[clang] [Feature]: support for the BC library file into the compile dependencies (PR #176072)

[via cfe-commits]

zhouronghua wrote:

> In offloading languages like CUDA / HIP my understanding is that the device-side compilations are not independent build targets, so we do not want to create dependencies for them separate from the host. This is why all of them are currently attached to the host compilation, which is why I'm leaning towards saying that the proper solution is to list these files as dependencies on the one we already have. There is no separate 'device' build to re-run as far as make is concerned, it's just the host object.

I understand your point. Since no one compiles CUDA/HIP kernel files separately to generate cubin/fatbin—instead, we get a host object file with embedded cubin/fatbin—we need to trigger incremental builds for the .cu file whenever kernel dependencies change. This ensures both the host code and the injected cubin/fatbin are regenerated.

Just like the example above, if we compile a host object file containing the SM70 cubin, and then sm_70_features.h is modified, we need a way to inform the build system that an incremental rebuild should be triggered, correct?

https://github.com/llvm/llvm-project/pull/176072