cpython/Lib/test/test_trace.py

230 lines
6.3 KiB
Python

# 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, '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')]
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_1_basic(self):
self.run_test(basic)
def test_2_arigo(self):
self.run_test(arigo_example)
def test_3_one_instr(self):
self.run_test(one_instr_line)
def test_4_no_pop_blocks(self):
self.run_test(no_pop_blocks)
def test_5_no_pop_tops(self):
self.run_test(no_pop_tops)
def test_6_call(self):
self.run_test(call)
def test_7_raise(self):
self.run_test(test_raise)
def test_8_settrace_and_return(self):
self.run_test2(settrace_and_return)
def test_9_settrace_and_raise(self):
self.run_test2(settrace_and_raise)
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_main():
test_support.run_unittest(TraceTestCase)
test_support.run_unittest(RaisingTraceFuncTestCase)
if __name__ == "__main__":
test_main()