[clang] [llvm] Generate `DW_AT_RUST_short_backtrace` attributes for `DISubprogram` nodes (PR #123683)

[David Blaikie via llvm-commits]

dwblaikie wrote:

> > For instance, the StartFrame/EndFrame feature, if I'm understanding it correctly, seems like maybe it could be skipped if we're emitting DWARF (& instead the skip attribute could be placed on all the calls between StartFrame and EndFrame?).
> 
> does [#123683 (comment)](https://github.com/llvm/llvm-project/pull/123683#discussion_r1923736531) address your concerns?

Ah, sorry I missed that. Didn't mean to have you repeat yourself.

I think a design discussion will make it more clear what these different features do and how they might be generalized. 

> i’m happy to post on https://discourse.llvm.org/ but i’m not entirely sure what the process is - do you want me to just say “here is my current design, feel free to leave design comments”?

Yep, pretty much that. Maybe some worked examples of behavior (given this code, with these attributes in these places, this is the raw backtrace and this is the attribute-influenced backtrace).

Maybe an attribute with "skip, don't skip, do whatever the caller did" would be the tool, perhaps - but let's see the worked examples in a post and hash it out there.



https://github.com/llvm/llvm-project/pull/123683