bpo-39934: Account for control blocks in 'except' in compiler.

[markshannon]

Pushes an artificial control "block" around the except part of a try-except.
This ensures that the computed depth in the compiler matches the actual depth in the runtime.

https://bugs.python.org/issue39934

[serhiy-storchaka]

Great work! I was going to write a similar fix, but you did it faster.

I have only comments about the test. The limit is CPython specific, other implementations can have different limit or do not have limit at all. Also, hardcoding the example makes more difficult to change the limit in CPython. I would move the test into separate function decorated with cpython_only and generate code dynamically.

[serhiy-storchaka]

👍

[miss-islington]

Thanks @markshannon for the PR 🌮🎉.. I'm working now to backport this PR to: 3.8, 3.9.
🐍🍒⛏🤖

[miss-islington]

Sorry, @markshannon, I could not cleanly backport this to 3.9 due to a conflict.
Please backport using cherry_picker on command line.
cherry_picker 02d126aa09d96d03dcf9c5b51c858ce5ef386601 3.9

[miss-islington]

Sorry @markshannon, I had trouble checking out the 3.8 backport branch.
Please backport using cherry_picker on command line.
cherry_picker 02d126aa09d96d03dcf9c5b51c858ce5ef386601 3.8

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot s390x RHEL8 3.x has failed when building commit 02d126a.

What do you need to do:

1. Don't panic.
2. Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
3. Go to the page of the buildbot that failed (https://buildbot.python.org/all/#builders/509/builds/110) and take a look at the build logs.
4. Check if the failure is related to this commit (02d126a) or if it is a false positive.
5. If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/all/#builders/509/builds/110

Summary of the results of the build (if available):

== Tests result: ENV CHANGED ==

408 tests OK.

10 slowest tests:

• test_concurrent_futures: 3 min 24 sec
• test_multiprocessing_spawn: 1 min 29 sec
• test_gdb: 1 min 25 sec
• test_peg_generator: 1 min 19 sec
• test_unparse: 1 min 18 sec
• test_multiprocessing_forkserver: 1 min 13 sec
• test_asyncio: 1 min 10 sec
• test_tokenize: 1 min 9 sec
• test_capi: 1 min 5 sec
• test_multiprocessing_fork: 1 min 3 sec

1 test altered the execution environment:
test_asyncio

14 tests skipped:
test_devpoll test_ioctl test_kqueue test_msilib test_nis
test_ossaudiodev test_startfile test_tix test_tk test_ttk_guionly
test_winconsoleio test_winreg test_winsound test_zipfile64

Total duration: 6 min 35 sec

Click to see traceback logs

Traceback (most recent call last): File "/home/dje/cpython-buildarea/3.x.edelsohn-rhel8-z/build/Lib/asyncio/sslproto.py", line 321, in __del__self.close() File "/home/dje/cpython-buildarea/3.x.edelsohn-rhel8-z/build/Lib/asyncio/sslproto.py", line 316, in closeself._ssl_protocol._start_shutdown() File "/home/dje/cpython-buildarea/3.x.edelsohn-rhel8-z/build/Lib/asyncio/sslproto.py", line 590, in _start_shutdownself._abort() File "/home/dje/cpython-buildarea/3.x.edelsohn-rhel8-z/build/Lib/asyncio/sslproto.py", line 731, in _abortself._transport.abort() File "/home/dje/cpython-buildarea/3.x.edelsohn-rhel8-z/build/Lib/asyncio/selector_events.py", line 680, in abortself._force_close(None) File "/home/dje/cpython-buildarea/3.x.edelsohn-rhel8-z/build/Lib/asyncio/selector_events.py", line 731, in _force_closeself._loop.call_soon(self._call_connection_lost, exc) File "/home/dje/cpython-buildarea/3.x.edelsohn-rhel8-z/build/Lib/asyncio/base_events.py", line 746, in call_soonself._check_closed() File "/home/dje/cpython-buildarea/3.x.edelsohn-rhel8-z/build/Lib/asyncio/base_events.py", line 510, in _check_closedraiseRuntimeError('Event loop is closed') RuntimeError: Event loop is closed

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot aarch64 RHEL8 3.x has failed when building commit 02d126a.

What do you need to do:

1. Don't panic.
2. Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
3. Go to the page of the buildbot that failed (https://buildbot.python.org/all/#builders/529/builds/78) and take a look at the build logs.
4. Check if the failure is related to this commit (02d126a) or if it is a false positive.
5. If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/all/#builders/529/builds/78

Summary of the results of the build (if available):

== Tests result: ENV CHANGED ==

409 tests OK.

10 slowest tests:

• test_concurrent_futures: 3 min 38 sec
• test_peg_generator: 3 min 1 sec
• test_unparse: 2 min 57 sec
• test_capi: 2 min 54 sec
• test_tokenize: 2 min 32 sec
• test_multiprocessing_spawn: 2 min 20 sec
• test_gdb: 2 min 10 sec
• test_asyncio: 2 min 8 sec
• test_lib2to3: 1 min 44 sec
• test_multiprocessing_forkserver: 1 min 30 sec

1 test altered the execution environment:
test_asyncio

13 tests skipped:
test_devpoll test_ioctl test_kqueue test_msilib test_ossaudiodev
test_startfile test_tix test_tk test_ttk_guionly test_winconsoleio
test_winreg test_winsound test_zipfile64

Total duration: 6 min 47 sec

Click to see traceback logs

Traceback (most recent call last): File "/home/buildbot/buildarea/3.x.cstratak-RHEL8-aarch64/build/Lib/asyncio/sslproto.py", line 321, in __del__self.close() File "/home/buildbot/buildarea/3.x.cstratak-RHEL8-aarch64/build/Lib/asyncio/sslproto.py", line 316, in closeself._ssl_protocol._start_shutdown() File "/home/buildbot/buildarea/3.x.cstratak-RHEL8-aarch64/build/Lib/asyncio/sslproto.py", line 590, in _start_shutdownself._abort() File "/home/buildbot/buildarea/3.x.cstratak-RHEL8-aarch64/build/Lib/asyncio/sslproto.py", line 731, in _abortself._transport.abort() File "/home/buildbot/buildarea/3.x.cstratak-RHEL8-aarch64/build/Lib/asyncio/selector_events.py", line 680, in abortself._force_close(None) File "/home/buildbot/buildarea/3.x.cstratak-RHEL8-aarch64/build/Lib/asyncio/selector_events.py", line 731, in _force_closeself._loop.call_soon(self._call_connection_lost, exc) File "/home/buildbot/buildarea/3.x.cstratak-RHEL8-aarch64/build/Lib/asyncio/base_events.py", line 746, in call_soonself._check_closed() File "/home/buildbot/buildarea/3.x.cstratak-RHEL8-aarch64/build/Lib/asyncio/base_events.py", line 510, in _check_closedraiseRuntimeError('Event loop is closed') RuntimeError: Event loop is closed

[bedevere-bot]

GH-23303 is a backport of this pull request to the 3.9 branch.