test_sys_settrace.py 文件源码

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.__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").