# Testing the line trace facility.

from test import support
import unittest
from unittest.mock import MagicMock
import sys
import difflib
import gc
from functools import wraps
import asyncio
from test.support import import_helper

support.requires_working_socket(module=True)

class tracecontext:
    """Context manager that traces its enter and exit."""
    def __init__(self, output, value):
        self.output = output
        self.value = value

    def __enter__(self):
        self.output.append(self.value)

    def __exit__(self, *exc_info):
        self.output.append(-self.value)

class asynctracecontext:
    """Asynchronous context manager that traces its aenter and aexit."""
    def __init__(self, output, value):
        self.output = output
        self.value = value

    async def __aenter__(self):
        self.output.append(self.value)

    async def __aexit__(self, *exc_info):
        self.output.append(-self.value)

async def asynciter(iterable):
    """Convert an iterable to an asynchronous iterator."""
    for x in iterable:
        yield x

def clean_asynciter(test):
    @wraps(test)
    async def wrapper(*args, **kwargs):
        cleanups = []
        def wrapped_asynciter(iterable):
            it = asynciter(iterable)
            cleanups.append(it.aclose)
            return it
        try:
            return await test(*args, **kwargs, asynciter=wrapped_asynciter)
        finally:
            while cleanups:
                await cleanups.pop()()
    return wrapper

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

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

# Many of the tests below are tricky because they involve pass statements.
# If there is implicit control flow around a pass statement (in an except
# clause or else clause) under what conditions do you set a line number
# following that clause?


# Some constructs like "while 0:", "if 0:" or "if 1:...else:..." could be optimized
# away.  Make sure that those lines aren't skipped.
def arigo_example0():
    x = 1
    del x
    while 0:
        pass
    x = 1

arigo_example0.events = [(0, 'call'),
                        (1, 'line'),
                        (2, 'line'),
                        (3, 'line'),
                        (5, 'line'),
                        (5, 'return')]

def arigo_example1():
    x = 1
    del x
    if 0:
        pass
    x = 1

arigo_example1.events = [(0, 'call'),
                        (1, 'line'),
                        (2, 'line'),
                        (3, 'line'),
                        (5, 'line'),
                        (5, 'return')]

def arigo_example2():
    x = 1
    del x
    if 1:
        x = 1
    else:
        pass
    return None

arigo_example2.events = [(0, 'call'),
                        (1, 'line'),
                        (2, 'line'),
                        (3, 'line'),
                        (4, 'line'),
                        (7, 'line'),
                        (7, '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():
    y = 1
    while not y:
        bla
    x = 1

no_pop_blocks.events = [(0, 'call'),
                        (1, 'line'),
                        (2, 'line'),
                        (4, 'line'),
                        (4, '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:
        pass

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:
        pass

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

# implicit return example
# This test is interesting because of the else: pass
# part of the code.  The code generate for the true
# part of the if contains a jump past the else branch.
# The compiler then generates an implicit "return None"
# Internally, the compiler visits the pass statement
# and stores its line number for use on the next instruction.
# The next instruction is the implicit return None.
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'),
                            (4, 'line'),
                            (5, 'line'),
                            (4, 'line'),
                            (5, 'line'),
                            (4, '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')]

def generator_function():
    try:
        yield True
        "continued"
    finally:
        "finally"
def generator_example():
    # any() will leave the generator before its end
    x = any(generator_function()); gc.collect()

    # the following lines were not traced
    for x in range(10):
        y = x

# On CPython, when the generator is decref'ed to zero, we see the trace
# for the "finally:" portion.  On PyPy, we don't see it before the next
# garbage collection.  That's why we put gc.collect() on the same line
# above.

generator_example.events = ([(0, 'call'),
                             (2, 'line'),
                             (-6, 'call'),
                             (-5, 'line'),
                             (-4, 'line'),
                             (-4, 'return'),
                             (-4, 'call'),
                             (-4, 'exception'),
                             (-1, 'line'),
                             (-1, 'return')] +
                            [(5, 'line'), (6, 'line')] * 10 +
                            [(5, 'line'), (5, 'return')])


class Tracer:
    def __init__(self, trace_line_events=None, trace_opcode_events=None):
        self.trace_line_events = trace_line_events
        self.trace_opcode_events = trace_opcode_events
        self.events = []

    def _reconfigure_frame(self, frame):
        if self.trace_line_events is not None:
            frame.f_trace_lines = self.trace_line_events
        if self.trace_opcode_events is not None:
            frame.f_trace_opcodes = self.trace_opcode_events

    def trace(self, frame, event, arg):
        self._reconfigure_frame(frame)
        self.events.append((frame.f_lineno, event))
        return self.trace

    def traceWithGenexp(self, frame, event, arg):
        self._reconfigure_frame(frame)
        (o for o in [1])
        self.events.append((frame.f_lineno, event))
        return self.trace


class TraceTestCase(unittest.TestCase):

    # Disable gc collection when tracing, otherwise the
    # deallocators may be traced as well.
    def setUp(self):
        self.using_gc = gc.isenabled()
        gc.disable()
        self.addCleanup(sys.settrace, sys.gettrace())

    def tearDown(self):
        if self.using_gc:
            gc.enable()

    @staticmethod
    def make_tracer():
        """Helper to allow test subclasses to configure tracers differently"""
        return Tracer()

    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([str(x) for x in expected_events],
                                        [str(x) for x in events])))

    def run_and_compare(self, func, events):
        tracer = self.make_tracer()
        sys.settrace(tracer.trace)
        func()
        sys.settrace(None)
        self.compare_events(func.__code__.co_firstlineno,
                            tracer.events, events)

    def run_test(self, func):
        self.run_and_compare(func, func.events)

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

    def test_set_and_retrieve_none(self):
        sys.settrace(None)
        assert sys.gettrace() is None

    def test_set_and_retrieve_func(self):
        def fn(*args):
            pass

        sys.settrace(fn)
        try:
            assert sys.gettrace() is fn
        finally:
            sys.settrace(None)

    def test_01_basic(self):
        self.run_test(basic)
    def test_02_arigo0(self):
        self.run_test(arigo_example0)
    def test_02_arigo1(self):
        self.run_test(arigo_example1)
    def test_02_arigo2(self):
        self.run_test(arigo_example2)
    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)

    def test_13_genexp(self):
        if self.using_gc:
            gc.enable()
            support.gc_collect()
        try:
            self.run_test(generator_example)
            # issue1265: if the trace function contains a generator,
            # and if the traced function contains another generator
            # that is not completely exhausted, the trace stopped.
            # Worse: the 'finally' clause was not invoked.
            tracer = self.make_tracer()
            sys.settrace(tracer.traceWithGenexp)
            generator_example()
            sys.settrace(None)
            self.compare_events(generator_example.__code__.co_firstlineno,
                                tracer.events, generator_example.events)
        finally:
            if self.using_gc:
                gc.disable()

    def test_14_onliner_if(self):
        def onliners():
            if True: x=False
            else: x=True
            return 0
        self.run_and_compare(
            onliners,
            [(0, 'call'),
             (1, 'line'),
             (3, 'line'),
             (3, 'return')])

    def test_15_loops(self):
        # issue1750076: "while" expression is skipped by debugger
        def for_example():
            for x in range(2):
                pass
        self.run_and_compare(
            for_example,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (1, 'line'),
             (2, 'line'),
             (1, 'line'),
             (1, 'return')])

        def while_example():
            # While expression should be traced on every loop
            x = 2
            while x > 0:
                x -= 1
        self.run_and_compare(
            while_example,
            [(0, 'call'),
             (2, 'line'),
             (3, 'line'),
             (4, 'line'),
             (3, 'line'),
             (4, 'line'),
             (3, 'line'),
             (3, 'return')])

    def test_16_blank_lines(self):
        namespace = {}
        exec("def f():\n" + "\n" * 256 + "    pass", namespace)
        self.run_and_compare(
            namespace["f"],
            [(0, 'call'),
             (257, 'line'),
             (257, 'return')])

    def test_17_none_f_trace(self):
        # Issue 20041: fix TypeError when f_trace is set to None.
        def func():
            sys._getframe().f_trace = None
            lineno = 2
        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line')])

    def test_18_except_with_name(self):
        def func():
            try:
                try:
                    raise Exception
                except Exception as e:
                    raise
                    x = "Something"
                    y = "Something"
            except Exception:
                pass

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (3, 'line'),
             (3, 'exception'),
             (4, 'line'),
             (5, 'line'),
             (8, 'line'),
             (9, 'line'),
             (9, 'return')])

    def test_19_except_with_finally(self):
        def func():
            try:
                try:
                    raise Exception
                finally:
                    y = "Something"
            except Exception:
                b = 23

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (3, 'line'),
             (3, 'exception'),
             (5, 'line'),
             (6, 'line'),
             (7, 'line'),
             (7, 'return')])

    def test_20_async_for_loop(self):
        class AsyncIteratorWrapper:
            def __init__(self, obj):
                self._it = iter(obj)

            def __aiter__(self):
                return self

            async def __anext__(self):
                try:
                    return next(self._it)
                except StopIteration:
                    raise StopAsyncIteration

        async def doit_async():
            async for letter in AsyncIteratorWrapper("abc"):
                x = letter
            y = 42

        def run(tracer):
            x = doit_async()
            try:
                sys.settrace(tracer)
                x.send(None)
            finally:
                sys.settrace(None)

        tracer = self.make_tracer()
        events = [
                (0, 'call'),
                (1, 'line'),
                (-12, 'call'),
                (-11, 'line'),
                (-11, 'return'),
                (-9, 'call'),
                (-8, 'line'),
                (-8, 'return'),
                (-6, 'call'),
                (-5, 'line'),
                (-4, 'line'),
                (-4, 'return'),
                (1, 'exception'),
                (2, 'line'),
                (1, 'line'),
                (-6, 'call'),
                (-5, 'line'),
                (-4, 'line'),
                (-4, 'return'),
                (1, 'exception'),
                (2, 'line'),
                (1, 'line'),
                (-6, 'call'),
                (-5, 'line'),
                (-4, 'line'),
                (-4, 'return'),
                (1, 'exception'),
                (2, 'line'),
                (1, 'line'),
                (-6, 'call'),
                (-5, 'line'),
                (-4, 'line'),
                (-4, 'exception'),
                (-3, 'line'),
                (-2, 'line'),
                (-2, 'exception'),
                (-2, 'return'),
                (1, 'exception'),
                (3, 'line'),
                (3, 'return')]
        try:
            run(tracer.trace)
        except Exception:
            pass
        self.compare_events(doit_async.__code__.co_firstlineno,
                            tracer.events, events)

    def test_async_for_backwards_jump_has_no_line(self):
        async def arange(n):
            for i in range(n):
                yield i
        async def f():
            async for i in arange(3):
                if i > 100:
                    break # should never be traced

        tracer = self.make_tracer()
        coro = f()
        try:
            sys.settrace(tracer.trace)
            coro.send(None)
        except Exception:
            pass
        finally:
            sys.settrace(None)

        events = [
            (0, 'call'),
            (1, 'line'),
            (-3, 'call'),
            (-2, 'line'),
            (-1, 'line'),
            (-1, 'return'),
            (1, 'exception'),
            (2, 'line'),
            (1, 'line'),
            (-1, 'call'),
            (-2, 'line'),
            (-1, 'line'),
            (-1, 'return'),
            (1, 'exception'),
            (2, 'line'),
            (1, 'line'),
            (-1, 'call'),
            (-2, 'line'),
            (-1, 'line'),
            (-1, 'return'),
            (1, 'exception'),
            (2, 'line'),
            (1, 'line'),
            (-1, 'call'),
            (-2, 'line'),
            (-2, 'return'),
            (1, 'exception'),
            (1, 'return'),
        ]
        self.compare_events(f.__code__.co_firstlineno,
                            tracer.events, events)

    def test_21_repeated_pass(self):
        def func():
            pass
            pass

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (2, 'return')])

    def test_loop_in_try_except(self):
        # https://bugs.python.org/issue41670

        def func():
            try:
                for i in []: pass
                return 1
            except:
                return 2

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (3, 'line'),
             (3, 'return')])

    def test_try_except_no_exception(self):

        def func():
            try:
                2
            except:
                4
            else:
                6
                if False:
                    8
                else:
                    10
                if func.__name__ == 'Fred':
                    12
            finally:
                14

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (6, 'line'),
             (7, 'line'),
             (10, 'line'),
             (11, 'line'),
             (14, 'line'),
             (14, 'return')])

    def test_try_exception_in_else(self):

        def func():
            try:
                try:
                    3
                except:
                    5
                else:
                    7
                    raise Exception
                finally:
                    10
            except:
                12
            finally:
                14

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (3, 'line'),
             (7, 'line'),
             (8, 'line'),
             (8, 'exception'),
             (10, 'line'),
             (11, 'line'),
             (12, 'line'),
             (14, 'line'),
             (14, 'return')])

    def test_nested_loops(self):

        def func():
            for i in range(2):
                for j in range(2):
                    a = i + j
            return a == 1

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (3, 'line'),
             (2, 'line'),
             (3, 'line'),
             (2, 'line'),
             (1, 'line'),
             (2, 'line'),
             (3, 'line'),
             (2, 'line'),
             (3, 'line'),
             (2, 'line'),
             (1, 'line'),
             (4, 'line'),
             (4, 'return')])

    def test_if_break(self):

        def func():
            seq = [1, 0]
            while seq:
                n = seq.pop()
                if n:
                    break   # line 5
            else:
                n = 99
            return n        # line 8

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (3, 'line'),
             (4, 'line'),
             (2, 'line'),
             (3, 'line'),
             (4, 'line'),
             (5, 'line'),
             (8, 'line'),
             (8, 'return')])

    def test_break_through_finally(self):

        def func():
            a, c, d, i = 1, 1, 1, 99
            try:
                for i in range(3):
                    try:
                        a = 5
                        if i > 0:
                            break                   # line 7
                        a = 8
                    finally:
                        c = 10
            except:
                d = 12                              # line 12
            assert a == 5 and c == 10 and d == 1    # line 13

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (3, 'line'),
             (4, 'line'),
             (5, 'line'),
             (6, 'line'),
             (8, 'line'),
             (10, 'line'),
             (3, 'line'),
             (4, 'line'),
             (5, 'line'),
             (6, 'line'),
             (7, 'line'),
             (10, 'line'),
             (13, 'line'),
             (13, 'return')])

    def test_continue_through_finally(self):

        def func():
            a, b, c, d, i = 1, 1, 1, 1, 99
            try:
                for i in range(2):
                    try:
                        a = 5
                        if i > 0:
                            continue                # line 7
                        b = 8
                    finally:
                        c = 10
            except:
                d = 12                              # line 12
            assert (a, b, c, d) == (5, 8, 10, 1)    # line 13

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (3, 'line'),
             (4, 'line'),
             (5, 'line'),
             (6, 'line'),
             (8, 'line'),
             (10, 'line'),
             (3, 'line'),
             (4, 'line'),
             (5, 'line'),
             (6, 'line'),
             (7, 'line'),
             (10, 'line'),
             (3, 'line'),
             (13, 'line'),
             (13, 'return')])

    def test_return_through_finally(self):

        def func():
            try:
                return 2
            finally:
                4

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (4, 'line'),
             (4, 'return')])

    def test_try_except_with_wrong_type(self):

        def func():
            try:
                2/0
            except IndexError:
                4
            finally:
                return 6

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (2, 'exception'),
             (3, 'line'),
             (6, 'line'),
             (6, 'return')])

    def test_break_to_continue1(self):

        def func():
            TRUE = 1
            x = [1]
            while x:
                x.pop()
                while TRUE:
                    break
                continue

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (3, 'line'),
             (4, 'line'),
             (5, 'line'),
             (6, 'line'),
             (7, 'line'),
             (3, 'line'),
             (3, 'return')])

    def test_break_to_continue2(self):

        def func():
            TRUE = 1
            x = [1]
            while x:
                x.pop()
                while TRUE:
                    break
                else:
                    continue

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (3, 'line'),
             (4, 'line'),
             (5, 'line'),
             (6, 'line'),
             (3, 'line'),
             (3, 'return')])

    def test_break_to_break(self):

        def func():
            TRUE = 1
            while TRUE:
                while TRUE:
                    break
                break

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (3, 'line'),
             (4, 'line'),
             (5, 'line'),
             (5, 'return')])

    def test_nested_ifs(self):

        def func():
            a = b = 1
            if a == 1:
                if b == 1:
                    x = 4
                else:
                    y = 6
            else:
                z = 8

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (3, 'line'),
             (4, 'line'),
             (4, 'return')])

    def test_nested_ifs_with_and(self):

        def func():
            if A:
                if B:
                    if C:
                        if D:
                            return False
                else:
                    return False
            elif E and F:
                return True

        A = B = True
        C = False

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (3, 'line'),
             (3, 'return')])

    def test_nested_try_if(self):

        def func():
            x = "hello"
            try:
                3/0
            except ZeroDivisionError:
                if x == 'raise':
                    raise ValueError()   # line 6
            f = 7

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (3, 'line'),
             (3, 'exception'),
             (4, 'line'),
             (5, 'line'),
             (7, 'line'),
             (7, 'return')])

    def test_if_false_in_with(self):

        class C:
            def __enter__(self):
                return self
            def __exit__(*args):
                pass

        def func():
            with C():
                if False:
                    pass

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (-5, 'call'),
             (-4, 'line'),
             (-4, 'return'),
             (2, 'line'),
             (1, 'line'),
             (-3, 'call'),
             (-2, 'line'),
             (-2, 'return'),
             (1, 'return')])

    def test_if_false_in_try_except(self):

        def func():
            try:
                if False:
                    pass
            except Exception:
                X

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (2, 'return')])

    def test_implicit_return_in_class(self):

        def func():
            class A:
                if 3 < 9:
                    a = 1
                else:
                    a = 2

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (1, 'call'),
             (1, 'line'),
             (2, 'line'),
             (3, 'line'),
             (3, 'return'),
             (1, 'return')])

    def test_try_in_try(self):
        def func():
            try:
                try:
                    pass
                except Exception as ex:
                    pass
            except Exception:
                pass

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (3, 'line'),
             (3, 'return')])

    def test_try_in_try_with_exception(self):

        def func():
            try:
                try:
                    raise TypeError
                except ValueError as ex:
                    5
            except TypeError:
                7

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (3, 'line'),
             (3, 'exception'),
             (4, 'line'),
             (6, 'line'),
             (7, 'line'),
             (7, 'return')])

        def func():
            try:
                try:
                    raise ValueError
                except ValueError as ex:
                    5
            except TypeError:
                7

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (3, 'line'),
             (3, 'exception'),
             (4, 'line'),
             (5, 'line'),
             (5, 'return')])

    def test_if_in_if_in_if(self):
        def func(a=0, p=1, z=1):
            if p:
                if a:
                    if z:
                        pass
                    else:
                        pass
            else:
                pass

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (2, 'return')])

    def test_early_exit_with(self):

        class C:
            def __enter__(self):
                return self
            def __exit__(*args):
                pass

        def func_break():
            for i in (1,2):
                with C():
                    break
            pass

        def func_return():
            with C():
                return

        self.run_and_compare(func_break,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (-5, 'call'),
             (-4, 'line'),
             (-4, 'return'),
             (3, 'line'),
             (2, 'line'),
             (-3, 'call'),
             (-2, 'line'),
             (-2, 'return'),
             (4, 'line'),
             (4, 'return')])

        self.run_and_compare(func_return,
            [(0, 'call'),
             (1, 'line'),
             (-11, 'call'),
             (-10, 'line'),
             (-10, 'return'),
             (2, 'line'),
             (1, 'line'),
             (-9, 'call'),
             (-8, 'line'),
             (-8, 'return'),
             (1, 'return')])

    def test_flow_converges_on_same_line(self):

        def foo(x):
            if x:
                try:
                    1/(x - 1)
                except ZeroDivisionError:
                    pass
            return x

        def func():
            for i in range(2):
                foo(i)

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (-8, 'call'),
             (-7, 'line'),
             (-2, 'line'),
             (-2, 'return'),
             (1, 'line'),
             (2, 'line'),
             (-8, 'call'),
             (-7, 'line'),
             (-6, 'line'),
             (-5, 'line'),
             (-5, 'exception'),
             (-4, 'line'),
             (-3, 'line'),
             (-2, 'line'),
             (-2, 'return'),
             (1, 'line'),
             (1, 'return')])

    def test_no_tracing_of_named_except_cleanup(self):

        def func():
            x = 0
            try:
                1/x
            except ZeroDivisionError as error:
                if x:
                    raise
            return "done"

        self.run_and_compare(func,
        [(0, 'call'),
            (1, 'line'),
            (2, 'line'),
            (3, 'line'),
            (3, 'exception'),
            (4, 'line'),
            (5, 'line'),
            (7, 'line'),
            (7, 'return')])

    def test_tracing_exception_raised_in_with(self):

        class NullCtx:
            def __enter__(self):
                return self
            def __exit__(self, *excinfo):
                pass

        def func():
            try:
                with NullCtx():
                    1/0
            except ZeroDivisionError:
                pass

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (-5, 'call'),
             (-4, 'line'),
             (-4, 'return'),
             (3, 'line'),
             (3, 'exception'),
             (2, 'line'),
             (-3, 'call'),
             (-2, 'line'),
             (-2, 'return'),
             (4, 'line'),
             (5, 'line'),
             (5, 'return')])

    def test_try_except_star_no_exception(self):

        def func():
            try:
                2
            except* Exception:
                4
            else:
                6
                if False:
                    8
                else:
                    10
                if func.__name__ == 'Fred':
                    12
            finally:
                14

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (6, 'line'),
             (7, 'line'),
             (10, 'line'),
             (11, 'line'),
             (14, 'line'),
             (14, 'return')])

    def test_try_except_star_named_no_exception(self):

        def func():
            try:
                2
            except* Exception as e:
                4
            else:
                6
            finally:
                8

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (6, 'line'),
             (8, 'line'),
             (8, 'return')])

    def test_try_except_star_exception_caught(self):

        def func():
            try:
                raise ValueError(2)
            except* ValueError:
                4
            else:
                6
            finally:
                8

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (2, 'exception'),
             (3, 'line'),
             (4, 'line'),
             (8, 'line'),
             (8, 'return')])

    def test_try_except_star_named_exception_caught(self):

        def func():
            try:
                raise ValueError(2)
            except* ValueError as e:
                4
            else:
                6
            finally:
                8

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (2, 'exception'),
             (3, 'line'),
             (4, 'line'),
             (8, 'line'),
             (8, 'return')])

    def test_try_except_star_exception_not_caught(self):

        def func():
            try:
                try:
                    raise ValueError(3)
                except* TypeError:
                    5
            except ValueError:
                7

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (3, 'line'),
             (3, 'exception'),
             (4, 'line'),
             (6, 'line'),
             (7, 'line'),
             (7, 'return')])

    def test_try_except_star_named_exception_not_caught(self):

        def func():
            try:
                try:
                    raise ValueError(3)
                except* TypeError as e:
                    5
            except ValueError:
                7

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (3, 'line'),
             (3, 'exception'),
             (4, 'line'),
             (6, 'line'),
             (7, 'line'),
             (7, 'return')])

    def test_try_except_star_nested(self):

        def func():
            try:
                try:
                    raise ExceptionGroup(
                        'eg',
                        [ValueError(5), TypeError('bad type')])
                except* TypeError as e:
                    7
                except* OSError:
                    9
                except* ValueError:
                    raise
            except* ValueError:
                try:
                    raise TypeError(14)
                except* OSError:
                    16
                except* TypeError as e:
                    18
            return 0

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (3, 'line'),
             (4, 'line'),
             (5, 'line'),
             (3, 'line'),
             (3, 'exception'),
             (6, 'line'),
             (7, 'line'),
             (8, 'line'),
             (10, 'line'),
             (11, 'line'),
             (12, 'line'),
             (13, 'line'),
             (14, 'line'),
             (14, 'exception'),
             (15, 'line'),
             (17, 'line'),
             (18, 'line'),
             (19, 'line'),
             (19, 'return')])

    def test_notrace_lambda(self):
        #Regression test for issue 46314

        def func():
            1
            lambda x: 2
            3

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (2, 'line'),
             (3, 'line'),
             (3, 'return')])

    def test_class_creation_with_docstrings(self):

        def func():
            class Class_1:
                ''' the docstring. 2'''
                def __init__(self):
                    ''' Another docstring. 4'''
                    self.a = 5

        self.run_and_compare(func,
            [(0, 'call'),
             (1, 'line'),
             (1, 'call'),
             (1, 'line'),
             (2, 'line'),
             (3, 'line'),
             (3, 'return'),
             (1, 'return')])

    @support.cpython_only
    def test_no_line_event_after_creating_generator(self):
        # Spurious line events before call events only show up with C tracer

        # Skip this test if the _testcapi module isn't available.
        _testcapi = import_helper.import_module('_testcapi')

        def gen():
            yield 1

        def func():
            for _ in (
                gen()
            ):
                pass

        EXPECTED_EVENTS = [
            (0, 'call'),
            (2, 'line'),
            (1, 'line'),
            (-3, 'call'),
            (-2, 'line'),
            (-2, 'return'),
            (4, 'line'),
            (1, 'line'),
            (-2, 'call'),
            (-2, 'return'),
            (1, 'return'),
        ]

        # C level events should be the same as expected and the same as Python level.

        events = []
        # Turning on and off tracing must be on same line to avoid unwanted LINE events.
        _testcapi.settrace_to_record(events); func(); sys.settrace(None)
        start_line = func.__code__.co_firstlineno
        events = [
            (line-start_line, EVENT_NAMES[what])
            for (what, line, arg) in events
        ]
        self.assertEqual(events, EXPECTED_EVENTS)

        self.run_and_compare(func, EXPECTED_EVENTS)

    def test_settrace_error(self):

        raised = False
        def error_once(frame, event, arg):
            nonlocal raised
            if not raised:
                raised = True
                raise Exception
            return error

        try:
            sys._getframe().f_trace = error_once
            sys.settrace(error_once)
            len([])
        except Exception as ex:
            count = 0
            tb = ex.__traceback__
            while tb:
                if tb.tb_frame.f_code.co_name == "test_settrace_error":
                    count += 1
                tb = tb.tb_next
            if count == 0:
                self.fail("Traceback is missing frame")
            elif count > 1:
                self.fail("Traceback has frame more than once")
        else:
            self.fail("No exception raised")
        finally:
            sys.settrace(None)

    @support.cpython_only
    def test_testcapi_settrace_error(self):

        # Skip this test if the _testcapi module isn't available.
        _testcapi = import_helper.import_module('_testcapi')

        try:
            _testcapi.settrace_to_error([])
            len([])
        except Exception as ex:
            count = 0
            tb = ex.__traceback__
            while tb:
                if tb.tb_frame.f_code.co_name == "test_testcapi_settrace_error":
                    count += 1
                tb = tb.tb_next
            if count == 0:
                self.fail("Traceback is missing frame")
            elif count > 1:
                self.fail("Traceback has frame more than once")
        else:
            self.fail("No exception raised")
        finally:
            sys.settrace(None)

    def test_very_large_function(self):
        # There is a separate code path when the number of lines > (1 << 15).
        d = {}
        exec("""def f():              # line 0
            x = 0                     # line 1
            y = 1                     # line 2
            %s                        # lines 3 through (1 << 16)
            x += 1                    #
            return""" % ('\n' * (1 << 16),), d)
        f = d['f']

        EXPECTED_EVENTS = [
            (0, 'call'),
            (1, 'line'),
            (2, 'line'),
            (65540, 'line'),
            (65541, 'line'),
            (65541, 'return'),
        ]

        self.run_and_compare(f, EXPECTED_EVENTS)


EVENT_NAMES = [
    'call',
    'exception',
    'line',
    'return'
]


class SkipLineEventsTraceTestCase(TraceTestCase):
    """Repeat the trace tests, but with per-line events skipped"""

    def compare_events(self, line_offset, events, expected_events):
        skip_line_events = [e for e in expected_events if e[1] != 'line']
        super().compare_events(line_offset, events, skip_line_events)

    @staticmethod
    def make_tracer():
        return Tracer(trace_line_events=False)


@support.cpython_only
class TraceOpcodesTestCase(TraceTestCase):
    """Repeat the trace tests, but with per-opcodes events enabled"""

    def compare_events(self, line_offset, events, expected_events):
        skip_opcode_events = [e for e in events if e[1] != 'opcode']
        if len(events) > 1:
            self.assertLess(len(skip_opcode_events), len(events),
                            msg="No 'opcode' events received by the tracer")
        super().compare_events(line_offset, skip_opcode_events, expected_events)

    @staticmethod
    def make_tracer():
        return Tracer(trace_opcode_events=True)


class RaisingTraceFuncTestCase(unittest.TestCase):
    def setUp(self):
        self.addCleanup(sys.settrace, sys.gettrace())

    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 range(sys.getrecursionlimit() + 1):
                sys.settrace(self.trace)
                try:
                    self.f()
                except ValueError:
                    pass
                else:
                    self.fail("exception not raised!")
        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.__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")


    def test_exception_arguments(self):
        def f():
            x = 0
            # this should raise an error
            x.no_such_attr
        def g(frame, event, arg):
            if (event == 'exception'):
                type, exception, trace = arg
                self.assertIsInstance(exception, Exception)
            return g

        existing = sys.gettrace()
        try:
            sys.settrace(g)
            try:
                f()
            except AttributeError:
                # this is expected
                pass
        finally:
            sys.settrace(existing)

    def test_line_event_raises_before_opcode_event(self):
        exception = ValueError("BOOM!")
        def trace(frame, event, arg):
            if event == "line":
                raise exception
            frame.f_trace_opcodes = True
            return trace
        def f():
            pass
        with self.assertRaises(ValueError) as caught:
            sys.settrace(trace)
            f()
        self.assertIs(caught.exception, exception)


# '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."""

    def __init__(self, function, jumpFrom, jumpTo, event='line',
                 decorated=False):
        self.code = function.__code__
        self.jumpFrom = jumpFrom
        self.jumpTo = jumpTo
        self.event = event
        self.firstLine = None if decorated else self.code.co_firstlineno
        self.done = False

    def trace(self, frame, event, arg):
        if self.done:
            return
        # frame.f_code.co_firstlineno is the first line of the decorator when
        # 'function' is decorated and the decorator may be written using
        # multiple physical lines when it is too long. Use the first line
        # trace event in 'function' to find the first line of 'function'.
        if (self.firstLine is None and frame.f_code == self.code and
                event == 'line'):
            self.firstLine = frame.f_lineno - 1
        if (event == self.event and self.firstLine is not None and
                frame.f_lineno == self.firstLine + self.jumpFrom):
            f = frame
            while f is not None and f.f_code != self.code:
                f = f.f_back
            if f is not None:
                # Cope with non-integer self.jumpTo (because of
                # no_jump_to_non_integers below).
                try:
                    frame.f_lineno = self.firstLine + self.jumpTo
                except TypeError:
                    frame.f_lineno = self.jumpTo
                self.done = True
        return self.trace

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

# 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 as 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 AssertionError("Trace-function-less jump failed to fail")


class JumpTestCase(unittest.TestCase):
    if sys.implementation.name == "pypy":
        no_jump_into_with_error = (ValueError, "body of a with statement")
    else:
        no_jump_into_with_error = (ValueError, "stack")

    def setUp(self):
        self.addCleanup(sys.settrace, sys.gettrace())
        sys.settrace(None)

    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, jumpFrom, jumpTo, expected, error=None,
                 event='line', decorated=False):
        wrapped = func
        while hasattr(wrapped, '__wrapped__'):
            wrapped = wrapped.__wrapped__

        tracer = JumpTracer(wrapped, jumpFrom, jumpTo, event, decorated)
        sys.settrace(tracer.trace)
        output = []
        if error is None:
            func(output)
        else:
            with self.assertRaisesRegex(*error):
                func(output)
        sys.settrace(None)
        self.compare_jump_output(expected, output)

    def run_async_test(self, func, jumpFrom, jumpTo, expected, error=None,
                 event='line', decorated=False):
        wrapped = func
        while hasattr(wrapped, '__wrapped__'):
            wrapped = wrapped.__wrapped__

        tracer = JumpTracer(wrapped, jumpFrom, jumpTo, event, decorated)
        sys.settrace(tracer.trace)
        output = []
        if error is None:
            asyncio.run(func(output))
        else:
            with self.assertRaisesRegex(*error):
                asyncio.run(func(output))
        sys.settrace(None)
        asyncio.set_event_loop_policy(None)
        self.compare_jump_output(expected, output)

    def jump_test(jumpFrom, jumpTo, expected, error=None, event='line'):
        """Decorator that creates a test that makes a jump
        from one place to another in the following code.
        """
        def decorator(func):
            @wraps(func)
            def test(self):
                self.run_test(func, jumpFrom, jumpTo, expected,
                              error=error, event=event, decorated=True)
            return test
        return decorator

    def async_jump_test(jumpFrom, jumpTo, expected, error=None, event='line'):
        """Decorator that creates a test that makes a jump
        from one place to another in the following asynchronous code.
        """
        def decorator(func):
            @wraps(func)
            def test(self):
                self.run_async_test(func, jumpFrom, jumpTo, expected,
                              error=error, event=event, decorated=True)
            return test
        return decorator

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

    @jump_test(1, 3, [3])
    def test_jump_simple_forwards(output):
        output.append(1)
        output.append(2)
        output.append(3)

    @jump_test(2, 1, [1, 1, 2])
    def test_jump_simple_backwards(output):
        output.append(1)
        output.append(2)

    @jump_test(1, 4, [5])
    def test_jump_is_none_forwards(output):
        x = None
        if x is None:
            output.append(3)
        else:
            output.append(5)

    @jump_test(6, 5, [3, 5, 6])
    def test_jump_is_none_backwards(output):
        x = None
        if x is None:
            output.append(3)
        else:
            output.append(5)
        output.append(6)

    @jump_test(1, 4, [5])
    def test_jump_is_not_none_forwards(output):
        x = None
        if x is not None:
            output.append(3)
        else:
            output.append(5)

    @jump_test(6, 5, [5, 5, 6])
    def test_jump_is_not_none_backwards(output):
        x = None
        if x is not None:
            output.append(3)
        else:
            output.append(5)
        output.append(6)

    @jump_test(3, 5, [2, 5])
    def test_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_test(6, 1, [1, 3, 5, 1, 3, 5, 6, 7])
    def test_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)

    @async_jump_test(4, 5, [3, 5])
    @clean_asynciter
    async def test_jump_out_of_async_for_block_forwards(output, asynciter):
        for i in [1]:
            async for i in asynciter([1, 2]):
                output.append(3)
                output.append(4)
            output.append(5)

    @async_jump_test(5, 2, [2, 4, 2, 4, 5, 6])
    @clean_asynciter
    async def test_jump_out_of_async_for_block_backwards(output, asynciter):
        for i in [1]:
            output.append(2)
            async for i in asynciter([1]):
                output.append(4)
                output.append(5)
            output.append(6)

    @jump_test(1, 2, [3])
    def test_jump_to_codeless_line(output):
        output.append(1)
        # Jumping to this line should skip to the next one.
        output.append(3)

    @jump_test(2, 2, [1, 2, 3])
    def test_jump_to_same_line(output):
        output.append(1)
        output.append(2)
        output.append(3)

    # Tests jumping within a finally block, and over one.
    @jump_test(4, 9, [2, 9])
    def test_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_test(6, 7, [2, 7], (ZeroDivisionError, ''))
    def test_jump_in_nested_finally_2(output):
        try:
            output.append(2)
            1/0
            return
        finally:
            output.append(6)
            output.append(7)
        output.append(8)

    @jump_test(6, 11, [2, 11], (ZeroDivisionError, ''))
    def test_jump_in_nested_finally_3(output):
        try:
            output.append(2)
            1/0
            return
        finally:
            output.append(6)
            try:
                output.append(8)
            finally:
                output.append(10)
            output.append(11)
        output.append(12)

    @jump_test(5, 11, [2, 4], (ValueError, 'exception'))
    def test_no_jump_over_return_try_finally_in_finally_block(output):
        try:
            output.append(2)
        finally:
            output.append(4)
            output.append(5)
            return
            try:
                output.append(8)
            finally:
                output.append(10)
            pass
        output.append(12)

    @jump_test(3, 4, [1], (ValueError, 'after'))
    def test_no_jump_infinite_while_loop(output):
        output.append(1)
        while True:
            output.append(3)
        output.append(4)

    @jump_test(2, 4, [4, 4])
    def test_jump_forwards_into_while_block(output):
        i = 1
        output.append(2)
        while i <= 2:
            output.append(4)
            i += 1

    @jump_test(5, 3, [3, 3, 3, 5])
    def test_jump_backwards_into_while_block(output):
        i = 1
        while i <= 2:
            output.append(3)
            i += 1
        output.append(5)

    @jump_test(2, 3, [1, 3])
    def test_jump_forwards_out_of_with_block(output):
        with tracecontext(output, 1):
            output.append(2)
        output.append(3)

    @async_jump_test(2, 3, [1, 3])
    async def test_jump_forwards_out_of_async_with_block(output):
        async with asynctracecontext(output, 1):
            output.append(2)
        output.append(3)

    @jump_test(3, 1, [1, 2, 1, 2, 3, -2])
    def test_jump_backwards_out_of_with_block(output):
        output.append(1)
        with tracecontext(output, 2):
            output.append(3)

    @async_jump_test(3, 1, [1, 2, 1, 2, 3, -2])
    async def test_jump_backwards_out_of_async_with_block(output):
        output.append(1)
        async with asynctracecontext(output, 2):
            output.append(3)

    @jump_test(2, 5, [5])
    def test_jump_forwards_out_of_try_finally_block(output):
        try:
            output.append(2)
        finally:
            output.append(4)
        output.append(5)

    @jump_test(3, 1, [1, 1, 3, 5])
    def test_jump_backwards_out_of_try_finally_block(output):
        output.append(1)
        try:
            output.append(3)
        finally:
            output.append(5)

    @jump_test(2, 6, [6])
    def test_jump_forwards_out_of_try_except_block(output):
        try:
            output.append(2)
        except:
            output.append(4)
            raise
        output.append(6)

    @jump_test(3, 1, [1, 1, 3])
    def test_jump_backwards_out_of_try_except_block(output):
        output.append(1)
        try:
            output.append(3)
        except:
            output.append(5)
            raise

    @jump_test(5, 7, [4, 7, 8])
    def test_jump_between_except_blocks(output):
        try:
            1/0
        except ZeroDivisionError:
            output.append(4)
            output.append(5)
        except FloatingPointError:
            output.append(7)
        output.append(8)

    @jump_test(5, 7, [4, 7, 8])
    def test_jump_from_except_to_finally(output):
        try:
            1/0
        except ZeroDivisionError:
            output.append(4)
            output.append(5)
        finally:
            output.append(7)
        output.append(8)

    @jump_test(5, 6, [4, 6, 7])
    def test_jump_within_except_block(output):
        try:
            1/0
        except:
            output.append(4)
            output.append(5)
            output.append(6)
        output.append(7)

    @jump_test(6, 1, [1, 5, 1, 5])
    def test_jump_over_try_except(output):
        output.append(1)
        try:
            1 / 0
        except ZeroDivisionError as e:
            output.append(5)
        x = 42  # has to be a two-instruction block

    @jump_test(2, 4, [1, 4, 5, -4])
    def test_jump_across_with(output):
        output.append(1)
        with tracecontext(output, 2):
            output.append(3)
        with tracecontext(output, 4):
            output.append(5)

    @async_jump_test(2, 4, [1, 4, 5, -4])
    async def test_jump_across_async_with(output):
        output.append(1)
        async with asynctracecontext(output, 2):
            output.append(3)
        async with asynctracecontext(output, 4):
            output.append(5)

    @jump_test(4, 5, [1, 3, 5, 6])
    def test_jump_out_of_with_block_within_for_block(output):
        output.append(1)
        for i in [1]:
            with tracecontext(output, 3):
                output.append(4)
            output.append(5)
        output.append(6)

    @async_jump_test(4, 5, [1, 3, 5, 6])
    async def test_jump_out_of_async_with_block_within_for_block(output):
        output.append(1)
        for i in [1]:
            async with asynctracecontext(output, 3):
                output.append(4)
            output.append(5)
        output.append(6)

    @jump_test(4, 5, [1, 2, 3, 5, -2, 6])
    def test_jump_out_of_with_block_within_with_block(output):
        output.append(1)
        with tracecontext(output, 2):
            with tracecontext(output, 3):
                output.append(4)
            output.append(5)
        output.append(6)

    @async_jump_test(4, 5, [1, 2, 3, 5, -2, 6])
    async def test_jump_out_of_async_with_block_within_with_block(output):
        output.append(1)
        with tracecontext(output, 2):
            async with asynctracecontext(output, 3):
                output.append(4)
            output.append(5)
        output.append(6)

    @jump_test(5, 6, [2, 4, 6, 7])
    def test_jump_out_of_with_block_within_finally_block(output):
        try:
            output.append(2)
        finally:
            with tracecontext(output, 4):
                output.append(5)
            output.append(6)
        output.append(7)

    @async_jump_test(5, 6, [2, 4, 6, 7])
    async def test_jump_out_of_async_with_block_within_finally_block(output):
        try:
            output.append(2)
        finally:
            async with asynctracecontext(output, 4):
                output.append(5)
            output.append(6)
        output.append(7)

    @jump_test(8, 11, [1, 3, 5, 11, 12])
    def test_jump_out_of_complex_nested_blocks(output):
        output.append(1)
        for i in [1]:
            output.append(3)
            for j in [1, 2]:
                output.append(5)
                try:
                    for k in [1, 2]:
                        output.append(8)
                finally:
                    output.append(10)
            output.append(11)
        output.append(12)

    @jump_test(3, 5, [1, 2, 5])
    def test_jump_out_of_with_assignment(output):
        output.append(1)
        with tracecontext(output, 2) \
                as x:
            output.append(4)
        output.append(5)

    @async_jump_test(3, 5, [1, 2, 5])
    async def test_jump_out_of_async_with_assignment(output):
        output.append(1)
        async with asynctracecontext(output, 2) \
                as x:
            output.append(4)
        output.append(5)

    @jump_test(3, 6, [1, 6, 8, 9])
    def test_jump_over_return_in_try_finally_block(output):
        output.append(1)
        try:
            output.append(3)
            if not output: # always false
                return
            output.append(6)
        finally:
            output.append(8)
        output.append(9)

    @jump_test(5, 8, [1, 3, 8, 10, 11, 13])
    def test_jump_over_break_in_try_finally_block(output):
        output.append(1)
        while True:
            output.append(3)
            try:
                output.append(5)
                if not output: # always false
                    break
                output.append(8)
            finally:
                output.append(10)
            output.append(11)
            break
        output.append(13)

    @jump_test(1, 7, [7, 8])
    def test_jump_over_for_block_before_else(output):
        output.append(1)
        if not output:  # always false
            for i in [3]:
                output.append(4)
        else:
            output.append(6)
            output.append(7)
        output.append(8)

    @async_jump_test(1, 7, [7, 8])
    async def test_jump_over_async_for_block_before_else(output):
        output.append(1)
        if not output:  # always false
            async for i in asynciter([3]):
                output.append(4)
        else:
            output.append(6)
            output.append(7)
        output.append(8)

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

    @jump_test(2, 3, [1], (ValueError, 'after'))
    def test_no_jump_too_far_forwards(output):
        output.append(1)
        output.append(2)

    @jump_test(2, -2, [1], (ValueError, 'before'))
    def test_no_jump_too_far_backwards(output):
        output.append(1)
        output.append(2)

    # Test each kind of 'except' line.
    @jump_test(2, 3, [4], (ValueError, 'except'))
    def test_no_jump_to_except_1(output):
        try:
            output.append(2)
        except:
            output.append(4)
            raise

    @jump_test(2, 3, [4], (ValueError, 'except'))
    def test_no_jump_to_except_2(output):
        try:
            output.append(2)
        except ValueError:
            output.append(4)
            raise

    @jump_test(2, 3, [4], (ValueError, 'except'))
    def test_no_jump_to_except_3(output):
        try:
            output.append(2)
        except ValueError as e:
            output.append(4)
            raise e

    @jump_test(2, 3, [4], (ValueError, 'except'))
    def test_no_jump_to_except_4(output):
        try:
            output.append(2)
        except (ValueError, RuntimeError) as e:
            output.append(4)
            raise e

    @jump_test(1, 3, [], (ValueError, 'into'))
    def test_no_jump_forwards_into_for_block(output):
        output.append(1)
        for i in 1, 2:
            output.append(3)

    @async_jump_test(1, 3, [], (ValueError, 'into'))
    async def test_no_jump_forwards_into_async_for_block(output):
        output.append(1)
        async for i in asynciter([1, 2]):
            output.append(3)
        pass

    @jump_test(3, 2, [2, 2], (ValueError, 'into'))
    def test_no_jump_backwards_into_for_block(output):
        for i in 1, 2:
            output.append(2)
        output.append(3)

    @async_jump_test(3, 2, [2, 2], (ValueError, "can't jump into the body of a for loop"))
    async def test_no_jump_backwards_into_async_for_block(output):
        async for i in asynciter([1, 2]):
            output.append(2)
        output.append(3)

    @jump_test(1, 3, [], no_jump_into_with_error)
    def test_no_jump_forwards_into_with_block(output):
        output.append(1)
        with tracecontext(output, 2):
            output.append(3)

    @async_jump_test(1, 3, [], no_jump_into_with_error)
    async def test_no_jump_forwards_into_async_with_block(output):
        output.append(1)
        async with asynctracecontext(output, 2):
            output.append(3)

    @jump_test(3, 2, [1, 2, -1], no_jump_into_with_error)
    def test_no_jump_backwards_into_with_block(output):
        with tracecontext(output, 1):
            output.append(2)
        output.append(3)

    @async_jump_test(3, 2, [1, 2, -1], no_jump_into_with_error)
    async def test_no_jump_backwards_into_async_with_block(output):
        async with asynctracecontext(output, 1):
            output.append(2)
        output.append(3)

    @jump_test(1, 3, [3, 5])
    def test_jump_forwards_into_try_finally_block(output):
        output.append(1)
        try:
            output.append(3)
        finally:
            output.append(5)

    @jump_test(5, 2, [2, 4, 2, 4, 5])
    def test_jump_backwards_into_try_finally_block(output):
        try:
            output.append(2)
        finally:
            output.append(4)
        output.append(5)

    @jump_test(1, 3, [3])
    def test_jump_forwards_into_try_except_block(output):
        output.append(1)
        try:
            output.append(3)
        except:
            output.append(5)
            raise

    @jump_test(6, 2, [2, 2, 6])
    def test_jump_backwards_into_try_except_block(output):
        try:
            output.append(2)
        except:
            output.append(4)
            raise
        output.append(6)

    # 'except' with a variable creates an implicit finally block
    @jump_test(5, 7, [4, 7, 8])
    def test_jump_between_except_blocks_2(output):
        try:
            1/0
        except ZeroDivisionError:
            output.append(4)
            output.append(5)
        except FloatingPointError as e:
            output.append(7)
        output.append(8)

    @jump_test(1, 5, [5])
    def test_jump_into_finally_block(output):
        output.append(1)
        try:
            output.append(3)
        finally:
            output.append(5)

    @jump_test(3, 6, [2, 6, 7])
    def test_jump_into_finally_block_from_try_block(output):
        try:
            output.append(2)
            output.append(3)
        finally:  # still executed if the jump is failed
            output.append(5)
            output.append(6)
        output.append(7)

    @jump_test(5, 1, [1, 3, 1, 3, 5])
    def test_jump_out_of_finally_block(output):
        output.append(1)
        try:
            output.append(3)
        finally:
            output.append(5)

    @jump_test(1, 5, [], (ValueError, "can't jump into an 'except' block as there's no exception"))
    def test_no_jump_into_bare_except_block(output):
        output.append(1)
        try:
            output.append(3)
        except:
            output.append(5)

    @jump_test(1, 5, [], (ValueError, "can't jump into an 'except' block as there's no exception"))
    def test_no_jump_into_qualified_except_block(output):
        output.append(1)
        try:
            output.append(3)
        except Exception:
            output.append(5)

    @jump_test(3, 6, [2, 5, 6], (ValueError, "can't jump into an 'except' block as there's no exception"))
    def test_no_jump_into_bare_except_block_from_try_block(output):
        try:
            output.append(2)
            output.append(3)
        except:  # executed if the jump is failed
            output.append(5)
            output.append(6)
            raise
        output.append(8)

    @jump_test(3, 6, [2], (ValueError, "can't jump into an 'except' block as there's no exception"))
    def test_no_jump_into_qualified_except_block_from_try_block(output):
        try:
            output.append(2)
            output.append(3)
        except ZeroDivisionError:
            output.append(5)
            output.append(6)
            raise
        output.append(8)

    @jump_test(7, 1, [1, 3, 6, 1, 3, 6, 7])
    def test_jump_out_of_bare_except_block(output):
        output.append(1)
        try:
            output.append(3)
            1/0
        except:
            output.append(6)
            output.append(7)

    @jump_test(7, 1, [1, 3, 6, 1, 3, 6, 7])
    def test_jump_out_of_qualified_except_block(output):
        output.append(1)
        try:
            output.append(3)
            1/0
        except Exception:
            output.append(6)
            output.append(7)

    @jump_test(3, 5, [1, 2, 5, -2])
    def test_jump_between_with_blocks(output):
        output.append(1)
        with tracecontext(output, 2):
            output.append(3)
        with tracecontext(output, 4):
            output.append(5)

    @async_jump_test(3, 5, [1, 2, 5, -2])
    async def test_jump_between_async_with_blocks(output):
        output.append(1)
        async with asynctracecontext(output, 2):
            output.append(3)
        async with asynctracecontext(output, 4):
            output.append(5)

    @jump_test(5, 7, [2, 4], (ValueError, "after"))
    def test_no_jump_over_return_out_of_finally_block(output):
        try:
            output.append(2)
        finally:
            output.append(4)
            output.append(5)
            return
        output.append(7)

    @jump_test(7, 4, [1, 6], (ValueError, 'into'))
    def test_no_jump_into_for_block_before_else(output):
        output.append(1)
        if not output:  # always false
            for i in [3]:
                output.append(4)
        else:
            output.append(6)
            output.append(7)
        output.append(8)

    @async_jump_test(7, 4, [1, 6], (ValueError, 'into'))
    async def test_no_jump_into_async_for_block_before_else(output):
        output.append(1)
        if not output:  # always false
            async for i in asynciter([3]):
                output.append(4)
        else:
            output.append(6)
            output.append(7)
        output.append(8)

    def test_no_jump_to_non_integers(self):
        self.run_test(no_jump_to_non_integers, 2, "Spam", [True])

    def test_no_jump_without_trace_function(self):
        # Must set sys.settrace(None) in setUp(), else condition is not
        # triggered.
        no_jump_without_trace_function()

    def test_large_function(self):
        d = {}
        exec("""def f(output):        # line 0
            x = 0                     # line 1
            y = 1                     # line 2
            '''                       # line 3
            %s                        # lines 4-1004
            '''                       # line 1005
            x += 1                    # line 1006
            output.append(x)          # line 1007
            return""" % ('\n' * 1000,), d)
        f = d['f']
        self.run_test(f, 2, 1007, [0])

    def test_jump_to_firstlineno(self):
        # This tests that PDB can jump back to the first line in a
        # file.  See issue #1689458.  It can only be triggered in a
        # function call if the function is defined on a single line.
        code = compile("""
# Comments don't count.
output.append(2)  # firstlineno is here.
output.append(3)
output.append(4)
""", "<fake module>", "exec")
        class fake_function:
            __code__ = code
        tracer = JumpTracer(fake_function, 4, 1)
        sys.settrace(tracer.trace)
        namespace = {"output": []}
        exec(code, namespace)
        sys.settrace(None)
        self.compare_jump_output([2, 3, 2, 3, 4], namespace["output"])

    @jump_test(2, 3, [1], event='call', error=(ValueError, "can't jump from"
               " the 'call' trace event of a new frame"))
    def test_no_jump_from_call(output):
        output.append(1)
        def nested():
            output.append(3)
        nested()
        output.append(5)

    @jump_test(2, 1, [1], event='return', error=(ValueError,
               "can only jump from a 'line' trace event"))
    def test_no_jump_from_return_event(output):
        output.append(1)
        return

    @jump_test(2, 1, [1], event='exception', error=(ValueError,
               "can only jump from a 'line' trace event"))
    def test_no_jump_from_exception_event(output):
        output.append(1)
        1 / 0

    @jump_test(3, 2, [2, 5], event='return')
    def test_jump_from_yield(output):
        def gen():
            output.append(2)
            yield 3
        next(gen())
        output.append(5)

    @jump_test(2, 3, [1, 3])
    def test_jump_forward_over_listcomp(output):
        output.append(1)
        x = [i for i in range(10)]
        output.append(3)

    # checking for segfaults.
    # See https://github.com/python/cpython/issues/92311
    @jump_test(3, 1, [])
    def test_jump_backward_over_listcomp(output):
        a = 1
        x = [i for i in range(10)]
        c = 3

    @jump_test(8, 2, [2, 7, 2])
    def test_jump_backward_over_listcomp_v2(output):
        flag = False
        output.append(2)
        if flag:
            return
        x = [i for i in range(5)]
        flag = 6
        output.append(7)
        output.append(8)

    @async_jump_test(2, 3, [1, 3])
    async def test_jump_forward_over_async_listcomp(output):
        output.append(1)
        x = [i async for i in asynciter(range(10))]
        output.append(3)

    @async_jump_test(3, 1, [])
    async def test_jump_backward_over_async_listcomp(output):
        a = 1
        x = [i async for i in asynciter(range(10))]
        c = 3

    @async_jump_test(8, 2, [2, 7, 2])
    async def test_jump_backward_over_async_listcomp_v2(output):
        flag = False
        output.append(2)
        if flag:
            return
        x = [i async for i in asynciter(range(5))]
        flag = 6
        output.append(7)
        output.append(8)

    # checking for segfaults.
    @jump_test(3, 7, [], error=(ValueError, "stack"))
    @support.cpython_only
    def test_jump_with_null_on_stack_load_global(output):
        a = 1
        print(
            output.append(3)
        )
        output.append(5)
        (
            ( # 7
                a
                +
                10
            )
            +
            13
        )
        output.append(15)

    # checking for segfaults.
    @jump_test(4, 8, [], error=(ValueError, "stack"))
    @support.cpython_only
    def test_jump_with_null_on_stack_push_null(output):
        a = 1
        f = print
        f(
            output.append(4)
        )
        output.append(6)
        (
            ( # 8
                a
                +
                11
            )
            +
            14
        )
        output.append(16)

    # checking for segfaults.
    @jump_test(3, 7, [], error=(ValueError, "stack"))
    @support.cpython_only
    def test_jump_with_null_on_stack_load_attr(output):
        a = 1
        list.append(
            output, 3
        )
        output.append(5)
        (
            ( # 7
                a
                +
                10
            )
            +
            13
        )
        output.append(15)

    @jump_test(2, 3, [1, 3])
    def test_jump_extended_args_unpack_ex_simple(output):
        output.append(1)
        _, *_, _ = output.append(2) or "Spam"
        output.append(3)

    @jump_test(3, 4, [1, 4, 4, 5])
    def test_jump_extended_args_unpack_ex_tricky(output):
        output.append(1)
        (
            _, *_, _
        ) = output.append(4) or "Spam"
        output.append(5)

    @support.requires_resource('cpu')
    def test_jump_extended_args_for_iter(self):
        # In addition to failing when extended arg handling is broken, this can
        # also hang for a *very* long time:
        source = [
            "def f(output):",
            "    output.append(1)",
            "    for _ in spam:",
            *(f"        output.append({i})" for i in range(3, 100_000)),
            f"    output.append(100_000)",
        ]
        namespace = {}
        exec("\n".join(source), namespace)
        f = namespace["f"]
        self.run_test(f,  2, 100_000, [1, 100_000])

    @jump_test(2, 3, [1, 3])
    def test_jump_or_pop(output):
        output.append(1)
        _ = output.append(2) and "Spam"
        output.append(3)


class TestExtendedArgs(unittest.TestCase):

    def setUp(self):
        self.addCleanup(sys.settrace, sys.gettrace())
        sys.settrace(None)

    def count_traces(self, func):
        # warmup
        for _ in range(20):
            func()

        counts = {"call": 0, "line": 0, "return": 0}
        def trace(frame, event, arg):
            counts[event] += 1
            return trace

        sys.settrace(trace)
        func()
        sys.settrace(None)

        return counts

    def test_trace_unpack_long_sequence(self):
        ns = {}
        code = "def f():\n  (" + "y,\n   "*300 + ") = range(300)"
        exec(code, ns)
        counts = self.count_traces(ns["f"])
        self.assertEqual(counts, {'call': 1, 'line': 301, 'return': 1})

    def test_trace_lots_of_globals(self):
        code = """if 1:
            def f():
                return (
                    {}
                )
        """.format("\n+\n".join(f"var{i}\n" for i in range(1000)))
        ns = {f"var{i}": i for i in range(1000)}
        exec(code, ns)
        counts = self.count_traces(ns["f"])
        self.assertEqual(counts, {'call': 1, 'line': 2000, 'return': 1})


class TestEdgeCases(unittest.TestCase):

    def setUp(self):
        self.addCleanup(sys.settrace, sys.gettrace())
        sys.settrace(None)

    @support.cpython_only
    def test_reentrancy(self):
        def foo(*args):
            ...

        def bar(*args):
            ...

        class A:
            def __call__(self, *args):
                pass

            def __del__(self):
                sys.settrace(bar)

        sys.settrace(A())
        with support.catch_unraisable_exception() as cm:
            sys.settrace(foo)
            self.assertEqual(cm.unraisable.object, A.__del__)
            self.assertIsInstance(cm.unraisable.exc_value, RuntimeError)

        self.assertEqual(sys.gettrace(), foo)


    def test_same_object(self):
        def foo(*args):
            ...

        sys.settrace(foo)
        del foo
        sys.settrace(sys.gettrace())


if __name__ == "__main__":
    unittest.main()
