arichardson added inline comments.
================ Comment at: clang/test/Driver/config-file3.c:27 -//--- Invocation qqq-clang-g++ tries to find config file qqq-clang-g++.cfg first. +//--- Invocation x86_64-unknown-linux-gnu-clang-g++ tries x86_64-unknown-linux-gnu-clang++.cfg first. // ---------------- sepavloff wrote: > mgorny wrote: > > sepavloff wrote: > > > mgorny wrote: > > > > sepavloff wrote: > > > > > mgorny wrote: > > > > > > sepavloff wrote: > > > > > > > mgorny wrote: > > > > > > > > arichardson wrote: > > > > > > > > > sepavloff wrote: > > > > > > > > > > Tests must check the case when target prefix is not a real > > > > > > > > > > triple as in the original test (qqq-clang). > > > > > > > > > It would be quite important for me that this continues to > > > > > > > > > work. I made use of that in the CheriBSD toolchain when > > > > > > > > > creating [[ > > > > > > > > > https://github.com/CTSRD-CHERI/cheribuild/blob/master/pycheribuild/projects/cross/llvm.py#L499 > > > > > > > > > | symlinked binaries to easily build for different ABIs]] > > > > > > > > > such as `cheribsd-riscv64-hybrid-clang++` and > > > > > > > > > `cheribsd-riscv64-purecap-clang-cpp`. It appears this > > > > > > > > > previously only worked if the prefix did not start with a > > > > > > > > > valid triple (which is why I put the OS before the > > > > > > > > > architecture). I think it would also be nice if the whole > > > > > > > > > prefix was checked even if it starts with a valid triple, but > > > > > > > > > this does not need to be changed in this patch (haven't > > > > > > > > > looked at it in detail so this might actually work). > > > > > > > > If the prefix is not a valid triple, then clang ignores it and > > > > > > > > uses host triple instead. And now we're back to square one. If > > > > > > > > I check both variants, it's too complex. If I don't, it's bad > > > > > > > > too. > > > > > > > Our customers use this feature. Target prefix may designate, for > > > > > > > example, debug build or build with specific framework. > > > > > > How are we supposed to avoid the "absurd" case where x86_64 configs > > > > > > are loaded for `-m32` invocation then? > > > > > In this case overloading target does not makes sense. You need to > > > > > analyze `RealTriple` in `Driver::loadDefaultConfigFiles` and if it is > > > > > wrong, use target prefix as if it is real target. > > > > What do you mean by "wrong"? The target triple is always a correct > > > > triple. > > > Not triple, sorry. Target prefix taken from `ClangNameParts.TargetPrefix`. > > Now I'm confused. Are you suggesting that we use prefix instead of target > > if it's… incorrect? > Basically yes. > > We need to support arbitrary target prefixes, because they are used now. If > `ClangNameParts.TargetPrefix` is not a valid triple, use it to build config > file names. > > We also need to use config files like `x86_64.cfg` where middle components > are dropped, they are also used. They also need to support target overloading. I can replace my approach with simple shell scripts that invoke clang --config=..., but IMO it would be nice if the logic was something like the first check being `if "explicit --target empty" and "ClangNameParts.TargetPrefix non-empty" and "ClangNameParts.TargetPrefix not a valid triple" -> load ClangNameParts.TargetPrefix + ".cfg"` followed by the current logic. I don't mind either way whether the first check should also load a driver-specific config file or not. I'd also be happy if the logic was "try loading ClangNameParts.TargetPrefix if explicit --target empty" regardless of whether it is a valid triple or not. Does this approach sound reasonable? CHANGES SINCE LAST ACTION https://reviews.llvm.org/D134337/new/ https://reviews.llvm.org/D134337 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
