Replace direct stdout printing with logging

[sim642]

Apparently this is something I started but never opened a PR for. The problem is that there's lots of direct printing to stdout throughout Goblint, which makes output uncontrollable and unpredictable. For example, server mode cannot use stdout because some random printing might get mixed in and break the whole JSON stream.

The idea is to add a Logs library, which is a bit like Messages. It has various logging levels that can be toggled globally (unlike direct printing). The difference is that Messages is for things related to analysis results and shown in IDE, while logging is about Goblint itself, e.g. those TD3 incremental changes lines.
Messages are unordered and incrementally preserved, while Logs just come out in the order they happen and aren't preserved like that.

TODO

• Fix conflicts with master. (latest: 2024-02-13)
• Replace all new direct printing on master with Logs. (latest: 2024-02-13)
• Add log level option.
• Maingoblint.check_arguments.
• Remove dbg.verbose.
• What to do with GobView printing hacks?
• Document Logs in developer guide.
• Adapt to Logs module in Goblint gobview#40.

[sim642]

There's now a "result" log level that by default goes to stdout for the handful of places that were pointed out. In server mode, it is also directed to stderr to allow clean JSON-RPC communication.

[michael-schwarz]

Looks good! I have a few remaining questions in some places 😄

[michael-schwarz]

It seems like there's only two open comments left. I'd suggest to merge as soon as these are addressed to avoid it going out-of-sync and requiring a lot of work again. Wdyt?

[sim642]

Indeed, but I cannot check if GobView still works because of

• Add alert for unsupported queries gobview#25 (comment)
• Remove unused Libmaincil module cil#165, Adapt to removed Libmaincil module #1350, Adapt to removed Libmaincil module gobview#39

[sim642]

On top of GobView fixes, I confirmed that it still works.