Make goto_symext::language_mode protected

[tautschnig]

This should be set via constructors. Remove bmc_util/setup_symex as all work is done through constructors.

Keeping as draft until #8643 has been merged (which is the first commit in this PR).

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 80.39%. Comparing base (6c3978f) to head (921218f).
⚠️ Report is 4 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #8646      +/-   ##
===========================================
- Coverage    80.39%   80.39%   -0.01%     
===========================================
  Files         1688     1688              
  Lines       207411   207405       -6     
  Branches        73       73              
===========================================
- Hits        166757   166750       -7     
- Misses       40654    40655       +1     

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[tautschnig]

Requires #8711 for CI to pass.

[peterschrammel]

Is this even called anywhere now?

[tautschnig]

Yes, it's called from initialize_worklist and resume_path in this class. Which is also why this needs to be kept: it will be called more than once in the single-path case. Yet the only actual code being executed is java_setup_symex, and I am wondering whether this needs to be re-done per path, or instead could be done just once when creating symex_bmct?

[peterschrammel]

java_setup_symex just installs a loop_unwind_handler. This should be done only once when creating symex_bmct.

[tautschnig]

Ah, when writing my earlier comment I had failed to consider that initialize_worklist and resume_path actually do create a fresh symex_bmct instance each time, so each time we do need to invoke java_setup_symex. So I'd argue the code is actually ok as it is?!

[peterschrammel]

Ah, yes.

[peterschrammel]

If you remove this then the virtual function won't even be called...

[tautschnig]

That's fine, there is no need for doing so.

[peterschrammel]

see above

[tautschnig]

That's fine, there is no need for doing so.