[Lldb-commits] [lldb] Reapply "[LLDB][ELF Core] Support all the Generic (Negative) SI Codes." (PR #141670)

[Pavel Labath via lldb-commits]

labath wrote:

> @labath
> 
> We need to handle situations where the core won't have a valid platform, and then fallback to other info (like PRSTATUS).
> 
> Please check the last commit in this patch. I think this will almost exclusively be an artifact of our tests, but I'm not sure how else to handle this

So, this particular failure is due to broken/incomplete support for these architectures (they weren't added to [this list](https://github.com/llvm/llvm-project/blob/f8ca9e59cb438bd35b29a6d7cf6d72f50673aec9/lldb/source/Plugins/Platform/Linux/PlatformLinux.cpp#L126)). The list only matters on mac because we probably end up somehow falling back to the host platform.

I expect adding them there would fix this. *However* I also think it makes sense to not fail catastrophically in case we cannot read/parse signal info, so I'm fine with the change you made in principle, but the I find the implementation somewhat unelegant. Do we actually need to access the platform class from `ELFLinuxSigInfo::Parse`? The data extractor should have already been set to the size of the siginfo note, right? Could we postpone the size check and move it closer to the place which actually uses the type? Thread::GetSiginfoValue maybe?

https://github.com/llvm/llvm-project/pull/141670