summaryrefslogtreecommitdiffstats
path: root/Lib/test/test_trace.py
blob: 944ff9ac701925b224263f04930246d1636117d1 (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
# Testing the line trace facility.

from test import test_support
import unittest
import sys
import difflib

# A very basic example.  If this fails, we're in deep trouble.
def basic():
    return 1

basic.events = [(0, 'call'),
                (1, 'line'),
                (1, 'return')]

# Armin Rigo's failing example:
def arigo_example():
    x = 1
    del x
    while 0:
        pass
    x = 1

arigo_example.events = [(0, 'call'),
                        (1, 'line'),
                        (2, 'line'),
                        (3, 'line'),
                        (5, 'line'),
                        (5, 'return')]

# check that lines consisting of just one instruction get traced:
def one_instr_line():
    x = 1
    del x
    x = 1

one_instr_line.events = [(0, 'call'),
                         (1, 'line'),
                         (2, 'line'),
                         (3, 'line'),
                         (3, 'return')]

def no_pop_tops():      # 0
    x = 1               # 1
    for a in range(2):  # 2
        if a:           # 3
            x = 1       # 4
        else:           # 5
            x = 1       # 6

no_pop_tops.events = [(0, 'call'),
                      (1, 'line'),
                      (2, 'line'),
                      (3, 'line'),
                      (6, 'line'),
                      (2, 'line'),
                      (3, 'line'),
                      (4, 'line'),
                      (2, 'line'),
                      (2, 'return')]

def no_pop_blocks():
    while 0:
        bla
    x = 1

no_pop_blocks.events = [(0, 'call'),
                        (1, 'line'),
                        (3, 'line'),
                        (3, 'return')]

def called(): # line -3
    x = 1

def call():   # line 0
    called()

call.events = [(0, 'call'),
               (1, 'line'),
               (-3, 'call'),
               (-2, 'line'),
               (-2, 'return'),
               (1, 'return')]

def raises():
    raise Exception

def test_raise():
    try:
        raises()
    except Exception, exc:
        x = 1

test_raise.events = [(0, 'call'),
                     (1, 'line'),
                     (2, 'line'),
                     (-3, 'call'),
                     (-2, 'line'),
                     (-2, 'exception'),
                     (-2, 'return'),
                     (2, 'exception'),
                     (3, 'line'),
                     (4, 'line'),
                     (4, 'return')]

def _settrace_and_return(tracefunc):
    sys.settrace(tracefunc)
    sys._getframe().f_back.f_trace = tracefunc
def settrace_and_return(tracefunc):
    _settrace_and_return(tracefunc)

settrace_and_return.events = [(1, 'return')]

def _settrace_and_raise(tracefunc):
    sys.settrace(tracefunc)
    sys._getframe().f_back.f_trace = tracefunc
    raise RuntimeError
def settrace_and_raise(tracefunc):
    try:
        _settrace_and_raise(tracefunc)
    except RuntimeError, exc:
        pass

settrace_and_raise.events = [(2, 'exception'),
                             (3, 'line'),
                             (4, 'line'),
                             (4, 'return')]

# implicit return example
def ireturn_example():
    a = 5
    b = 5
    if a == b:
        b = a+1
    else:
        pass

ireturn_example.events = [(0, 'call'),
                          (1, 'line'),
                          (2, 'line'),
                          (3, 'line'),
                          (4, 'line'),
                          (4, 'return')]

# Tight loop with while(1) example (SF #765624)
def tightloop_example():
    items = range(0, 3)
    try:
        i = 0
        while 1:
            b = items[i]; i+=1
    except IndexError:
        pass

tightloop_example.events = [(0, 'call'),
                            (1, 'line'),
                            (2, 'line'),
                            (3, 'line'),
                            (4, 'line'),
                            (5, 'line'),
                            (5, 'line'),
                            (5, 'line'),
                            (5, 'line'),
                            (5, 'exception'),
                            (6, 'line'),
                            (7, 'line'),
                            (7, 'return')]

def tighterloop_example():
    items = range(1, 4)
    try:
        i = 0
        while 1: i = items[i]
    except IndexError:
        pass

tighterloop_example.events = [(0, 'call'),
                            (1, 'line'),
                            (2, 'line'),
                            (3, 'line'),
                            (4, 'line'),
                            (4, 'line'),
                            (4, 'line'),
                            (4, 'line'),
                            (4, 'exception'),
                            (5, 'line'),
                            (6, 'line'),
                            (6, 'return')]

class Tracer:
    def __init__(self):
        self.events = []
    def trace(self, frame, event, arg):
        self.events.append((frame.f_lineno, event))
        return self.trace

class TraceTestCase(unittest.TestCase):
    def compare_events(self, line_offset, events, expected_events):
        events = [(l - line_offset, e) for (l, e) in events]
        if events != expected_events:
            self.fail(
                "events did not match expectation:\n" +
                "\n".join(difflib.ndiff(map(str, expected_events),
                                        map(str, events))))


    def run_test(self, func):
        tracer = Tracer()
        sys.settrace(tracer.trace)
        func()
        sys.settrace(None)
        self.compare_events(func.func_code.co_firstlineno,
                            tracer.events, func.events)

    def run_test2(self, func):
        tracer = Tracer()
        func(tracer.trace)
        sys.settrace(None)
        self.compare_events(func.func_code.co_firstlineno,
                            tracer.events, func.events)

    def test_01_basic(self):
        self.run_test(basic)
## XXX: These tests fail with the new ast compiler.  They must
## be fixed before a release.
##    def test_02_arigo(self):
##        self.run_test(arigo_example)
    def test_03_one_instr(self):
        self.run_test(one_instr_line)
##    def test_04_no_pop_blocks(self):
##        self.run_test(no_pop_blocks)
##    def test_05_no_pop_tops(self):
##        self.run_test(no_pop_tops)
    def test_06_call(self):
        self.run_test(call)
    def test_07_raise(self):
        self.run_test(test_raise)

    def test_08_settrace_and_return(self):
        self.run_test2(settrace_and_return)
    def test_09_settrace_and_raise(self):
        self.run_test2(settrace_and_raise)
##    def test_10_ireturn(self):
##        self.run_test(ireturn_example)
    def test_11_tightloop(self):
        self.run_test(tightloop_example)
    def test_12_tighterloop(self):
        self.run_test(tighterloop_example)

class RaisingTraceFuncTestCase(unittest.TestCase):
    def trace(self, frame, event, arg):
        """A trace function that raises an exception in response to a
        specific trace event."""
        if event == self.raiseOnEvent:
            raise ValueError # just something that isn't RuntimeError
        else:
            return self.trace

    def f(self):
        """The function to trace; raises an exception if that's the case
        we're testing, so that the 'exception' trace event fires."""
        if self.raiseOnEvent == 'exception':
            x = 0
            y = 1/x
        else:
            return 1

    def run_test_for_event(self, event):
        """Tests that an exception raised in response to the given event is
        handled OK."""
        self.raiseOnEvent = event
        try:
            for i in xrange(sys.getrecursionlimit() + 1):
                sys.settrace(self.trace)
                try:
                    self.f()
                except ValueError:
                    pass
                else:
                    self.fail("exception not thrown!")
        except RuntimeError:
            self.fail("recursion counter not reset")

    # Test the handling of exceptions raised by each kind of trace event.
    def test_call(self):
        self.run_test_for_event('call')
    def test_line(self):
        self.run_test_for_event('line')
    def test_return(self):
        self.run_test_for_event('return')
    def test_exception(self):
        self.run_test_for_event('exception')

    def test_trash_stack(self):
        def f():
            for i in range(5):
                print i  # line tracing will raise an exception at this line

        def g(frame, why, extra):
            if (why == 'line' and
                frame.f_lineno == f.func_code.co_firstlineno + 2):
                raise RuntimeError, "i am crashing"
            return g

        sys.settrace(g)
        try:
            f()
        except RuntimeError:
            # the test is really that this doesn't segfault:
            import gc
            gc.collect()
        else:
            self.fail("exception not propagated")


# 'Jump' tests: assigning to frame.f_lineno within a trace function
# moves the execution position - it's how debuggers implement a Jump
# command (aka. "Set next statement").

class JumpTracer:
    """Defines a trace function that jumps from one place to another,
    with the source and destination lines of the jump being defined by
    the 'jump' property of the function under test."""

    def __init__(self, function):
        self.function = function
        self.jumpFrom = function.jump[0]
        self.jumpTo = function.jump[1]
        self.done = False

    def trace(self, frame, event, arg):
        if not self.done and frame.f_code == self.function.func_code:
            firstLine = frame.f_code.co_firstlineno
            if frame.f_lineno == firstLine + self.jumpFrom:
                # Cope with non-integer self.jumpTo (because of
                # no_jump_to_non_integers below).
                try:
                    frame.f_lineno = firstLine + self.jumpTo
                except TypeError:
                    frame.f_lineno = self.jumpTo
                self.done = True
        return self.trace

# The first set of 'jump' tests are for things that are allowed:

def jump_simple_forwards(output):
    output.append(1)
    output.append(2)
    output.append(3)

jump_simple_forwards.jump = (1, 3)
jump_simple_forwards.output = [3]

def jump_simple_backwards(output):
    output.append(1)
    output.append(2)

jump_simple_backwards.jump = (2, 1)
jump_simple_backwards.output = [1, 1, 2]

def jump_out_of_block_forwards(output):
    for i in 1, 2:
        output.append(2)
        for j in [3]:  # Also tests jumping over a block
            output.append(4)
    output.append(5)

jump_out_of_block_forwards.jump = (3, 5)
jump_out_of_block_forwards.output = [2, 5]

def jump_out_of_block_backwards(output):
    output.append(1)
    for i in [1]:
        output.append(3)
        for j in [2]:  # Also tests jumping over a block
            output.append(5)
        output.append(6)
    output.append(7)

jump_out_of_block_backwards.jump = (6, 1)
jump_out_of_block_backwards.output = [1, 3, 5, 1, 3, 5, 6, 7]

def jump_to_codeless_line(output):
    output.append(1)
    # Jumping to this line should skip to the next one.
    output.append(3)

jump_to_codeless_line.jump = (1, 2)
jump_to_codeless_line.output = [3]

def jump_to_same_line(output):
    output.append(1)
    output.append(2)
    output.append(3)

jump_to_same_line.jump = (2, 2)
jump_to_same_line.output = [1, 2, 3]

# Tests jumping within a finally block, and over one.
def jump_in_nested_finally(output):
    try:
        output.append(2)
    finally:
        output.append(4)
        try:
            output.append(6)
        finally:
            output.append(8)
        output.append(9)

jump_in_nested_finally.jump = (4, 9)
jump_in_nested_finally.output = [2, 9]

# The second set of 'jump' tests are for things that are not allowed:

def no_jump_too_far_forwards(output):
    try:
        output.append(2)
        output.append(3)
    except ValueError, e:
        output.append('after' in str(e))

no_jump_too_far_forwards.jump = (3, 6)
no_jump_too_far_forwards.output = [2, True]

def no_jump_too_far_backwards(output):
    try:
        output.append(2)
        output.append(3)
    except ValueError, e:
        output.append('before' in str(e))

no_jump_too_far_backwards.jump = (3, -1)
no_jump_too_far_backwards.output = [2, True]

# Test each kind of 'except' line.
def no_jump_to_except_1(output):
    try:
        output.append(2)
    except:
        e = sys.exc_info()[1]
        output.append('except' in str(e))

no_jump_to_except_1.jump = (2, 3)
no_jump_to_except_1.output = [True]

def no_jump_to_except_2(output):
    try:
        output.append(2)
    except ValueError:
        e = sys.exc_info()[1]
        output.append('except' in str(e))

no_jump_to_except_2.jump = (2, 3)
no_jump_to_except_2.output = [True]

def no_jump_to_except_3(output):
    try:
        output.append(2)
    except ValueError, e:
        output.append('except' in str(e))

no_jump_to_except_3.jump = (2, 3)
no_jump_to_except_3.output = [True]

def no_jump_to_except_4(output):
    try:
        output.append(2)
    except (ValueError, RuntimeError), e:
        output.append('except' in str(e))

no_jump_to_except_4.jump = (2, 3)
no_jump_to_except_4.output = [True]

def no_jump_forwards_into_block(output):
    try:
        output.append(2)
        for i in 1, 2:
            output.append(4)
    except ValueError, e:
        output.append('into' in str(e))

no_jump_forwards_into_block.jump = (2, 4)
no_jump_forwards_into_block.output = [True]

def no_jump_backwards_into_block(output):
    try:
        for i in 1, 2:
            output.append(3)
        output.append(4)
    except ValueError, e:
        output.append('into' in str(e))

no_jump_backwards_into_block.jump = (4, 3)
no_jump_backwards_into_block.output = [3, 3, True]

def no_jump_into_finally_block(output):
    try:
        try:
            output.append(3)
            x = 1
        finally:
            output.append(6)
    except ValueError, e:
        output.append('finally' in str(e))

no_jump_into_finally_block.jump = (4, 6)
no_jump_into_finally_block.output = [3, 6, True]  # The 'finally' still runs

def no_jump_out_of_finally_block(output):
    try:
        try:
            output.append(3)
        finally:
            output.append(5)
            output.append(6)
    except ValueError, e:
        output.append('finally' in str(e))

no_jump_out_of_finally_block.jump = (5, 1)
no_jump_out_of_finally_block.output = [3, True]

# This verifies the line-numbers-must-be-integers rule.
def no_jump_to_non_integers(output):
    try:
        output.append(2)
    except ValueError, e:
        output.append('integer' in str(e))

no_jump_to_non_integers.jump = (2, "Spam")
no_jump_to_non_integers.output = [True]

# This verifies that you can't set f_lineno via _getframe or similar
# trickery.
def no_jump_without_trace_function():
    try:
        previous_frame = sys._getframe().f_back
        previous_frame.f_lineno = previous_frame.f_lineno
    except ValueError, e:
        # This is the exception we wanted; make sure the error message
        # talks about trace functions.
        if 'trace' not in str(e):
            raise
    else:
        # Something's wrong - the expected exception wasn't raised.
        raise RuntimeError, "Trace-function-less jump failed to fail"


class JumpTestCase(unittest.TestCase):
    def compare_jump_output(self, expected, received):
        if received != expected:
            self.fail( "Outputs don't match:\n" +
                       "Expected: " + repr(expected) + "\n" +
                       "Received: " + repr(received))

    def run_test(self, func):
        tracer = JumpTracer(func)
        sys.settrace(tracer.trace)
        output = []
        func(output)
        sys.settrace(None)
        self.compare_jump_output(func.output, output)

    def test_01_jump_simple_forwards(self):
        self.run_test(jump_simple_forwards)
    def test_02_jump_simple_backwards(self):
        self.run_test(jump_simple_backwards)
    def test_03_jump_out_of_block_forwards(self):
        self.run_test(jump_out_of_block_forwards)
    def test_04_jump_out_of_block_backwards(self):
        self.run_test(jump_out_of_block_backwards)
    def test_05_jump_to_codeless_line(self):
        self.run_test(jump_to_codeless_line)
    def test_06_jump_to_same_line(self):
        self.run_test(jump_to_same_line)
    def test_07_jump_in_nested_finally(self):
        self.run_test(jump_in_nested_finally)
    def test_08_no_jump_too_far_forwards(self):
        self.run_test(no_jump_too_far_forwards)
    def test_09_no_jump_too_far_backwards(self):
        self.run_test(no_jump_too_far_backwards)
# XXX: These tests cause the interpreter to crash.  The frame_setlineno()
# function no longer works correctly because the lineno table generated by
# the AST compiler is slightly different than with the old compiler.
#    def test_10_no_jump_to_except_1(self):
#        self.run_test(no_jump_to_except_1)
#    def test_11_no_jump_to_except_2(self):
#        self.run_test(no_jump_to_except_2)
#    def test_12_no_jump_to_except_3(self):
#        self.run_test(no_jump_to_except_3)
#    def test_13_no_jump_to_except_4(self):
#        self.run_test(no_jump_to_except_4)
    def test_14_no_jump_forwards_into_block(self):
        self.run_test(no_jump_forwards_into_block)
    def test_15_no_jump_backwards_into_block(self):
        self.run_test(no_jump_backwards_into_block)
    def test_16_no_jump_into_finally_block(self):
        self.run_test(no_jump_into_finally_block)
    def test_17_no_jump_out_of_finally_block(self):
        self.run_test(no_jump_out_of_finally_block)
    def test_18_no_jump_to_non_integers(self):
        self.run_test(no_jump_to_non_integers)
    def test_19_no_jump_without_trace_function(self):
        no_jump_without_trace_function()

def test_main():
    test_support.run_unittest(
        TraceTestCase,
        RaisingTraceFuncTestCase,
        JumpTestCase
    )

if __name__ == "__main__":
    test_main()