gh-107265: Fix code_richcompare for ENTER_EXECUTOR case

[corona10]

• Issue: Decoding instructions should handle ENTER_EXECUTOR #107265

[gvanrossum]

LG, but could you add a test for this? You could add it to test_capi/test_misc.py in TestOptimizerAPI.

[corona10]

LG, but could you add a test for this? You could add it to test_capi/test_misc.py in TestOptimizerAPI.

Thanks, I added the test, and if I understand the intention correctly.
co_instr.op.arg and cp_instr.op.arg should also be updated.
If not, comparing co_instr.cache == cp_instr.cache will be failed anyway.

Please let me know if I understand wrongly.

[corona10]

pydoc test failure is unrelated to this PR, I checked it locally and asked to Discord too

[gvanrossum]

Yes, the arg must also be restored, since it is overwritten (with the index of the executor to be used in this code object's array of executors). So it looks like writing the test was useful!

[markshannon]

Comparing two code objects must not modify the code object.

The interaction between executor, the specializer and instrumentation is subtle and likely to break without care.
This will leak executors, as it flip-flops between JUMP_BACKWARDS and ENTER_EXECUTOR, or worse if an optimizer assumes that a single instruction will only be seen once.

[markshannon]

Likewise

[markshannon]

Please revert this. It will leak, and may not be safe.

[markshannon]

#101346

[gvanrossum]

@corona10 We can fix this in the hash PR you are working on.

[corona10]

@corona10 We can fix this in the hash PR you are working on.

Okay got it.