aganea added a subscriber: dexonsmith. aganea added a comment. In D80833#3052551 <https://reviews.llvm.org/D80833#3052551>, @dexonsmith wrote:
> In D80833#2069411 <https://reviews.llvm.org/D80833#2069411>, @aganea wrote: > >> In D80833#2069246 <https://reviews.llvm.org/D80833#2069246>, @amccarth wrote: >> >>> Does embedding full paths affect distributed builds or build >>> reproducibility? >> >> It does affect reproducibility for distributed builds, the contents of >> `LF_BUILDINFO` for a remotely-compiled .OBJ will be different in the final >> .PDB. > > I don't think the path to the compiler is the only concern regarding > reproducible builds. Including the full command-line means that artifacts > change when options that have no (other) effect on the output are added. > E.g., adding `-Wall` will create a different object file than `-Wmost`. I > worry this is the wrong direction for default clang behaviour. In my sense, the fact that an option doesn't change the output is orthogonal to producing a deterministic output. I think most caching systems treat the compiler as a black box, by simply hashing the command-line and assuming the same .OBJ will be generated from that command-line. The build system could filter out options that are known to have effect on the output, to address your concern. But I feel this outside of the scope of this patch? > Should this new instability be restricted to when users explicitly request it? The goal of this patch (and D43002 <https://reviews.llvm.org/D43002>) is simply to be on-par with what MSVC generates by default. It seems a bit counter-intuitive to provide `-grecord-command-line` to clang-cl only to match the MSVC behavior, but if that's the general consensus, I'm fine as long as `LF_BUILDINFO` is supported in LLVM. In D80833#3052741 <https://reviews.llvm.org/D80833#3052741>, @dexonsmith wrote: > If you do go with "off-by-default", the natural driver option to use would be > the existing `-grecord-command-line`. You could use the same plumbing through > `-cc1` that it does. You mean using the `llvm.commandline` metadata? That's an interesting idea which should be explored. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D80833/new/ https://reviews.llvm.org/D80833 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
