[PATCH] D132975: [CMake] Add clang-bolt target

[Fangrui Song via Phabricator via cfe-commits]

MaskRay added inline comments.


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Comment at: clang/CMakeLists.txt:930-937
+                -DCMAKE_INSTALL_PREFIX=${CMAKE_INSTALL_PREFIX}
+                -DCMAKE_C_COMPILER=${CLANG_INSTRUMENTED}
+                -DCMAKE_CXX_COMPILER=${CLANGXX_INSTRUMENTED}
+                -DCMAKE_ASM_COMPILER=${CLANG_INSTRUMENTED}
+                -DCMAKE_ASM_COMPILER_ID=Clang
+                -DCMAKE_BUILD_TYPE=Release
+                -DLLVM_ENABLE_PROJECTS=${CLANG_BOLT_INSTRUMENT_PROJECTS}
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phosek wrote:
> I don't think this is sufficient in the general case, we would need to pass additional variables like `CMAKE_AR` the same way we do for the existing bootstrap logic, see https://github.com/llvm/llvm-project/blob/dc549bf0013e11e8fcccba8a8d59c3a4bb052a3b/clang/CMakeLists.txt#L825.
> 
> For example, on Fuchsia builders we don't have any system-wide toolchain installation, instead we manually set  all necessary `CMAKE_<TOOL>` variables for the first stage, so this call will fail for us because it won't be able to find tools like the archiver.
> 
> Since handling this properly would likely duplicate a lot of the existing logic from the existing bootstrap logic, I'm wondering if we should instead try to refactor the existing logic and break it up into macros/functions which could then be reused here as well.
Supporting other cmake variables will be awesome. I use something like `-DCMAKE_CXX_ARCHIVE_CREATE="$HOME/llvm/out/stable/bin/llvm-ar qcS --thin <TARGET> <OBJECTS>" -DCMAKE_CXX_ARCHIVE_FINISH=:` to make my build smaller.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D132975/new/

https://reviews.llvm.org/D132975