[llvm] [dsymutil] Add option to copy swiftmodules built from interface (PR #165293)

[Adrian Prantl via llvm-commits]

adrian-prantl wrote:

Sorry for the delayed reply @royitaqi. As @JDevlieghere mentioned I'm still catching up with my review queue after the LLVM dev meeting. This patch is solving a real problem and I don't have an issue with bypassing the check per se, however, I also wanted to share with you that we are concurrently working on a different solution to the same problem:

The goal is to remove binary Swift modules from dSYMs altogether, because binary Swift modules — being version locked with the compiler — are at odds with the long-term archive promise of dSYM bundles. Instead, we will rely on binary Swift modules recording their binary Swift module dependencies (similar to how they record their clang dependencies, see  https://github.com/swiftlang/swift/pull/84412), and having a link from DWARF to every compile unit's own Swift module (see https://github.com/swiftlang/swift/pull/85100). With that in place, we would then retire the linker's `-add_ast_path` option and dsymutil's handling of Swift modules and interfaces. I understand that that has some consequences for users maintaining their own build systems, but I'm confident it will actually make it much easier. The paths in DWARF are fully remappable, and/or can be CAS cache keys, so it will also play well with caching and reproducible builds.

https://github.com/llvm/llvm-project/pull/165293