[BUILD] Configure ryml to use exceptions when using CMAKE

[BugelNiels]

Fixes #3851

Changes

When building opentelemetry-cpp and ryml is fetched from the repo using CMake, ryml will use abort() when it encounters errors. This results in unintended crashes and prevents the calling application from gracefully dealing with these errors. This PR ensures that when we fetch ryml, we configure it to use exceptions instead.

For significant contributions please make sure you have completed the following items:

• CHANGELOG.md updated for non-trivial changes
• Unit tests have been added
• Changes in public API reviewed

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: marcalff / name: Marc Alff (c3f9fb6)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.99%. Comparing base (6859b68) to head (c3f9fb6).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3852   +/-   ##
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  Coverage   89.99%   89.99%           
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  Files         225      225           
  Lines        7170     7170           
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  Hits         6452     6452           
  Misses        718      718           

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[BugelNiels]

Waiting for my employer to hear back regarding the CLA; will get back to this as soon as I have the required info.

[rochaporto]

@krook can you check here? I've added @BugelNiels to our org, how do we trigger a recheck for the CLA?

[rochaporto]

@krook can you check here? I've added @BugelNiels to our org, how do we trigger a recheck for the CLA?

Nevermind, force push did it and i see the check now passes.

[BugelNiels]

@rochaporto thanks for the effort! I did a rebase of the branch and all seems good now.

[lalitb]

Thanks. LGTM.

Side note (not related to this PR): unlike the core API/SDK which were designed to compile with -fno-exceptions, the configuration module relies on exceptions by design. @marcalff - curious if there are any thoughts on this for the future, or if this is the intended direction for the configuration module?

[marcalff]

Thanks. LGTM.

Side note (not related to this PR): unlike the core API/SDK which were designed to compile with -fno-exceptions, the configuration module relies on exceptions by design. @marcalff - curious if there are any thoughts on this for the future, or if this is the intended direction for the configuration module?

@lalitb

The configuration code relies on a yaml parser, and currently requires to use exceptions, this is intended.

To have the same feature without exceptions:

• the yaml parser itself will need to work without exceptions, and every single call to ryml needs to be checked
• all the code in configuration_parser.cc, like below, needs to handle return codes instead.

  /* with exceptions */
  model->file_format = node->GetRequiredString("file_format");

Not sure if this is feasible with the yaml parser, and in any case this will make the code in configuration_parser.cc very tedious, bug prone, and harder to maintain, so this is not desirable.

The feature is optional, and not available without exception support.

[marcalff]

LGTM, thanks for the fix.