[Lldb-commits] [lldb] [WIP] [lldb][Progress] Report progress when completing types from DWARF (PR #91452)

[Michael Buch via lldb-commits]

Michael137 wrote:

> I am somewhat worried about this slowing down the actual operations it is reporting progress on. I didn't really measure this, but intuitively, I'd expect that a one of these operations (parsing/importing one type) would be pretty fast, and that the whole process takes so long simply because performing a very large number of these ops.
> 
> Can you get some numbers on this? E.g., the number of events (per second?) that this generates, the timings of expression evaluation with/without the patch, or something like that?

I've been living on this patch for the past two weeks, debugging Clang/LLDB and haven't noticed a slowdown in the expression evaluator, but I'll try to follow-up with some concrete numbers.

> Is the code that emits the progress event recursive too? The reason I ask is because on the command line, nested progress events will get shadowed. The same is true for coalesced progress events. I'm not sure how VSCode/DAP clients deal with this, so maybe they're shown there?
> Anyway, if the code is recursive, we might need to do something like we did for Swift, with one top-level event and callback that updates the details.

Yes it is recursive, and some of the progress events do shadow each other. I'll take a look at what Swift does, thanks for the pointer!

https://github.com/llvm/llvm-project/pull/91452