[clang] [DebugInfo] Add flag to only emit referenced member functions (PR #87018)

[David Blaikie via cfe-commits]

dwblaikie wrote:

> Looking forward to trying this out!
> 
> Should the new flag have some docs and maybe be mentioned in the release notes, or do we think it's not ready for prime time yet for some reason?

I'm /pretty/ neutral on that - it's got pretty clear behavior, etc (& in fact some class members already had this handling -implicit special members, member templates, and nested types) - but I expect the ecosystem (debuggers - gdb and lldb) won't work well with this.

It's not too hard to observe GDB showing a version of a different type depending on the context you're in - so name resolution will fail depending on which copy of the type the debugger is using at the time. LLDB I expect will fail even harder, because it creates fewer copies of a type - -so it'll pick one seemingly at random and only give you that view, even in some other context where GDB would give the type view local to that context at least, I think.

https://github.com/llvm/llvm-project/pull/87018