Rejuvenate log levels

[yiming-tang-cs]

Here's a reissue of #2978 which is closed due to inactivity and conflicts. We have run our logging tool on the last version of the project and solved all conflicts. We appreciate any feedback and are willing to make further changes if you wish to incorporate our PR into your project.

Settings

We have several analysis settings. We can vary these settings and rerun if you desire. The settings we are using in this pull request are:

• Treat CONFIG, WARNING, and SEVERE levels as a category and not a traditional level, i.e., our tool ignores these log levels.
• Never lower the logging level of logging statements within catch blocks.
• Never lower the logging level of logging statements within if statements.
• Never lower the logging level of logging statements containing certain (important) keywords.
• Never raise the logging level of logging statements without particular keywords in their messages.
• Avoid log wrapping by disregarding logging statements contained in if statements mentioning log levels.
• Only consistently transform the level of logging statements appearing in overriding methods.
• Adjust transformations if their transformation distances are over maximum transformation distance.

The greatest number of commits from HEAD evaluated: 5000.
The head at the time of analysis was: a31748b

OCA

I signed and emailed the OCA to Oracle. I am also providing a written acceptance of the OCA line:

I am signing on behalf of myself as an individual and no other person or entity, including my employer, has or will have rights with respect my contributions.

[ahornace]

Cool! Are there any articles (thesis) publicly available which look at the tool in detail? I'd like to read more on that :)

[yiming-tang-cs]

We have a research paper for this project: https://arxiv.org/pdf/2104.07736.pdf. Please feel free to contact us if you have any questions.

[vladak]

I think we should probably pick just some pieces, not the whole thing.

[khatchad]

If comment on the lines, @saledouble can revert those specific lines. If you can comment on why a particular transformation is undesirable, that would be very helpful. Thank you again for your help!