s)

    opts.ignore_module = [mod.strip()
                          for i in opts.ignore_module for mod in i.split(',')]
    opts.ignore_dir = [parse_ignore_dir(s)
                       for i in opts.ignore_dir for s in i.split(os.pathsep)]

    if opts.report:
        if not opts.file:
            parser.error('-r/--report requires -f/--file')
        results = CoverageResults(infile=opts.file, outfile=opts.file)
        return results.write_results(opts.missing, opts.summary, opts.coverdir)

    if not any([opts.trace, opts.count, opts.listfuncs, opts.trackcalls]):
        parser.error('must specify one of --trace, --count, --report, '
                     '--listfuncs, or --trackcalls')

    if opts.listfuncs and (opts.count or opts.trace):
        parser.error('cannot specify both --listfuncs and (--trace or --count)')

    if opts.summary and not opts.count:
        parser.error('--summary can only be used with --count or --report')

    if opts.filename is None:
        parser.error('filename is missing: required with the main options')

    sys.argv = opts.filename, *opts.arguments
    sys.path[0] = os.path.dirname(opts.filename)

    t = Trace(opts.count, opts.trace, countfuncs=opts.listfuncs,
              countcallers=opts.trackcalls, ignoremods=opts.ignore_module,
              ignoredirs=opts.ignore_dir, infile=opts.file,
              outfile=opts.file, timing=opts.timing)
    try:
        with open(opts.filename) as fp:
            code = compile(fp.read(), opts.filename, 'exec')
        # try to emulate __main__ namespace as much as possible
        globs = {
            '__file__': opts.filename,
            '__name__': '__main__',
            '__package__': None,
            '__cached__': None,
        }
        t.runctx(code, globs, globs)
    except OSError as err:
        sys.exit("Cannot run file %r because: %s" % (sys.argv[0], err))
    except SystemExit:
        pass

    results = t.results()

    if not opts.no_report:
        results.write_results(opts.missing, opts.summary, opts.coverdir)

if __name__=='__main__':
    main()