[llvm] [DebugInfo] DWARF Units without DIEs are okay (PR #88840)

[David Blaikie via llvm-commits]

dwblaikie wrote:

Really appreciate your usage and feedback, though... 

> Nothing prevents a DWARF Unit from having no DIEs. 

I think the DWARF spec does?

> For each compilation unit compiled with a DWARF producer, a contribution is made to the .debug_info section of the object file. Each such contribution consists of a compilation unit header (see Section 7.5.1.1 on page 200) followed by a single DW_TAG_compile_unit or DW_TAG_partial_unit debugging information entry, together with its children.

(bit out of date/incomplete - doesn't mention all the other valid top level tags (it does mention type units in the next sentence, but doesn't mention skeleton units until a fair bit later))

So I'm not sure it's super helpful to more seamlessly support this situation?

What's the use case you have in mind here?

https://github.com/llvm/llvm-project/pull/88840