MaskRay added a comment. In D143306#4144541 <https://reviews.llvm.org/D143306#4144541>, @jdoerfert wrote:
> I'm worried this makes use of LLVM on HPC machines even harder. That said, > I'm open to suggestions and I am not well versed in all the ways we can make > it work. > Our problem is that there are N `libomptarget.so` files and N > `libomptarget.nvptx.so` files on a system, including in system directories > and in directories you have on your LD_LIBRARY_PATH. > However, we want a clang to pick up its own versions of those files. The > former is linked into clang, the latter is dynamically loaded with dlopen. > That is, IIRC, roughly our use case. > >> I'd argue that such systems should specify -Wl,-rpath explicitly or in a >> Clang configuration file. > > Could you work me through this, please. We can't install a config file in a > user or system directory. So all we have is the clang install directory. > Should we not set this flag but then install a file (by default) that says > `-Wl,-rpath=...`. Is that what you mean? If so, what's the difference for the > user? > Or would we add `--offload-add-rpath` to the clang build if OpenMP offload is > enabled? This part of https://clang.llvm.org/docs/UsersManual.html#configuration-files is relevant "... is searched for sequentially in the directories". Say my `clang` executable is at `/tmp/opt/Rel/bin/clang`. I can just create `/tmp/opt/Rel/bin/clang.cfg` with one line `-Wl,-rpath=/tmp/opt/Rel/lib` (there is no magic expansion as in a shell). Invoking `/tmp/opt/Rel/bin/clang` will get this default option (without an unused command line option warning) unless `--no-default-config` is specified. The difference is that the rpath is now the default, instead of only when `-fopenmp=libomp` is specified. But such HPC users don't appear to be averse to rpath as much as we do. It should be fairly trivial to adjust one's llvm-project build/install script to create such a `clang.cfg` file. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D143306/new/ https://reviews.llvm.org/D143306 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
