GH-112383: Fix test_loop_quicken when an executor is installed

[brandtbucher]

test.test_dis.DisWithFileTests.test_loop_quicken fails when tier two is enabled, since the ENTER_EXECUTOR instruction isn't handled correctly:

% ./python.exe -m test test_dis
Using random seed: 969128318
0:00:00 load avg: 3.43 Run 1 test sequentially
0:00:00 load avg: 3.43 [1/1] test_dis

== Tests result: SUCCESS ==

1 test OK.

Total duration: 445 ms
Total tests: run=127
Total test files: run=1/1
Result: SUCCESS

% ./python.exe -Xuops -m test test_dis
Using random seed: 2915026187
0:00:00 load avg: 3.55 Run 1 test sequentially
0:00:00 load avg: 3.55 [1/1] test_dis
test test_dis failed -- Traceback (most recent call last):
  File "/Users/brandtbucher/cpython/Lib/test/test_dis.py", line 1214, in test_loop_quicken
    self.do_disassembly_compare(got, expected)
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^
  File "/Users/brandtbucher/cpython/Lib/test/test_dis.py", line 895, in do_disassembly_compare
    self.assertEqual(got, expected)
    ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^
AssertionError: '828 [599 chars]   16\n\n829   L2:     END_FOR\n              [31 chars]e)\n' != '828 [599 chars]   16 (to L1)\n\n829   L2:     END_FOR\n      [39 chars]e)\n'
  828           RESUME_CHECK             0
  
  829           BUILD_LIST               0
                LOAD_CONST               1 ((1, 2, 3))
                LIST_EXTEND              1
                LOAD_CONST               2 (3)
                BINARY_OP                5 (*)
                GET_ITER
        L1:     FOR_ITER_LIST           14 (to L2)
                STORE_FAST               0 (i)
  
  830           LOAD_GLOBAL_MODULE       1 (load_test + NULL)
                LOAD_FAST                0 (i)
                CALL_PY_WITH_DEFAULTS    1
                POP_TOP
-               JUMP_BACKWARD           16
+               JUMP_BACKWARD           16 (to L1)
?                                         ++++++++
  
  829   L2:     END_FOR
                RETURN_CONST             0 (None)


test_dis failed (1 failure)

== Tests result: FAILURE ==

1 test failed:
    test_dis

Total duration: 449 ms
Total tests: run=127 failures=1
Total test files: run=1/1 failed=1
Result: FAILURE

Instead of the current approach of trying to "fix" the test output in the presence of ENTER_EXECUTOR, just skip the test.

• Issue: teach dis how to interpret the oparg of ENTER_EXECUTOR  #112383

[iritkatriel]

I think ultimately we want this to work. Can we adjust the expected value instead of disabling so that we won't forget to reverse the change once it's fixed?

[brandtbucher]

Good idea. I've updated the comment, too.

[gvanrossum]

We really need an API on executor objects so you can access the vm_data field. We the API to get the executors should be an (unstable) method on PyCodeObject, not a function in _testinternalcapi.

[brandtbucher]

Do we need it though? Given the code object, we can always recover the original opcode and oparg using co_code (instead of _co_code_adaptive, which gives us the executor and index).

[gvanrossum]

Ah, that works too. I guess my main point was that we shouldn't blindly assume ENTER_EXECUTOR sits on top of JUMP_BACKWARD. Although that is currently the case (and will still be so if/when my side-exits PR lands).