[lld] [llvm] [DTLTO][LLD][ELF] Add support for Integrated Distributed ThinLTO (PR #142757)

[via llvm-commits]

bd1976bris wrote:

@teresajohnson, I've added some code to this PR (see Input.cpp) to handle ThinLTO bitcode members in thin archives by making the identifier for such members the path to the actual bitcode file on disk for that member. Could a similar approach work to support bitcode members in thin archives for Bazel distribution (--thinlto-index-only)?

It would be great if whatever archive scheme we end up with has a fighting chance of being useful to the Bazel distribution (`--thinlto-index-only`) eventually. The full scheme we have in our downstream codebase supports thin archive bitcode members using the approach in this PR, and supports non-thin archive bitcode members by converting any non-thin archives to thin ones - conceptually - before the linker even looks at the members (the conversion is also cached).

Apologies - I think I meant to raise this question earlier.

https://github.com/llvm/llvm-project/pull/142757