1import sys
2
3try:
4    sys.settrace
5except AttributeError:
6    print("SKIP")
7    raise SystemExit
8
9
10def print_stacktrace(frame, level=0):
11    # Ignore CPython specific helpers.
12    if frame.f_globals["__name__"].find("importlib") != -1:
13        print_stacktrace(frame.f_back, level)
14        return
15
16    print(
17        "%2d: %s@%s:%s => %s:%d"
18        % (
19            level,
20            "  ",
21            frame.f_globals["__name__"],
22            frame.f_code.co_name,
23            # Keep just the filename.
24            "sys_settrace_" + frame.f_code.co_filename.split("sys_settrace_")[-1],
25            frame.f_lineno,
26        )
27    )
28
29    if frame.f_back:
30        print_stacktrace(frame.f_back, level + 1)
31
32
33class _Prof:
34    trace_count = 0
35
36    def trace_tick(self, frame, event, arg):
37        self.trace_count += 1
38        print_stacktrace(frame)
39
40
41__prof__ = _Prof()
42
43alice_handler_set = False
44
45
46def trace_tick_handler_alice(frame, event, arg):
47    print("### trace_handler::Alice event:", event)
48    __prof__.trace_tick(frame, event, arg)
49    return trace_tick_handler_alice
50
51
52bob_handler_set = False
53
54
55def trace_tick_handler_bob(frame, event, arg):
56    print("### trace_handler::Bob event:", event)
57    __prof__.trace_tick(frame, event, arg)
58    return trace_tick_handler_bob
59
60
61def trace_tick_handler(frame, event, arg):
62    # Ignore CPython specific helpers.
63    to_ignore = ["importlib", "zipimport", "encodings"]
64    frame_name = frame.f_globals["__name__"]
65    if any(name in frame_name for name in to_ignore):
66        return
67
68    print("### trace_handler::main event:", event)
69    __prof__.trace_tick(frame, event, arg)
70
71    if frame.f_code.co_name != "factorial":
72        return trace_tick_handler
73
74    global alice_handler_set
75    if event == "call" and not alice_handler_set:
76        alice_handler_set = True
77        return trace_tick_handler_alice
78
79    global bob_handler_set
80    if event == "call" and not bob_handler_set:
81        bob_handler_set = True
82        return trace_tick_handler_bob
83
84    return trace_tick_handler
85
86
87def factorial(n):
88    if n == 0:
89        return 1
90    else:
91        return n * factorial(n - 1)
92
93
94def do_tests():
95    # These commands are here to demonstrate some execution being traced.
96    print("Who loves the sun?")
97    print("Not every-", factorial(3))
98
99    from sys_settrace_subdir import sys_settrace_generic
100
101    sys_settrace_generic.run_tests()
102    return
103
104
105sys.settrace(trace_tick_handler)
106do_tests()
107sys.settrace(None)
108
109print("\n------------------ script exited ------------------")
110print("Total traces executed: ", __prof__.trace_count)
111