[BUG] Extremely slow checking of apparently simple OpenSUT code

[peterohanley]

Summary

Adding a few more specs to the OpenSUT (trying to work around lack of accesses in declaration specs) has resulted in code that takes a very long time to check. I don't know how long because it hasn't finished but more than an hour. Before I added these specs it was taking about 90s.

Bug

Noticed on

% cn --version
git-9a71b713c [2024-09-12 00:45:26 +0100]

Appears still present on

% cn --version
git-98434f0d7 [2024-09-25 18:54:24 +0100]

# this is HEAD of branch 11-implement-mps currently
git checkout e2be19d6417b7cbb6f0dbd9f608e3085669fe8c3
cd components/mission_protection_system/src
make -f cn.mk -k -j4 components/actuation_unit.cn

Acceptance Criteria

CN accepts or rejects this code much faster. I would like to know what behavior caused this performance crash but a mine like this in the tool is very bad.

Do

• assign issue to a Milestone
• define acceptance criteria
• add appropriate labels
• Update this section to based on the Acceptance Criteria

[podhrmic]

The commit leading to the poor performance is GaloisInc/VERSE-OpenSUT@e2be19d

[peterohanley]

Reduced to rems-project/cerberus#613