MaskRay added a comment. In D111367#3050061 <https://reviews.llvm.org/D111367#3050061>, @tstellar wrote:
> In D111367#3049772 <https://reviews.llvm.org/D111367#3049772>, @MaskRay wrote: > >> In D111367#3049700 <https://reviews.llvm.org/D111367#3049700>, @hvdijk wrote: >> >>> Does Red Hat actually use `x86_64-redhat-linux` with LLVM (other than for >>> finding the GCC installation)? I didn't see this on Fedora, I think they >>> use the config.guess-determined target name, and I think that's the right >>> thing for them to do. That only affects whether you've got a realistic >>> testcase though, the main change makes sense to me. >> >> Thanks. >> >> According to https://reviews.llvm.org/D110900#3041312 Red Hat GCC uses >> `x86_64-redhat-linux`. >> I don't know what its Clang currently does. > > I've been working on this for a few weeks now, and I think what I'm going to > do for Red Hat clang is to use current triples generated from config.guess, > but replace the unknown vendor with redhat (e.g. x86_64-redhat-linux-gnu). > This will be a no-op change since llvm treats the redhat vendor as unknown, > but will at least allow me to identify the triple as a redhat triple, so I > can patch the clang driver to select the correct gcc install. > > It seems to me it will be difficult to have one triple that both controls > clang's behavior and selects the desired gcc install, because clang and gcc > have different conventions. I wonder if we should have a more explicit way > to select the gcc install. If GCC installation has library files under `lib/x86_64-redhat-linux`, I think inferred `LLVM_DEFAULT_TARGET_TRIPLE` should be `x86_64-redhat-linux`, instead of `x86_64-redhat-linux-gnu`. With correct `LLVM_DEFAULT_TARGET_TRIPLE`, `clang a.c` should just work; with incorrect `LLVM_DEFAULT_TARGET_TRIPLE`, it's fair for `clang a.c` NOT to find GCC crtbegin.o/libgcc_s.so.1/etc. For older Clang with broken target triple, I think it is fair to ask the user to specify correct `LLVM_DEFAULT_TARGET_TRIPLE` (or `LLVM_HOST_TRIPLE`). I hope both `clang --version` and `clang -dumpmachine` print `LLVM_DEFAULT_TARGET_TRIPLE` in a verbatim way. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D111367/new/ https://reviews.llvm.org/D111367 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
