[Lldb-commits] [lldb] [lldb] Implement DW_CFA_val_offset and DW_CFA_val_offset_sf (PR #150732)

[Pavel Labath via lldb-commits]

https://github.com/labath approved this pull request.

> I don't think the non-standard return pointer bit from eh-frame-dwarf-unwind.test should be necessary but if I remove it, lldb starts trying to read the code instead of using the CFI and it stops unwinding correctly

Yeah, that's because of lldb prefers the assembly unwind plan for frame zero unless it thinks the function is using a non-standard calling convention. (see `FuncUnwinders::GetUnwindPlanAtNonCallSite`). Using a non-standard rule for the PC disables that. It doesn't need to be that complicated, but I think it's okay -- just add a comment that this is there to force the usage of eh_frame for frame zero.

https://github.com/llvm/llvm-project/pull/150732