summaryrefslogtreecommitdiffstats
path: root/Lib/test/test_sys.py
blob: 62030611fb7d0cec1c4e0a68604f2aee19c0b5be (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
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
import unittest, test.support
import sys, io, os
import struct
import subprocess
import textwrap
import warnings
import operator
import codecs

# count the number of test runs, used to create unique
# strings to intern in test_intern()
numruns = 0

try:
    import threading
except ImportError:
    threading = None

class SysModuleTest(unittest.TestCase):

    def setUp(self):
        self.orig_stdout = sys.stdout
        self.orig_stderr = sys.stderr
        self.orig_displayhook = sys.displayhook

    def tearDown(self):
        sys.stdout = self.orig_stdout
        sys.stderr = self.orig_stderr
        sys.displayhook = self.orig_displayhook
        test.support.reap_children()

    def test_original_displayhook(self):
        import builtins
        out = io.StringIO()
        sys.stdout = out

        dh = sys.__displayhook__

        self.assertRaises(TypeError, dh)
        if hasattr(builtins, "_"):
            del builtins._

        dh(None)
        self.assertEqual(out.getvalue(), "")
        self.assertTrue(not hasattr(builtins, "_"))
        dh(42)
        self.assertEqual(out.getvalue(), "42\n")
        self.assertEqual(builtins._, 42)

        del sys.stdout
        self.assertRaises(RuntimeError, dh, 42)

    def test_lost_displayhook(self):
        del sys.displayhook
        code = compile("42", "<string>", "single")
        self.assertRaises(RuntimeError, eval, code)

    def test_custom_displayhook(self):
        def baddisplayhook(obj):
            raise ValueError
        sys.displayhook = baddisplayhook
        code = compile("42", "<string>", "single")
        self.assertRaises(ValueError, eval, code)

    def test_original_excepthook(self):
        err = io.StringIO()
        sys.stderr = err

        eh = sys.__excepthook__

        self.assertRaises(TypeError, eh)
        try:
            raise ValueError(42)
        except ValueError as exc:
            eh(*sys.exc_info())

        self.assertTrue(err.getvalue().endswith("ValueError: 42\n"))

    def test_excepthook(self):
        with test.support.captured_output("stderr") as stderr:
            sys.excepthook(1, '1', 1)
        self.assertTrue("TypeError: print_exception(): Exception expected for " \
                         "value, str found" in stderr.getvalue())

    # FIXME: testing the code for a lost or replaced excepthook in
    # Python/pythonrun.c::PyErr_PrintEx() is tricky.

    def test_exit(self):

        self.assertRaises(TypeError, sys.exit, 42, 42)

        # call without argument
        try:
            sys.exit(0)
        except SystemExit as exc:
            self.assertEquals(exc.code, 0)
        except:
            self.fail("wrong exception")
        else:
            self.fail("no exception")

        # call with tuple argument with one entry
        # entry will be unpacked
        try:
            sys.exit(42)
        except SystemExit as exc:
            self.assertEquals(exc.code, 42)
        except:
            self.fail("wrong exception")
        else:
            self.fail("no exception")

        # call with integer argument
        try:
            sys.exit((42,))
        except SystemExit as exc:
            self.assertEquals(exc.code, 42)
        except:
            self.fail("wrong exception")
        else:
            self.fail("no exception")

        # call with string argument
        try:
            sys.exit("exit")
        except SystemExit as exc:
            self.assertEquals(exc.code, "exit")
        except:
            self.fail("wrong exception")
        else:
            self.fail("no exception")

        # call with tuple argument with two entries
        try:
            sys.exit((17, 23))
        except SystemExit as exc:
            self.assertEquals(exc.code, (17, 23))
        except:
            self.fail("wrong exception")
        else:
            self.fail("no exception")

        # test that the exit machinery handles SystemExits properly
        rc = subprocess.call([sys.executable, "-c",
                              "raise SystemExit(47)"])
        self.assertEqual(rc, 47)

        def check_exit_message(code, expected, env=None):
            process = subprocess.Popen([sys.executable, "-c", code],
                                       stderr=subprocess.PIPE, env=env)
            stdout, stderr = process.communicate()
            self.assertEqual(process.returncode, 1)
            self.assertTrue(stderr.startswith(expected),
                "%s doesn't start with %s" % (ascii(stderr), ascii(expected)))

        # test that stderr buffer if flushed before the exit message is written
        # into stderr
        check_exit_message(
            r'import sys; sys.stderr.write("unflushed,"); sys.exit("message")',
            b"unflushed,message")

        # test that the exit message is written with backslashreplace error
        # handler to stderr
        check_exit_message(
            r'import sys; sys.exit("surrogates:\uDCFF")',
            b"surrogates:\\udcff")

        # test that the unicode message is encoded to the stderr encoding
        # instead of the default encoding (utf8)
        env = os.environ.copy()
        env['PYTHONIOENCODING'] = 'latin-1'
        check_exit_message(
            r'import sys; sys.exit("h\xe9")',
            b"h\xe9", env=env)

    def test_getdefaultencoding(self):
        self.assertRaises(TypeError, sys.getdefaultencoding, 42)
        # can't check more than the type, as the user might have changed it
        self.assertIsInstance(sys.getdefaultencoding(), str)

    # testing sys.settrace() is done in test_sys_settrace.py
    # testing sys.setprofile() is done in test_sys_setprofile.py

    def test_setcheckinterval(self):
        with warnings.catch_warnings():
            warnings.simplefilter("ignore")
            self.assertRaises(TypeError, sys.setcheckinterval)
            orig = sys.getcheckinterval()
            for n in 0, 100, 120, orig: # orig last to restore starting state
                sys.setcheckinterval(n)
                self.assertEquals(sys.getcheckinterval(), n)

    @unittest.skipUnless(threading, 'Threading required for this test.')
    def test_switchinterval(self):
        self.assertRaises(TypeError, sys.setswitchinterval)
        self.assertRaises(TypeError, sys.setswitchinterval, "a")
        self.assertRaises(ValueError, sys.setswitchinterval, -1.0)
        self.assertRaises(ValueError, sys.setswitchinterval, 0.0)
        orig = sys.getswitchinterval()
        # sanity check
        self.assertTrue(orig < 0.5, orig)
        try:
            for n in 0.00001, 0.05, 3.0, orig:
                sys.setswitchinterval(n)
                self.assertAlmostEquals(sys.getswitchinterval(), n)
        finally:
            sys.setswitchinterval(orig)

    def test_recursionlimit(self):
        self.assertRaises(TypeError, sys.getrecursionlimit, 42)
        oldlimit = sys.getrecursionlimit()
        self.assertRaises(TypeError, sys.setrecursionlimit)
        self.assertRaises(ValueError, sys.setrecursionlimit, -42)
        sys.setrecursionlimit(10000)
        self.assertEqual(sys.getrecursionlimit(), 10000)
        sys.setrecursionlimit(oldlimit)

    def test_recursionlimit_recovery(self):
        # NOTE: this test is slightly fragile in that it depends on the current
        # recursion count when executing the test being low enough so as to
        # trigger the recursion recovery detection in the _Py_MakeEndRecCheck
        # macro (see ceval.h).
        oldlimit = sys.getrecursionlimit()
        def f():
            f()
        try:
            for i in (50, 1000):
                # Issue #5392: stack overflow after hitting recursion limit twice
                sys.setrecursionlimit(i)
                self.assertRaises(RuntimeError, f)
                self.assertRaises(RuntimeError, f)
        finally:
            sys.setrecursionlimit(oldlimit)

    def test_recursionlimit_fatalerror(self):
        # A fatal error occurs if a second recursion limit is hit when recovering
        # from a first one.
        if os.name == "nt":
            raise unittest.SkipTest(
                "under Windows, test would generate a spurious crash dialog")
        code = textwrap.dedent("""
            import sys

            def f():
                try:
                    f()
                except RuntimeError:
                    f()

            sys.setrecursionlimit(%d)
            f()""")
        for i in (50, 1000):
            sub = subprocess.Popen([sys.executable, '-c', code % i],
                stderr=subprocess.PIPE)
            err = sub.communicate()[1]
            self.assertTrue(sub.returncode, sub.returncode)
            self.assertTrue(
                b"Fatal Python error: Cannot recover from stack overflow" in err,
                err)

    def test_getwindowsversion(self):
        # Raise SkipTest if sys doesn't have getwindowsversion attribute
        test.support.get_attribute(sys, "getwindowsversion")
        v = sys.getwindowsversion()
        self.assertEqual(len(v), 5)
        self.assertIsInstance(v[0], int)
        self.assertIsInstance(v[1], int)
        self.assertIsInstance(v[2], int)
        self.assertIsInstance(v[3], int)
        self.assertIsInstance(v[4], str)
        self.assertRaises(IndexError, operator.getitem, v, 5)
        self.assertIsInstance(v.major, int)
        self.assertIsInstance(v.minor, int)
        self.assertIsInstance(v.build, int)
        self.assertIsInstance(v.platform, int)
        self.assertIsInstance(v.service_pack, str)
        self.assertIsInstance(v.service_pack_minor, int)
        self.assertIsInstance(v.service_pack_major, int)
        self.assertIsInstance(v.suite_mask, int)
        self.assertIsInstance(v.product_type, int)
        self.assertEqual(v[0], v.major)
        self.assertEqual(v[1], v.minor)
        self.assertEqual(v[2], v.build)
        self.assertEqual(v[3], v.platform)
        self.assertEqual(v[4], v.service_pack)

        # This is how platform.py calls it. Make sure tuple
        #  still has 5 elements
        maj, min, buildno, plat, csd = sys.getwindowsversion()

    def test_call_tracing(self):
        self.assertRaises(TypeError, sys.call_tracing, type, 2)

    def test_dlopenflags(self):
        if hasattr(sys, "setdlopenflags"):
            self.assertTrue(hasattr(sys, "getdlopenflags"))
            self.assertRaises(TypeError, sys.getdlopenflags, 42)
            oldflags = sys.getdlopenflags()
            self.assertRaises(TypeError, sys.setdlopenflags)
            sys.setdlopenflags(oldflags+1)
            self.assertEqual(sys.getdlopenflags(), oldflags+1)
            sys.setdlopenflags(oldflags)

    def test_refcount(self):
        # n here must be a global in order for this test to pass while
        # tracing with a python function.  Tracing calls PyFrame_FastToLocals
        # which will add a copy of any locals to the frame object, causing
        # the reference count to increase by 2 instead of 1.
        global n
        self.assertRaises(TypeError, sys.getrefcount)
        c = sys.getrefcount(None)
        n = None
        self.assertEqual(sys.getrefcount(None), c+1)
        del n
        self.assertEqual(sys.getrefcount(None), c)
        if hasattr(sys, "gettotalrefcount"):
            self.assertIsInstance(sys.gettotalrefcount(), int)

    def test_getframe(self):
        self.assertRaises(TypeError, sys._getframe, 42, 42)
        self.assertRaises(ValueError, sys._getframe, 2000000000)
        self.assertTrue(
            SysModuleTest.test_getframe.__code__ \
            is sys._getframe().f_code
        )

    # sys._current_frames() is a CPython-only gimmick.
    def test_current_frames(self):
        have_threads = True
        try:
            import _thread
        except ImportError:
            have_threads = False

        if have_threads:
            self.current_frames_with_threads()
        else:
            self.current_frames_without_threads()

    # Test sys._current_frames() in a WITH_THREADS build.
    @test.support.reap_threads
    def current_frames_with_threads(self):
        import threading, _thread
        import traceback

        # Spawn a thread that blocks at a known place.  Then the main
        # thread does sys._current_frames(), and verifies that the frames
        # returned make sense.
        entered_g = threading.Event()
        leave_g = threading.Event()
        thread_info = []  # the thread's id

        def f123():
            g456()

        def g456():
            thread_info.append(_thread.get_ident())
            entered_g.set()
            leave_g.wait()

        t = threading.Thread(target=f123)
        t.start()
        entered_g.wait()

        # At this point, t has finished its entered_g.set(), although it's
        # impossible to guess whether it's still on that line or has moved on
        # to its leave_g.wait().
        self.assertEqual(len(thread_info), 1)
        thread_id = thread_info[0]

        d = sys._current_frames()

        main_id = _thread.get_ident()
        self.assertIn(main_id, d)
        self.assertIn(thread_id, d)

        # Verify that the captured main-thread frame is _this_ frame.
        frame = d.pop(main_id)
        self.assertTrue(frame is sys._getframe())

        # Verify that the captured thread frame is blocked in g456, called
        # from f123.  This is a litte tricky, since various bits of
        # threading.py are also in the thread's call stack.
        frame = d.pop(thread_id)
        stack = traceback.extract_stack(frame)
        for i, (filename, lineno, funcname, sourceline) in enumerate(stack):
            if funcname == "f123":
                break
        else:
            self.fail("didn't find f123() on thread's call stack")

        self.assertEqual(sourceline, "g456()")

        # And the next record must be for g456().
        filename, lineno, funcname, sourceline = stack[i+1]
        self.assertEqual(funcname, "g456")
        self.assertIn(sourceline, ["leave_g.wait()", "entered_g.set()"])

        # Reap the spawned thread.
        leave_g.set()
        t.join()

    # Test sys._current_frames() when thread support doesn't exist.
    def current_frames_without_threads(self):
        # Not much happens here:  there is only one thread, with artificial
        # "thread id" 0.
        d = sys._current_frames()
        self.assertEqual(len(d), 1)
        self.assertIn(0, d)
        self.assertTrue(d[0] is sys._getframe())

    def test_attributes(self):
        self.assertIsInstance(sys.api_version, int)
        self.assertIsInstance(sys.argv, list)
        self.assertIn(sys.byteorder, ("little", "big"))
        self.assertIsInstance(sys.builtin_module_names, tuple)
        self.assertIsInstance(sys.copyright, str)
        self.assertIsInstance(sys.exec_prefix, str)
        self.assertIsInstance(sys.executable, str)
        self.assertEqual(len(sys.float_info), 11)
        self.assertEqual(sys.float_info.radix, 2)
        self.assertEqual(len(sys.int_info), 2)
        self.assertTrue(sys.int_info.bits_per_digit % 5 == 0)
        self.assertTrue(sys.int_info.sizeof_digit >= 1)
        self.assertEqual(type(sys.int_info.bits_per_digit), int)
        self.assertEqual(type(sys.int_info.sizeof_digit), int)
        self.assertIsInstance(sys.hexversion, int)

        self.assertEqual(len(sys.hash_info), 5)
        self.assertLess(sys.hash_info.modulus, 2**sys.hash_info.width)
        # sys.hash_info.modulus should be a prime; we do a quick
        # probable primality test (doesn't exclude the possibility of
        # a Carmichael number)
        for x in range(1, 100):
            self.assertEqual(
                pow(x, sys.hash_info.modulus-1, sys.hash_info.modulus),
                1,
                "sys.hash_info.modulus {} is a non-prime".format(
                    sys.hash_info.modulus)
                )
        self.assertIsInstance(sys.hash_info.inf, int)
        self.assertIsInstance(sys.hash_info.nan, int)
        self.assertIsInstance(sys.hash_info.imag, int)

        self.assertIsInstance(sys.maxsize, int)
        self.assertIsInstance(sys.maxunicode, int)
        self.assertIsInstance(sys.platform, str)
        self.assertIsInstance(sys.prefix, str)
        self.assertIsInstance(sys.version, str)
        vi = sys.version_info
        self.assertIsInstance(vi[:], tuple)
        self.assertEqual(len(vi), 5)
        self.assertIsInstance(vi[0], int)
        self.assertIsInstance(vi[1], int)
        self.assertIsInstance(vi[2], int)
        self.assertIn(vi[3], ("alpha", "beta", "candidate", "final"))
        self.assertIsInstance(vi[4], int)
        self.assertIsInstance(vi.major, int)
        self.assertIsInstance(vi.minor, int)
        self.assertIsInstance(vi.micro, int)
        self.assertIn(vi.releaselevel, ("alpha", "beta", "candidate", "final"))
        self.assertIsInstance(vi.serial, int)
        self.assertEqual(vi[0], vi.major)
        self.assertEqual(vi[1], vi.minor)
        self.assertEqual(vi[2], vi.micro)
        self.assertEqual(vi[3], vi.releaselevel)
        self.assertEqual(vi[4], vi.serial)
        self.assertTrue(vi > (1,0,0))
        self.assertIsInstance(sys.float_repr_style, str)
        self.assertIn(sys.float_repr_style, ('short', 'legacy'))

    def test_43581(self):
        # Can't use sys.stdout, as this is a StringIO object when
        # the test runs under regrtest.
        self.assertEqual(sys.__stdout__.encoding, sys.__stderr__.encoding)

    def test_intern(self):
        global numruns
        numruns += 1
        self.assertRaises(TypeError, sys.intern)
        s = "never interned before" + str(numruns)
        self.assertTrue(sys.intern(s) is s)
        s2 = s.swapcase().swapcase()
        self.assertTrue(sys.intern(s2) is s)

        # Subclasses of string can't be interned, because they
        # provide too much opportunity for insane things to happen.
        # We don't want them in the interned dict and if they aren't
        # actually interned, we don't want to create the appearance
        # that they are by allowing intern() to succeeed.
        class S(str):
            def __hash__(self):
                return 123

        self.assertRaises(TypeError, sys.intern, S("abc"))

    # On Windows, pass bytes to subprocess doesn't test how Python decodes the
    # command line, but how subprocess does decode bytes to unicode. Python
    # doesn't decode the command line because Windows provides directly the
    # arguments as unicode (using wmain() instead of main()).
    @unittest.skipIf(sys.platform == 'win32',
                     'Windows has a native unicode API')
    def test_undecodable_code(self):
        undecodable = b"\xff"
        env = os.environ.copy()
        # Use C locale to get ascii for the locale encoding
        env['LC_ALL'] = 'C'
        code = (
            b'import locale; '
            b'print(ascii("' + undecodable + b'"), '
                b'locale.getpreferredencoding())')
        p = subprocess.Popen(
            [sys.executable, "-c", code],
            stdout=subprocess.PIPE, stderr=subprocess.STDOUT,
            env=env)
        stdout, stderr = p.communicate()
        if p.returncode == 1:
            # _Py_char2wchar() decoded b'\xff' as '\udcff' (b'\xff' is not
            # decodable from ASCII) and run_command() failed on
            # PyUnicode_AsUTF8String(). This is the expected behaviour on
            # Linux.
            pattern = b"Unable to decode the command from the command line:"
        elif p.returncode == 0:
            # _Py_char2wchar() decoded b'\xff' as '\xff' even if the locale is
            # C and the locale encoding is ASCII. It occurs on FreeBSD, Solaris
            # and Mac OS X.
            pattern = b"'\\xff' "
            # The output is followed by the encoding name, an alias to ASCII.
            # Examples: "US-ASCII" or "646" (ISO 646, on Solaris).
        else:
            raise AssertionError("Unknown exit code: %s, output=%a" % (p.returncode, stdout))
        if not stdout.startswith(pattern):
            raise AssertionError("%a doesn't start with %a" % (stdout, pattern))

    def test_sys_flags(self):
        self.assertTrue(sys.flags)
        attrs = ("debug", "division_warning",
                 "inspect", "interactive", "optimize", "dont_write_bytecode",
                 "no_user_site", "no_site", "ignore_environment", "verbose",
                 "bytes_warning")
        for attr in attrs:
            self.assertTrue(hasattr(sys.flags, attr), attr)
            self.assertEqual(type(getattr(sys.flags, attr)), int, attr)
        self.assertTrue(repr(sys.flags))
        self.assertEqual(len(sys.flags), len(attrs))

    def test_clear_type_cache(self):
        sys._clear_type_cache()

    def test_ioencoding(self):
        env = dict(os.environ)

        # Test character: cent sign, encoded as 0x4A (ASCII J) in CP424,
        # not representable in ASCII.

        env["PYTHONIOENCODING"] = "cp424"
        p = subprocess.Popen([sys.executable, "-c", 'print(chr(0xa2))'],
                             stdout = subprocess.PIPE, env=env)
        out = p.communicate()[0].strip()
        self.assertEqual(out, "\xa2\n".encode("cp424"))

        env["PYTHONIOENCODING"] = "ascii:replace"
        p = subprocess.Popen([sys.executable, "-c", 'print(chr(0xa2))'],
                             stdout = subprocess.PIPE, env=env)
        out = p.communicate()[0].strip()
        self.assertEqual(out, b'?')

    def test_executable(self):
        # Issue #7774: Ensure that sys.executable is an empty string if argv[0]
        # has been set to an non existent program name and Python is unable to
        # retrieve the real program name

        # For a normal installation, it should work without 'cwd'
        # argument. For test runs in the build directory, see #7774.
        python_dir = os.path.dirname(os.path.realpath(sys.executable))
        p = subprocess.Popen(
            ["nonexistent", "-c",
             'import sys; print(sys.executable.encode("ascii", "backslashreplace"))'],
            executable=sys.executable, stdout=subprocess.PIPE, cwd=python_dir)
        stdout = p.communicate()[0]
        executable = stdout.strip().decode("ASCII")
        p.wait()
        self.assertIn(executable, ["b''", repr(sys.executable.encode("ascii", "backslashreplace"))])

    def check_fsencoding(self, fs_encoding, expected=None):
        self.assertIsNotNone(fs_encoding)
        codecs.lookup(fs_encoding)
        if expected:
            self.assertEqual(fs_encoding, expected)

    def test_getfilesystemencoding(self):
        fs_encoding = sys.getfilesystemencoding()
        if sys.platform == 'darwin':
            expected = 'utf-8'
        elif sys.platform == 'win32':
            expected = 'mbcs'
        else:
            expected = None
        self.check_fsencoding(fs_encoding, expected)


class SizeofTest(unittest.TestCase):

    TPFLAGS_HAVE_GC = 1<<14
    TPFLAGS_HEAPTYPE = 1<<9

    def setUp(self):
        self.c = len(struct.pack('c', ' '))
        self.H = len(struct.pack('H', 0))
        self.i = len(struct.pack('i', 0))
        self.l = len(struct.pack('l', 0))
        self.P = len(struct.pack('P', 0))
        # due to missing size_t information from struct, it is assumed that
        # sizeof(Py_ssize_t) = sizeof(void*)
        self.header = 'PP'
        self.vheader = self.header + 'P'
        if hasattr(sys, "gettotalrefcount"):
            self.header += '2P'
            self.vheader += '2P'
        self.longdigit = sys.int_info.sizeof_digit
        import _testcapi
        self.gc_headsize = _testcapi.SIZEOF_PYGC_HEAD
        self.file = open(test.support.TESTFN, 'wb')

    def tearDown(self):
        self.file.close()
        test.support.unlink(test.support.TESTFN)

    def check_sizeof(self, o, size):
        result = sys.getsizeof(o)
        # add GC header size
        if ((type(o) == type) and (o.__flags__ & self.TPFLAGS_HEAPTYPE) or\
           ((type(o) != type) and (type(o).__flags__ & self.TPFLAGS_HAVE_GC))):
            size += self.gc_headsize
        msg = 'wrong size for %s: got %d, expected %d' \
              % (type(o), result, size)
        self.assertEqual(result, size, msg)

    def calcsize(self, fmt):
        """Wrapper around struct.calcsize which enforces the alignment of the
        end of a structure to the alignment requirement of pointer.

        Note: This wrapper should only be used if a pointer member is included
        and no member with a size larger than a pointer exists.
        """
        return struct.calcsize(fmt + '0P')

    def test_gc_head_size(self):
        # Check that the gc header size is added to objects tracked by the gc.
        h = self.header
        vh = self.vheader
        size = self.calcsize
        gc_header_size = self.gc_headsize
        # bool objects are not gc tracked
        self.assertEqual(sys.getsizeof(True), size(vh) + self.longdigit)
        # but lists are
        self.assertEqual(sys.getsizeof([]), size(vh + 'PP') + gc_header_size)

    def test_default(self):
        h = self.header
        vh = self.vheader
        size = self.calcsize
        self.assertEqual(sys.getsizeof(True), size(vh) + self.longdigit)
        self.assertEqual(sys.getsizeof(True, -1), size(vh) + self.longdigit)

    def test_objecttypes(self):
        # check all types defined in Objects/
        h = self.header
        vh = self.vheader
        size = self.calcsize
        check = self.check_sizeof
        # bool
        check(True, size(vh) + self.longdigit)
        # buffer
        # XXX
        # builtin_function_or_method
        check(len, size(h + '3P'))
        # bytearray
        samples = [b'', b'u'*100000]
        for sample in samples:
            x = bytearray(sample)
            check(x, size(vh + 'iPP') + x.__alloc__() * self.c)
        # bytearray_iterator
        check(iter(bytearray()), size(h + 'PP'))
        # cell
        def get_cell():
            x = 42
            def inner():
                return x
            return inner
        check(get_cell().__closure__[0], size(h + 'P'))
        # code
        check(get_cell().__code__, size(h + '5i8Pi3P'))
        # complex
        check(complex(0,1), size(h + '2d'))
        # method_descriptor (descriptor object)
        check(str.lower, size(h + '2PP'))
        # classmethod_descriptor (descriptor object)
        # XXX
        # member_descriptor (descriptor object)
        import datetime
        check(datetime.timedelta.days, size(h + '2PP'))
        # getset_descriptor (descriptor object)
        import collections
        check(collections.defaultdict.default_factory, size(h + '2PP'))
        # wrapper_descriptor (descriptor object)
        check(int.__add__, size(h + '2P2P'))
        # method-wrapper (descriptor object)
        check({}.__iter__, size(h + '2P'))
        # dict
        check({}, size(h + '3P2P' + 8*'P2P'))
        longdict = {1:1, 2:2, 3:3, 4:4, 5:5, 6:6, 7:7, 8:8}
        check(longdict, size(h + '3P2P' + 8*'P2P') + 16*size('P2P'))
        # dictionary-keyiterator
        check({}.keys(), size(h + 'P'))
        # dictionary-valueiterator
        check({}.values(), size(h + 'P'))
        # dictionary-itemiterator
        check({}.items(), size(h + 'P'))
        # dictproxy
        class C(object): pass
        check(C.__dict__, size(h + 'P'))
        # BaseException
        check(BaseException(), size(h + '5P'))
        # UnicodeEncodeError
        check(UnicodeEncodeError("", "", 0, 0, ""), size(h + '5P 2P2PP'))
        # UnicodeDecodeError
        # XXX
#        check(UnicodeDecodeError("", "", 0, 0, ""), size(h + '5P2PP'))
        # UnicodeTranslateError
        check(UnicodeTranslateError("", 0, 1, ""), size(h + '5P 2P2PP'))
        # ellipses
        check(Ellipsis, size(h + ''))
        # EncodingMap
        import codecs, encodings.iso8859_3
        x = codecs.charmap_build(encodings.iso8859_3.decoding_table)
        check(x, size(h + '32B2iB'))
        # enumerate
        check(enumerate([]), size(h + 'l3P'))
        # reverse
        check(reversed(''), size(h + 'PP'))
        # float
        check(float(0), size(h + 'd'))
        # sys.floatinfo
        check(sys.float_info, size(vh) + self.P * len(sys.float_info))
        # frame
        import inspect
        CO_MAXBLOCKS = 20
        x = inspect.currentframe()
        ncells = len(x.f_code.co_cellvars)
        nfrees = len(x.f_code.co_freevars)
        extras = x.f_code.co_stacksize + x.f_code.co_nlocals +\
                  ncells + nfrees - 1
        check(x, size(vh + '12P3i' + CO_MAXBLOCKS*'3i' + 'P' + extras*'P'))
        # function
        def func(): pass
        check(func, size(h + '11P'))
        class c():
            @staticmethod
            def foo():
                pass
            @classmethod
            def bar(cls):
                pass
            # staticmethod
            check(foo, size(h + 'P'))
            # classmethod
            check(bar, size(h + 'P'))
        # generator
        def get_gen(): yield 1
        check(get_gen(), size(h + 'Pi2P'))
        # iterator
        check(iter('abc'), size(h + 'lP'))
        # callable-iterator
        import re
        check(re.finditer('',''), size(h + '2P'))
        # list
        samples = [[], [1,2,3], ['1', '2', '3']]
        for sample in samples:
            check(sample, size(vh + 'PP') + len(sample)*self.P)
        # sortwrapper (list)
        # XXX
        # cmpwrapper (list)
        # XXX
        # listiterator (list)
        check(iter([]), size(h + 'lP'))
        # listreverseiterator (list)
        check(reversed([]), size(h + 'lP'))
        # long
        check(0, size(vh))
        check(1, size(vh) + self.longdigit)
        check(-1, size(vh) + self.longdigit)
        PyLong_BASE = 2**sys.int_info.bits_per_digit
        check(int(PyLong_BASE), size(vh) + 2*self.longdigit)
        check(int(PyLong_BASE**2-1), size(vh) + 2*self.longdigit)
        check(int(PyLong_BASE**2), size(vh) + 3*self.longdigit)
        # memory
        check(memoryview(b''), size(h + 'P PP2P2i7P'))
        # module
        check(unittest, size(h + '3P'))
        # None
        check(None, size(h + ''))
        # NotImplementedType
        check(NotImplemented, size(h))
        # object
        check(object(), size(h + ''))
        # property (descriptor object)
        class C(object):
            def getx(self): return self.__x
            def setx(self, value): self.__x = value
            def delx(self): del self.__x
            x = property(getx, setx, delx, "")
            check(x, size(h + '4Pi'))
        # PyCapsule
        # XXX
        # rangeiterator
        check(iter(range(1)), size(h + '4l'))
        # reverse
        check(reversed(''), size(h + 'PP'))
        # range
        check(range(1), size(h + '3P'))
        check(range(66000), size(h + '3P'))
        # set
        # frozenset
        PySet_MINSIZE = 8
        samples = [[], range(10), range(50)]
        s = size(h + '3P2P' + PySet_MINSIZE*'lP' + 'lP')
        for sample in samples:
            minused = len(sample)
            if minused == 0: tmp = 1
            # the computation of minused is actually a bit more complicated
            # but this suffices for the sizeof test
            minused = minused*2
            newsize = PySet_MINSIZE
            while newsize <= minused:
                newsize = newsize << 1
            if newsize <= 8:
                check(set(sample), s)
                check(frozenset(sample), s)
            else:
                check(set(sample), s + newsize*struct.calcsize('lP'))
                check(frozenset(sample), s + newsize*struct.calcsize('lP'))
        # setiterator
        check(iter(set()), size(h + 'P3P'))
        # slice
        check(slice(0), size(h + '3P'))
        # super
        check(super(int), size(h + '3P'))
        # tuple
        check((), size(vh))
        check((1,2,3), size(vh) + 3*self.P)
        # type
        # (PyTypeObject + PyNumberMethods + PyMappingMethods +
        #  PySequenceMethods + PyBufferProcs)
        s = size(vh + 'P2P15Pl4PP9PP11PI') + size('16Pi17P 3P 10P 2P 2P')
        check(int, s)
        # class
        class newstyleclass(object): pass
        check(newstyleclass, s)
        # unicode
        usize = len('\0'.encode('unicode-internal'))
        samples = ['', '1'*100]
        # we need to test for both sizes, because we don't know if the string
        # has been cached
        for s in samples:
            basicsize =  size(h + 'PPliP') + usize * (len(s) + 1)
            check(s, basicsize)
        # weakref
        import weakref
        check(weakref.ref(int), size(h + '2Pl2P'))
        # weakproxy
        # XXX
        # weakcallableproxy
        check(weakref.proxy(int), size(h + '2Pl2P'))

    def test_pythontypes(self):
        # check all types defined in Python/
        h = self.header
        vh = self.vheader
        size = self.calcsize
        check = self.check_sizeof
        # _ast.AST
        import _ast
        check(_ast.AST(), size(h + ''))
        # imp.NullImporter
        import imp
        check(imp.NullImporter(self.file.name), size(h + ''))
        try:
            raise TypeError
        except TypeError:
            tb = sys.exc_info()[2]
            # traceback
            if tb != None:
                check(tb, size(h + '2P2i'))
        # symtable entry
        # XXX
        # sys.flags
        check(sys.flags, size(vh) + self.P * len(sys.flags))


def test_main():
    test.support.run_unittest(SysModuleTest, SizeofTest)

if __name__ == "__main__":
    test_main()